Hello friends!
We're on the last post of this series ("A Gentle Introduction to NOPE"), where we get to use all the Big Boy Concepts (TM) we've discussed in the prior posts and put them all together. Some words before we begin:

1. This post will be massively theoretical, in the sense that my own speculation and inferences will be largely peppered throughout the post. Are those speculations right? I think so, or I wouldn't be posting it, but they could also be incorrect.
2. I will briefly touch on using the NOPE this slide, but I will make a secondary post with much more interesting data and trends I've observed. This is primarily for explaining what NOPE is and why it potentially works, and what it potentially measures.

My advice before reading this is to glance at my prior posts, and either read those fully or at least make sure you understand the tl;drs:
https://www.reddit.com/thecorporation/collection/27dc72ad-4e78-44cd-a788-811cd666e32a
Depending on popular demand, I will also make a last-last post called FAQ, where I'll tabulate interesting questions you guys ask me in the comments!
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So a brief recap before we begin.
Market Maker ("Mr. MM"): An individual or firm who makes money off the exchange fees and bid-ask spread for an asset, while usually trying to stay neutral about the direction the asset moves.
Delta-gamma hedging: The process Mr. MM uses to stay neutral when selling you shitty OTM options, by buying/selling shares (usually) of the underlying as the price moves.
Law of Surprise [Lily-ism]: Effectively, the expected profit of an options trade is zero for both the seller and the buyer.
Random Walk: A special case of a deeper probability probability called a martingale, which basically models stocks or similar phenomena randomly moving every step they take (for stocks, roughly every millisecond). This is one of the most popular views of how stock prices move, especially on short timescales.
Future Expected Payoff Function [Lily-ism]: This is some hidden function that every market participant has about an asset, which more or less models all the possible future probabilities/values of the assets to arrive at a "fair market price". This is a more generalized case of a pricing model like Black-Scholes, or DCF.
Counter-party: The opposite side of your trade (if you sell an option, they buy it; if you buy an option, they sell it).
Price decoherence ]Lily-ism]: A more generalized notion of IV Crush, price decoherence happens when instead of the FEPF changing gradually over time (price formation), the FEPF rapidly changes, due usually to new information being added to the system (e.g. Vermin Supreme winning the 2020 election).
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One of the most popular gambling events for option traders to play is earnings announcements, and I do owe the concept of NOPE to hypothesizing specifically about the behavior of stock prices at earnings. Much like a black hole in quantum mechanics, most conventional theories about how price should work rapidly break down briefly before, during, and after ER, and generally experienced traders tend to shy away from playing earnings, given their similar unpredictability.
Before we start: what is NOPE? NOPE is a funny backronym from Net Options Pricing Effect, which in its most basic sense, measures the impact option delta has on the underlying price, as compared to share price. When I first started investigating NOPE, I called it OPE (options pricing effect), but NOPE sounds funnier.
The formula for it is dead simple, but I also have no idea how to do LaTeX on reddit, so this is the best I have:
​
https://preview.redd.it/ais37icfkwt51.png?width=826&format=png&auto=webp&s=3feb6960f15a336fa678e945d93b399a8e59bb49
Since I've already encountered this, put delta in this case is the absolute value (50 delta) to represent a put. If you represent put delta as a negative (the conventional way), do not subtract it; add it.
To keep this simple for the non-mathematically minded: the NOPE today is equal to the weighted sum (weighted by volume) of the delta of every call minus the delta of every put for all options chains extending from today to infinity. Finally, we then divide that number by the # of shares traded today in the market session (ignoring pre-market and post-market, since options cannot trade during those times).
Effectively, NOPE is a rough and dirty way to approximate the impact of delta-gamma hedging as a function of share volume, with us hand-waving the following factors:

1. To keep calculations simple, we assume that all counter-parties are hedged. This is obviously not true, especially for idiots who believe theta ganging is safe, but holds largely true especially for highly liquid tickers, or tickers will designated market makers (e.g. any ticker in the NASDAQ, for instance).
2. We assume that all hedging takes place via shares. For SPY and other products tracking the S&P, for instance, market makers can actually hedge via futures or other options. This has the benefit for large positions of not moving the underlying price, but still makes up a fairly small amount of hedges compared to shares.

Winding and Unwinding

I briefly touched on this in a past post, but two properties of NOPE seem to apply well to EER-like behavior (aka any binary catalyst event):

1. NOPE measures sentiment - In general, the options market is seen as better informed than share traders (e.g. insiders trade via options, because of leverage + easier to mask positions). Therefore, a heavy call/put skew is usually seen as a bullish sign, while the reverse is also true.
2. NOPE measures system stability

I'm not going to one-sentence explain #2, because why say in one sentence what I can write 1000 words on. In short, NOPE intends to measure sensitivity of the system (the ticker) to disruption. This makes sense, when you view it in the context of delta-gamma hedging. When we assume all counter-parties are hedged, this means an absolutely massive amount of shares get sold/purchased when the underlying price moves. This is because of the following:
a) Assume I, Mr. MM sell 1000 call options for NKLA 25C 10/23 and 300 put options for NKLA 15p 10/23. I'm just going to make up deltas because it's too much effort to calculate them - 30 delta call, 20 delta put.
This implies Mr. MM needs the following to delta hedge: (1000 call options * 30 shares to buy for each) [to balance out writing calls) - (300 put options * 20 shares to sell for each) = 24,000 net shares Mr. MM needs to acquire to balance out his deltas/be fully neutral.
b) This works well when NKLA is at $20. But what about when it hits $19 (because it only can go down, just like their trucks). Thanks to gamma, now we have to recompute the deltas, because they've changed for both the calls (they went down) and for the puts (they went up).
Let's say to keep it simple that now my calls are 20 delta, and my puts are 30 delta. From the 24,000 net shares, Mr. MM has to now have:
(1000 call options * 20 shares to have for each) - (300 put options * 30 shares to sell for each) = 11,000 shares.
Therefore, with a $1 shift in price, now to hedge and be indifferent to direction, Mr. MM has to go from 24,000 shares to 11,000 shares, meaning he has to sell 13,000 shares ASAP, or take on increased risk. Now, you might be saying, "13,000 shares seems small. How would this disrupt the system?"
(This process, by the way, is called hedge unwinding)
It won't, in this example. But across thousands of MMs and millions of contracts, this can - especially in highly optioned tickers - make up a substantial fraction of the net flow of shares per day. And as we know from our desk example, the buying or selling of shares directly changes the price of the stock itself.
This, by the way, is why the NOPE formula takes the shape it does. Some astute readers might notice it looks similar to GEX, which is not a coincidence. GEX however replaces daily volume with open interest, and measures gamma over delta, which I did not find good statistical evidence to support, especially for earnings.
So, with our example above, why does NOPE measure system stability? We can assume for argument's sake that if someone buys a share of NKLA, they're fine with moderate price swings (+- $20 since it's NKLA, obviously), and in it for the long/medium haul. And in most cases this is fine - we can own stock and not worry about minor swings in price. But market makers can't* (they can, but it exposes them to risk), because of how delta works. In fact, for most institutional market makers, they have clearly defined delta limits by end of day, and even small price changes require them to rebalance their hedges.
This over the whole market adds up to a lot shares moving, just to balance out your stupid Robinhood YOLOs. While there are some tricks (dark pools, block trades) to not impact the price of the underlying, the reality is that the more options contracts there are on a ticker, the more outsized influence it will have on the ticker's price. This can technically be exactly balanced, if option put delta is equal to option call delta, but never actually ends up being the case. And unlike shares traded, the shares representing the options are more unstable, meaning they will be sold/bought in response to small price shifts. And will end up magnifying those price shifts, accordingly.

NOPE and Earnings

So we have a new shiny indicator, NOPE. What does it actually mean and do?
There's much literature going back to the 1980s that options markets do have some level of predictiveness towards earnings, which makes sense intuitively. Unlike shares markets, where you can continue to hold your share even if it dips 5%, in options you get access to expanded opportunity to make riches... and losses. An options trader betting on earnings is making a risky and therefore informed bet that he or she knows the outcome, versus a share trader who might be comfortable bagholding in the worst case scenario.
As I've mentioned largely in comments on my prior posts, earnings is a special case because, unlike popular misconceptions, stocks do not go up and down solely due to analyst expectations being meet, beat, or missed. In fact, stock prices move according to the consensus market expectation, which is a function of all the participants' FEPF on that ticker. This is why the price moves so dramatically - even if a stock beats, it might not beat enough to justify the high price tag (FSLY); even if a stock misses, it might have spectacular guidance or maybe the market just was assuming it would go bankrupt instead.
To look at the impact of NOPE and why it may play a role in post-earnings-announcement immediate price moves, let's review the following cases:

1. Stock Meets/Exceeds Market Expectations (aka price goes up) - In the general case, we would anticipate post-ER market participants value the stock at a higher price, pushing it up rapidly. If there's a high absolute value of NOPE on said ticker, this should end up magnifying the positive move since:

a) If NOPE is high negative - This means a ton of put buying, which means a lot of those puts are now worthless (due to price decoherence). This means that to stay delta neutral, market makers need to close out their sold/shorted shares, buying them, and pushing the stock price up.
b) If NOPE is high positive - This means a ton of call buying, which means a lot of puts are now worthless (see a) but also a lot of calls are now worth more. This means that to stay delta neutral, market makers need to close out their sold/shorted shares AND also buy more shares to cover their calls, pushing the stock price up.
2) Stock Meets/Misses Market Expectations (aka price goes down) - Inversely to what I mentioned above, this should push to the stock price down, fairly immediately. If there's a high absolute value of NOPE on said ticker, this should end up magnifying the negative move since:
a) If NOPE is high negative - This means a ton of put buying, which means a lot of those puts are now worth more, and a lot of calls are now worth less/worth less (due to price decoherence). This means that to stay delta neutral, market makers need to sell/short more shares, pushing the stock price down.
b) If NOPE is high positive - This means a ton of call buying, which means a lot of calls are now worthless (see a) but also a lot of puts are now worth more. This means that to stay delta neutral, market makers need to sell even more shares to keep their calls and puts neutral, pushing the stock price down.
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Based on the above two cases, it should be a bit more clear why NOPE is a measure of sensitivity to system perturbation. While we previously discussed it in the context of magnifying directional move, the truth is it also provides a directional bias to our "random" walk. This is because given a price move in the direction predicted by NOPE, we expect it to be magnified, especially in situations of price decoherence. If a stock price goes up right after an ER report drops, even based on one participant deciding to value the stock higher, this provides a runaway reaction which boosts the stock price (due to hedging factors as well as other participants' behavior) and inures it to drops.

NOPE and NOPE_MAD

I'm going to gloss over this section because this is more statistical methods than anything interesting. In general, if you have enough data, I recommend using NOPE_MAD over NOPE. While NOPE in theory represents a "real" quantity (net option delta over net share delta), NOPE_MAD (the median absolute deviation of NOPE) does not. NOPE_MAD simply answecompare the following:

1. How exceptional is today's NOPE versus historic baseline (30 days prior)?
2. How do I compare two tickers' NOPEs effectively (since some tickers, like TSLA, have a baseline positive NOPE, because Elon memes)? In the initial stages, we used just a straight numerical threshold (let's say NOPE >= 20), but that quickly broke down. NOPE_MAD aims to detect anomalies, because anomalies in general give you tendies.

I might add the formula later in Mathenese, but simply put, to find NOPE_MAD you do the following:

1. Calculate today's NOPE score (this can be done end of day or intraday, with the true value being EOD of course)
2. Calculate the end of day NOPE scores on the ticker for the previous 30 trading days
3. Compute the median of the previous 30 trading days' NOPEs
4. From the median, find the 30 days' median absolute deviation (https://en.wikipedia.org/wiki/Median_absolute_deviation)
5. Find today's deviation as compared to the MAD calculated by: [(today's NOPE) - (median NOPE of last 30 days)] / (median absolute deviation of last 30 days)

This is usually reported as sigma (σ), and has a few interesting properties:

1. The mean of NOPE_MAD for any ticker is almost exactly 0.
2. [Lily's Speculation's Speculation] NOPE_MAD acts like a spring, and has a tendency to reverse direction as a function of its magnitude. No proof on this yet, but exploring it!

Using the NOPE to predict ER

So the last section was a lot of words and theory, and a lot of what I'm mentioning here is empirically derived (aka I've tested it out, versus just blabbered).
In general, the following holds true:

1. 3 sigma NOPE_MAD tends to be "the threshold": For very low NOPE_MAD magnitudes (+- 1 sigma), it's effectively just noise, and directionality prediction is low, if not non-existent. It's not exactly like 3 sigma is a play and 2.9 sigma is not a play; NOPE_MAD accuracy increases as NOPE_MAD magnitude (either positive or negative) increases.
2. NOPE_MAD is only useful on highly optioned tickers: In general, I introduce another parameter for sifting through "candidate" ERs to play: option volume * 100/share volume. When this ends up over let's say 0.4, NOPE_MAD provides a fairly good window into predicting earnings behavior.
3. NOPE_MAD only predicts during the after-market/pre-market session: I also have no idea if this is true, but my hunch is that next day behavior is mostly random and driven by market movement versus earnings behavior. NOPE_MAD for now only predicts direction of price movements right between the release of the ER report (AH or PM) and the ending of that market session. This is why in general I recommend playing shares, not options for ER (since you can sell during the AH/PM).
4. NOPE_MAD only predicts direction of price movement: This isn't exactly true, but it's all I feel comfortable stating given the data I have. On observation of ~2700 data points of ER-ticker events since Mar 2019 (SPY 500), I only so far feel comfortable predicting whether stock price goes up (>0 percent difference) or down (<0 price difference). This is +1 for why I usually play with shares.

Some statistics:
#0) As a baseline/null hypothesis, after ER on the SPY500 since Mar 2019, 50-51% price movements in the AH/PM are positive (>0) and ~46-47% are negative (<0).
#1) For NOPE_MAD >= +3 sigma, roughly 68% of price movements are positive after earnings.
#2) For NOPE_MAD <= -3 sigma, roughly 29% of price movements are positive after earnings.
#3) When using a logistic model of only data including NOPE_MAD >= +3 sigma or NOPE_MAD <= -3 sigma, and option/share vol >= 0.4 (around 25% of all ERs observed), I was able to achieve 78% predictive accuracy on direction.

Caveats/Read This

Like all models, NOPE is wrong, but perhaps useful. It's also fairly new (I started working on it around early August 2020), and in fact, my initial hypothesis was exactly incorrect (I thought the opposite would happen, actually). Similarly, as commenters have pointed out, the timeline of data I'm using is fairly compressed (since Mar 2019), and trends and models do change. In fact, I've noticed significantly lower accuracy since the coronavirus recession (when I measured it in early September), but I attribute this mostly to a smaller date range, more market volatility, and honestly, dumber option traders (~65% accuracy versus nearly 80%).
My advice so far if you do play ER with the NOPE method is to use it as following:

1. Buy/short shares approximately right when the market closes before ER. Ideally even buying it right before the earnings report drops in the AH session is not a bad idea if you can.
2. Sell/buy to close said shares at the first sign of major weakness (e.g. if the NOPE predicted outcome is incorrect).
3. Sell/buy to close shares even if it is correct ideally before conference call, or by the end of the after-market/pre-market session.
4. Only play tickers with high NOPE as well as high option/share vol.

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In my next post, which may be in a few days, I'll talk about potential use cases for SPY and intraday trends, but I wanted to make sure this wasn't like 7000 words by itself.
Cheers.
- Lily

2020 Childfree Subreddit Survey

1. Introduction

Once a year, this subreddit hosts a survey in order to get to know the community a little bit and in order to answer questions that are frequently asked here. Earlier this summer, several thousand of you participated in the 2020 Subreddit Demographic Survey. Only those participants who meet our wiki definition of being childfree's results were recorded and analysed.
Of these people, multiple areas of your life were reviewed. They are separated as follows:

• Child Status
• General Demographics
• Education Level
• Career and Finances
• Location
• Religion and Spirituality
• Sexual and Romantic Life
• Childhood and Family Life
• Sterilisation
• Childfreedom
• State of the Subreddit

2. Methodology

Our sample is redditors who saw that we had a survey currently active and were willing to complete the survey. A stickied post was used to advertise the survey to members.

3. Results

The raw data may be found via this link.
7305 people participated in the survey from July 2020 to October 2020. People who did not meet our wiki definition of being childfree were excluded from the survey. The results of 5134 responders, or 70.29% of those surveyed, were collated and analysed below. Percentages are derived from the respondents per question.

General Demographics

Age group

Age group	Participants	Percentage
18 or younger	309	6.02%
19 to 24	1388	27.05%
25 to 29	1435	27.96%
30 to 34	1089	21.22%
35 to 39	502	9.78%
40 to 44	223	4.35%
45 to 49	81	1.58%
50 to 54	58	1.13%
55 to 59	25	0.49%
60 to 64	13	0.25%
65 to 69	7	0.14%
70 to 74	2	0.04%

82.25% of the sub is under the age of 35.

Gender and Gender Identity

Age group	Participants #	Percentage
Agender	62	1.21%
Female	3747	73.04%
Male	1148	22.38%
Non-binary	173	3.37%

Sexual Orientation

Sexual Orientation	Participants #	Percentage
Asexual	379	7.39%
Bisexual	1177	22.93%
Heterosexual	2833	55.20%
Homosexual	264	5.14%
It's fluid	152	2.96%
Other	85	1.66%
Pansexual	242	4.72%

Birth Location

Because the list contains over 120 countries, we'll show the top 20 countries:

Country of birth	Participants #	Percentage
United States	2775	57.47%
United Kingdom	367	7.60%
Canada	346	7.17%
Australia	173	3.58%
Germany	105	2.17%
Netherlands	67	1.39%
India	63	1.30%
Poland	57	1.18%
France	47	0.97%
New Zealand	42	0.87%
Mexico	40	0.83%
Brazil	40	0.83%
Sweden	38	0.79%
Finland	31	0.64%
South Africa	30	0.62%
Denmark	28	0.58%
China	27	0.56%
Ireland	27	0.56%
Phillipines	24	0.50%
Russia	23	0.48%

90.08% of the participants were born in these countries.
These participants would describe their current city, town or neighborhood as:

Region	Participants #	Percentage
Rural	705	13.76
Suburban	2661	51.95
Urban	1756	34.28

Ethnicity

Ethnicity	Participants #	Percentage
African Descent/Black	157	3.07%
American Indian or Alaskan Native	18	0.35%
Arabic/Middle Eastern/Near Eastern	34	0.66%
Bi/Multiracial	300	5.86%
Caucasian/White	3946	77.09%
East Asian	105	2.05%
Hispanic/Latinx	271	5.29%
Indian/South Asian	116	2.27%
Indigenous Australian/Torres Straight IslandeMaori	8	0.16%
Jewish (the ethnicity, not religion)	50	0.98%
Other	32	0.63%
Pacific IslandeMelanesian	4	0.08%
South-East Asian	78	1.52%

Education

Highest Current Level of Education

Highest Current Level of Education	Participants #	Percentage
Associate's degree	233	4.55%
Bachelor's degree	1846	36.05%
Did not complete elementary school	2	0.04%
Did not complete high school	135	2.64%
Doctorate degree	121	2.36%
Graduated high school / GED	559	10.92%
Master's degree	714	13.95%
Post Doctorate	19	0.37%
Professional degree	107	2.09%
Some college / university	1170	22.85%
Trade / Technical / Vocational training	214	4.18%

Degree (Major)	Participants #	Percentage
Architecture	23	0.45%
Arts and Humanities	794	15.54%
Business and Economics	422	8.26%
Computer Science	498	9.75%
Education	166	3.25%
Engineering Technology	329	6.44%
I don't have a degree or a major	1028	20.12%
Law	124	2.43%
Life Sciences	295	5.77%
Medicine and Allied Health	352	6.89%
Other	450	8.81%
Physical Sciences	199	3.89%
Social Sciences	430	8.41%

Career and Finances

The top 10 industries our participants are working in are:

Industry	Participants #	Percentage
Information Technology	317	6.68%
Health Care	311	6.56%
Education - Teaching	209	4.41%
Engineering	203	4.28%
Retail	182	3.84%
Government	172	3.63%
Admin & Clerical	154	3.25%
Restaurant - Food Service	148	3.12%
Customer Service	129	2.72%
Design	127	2.68%

Note that "other", "I'm a student", "currently unemployed" and "I'm out of the work force for health or other reasons" have been disregarded for this part of the evaluation.
Out of the 3729 participants active in the workforce, the majority (1824 or 48.91%) work between 40-50 hours per week with 997 or 26.74% working 30-40 hours weekly. 6.62% work 50 hours or more per week, and 17.73% less than 30 hours.
513 or 10.13% are engaged in managerial responsibilities (ranging from Jr. to Sr. Management).
On a scale of 1 (lowest) to 10 (highest), the overwhelming majority (3340 or 70%) indicated that career plays a very important role in their lives, attributing a score of 7 and higher.
1065 participants decided not to disclose their income brackets. The remaining 4,849 are distributed as follows:

Income	Participants #	Percentage
$0 to $14,999	851	21.37%
$15,000 to $29,999	644	16.17%
$30,000 to $59,999	1331	33.42%
$60,000 to $89,999	673	16.90%
$90,000 to $119,999	253	6.35%
$120,000 to $149,999	114	2.86%
$150,000 to $179,999	51	1.28%
$180,000 to $209,999	25	0.63%
$210,000 to $239,999	9	0.23%
$240,000 to $269,999	10	0.25%
$270,000 to $299,999	7	0.18%
$300,000 or more	15	0.38%

87.85% earn under $90,000 USD a year.
65.82% of our childfree participants do not have a concrete retirement plan (savings, living will).

Religion and Spirituality

Faith Originally Raised In

There were more than 50 options of faith, so we aimed to show the top 10 most chosen beliefs.

Faith	Participants #	Percentage
Catholicism	1573	30.76%
None (≠ Atheism. Literally, no notion of spirituality or religion in the upbringing)	958	18.73%
Protestantism	920	17.99%
Other	431	8.43%
Atheism	318	6.22%
Agnosticism	254	4.97%
Anglicanism	186	3.64%
Judaism	77	1.51%
Hinduism	75	1.47%
Islam	71	1.39%

This top 10 amounts to 95.01% of the total participants.

Current Faith

There were more than 50 options of faith, so we aimed to show the top 10 most chosen beliefs:

Faith	Participants #	Percentage
Atheism	1849	36.23%
None (≠ Atheism. Literally, no notion of spirituality or religion currently)	1344	26.33%
Agnosticism	789	15.46%
Other	204	4.00%
Protestantism	159	3.12%
Paganism	131	2.57%
Spiritualism	101	1.98%
Catholicism	96	1.88%
Satanism	92	1.80%
Wicca	66	1.29%

This top 10 amounts to 94.65% of the participants.

Level of Current Religious Practice

Level	Participants #	Percentage
Wholly seculanon religious	3733	73.73%
Identify with religion, but don't practice strictly	557	11.00%
Lapsed/not serious/in name only	393	7.76%
Observant at home only	199	3.93%
Observant at home. Church/Temple/Mosque/etc. attendance	125	2.47%
Strictly observant, Church/Temple/Mosque/etc. attendance, religious practice/prayeworship impacting daily life	56	1.11%

Effect of Faith over Childfreedom

Figure 1

Effect of Childfreedom over Faith

Figure 2

Romantic and Sexual Life

Current Dating Situation

Status	Participants #	Percentage
Divorced	46	0.90%
Engaged	207	4.04%
Long term relationship, living together	1031	20.10%
Long term relationship, not living with together	512	9.98%
Married	1230	23.98%
Other	71	1.38%
Separated	18	0.35%
Short term relationship	107	2.09%
Single and dating around, but not looking for anything serious	213	4.15%
Single and dating around, looking for something serious	365	7.12%
Single and not looking	1324	25.81%
Widowed	5	0.10%

Childfree Partner

Is your partner childfree? If your partner wants children and/or has children of their own and/or are unsure about their position, please consider them "not childfree" for this question.

Partner	Participants #	Percentage
I don't have a partner	1922	37.56%
I have more than one partner and none are childfree	3	0.06%
I have more than one partner and some are childfree	35	0.68%
I have more than one partner and they are all childfree	50	0.98
No	474	9.26%
Yes	2633	51.46%

Dating a Single Parent

Would the childfree participants be willing to date a single parent?

Answer	Participants #	Percentage
No, I'm not interested in single parents and their ties to parenting life	4610	90.13%
Yes, but only if it's a short term arrangement of some sort	162	3.17%
Yes, whether for long term or short term, but with some conditions (must not have child custody, no kid talk, etc.), as long as I like them and long as we're compatible	199	3.89%
Yes, whether for long term or short term, with no conditions, as long as I like them and as long as we are compatible	144	2.82%

Childhood and Family Life

On a scale from 1 (very unhappy) to 10 (very happy), how would you rate your childhood?
Figure 3
Of the 5125 childfree people who responded to the question, 67.06% have a pet or are heavily involved in the care of someone else's pet.

Sterilisation

Sterilisation Status

Sterilisation Status	Participants #	Percentage
No, I am not sterilised and, for medical, practical or other reasons, I do not need to be	869	16.96%
No. However, I've been approved for the procedure and I'm waiting for the date to arrive	86	1.68%
No. I am not sterilised and don't want to be	634	12.37%
No. I want to be sterilised but I have started looking for a doctorequested the procedure	594	11.59%
No. I want to be sterilised but I haven't started looking for a doctorequested the procedure yet	2317	45.21%
Yes. I am sterilised	625	12.20%

Age when starting doctor shopping or addressing issue with doctor. Percentages exclude those who do not want to be sterilised and who have not discussed sterilisation with their doctor.

Age group	Participants #	Percentage
18 or younger	207	12.62%
19 to 24	588	35.85%
25 to 29	510	31.10%
30 to 34	242	14.76%
35 to 39	77	4.70%
40 to 44	9	0.55%
45 to 49	5	0.30%
50 to 54	1	0.06%
55 or older	1	0.06%

Age at the time of sterilisation. Percentages exclude those who have not and do not want to be sterilised.

Age group	Participants #	Percentage
18 or younger	5	0.79%
19 to 24	123	19.34%
25 to 29	241	37.89%
30 to 34	168	26.42%
35 to 39	74	11.64%
40 to 44	19	2.99%
45 to 49	1	0.16%
50 to 54	2	0.31%
55 or older	3	0.47%

Elapsed time between requesting procedure and undergoing procedure. Percentages exclude those who have not and do not want to be sterilised.

Time	Participants #	Percentage
Less than 3 months	330	50.46%
Between 3 and 6 months	111	16.97%
Between 6 and 9 months	33	5.05%
Between 9 and 12 months	20	3.06%
Between 12 and 18 months	22	3.36%
Between 18 and 24 months	15	2.29%
Between 24 and 30 months	6	0.92%
Between 30 and 36 months	2	0.31%
Between 3 and 5 years	40	6.12%
Between 5 and 7 years	25	3.82%
More than 7 years	50	7.65%

How many doctors refused at first, before finding one who would accept?

Doctor #	Participants #	Percentage
None. The first doctor I asked said yes	604	71.73%
One. The second doctor I asked said yes	93	11.05%
Two. The third doctor I asked said yes	54	6.41%
Three. The fourth doctor I asked said yes	29	3.44%
Four. The fifth doctor I asked said yes	12	1.43%
Five. The sixth doctor I asked said yes	8	0.95%
Six. The seventh doctor I asked said yes	10	1.19%
Seven. The eighth doctor I asked said yes	4	0.48%
Eight. The ninth doctor I asked said yes	2	0.24%
I asked more than 10 doctors before finding one who said yes	26	3.09%

Childfreedom

Primary Reason to Not Have Children

Reason	Participants #	Percentage
Aversion towards children ("I don't like children")	1455	28.36%
Childhood trauma	135	2.63%
Current state of the world	110	2.14%
Environmental (including overpopulation)	158	3.08%
Eugenics ("I have 'bad genes'")	57	1.11%
Financial	175	3.41%
I already raised somebody else who isn't my child	83	1.62%
Lack of interest towards parenthood ("I don't want to raise children")	2293	44.69%
Maybe interested for parenthood, but not suited for parenthood	48	0.94%
Medical ("I have a condition that makes conceiving/bearing/birthing children difficult, dangerous or lethal")	65	1.27%
Other	68	1.33%
Philosophical / Moral (e.g. antinatalism)	193	3.76%
Tokophobia (aversion/fear of pregnancy and/or chidlbirth)	291	5.67%

95.50% of childfree people are pro-choice, however only 55.93% of childfree people support financial abortion.

Dislike Towards Children

Figure 4

Working With Children

Work	Participants #	Percentage
I'm a student and my future job/career will heavily makes me interact with children on a daily basis	67	1.30%
I'm retired, but I used to have a job that heavily makes me interact with children on a daily basis	6	0.12%
I'm unemployed, but I used to have a job that heavily makes me interact with children on a daily basis	112	2.19%
No, I do not have a job that makes me heavily interact with children on a daily basis	4493	87.81%
Other	148	2.89%
Yes, I do have a job that heavily makes me interact with children on a daily basis	291	5.69%

4. Discussion

Child Status

This section solely existed to sift the childfree from the fencesitters and the non childfree in order to get answers only from the childfree. Childfree, as it is defined in the subreddit, is "I do not have children nor want to have them in any capacity (biological, adopted, fostered, step- or other) at any point in the future." 70.29% of participants actually identify as childfree, slightly up from the 2019 survey, where 68.5% of participants identified as childfree. This is suprising in reflection of the overall reputation of the subreddit across reddit, where the subreddit is often described as an "echo chamber".

General Demographics

The demographics remain largely consistent with the 2019 survey. However, the 2019 survey collected demographic responses from all participants in the survey, removing those who did not identify as childfree when querying subreddit specific questions, while the 2020 survey only collected responses from people who identified as childfree. This must be considered when comparing results.
82.25% of the participants are under 35, compared with 85% of the subreddit in the 2019 survey. A slight downward trend is noted compared over the last two years suggesting the userbase may be getting older on average. 73.04% of the subreddit identify as female, compared with 71.54% in the 2019 survey. Again, when compared with the 2019 survey, this suggests a slight increase in the number of members who identify as female. This is in contrast to the overall membership of Reddit, estimated at 74% male according to Reddit's Wikipedia page [https://en.wikipedia.org/wiki/Reddit#Users_and_moderators]. The ratio of members who identify as heterosexual remained consistent, from 54.89% in the 2019 survey to 55.20% in the 2020 survey.
Ethnicity wise, 77% of members identified as primarily Caucasian, consistent with the 2019 results. While the ethnicities noted to be missing in the 2019 survey have been included in the 2020 survey, some users noted the difficulty of responding when fitting multiple ethnicities, and this will be addressed in the 2021 survey.

Education level

As it did in the 2019 survey, this section highlights the stereotype of childfree people as being well educated. 2.64% of participants did not complete high school, which is a slight decrease from the 2019 survey, where 4% of participants did not graduate high school. However, 6.02% of participants are under 18, compared with 8.22% in the 2019 survey. 55% of participants have a bachelors degree or higher, while an additional 23% have completed "some college or university".
At the 2020 survey, the highest percentage of responses under the: What is your degree/major? question fell under "I don't have a degree or a major" (20.12%). Arts and Humanities, and Computer Science have overtaken Health Sciences and Engineering as the two most popular majors. However, the list of majors was pared down to general fields of study rather than highly specific degree majors to account for the significant diversity in majors studied by the childfree community, which may account for the different results.

Career and Finances

The highest percentage of participants at 21.61% listed themselves as trained professionals.
One of the stereotypes of the childfree is of wealth. However this is not demonstrated in the survey results. 70.95% of participants earn under $60,000 USD per annum, while 87.85% earn under $90,000 per annum. 21.37% are earning under $15,000 per annum. 1065 participants, or 21.10% chose not to disclose this information. It is possible that this may have skewed the results if a significant proportion of these people were our high income earners, but impossible to explore.
A majority of our participants work between 30 and 50 hours per week (75.65%) which is slightly increased from the 2019 survey, where 71.2% of participants worked between 30 and 50 hours per week.

Location

The location responses are largely similar to the 2019 survey with a majority of participants living in a suburban and urban area. 86.24% of participants in the 2020 survey live in urban and suburban regions, with 86.7% of participants living in urban and suburban regions in the 2019 survey. There is likely a multifactorial reason for this, encompassing the younger, educated skew of participants and the easier access to universities and employment, and the fact that a majority of the population worldwide localises to urban centres. There may be an element of increased progressive social viewpoints and identities in urban regions, however this would need to be explored further from a sociological perspective to draw any definitive conclusions.
A majority of our participants (57.47%) were born in the USA. The United Kingdom (7.6%), Canada (7.17%), Australia (3.58%) and Germany (2.17%) encompass the next 4 most popular responses. This is largely consistent with the responses in the 2019 survey.

Religion and Spirituality

For the 2020 survey Christianity (the most popular result in 2019) was split into it's major denominations, Catholic, Protestant, Anglican, among others. This appears to be a linguistic/location difference that caused a lot of confusion among some participants. However, Catholicism at 30.76% remained the most popular choice for the religion participants were raised in. However, of our participant's current faith, Aetheism at 36.23% was the most popular choice. A majority of 78.02% listed their current religion as Aetheist, no religious or spiritual beliefs, or Agnostic.
A majority of participants (61%) rated religion as "not at all influential" to the childfree choice. This is consistent with the 2019 survey where 62.8% rated religion as "not at all influential". Despite the high percentage of participants who identify as aetheist or agnostic, this does not appear to be related to or have an impact on the childfree choice.

Romantic and Sexual Life

60.19% of our participants are in a relationship at the time of the survey. This is consistent with the 2019 survey, where 60.7% of our participants were in a relationship. A notable proportion of our participants are listed as single and not looking (25.81%) which is consistent with the 2019 survey. Considering the frequent posts seeking dating advice as a childfree person, it is surprising that such a high proportion of the participants are not actively seeking out a relationship. Unsurprisingly 90.13% of our participants would not consider dating someone with children. 84% of participants with partners of some kind have at least one childfree partner. This is consistent with the often irreconcilable element of one party desiring children and the other wishing to abstain from having children.

Childhood and Family Life

Overall, the participants skew towards a happier childhood.

Sterilisation

While just under half of our participants wish to be sterilised, 45.21%, only 12.2% have been successful in achieving sterilisation. This is likely due to overarching resistance from the medical profession however other factors such as the logistical elements of surgery and the cost may also contribute. There is a slight increase from the percentage of participants sterilised in the 2019 survey (11.7%). 29.33% of participants do not wish to be or need to be sterilised suggesting a partial element of satisfaction from temporary birth control methods or non-necessity of contraception due to their current lifestyle practices. Participants who indicated that they do not wish to be sterilised or haven't achieved sterilisation were excluded from the percentages where necessary in this section.
Of the participants who did achieve sterilisation, a majority began the search between 19 and 29, with the highest proportion being in the 19-24 age group (35.85%) This is a marked increase from the 2019 survey where 27.3% of people who started the search were between 19-24. This may be due to increased education about permanent contraception or possibly due to an increase in instability around world events.
The majority of participants who sought out and were successful at achieving sterilisation, were however in the 25-29 age group (37.9%). This is consistent with the 2019 survey results.
The time taken between seeking out sterilisation and achieving it continues to increase, with only 50.46% of participants achieving sterilisation in under 3 months. This is a decline from the number of participants who achieved sterilisation in 3 months in the 2019 survey (58.5%). A potential cause of this decrease is to Covid-19 shutdowns in the medical industry leading to an increase in procedure wait times. The proportion of participants who have had one or more doctors refuse to perform the procedure has stayed consistent between the two surveys.

Childfreedom

The main reasons for people choosing the childfree lifestyle are a lack of interest towards parenthood and an aversion towards children which is consistent with the 2019 survey. Of the people surveyed 67.06% are pet owners or involved in a pet's care, suggesting that this lack of interest towards parenthood does not necessarily mean a lack of interest in all forms of caretaking. The community skews towards a dislike of children overall which correlates well with the 87.81% of users choosing "no, I do not have, did not use to have and will not have a job that makes me heavily interact with children on a daily basis" in answer to, "do you have a job that heavily makes you interact with children on a daily basis?". This is an increase from the 2019 survey.
A vast majority of the subreddit identifes as pro-choice (95.5%), a slight increase from the 2019 results. This is likely due to a high level of concern about bodily autonomy and forced birth/parenthood. However only 55.93% support financial abortion, aka for the non-pregnant person in a relationship to sever all financial and parental ties with a child. This is a marked decrease from the 2019 results, where 70% of participants supported financial abortion.
Most of our users realised that did not want children young. 58.72% of participants knew they did not want children by the age of 18, with 95.37% of users realising this by age 30. This correlates well with the age distribution of participants. Despite this early realisation of our childfree stance, 80.59% of participants have been "bingoed" at some stage in their lives.

The Subreddit

Participants who identify as childfree were asked about their interaction with and preferences with regards to the subreddit at large. Participants who do not meet our definition of being childfree were excluded from these questions.
By and large our participants were lurkers (72.32%). Our participants were divided on their favourite flairs with 38.92% selecting "I have no favourite". The next most favourite flair was "Rant", at 16.35%. Our participants were similarly divided on their least favourite flair, with 63.40% selecting "I have no least favourite". In light of these results the flairs on offer will remain as they have been through 2019.
With regards to "lecturing" posts, this is defined as a post which seeks to re-educate the childfree on the practices, attitudes and values of the community, particularly with regards to attitudes towards parenting and children, whether at home or in the community. A commonly used descriptor is "tone policing". A small minority of the survey participants (3.36%) selected "yes" to allowing all lectures, however 33.54% responded "yes" to allowing polite, respectful lectures only. In addition, 45.10% of participants indicated that they were not sure if lectures should be allowed. Due to the ambiguity of responses, lectures will continue to be not allowed and removed.
Many of our participants (36.87%) support the use of terms such as breeder, mombie/moo, daddict/duh on the subreddit, with a further 32.63% supporting use of these terms in context of bad parents only. This is a slight drop from the 2019 survey. In response to this use of the above and similar terms to describe parents remains permitted on this subreddit. However, we encourage users to keep the use of these terms to bad parents only.
44.33% of users support the use of terms to describe children such as crotchfruit on the subreddit, a drop from 55.3% last year. A further 25.80% of users supporting the use of this and similar terms in context of bad children only, an increase from 17.42% last year. In response to this use of the above and similar terms to describe children remains permitted on this subreddit.
69.17% of participants answered yes to allowing parents to post, provided they stay respectful. In response to this, parent posts will continue to be allowed on the subreddit. As for regret posts, which were to be revisited in this year's survey, only 9.5% of participants regarded them as their least favourite post. As such they will continue to stay allowed.
64% of participants support under 18's who are childfree participating in the subreddit with a further 19.59% allowing under 18's to post dependent on context. Therefore we will continue to allow under 18's that stay within the overall Reddit age requirement.
There was divide among participants as to whether "newbie" questions should be removed. An even spread was noted among participants who selected remove and those who selected to leave them as is. We have therefore decided to leave them as is. 73.80% of users selected "yes, in their own post, with their own "Leisure" flair" to the question, "Should posts about pets, travel, jetskis, etc be allowed on the sub?" Therefore we will continue to allow these posts provided they are appropriately flaired.

5. Conclusion

Thank you to our participants who contributed to the survey. This has been an unusual and difficult year for many people. Stay safe, and stay childfree.

Hello Reddit!
My name is Keenan Dakota, I have lived at Twin Oaks, an income-sharing, intentional community in rural Virginia for 36 years, since 1983. I grew up in northern Virginia, my parents worked in government. I went to George Mason University where I studied business management. I joined Twin Oaks when I was 23 because I lost faith in the underpinnings of capitalism and looking for a better model. I have stayed because over time capitalism hasn't looked any better, and its a great place to raise children. While at Twin Oaks, I raised two boys to adulthood, constructed several buildings, managed the building maintenance program, have managed some of the business lines at different times.
Proof this is me. A younger photo of me at Twin Oaks. Here is a video interview of me about living at Twin Oaks. Photo of Twin Oaks members at the 50th anniversary.
Some things that make life here different from the mainstream:

• The labor system - all work is considered equal, whether you are earning income for the community or not. Cooking/cleaning counts the same as planning the annual budget. Also, you don't have to do the same job all week - your day can be a mix of indoor and outdoor work, you have freedom to arrange your day, and you can gain skills in a wide array of tasks and trades.
• Non-gender binary, queer and trans people are very welcome at Twin Oaks. People introduce themselves with their pronouns and a significant number of our members go by they/them.
• Verbal consent culture is very important here. It is not okay to touch anyone without asking.
• Nudity and partial nudity is allowed in some parts of the farm, such as in the sauna, swimming hole, on the hiking trails, etc.
• Our social norms prohibit using phones in common areas when other members are present, with the exception of a few cafe-style spaces.
• Every day we provide a home-cooked, plant-based lunch and dinner with options for special diets including vegetarian, vegan, gluten-free, and no onions & garlic.
• Raising kids here is easier. Some of the time that parents spend raising their children counts towards their labor quota. Many of the kids are home-schooled or "unschooled", and they spend more time outside than in front of a screen. The kids have no problem passing the state's annual standardized test to move onto the next grade level.
• We have a shared clothing resource called Commie Clothes, which is like a free thrift store. Borrow something and then return it dirty, and it gets washed and re-hung up.

More about Twin Oaks:
Twin Oaks is an intentional community in rural central Virginia, made up of around 90 adult members and 15 children. Since the community's beginning in 1967, our way of life has reflected our values of cooperation, sharing, nonviolence, equality, and ecology.
We do not have a group religion; our beliefs are diverse. We do not have a central leader; we govern ourselves by a form of democracy with responsibility shared among various managers, planners, and committees. We are self-supporting economically, and partly self-sufficient. We are income-sharing. Each member works 42 hours a week in the community's business and domestic areas. Each member receives housing, food, healthcare, and personal spending money from the community.
We have open-slots and are accepting applications for new members. All prospective new members must participate in a three-week visitor program. Applicants to join must leave for 30 days after their visit while the community decides on their application.
We offer a $5 tour on Saturdays of the property, starting in March. More info here.
Ask me anything!
TL;DR: Opted out of the rat-race and retired at 23 to live in the woods with a bunch of hippies.
EDIT: Thanks for all the questions! If you want some photos of the farm, you can check out our instagram.
EDIT2: I'm answering new, original questions again today. Sort by new and scroll through the trolls to see more of my responses.
EDIT3: We DO have food with onion & garlic! At meals, there is the regular food, PLUS alternative options for vegan/vegetarian/no gluten/no onions & garlic.
EDIT4: Some of you have been asking if we are a cult. No, we are not. We don't have a central leader or common religion. Here are characteristics of cults, FYI.
Edit: Yikes! Did I mention that I am 60? Reddit is not my native land. I don't understand the hostile, angry and seemingly deliberately obtuse comments on here. And Soooo many people!
Anyway, to the angry crowd: Twin Oaks poses no threat to anyone, we are 100 people out of a country of 330 million? Twin Oaks reached its current maximum population about 25 years ago, so not growing fast, or at all. Members come and go from Twin Oaks. There are, my guess is, 800 ex-members of Twin Oaks, so we aren't holding on to everyone who joins—certainly, no one is held against their will.
Twin Oaks is in rural Virginia, but we really aren't insular, isolated, gated or scared of the mainstream culture. We have scheduled tours of the whole property. Local government officials, like building inspectors, come to Twin Oaks with some frequency. People at Twin Oaks like to travel and manage to do so. I personally, know lots of people in the area, I am also a runner, so I leave the property probably every day. There are lots of news stories about Twin Oaks over the years. If you are worried about Twin Oaks, maybe you could go read what the mainstream (and alternative) media have to say.
Except about equality Twin Oaks is not particularly dogmatic about anything. (I know some people at Twin Oaks will disagree with that statement.) Twin Oaks isn't really hypocritical about Capitalism, Socialism, or Communism, we just don't identify those concepts as something that we are trying to do. Twin Oaks is not trying to DO Communism, we are trying to live a good life with equally empowered citizens—which has led us to try to maintain economic parity among members. Communists also do that. In making decisions in the community I don't remember anyone trying to support or oppose an idea due to excess or insufficient Communism, Socialism, or Capitalism. In most practical senses those words aren't useful and don't mean anything. So, no need to hammer Twin Oaks for being insufficiently pure, or hypocritical.
Twin Oaks is very similar to the Kibbutz in Israel. If anyone has concerns or questions about what would happen if places like Twin Oaks suddenly became much larger and more common, read about the history of the Kibbutz, which may have grown to possibly 1% of the population at their largest? There was and is no fight with Capitalism from the kibbutz—or with the State. My point is—not a threat.
To the other people who think that the ideas of Twin Oaks are interesting, I want you to know it is possible to live at Twin Oaks (or places like Twin Oaks) and happily live ones entire life. There is no central, critical failing that makes the idea not work. And plenty of upside. But do lots of research first. Twin Oaks maintains a massive web site. (Anyway, it takes a long time to read.)
But what I would like to see is more people starting more egalitarian, income-sharing communities. I think that there is a need for a community that is designed and built by families, and who also share income, and provide mutual support with labor and money. If you love this concept, maybe consider gathering together other people and starting your own.
Ideologically speaking:
-Ecology: the best response to ecological problems is for humans to use fewer resources. The easiest way to use fewer resources is to share resources. Living communally vastly cuts down on resource use without reducing quality of life.
-Equality: ideologically speaking, most people accept the idea that all humans have equal rights, but most social structures operate in ways that are fundamentally unequal. If we truly believe in equality then we ought to be willing to put our bodies where our ideology is. In a truly equal world, the issues of sexism and racism and all other forms of discrimination would, essentially, not exist.
-Democracy: Twin Oaks uses all manner of decision-making models and tools to try to include everyone and to keep people equally empowered. There is no useful word for this. We do use a majority vote sometimes, as a fallback. But sometimes we use consensus. We sometimes use sociocracy (dynamic governance). The word "Isocracy" (decision-making among equals), would be useful to describe Twin Oaks' decision-making model, but Lev in Australia has written an incomprehensible "definition" on Wikipedia, that he keeps changing back when someone corrects it.
-Happiness: The overarching goal of all ideologies is to make people happy, right? I mean, isn't it? Capitalism is based upon the belief that motivation is crucial to human aspiration and success (and therefore more happiness). Under Capitalism, equality is a detriment because it hinders motivation (less fear of failure, or striving for success). Twin Oaks believes that humans are happier when they are equal, and equally empowered. So the place to start up the ladder of happiness is to first make everyone equal. Well, Twin Oaks is mainly still working on that first step.
EDIT5: Some have asked about videos - here are links to documentaries about Twin Oaks by BBC, VICE and RT.

Hi everyone, this is my first ever post here.
I run a little website called The Thought Experiment where I talk about various issues, some of them Singapore related. And one of my main interests is Singaporean politics. With the GE2020 election results, I thought I should pen down my take on what us as the electorate were trying to say.
If you like what I wrote, I also wrote another article on the state of play for GE2020 during the campaigning period, as well as 2 other articles related to GE2015 back when it was taking place.
If you don't like what I wrote, that's ok! I think the beauty of freedom of expression is that everyone is entitled to their opinion. I'm always happy to get feedback, because I do think that more public discourse about our local politics helps us to be more politically aware as a whole.
Just thought I'll share my article here to see what you guys make of it :D
Article Starts Here:
During the campaigning period, both sides sought to portray an extreme scenario of what would happen if voters did not vote for them. The Peoples’ Action Party (PAP) warned that Singaporeans that their political opponents “might eventually replace the government after July 10”. Meanwhile, the Worker’s Party (WP) stated that “there was a real risk of a wipeout of elected opposition MPs at the July 10 polls”.
Today is July 11th. As we all know, neither of these scenarios came to pass. The PAP comfortably retained its super-majority in Parliament, winning 83 out of 93 elected MP seats. But just as in GE2011, another Group Representation Constituency (GRC) has fallen to the WP. In addition, the PAP saw its vote share drop drastically, down almost 9% to 61.2% from 69.9% in GE2015.
Singapore’s electorate is unique in that a significant proportion is comprised of swing voters: Voters who don’t hold any blind allegiance to any political party, but vote based on a variety of factors both micro and macro. The above extreme scenarios were clearly targeted at these swing voters. Well, the swing voters have made their choice, their roar sending 4 more elected opposition MPs into Parliament. This article aims to unpack that roar and what it means for the state of Singaporean politics going forward.
1. The PAP is still the preferred party to form Singapore’s Government
Yes, this may come across as blindingly obvious, but it still needs to be said. The swing voter is by its very definition, liable to changes of opinion. And a large factor that determines how a swing voter votes is their perception of how their fellow swing voters are voting. If swing voters perceive that most swing voters are leaning towards voting for the opposition, they might feel compelled to vote for the incumbent. And if the reverse is true, swing voters might feel the need to shore up opposition support.
Why is this so? This is because the swing voter is trying to push the vote result into a sweet spot – one that lies between the two extreme scenarios espoused by either side. They don’t want the PAP to sweep all 93 seats in a ‘white tsunami’. Neither do they want the opposition to claim so much territory that the PAP is too weak to form the Government on its own. But because each swing voter only has a binary choice: either they vote for one side or the other (I’m ignoring the third option where they simply spoil their vote), they can’t very well say “I want to vote 0.6 for the PAP and 0.4 for the Opposition with my vote”. And so we can expect the swing voter bloc to continue being a source of uncertainty for both sides in future elections, as long as swing voters are still convinced that the PAP should be the Government.
2. Voters no longer believe that the PAP needs a ‘strong mandate’ to govern. They also don’t buy into the NCMP scheme.
Throughout the campaign period, the PAP repeatedly exhorted voters to vote for them alone. Granted, they couldn’t very well give any ground to the opposition without a fight. And therefore there was an attempt to equate voting for the PAP as voting for Singapore’s best interests. However, the main message that voters got was this: PAP will only be able to steer Singapore out of the Covid-19 pandemic if it has a strong mandate from the people.
What is a strong mandate, you may ask? While no PAP candidate publicly confirmed it, their incessant harping on the Non-Constituency Member of Parliament (NCMP) scheme as the PAP’s win-win solution for having the PAP in power and a largely de-fanged opposition presence in parliament shows that the PAP truly wanted a parliament where it held every single seat.
Clearly, the electorate has different ideas, handing Sengkang GRC to the WP and slashing the PAP’s margins in previous strongholds such as West Coast, Choa Chu Kang and Tanjong Pagar by double digit percentages. There is no doubt from the results that swing voters are convinced that a PAP supermajority is not good for Singapore. They are no longer convinced that to vote for the opposition is a vote against Singapore. They have realized, as members of a maturing democracy surely must, that one can vote for the opposition, yet still be pro-Singapore.
3. Social Media and the Internet are rewriting the electorate’s perception.
In the past, there was no way to have an easily accessible record of historical events. With the only information source available being biased mainstream media, Singaporeans could only rely on that to fill in the gaps in their memories. Therefore, Operation Coldstore became a myth of the past, and Chee Soon Juan became a crackpot in the eyes of the people, someone who should never be allowed into Parliament.
Fast forward to today. Chee won 45.2% of the votes in Bukit Batok’s Single Member Constituency (SMC). His party-mate, Dr. Paul Tambyah did even better, winning 46.26% of the votes in Bukit Panjang SMC. For someone previously seen as unfit for public office, this is an extremely good result.
Chee has been running for elections in Singapore for a long time, and only now is there a significant change in the way he is perceived (and supported) by the electorate. Why? Because of social media and the internet, two things which the PAP does not have absolute control over. With the ability to conduct interviews with social media personalities as well as upload party videos on Youtube, he has been able to display a side of himself to people that the PAP did not want them to see: someone who is merely human just like them, but who is standing up for what he believes in.
4. Reserved Election Shenanigans and Tan Cheng Block: The electorate has not forgotten.
Tan Cheng Bock almost became our President in 2011. There are many who say that if Tan Kin Lian and Tan Jee Say had not run, Tony Tan would not have been elected. In March 2016, Tan Cheng Bock publicly declared his interest to run for the next Presidential Election that would be held in 2017. The close result of 2011 and Tan Cheng Bock’s imminent candidacy made the upcoming Presidential Election one that was eagerly anticipated.
That is, until the PAP shut down his bid for the presidency just a few months later in September 2016, using its supermajority in Parliament to pass a “reserved election” in which only members of a particular race could take part. Under the new rules that they had drawn up for themselves, it was decreed that only Malays could take part. And not just any Malay. The candidate had to either be a senior executive managing a firm that had S$500 million in shareholders’ equity, or be the Speaker of Parliament or a similarly high post in the public sector (the exact criteria are a bit more in-depth than this, but this is the gist of it. You can find the full criteria here). And who was the Speaker of Parliament at the time? Mdm Halimah, who was conveniently of the right race (Although there was some hooha about her actually being Indian). With the extremely strict private sector criteria and the PAP being able to effectively control who the public sector candidate was, it came as no surprise that Mdm Halimah was declared the only eligible candidate on Nomination Day. A day later, she was Singapore’s President. And all without a single vote cast by any Singaporean.
Of course, the PAP denied that this was a move specifically aimed at blocking Tan Cheng Bock’s bid for the presidency. Chan Chun Sing, Singapore’s current Minister of Trade and Industry, stated in 2017 that the Government was prepared to pay the political price over making these changes to the Constitution.
We can clearly see from the GE2020 results that a price was indeed paid. A loss of almost 9% of vote share is very significant, although a combination of the first-past-the-post rule and the GRC system ensured that the PAP still won 89.2% of the seats in Parliament despite only garnering 61.2% of the votes. On the whole, it’s naught but a scratch to the PAP’s overwhelming dominance in Parliament. The PAP still retains its supermajority and can make changes to the Constitution anytime that it likes. But the swing voters have sent a clear signal that they have not been persuaded by the PAP’s rationale.
5. Swing Voters do not want Racial Politics.
In 2019, Heng Swee Keat, Singapore’s Deputy Prime Minister and the man who is next in line to be Prime Minister (PM) commented that Singapore was not ready to have a non-Chinese PM. He further added that race is an issue that always arises at election-time in Singapore.
Let us now consider the GE2015 results. Tharman Shanmugaratnam, Singapore’s Senior Minister and someone whom many have expressed keenness to be Singapore’s next PM, obtained 79.28% of the vote share in Jurong GRC. This was above even the current Prime Minister Lee Hsien Loong, who scored 78.63% in Ang Mo Kio GRC. Tharman’s score was the highest in the entire election.
And now let us consider the GE2020 results. Tharman scored 74.62% in Jurong, again the highest scorer of the entire election, while Hsien Loong scored 71.91%. So Tharman beat the current PM again, and by an even bigger margin than the last time. Furthermore, Swee Keat, who made the infamous comments above, scored just 53.41% in East Coast.
Yes, I know I’m ignoring a lot of other factors that influenced these results. But don’t these results show conclusively that Heng’s comments were wrong? We have an Indian leading both the current and future PM in both elections, but yet PAP still feels the need to say that Singapore “hasn’t arrived” at a stage where we can vote without race in mind. In fact, this was the same rationale that supposedly led to the reserved presidency as mentioned in my earlier point.
The swing voters have spoken, and it is exceedingly clear to me that the electorate does not care what our highest office-holders are in terms of race, whether it be the PM or the President. Our Singapore pledge firmly states “regardless of race”, and I think the results have shown that we as a people have taken it to heart. But has the PAP?
6. Voters will not be so easily manipulated.
On one hand, Singaporeans were exhorted to stay home during the Covid-19 pandemic. Contact tracing became mandatory, and groups of more than 5 are prohibited.
But on the other hand, we are also told that it’s absolutely necessary to hold an election during this same period, for Singaporeans to wait in long lines and in close proximity to each other as we congregate to cast our vote, all because the PAP needs a strong mandate.
On one hand, Heng Swee Keat lambasted the Worker’s Party, claiming that it was “playing games with voters” over their refusal to confirm if they would accept NCMP seats.
But on the other hand, Heng Swee Keat was moved to the East Coast GRC at the eleventh hour in a surprise move to secure the constituency. (As mentioned above, he was aptly rewarded for this with a razor-thin margin of just 53.41% of the votes.)
On one hand, Masagos Zulkifli, PAP Vice-Chairman stated that “candidates should not be defined by a single moment in time or in their career, but judged instead by their growth throughout their life”. He said this in defense of Ivan Lim, who appears to be the very first candidate in Singaporean politics to have been pushed into retracting his candidacy by the power of non-mainstream media.
But on the other hand, the PAP called on the WP to make clear its stand on Raeesah Khan, a WP candidate who ran (and won) in Sengkang GRC for this election, stating that the Police investigation into Raeesah’s comments made on social media was “a serious matter which goes to the fundamental principles on which our country has been built”.
On one hand, Chan Chun Sing stated in 2015, referring to SingFirst’s policies about giving allowances to the young and the elderly, “Some of them promised you $300 per month. I say, please don’t insult my residents. You think…. they are here to be bribed?”
On the other hand, the PAP Government has just given out several handouts under its many budgets to help Singaporeans cope with the Covid-19 situation. [To be clear, I totally approve of these handouts. What I don’t approve is that the PAP felt the need to lambast similar policies as bribery in the past. Comparing a policy with a crime is a political low blow in my book.]
I could go on, but I think I’ve made my point. And so did the electorate in this election, putting their vote where it counted to show their disdain for the heavy-handedness and double standards that the PAP has displayed for this election.
Conclusion
I don’t say the above to put down the PAP. The PAP would have you believe that to not support them is equivalent to not wanting what’s best for Singapore. This is a false dichotomy that must be stamped out, and I am glad to see our swing voters taking a real stand with this election.
No, I say the above as a harsh but ultimately supportive letter to the PAP. As everyone can see from the results, we all still firmly believe that the PAP should be the Government. We still have faith that PAP has the leadership to take us forward and out of the Covid-19 crisis.
But we also want to send the PAP a strong signal with this vote, to bring them down from their ivory towers and down to the ground. Enough with the double standards. Enough with the heavy-handedness. Singaporeans have clearly stated their desire for a more mature democracy, and that means more alternative voices in Parliament. The PAP needs to stop acting as the father who knows it all, and to start acting as the bigger brother who can work hand in hand with his alternative younger brother towards what’s best for the entire family: Singapore.
There is a real chance that the PAP will not listen, though. As Lee Hsien Loong admitted in a rally in 2006, “if there are 10, 20… opposition members in Parliament… I have to spent my time thinking what is the right way to fix them”.
Now, the PAP has POFMA at its disposal. It still has the supermajority in Parliament, making them able to change any law in Singapore, even the Constitution at will. We have already seen them put these tools to use for its own benefit. Let us see if the PAP will continue as it has always done, or will it take this opportunity to change itself for the better. Whatever the case, we will be watching, and we will be waiting to make our roar heard once again five years down the road.
Majulah Singapura!
Article Ends Here.
Here's the link to the actual article:
https://thethoughtexperiment.org/2020/07/11/ge2020-the-roar-of-the-swing-vote
And here's the link to the other political articles I've written about Singapore:
https://thethoughtexperiment.org/2020/07/07/ge2020-the-state-of-play/
https://thethoughtexperiment.org/2015/09/10/ge2015-voting-wisely/
https://thethoughtexperiment.org/2015/09/05/expectations-of-the-opposition/

After the positive response to my first tutorial on expanding the RAM, I thought I'd continue the fun by expanding the capabilities of Ben's 8-bit CPU even further. That said, you'll need to have done the work in the previous post to be able to do this. You can get a sense for what we'll do in this Imgur gallery.
In this tutorial, we'll balance software and hardware improvements to make this a pretty capable machine:

• Use an Arduino and an assembler to enable faster, more complex programming.
• Expand control lines without additional ROMs, using 74LS138 decoders.
• Add a stack pointer and stack to support subroutines with 74LS193 counters.
• Bonus: Enable B register output and add a Schmitt trigger to clean up your clock signal.

Parts List

To only update the hardware, you'll need:

• 2x 74LS138 (Datasheet, Jameco) which are decoders used to expand the control lines. You can reuse one from the step counter if you don't mind reading binary numbers vs. an LED for each step.
• 1x 74LS04 (Datasheet, Jameco) which is an inverter to help expand the control lines.
• 2x 74LS193 (Datasheet, Jameco) which is a 4-bit up/down counter used to create the stack pointer.
• 1x 74LS245 (Datasheet, Jameco) which is a bus transceiver. You may have a spare one if you did my previous build.
• 1x 74LS00 (Datasheet, Jameco) which is a NAND gate to control the stack pointer.
• 8x Green LED, 1x Yellow LED, 4x Blue LEDs, 13x 220 Ohm resistors to display the stack pointer (green), the stack address (yellow), and the additional control lines (blue).

If you want to update the toolchain, you'll need:

1. Arduino Mega 2560 (Amazon) to create the programmer.
2. Ribbon Jumper Cables (Amazon) to connect the Arduino to the breadboard.
3. TL866 II Plus EEPROM Programmer (Amazon) to program the ROM.

Bonus Clock Improvement: One additional thing I did is replace the 74LS04 inverter in Ben's clock circuit with a 74LS14 inverting Schmitt trigger (datasheet, Jameco). The pinouts are identical! Just drop it in, wire the existing lines, and then run the clock output through it twice (since it's inverting) to get a squeaky clean clock signal. Useful if you want to go even faster with the CPU.

Step 1: Program with an Arduino and Assembler (Image 1, Image 2)

There's a certain delight in the physical programming of a computer with switches. This is how Bill Gates and Paul Allen famously programmed the Altair 8800 and started Microsoft. But at some point, the hardware becomes limited by how effectively you can input the software. After upgrading the RAM, I quickly felt constrained by how long it took to program everything.
You can continue to program the computer physically if you want and even after upgrading that option is still available, so this step is optional. There's probably many ways to approach the programming, but this way felt simple and in the spirit of the build. We'll use an Arduino Mega 2560, like the one in Ben's 6502 build, to program the RAM. We'll start with a homemade assembler then switch to something more robust.
Preparing the Physical Interface
The first thing to do is prepare the CPU to be programmed by the Arduino. We already did the hard work on this in the RAM upgrade tutorial by using the bus to write to the RAM and disconnecting the control ROM while in program mode. Now we just need to route the appropriate lines to a convenient spot on the board to plug the Arduino into.

1. This is optional, but I rewired all the DIP switches to have ground on one side, rather than alternating sides like Ben's build. This just makes it easier to route wires.
2. Wire the 8 address lines from the DIP switch, connecting the side opposite to ground (the one going to the chips) to a convenient point on the board. I put them on the far left, next to the address LEDs and above the write button circuit.
3. Wire the 8 data lines from the DIP switch, connecting the side opposite to ground (the one going to the chips) directly below the address lines. Make sure they're separated by the gutter so they're not connected.
4. Wire a line from the write button to your input area. You want to connect the side of the button that's not connected to ground (the one going to the chip).

So now you have one convenient spot with 8 address lines, 8 data lines, and a write line. If you want to get fancy, you can wire them into some kind of connector, but I found that ribbon jumper cables work nicely and keep things tidy.
The way we'll program the RAM is to enter program mode and set all the DIP switches to the high position (e.g., 11111111). Since the switches are upside-down, this means they'll all be disconnected and not driving to ground. The address and write lines will simply be floating and the data lines will be weakly pulled up by 1k resistors. Either way, the Arduino can now drive the signals going into the chips using its outputs.
Creating the Arduino Programmer
Now that we can interface with an Arduino, we need to write some software. If you follow Ben's 6502 video, you'll have all the knowledge you need to get this working. If you want some hints and code, see below (source code):

1. Create arrays for your data and address lines. For example: const char ADDRESS_LINES[] = {39, 41, 43, 45, 47, 49, 51, 53};. Create your write line with #define RAM_WRITE 3.
2. Create functions to enable and disable your address and data lines. You want to enable them before writing. Make sure to disable them afterward so that you can still manually program using DIP switches without disconnecting the Arduino. The code looks like this (just change INPUT to OUTPUT accordingly): for(int n = 0; n < 8; n += 1) { pinMode(ADDRESS_LINES[n], OUTPUT); }
3. Create a function to write to an address. It'll look like void writeData(byte writeAddress, byte writeData) and basically use two loops, one for address and one for data, followed by toggling the write.
4. Create a char array that contains your program and data. You can use #define to create opcodes like #define LDA 0x01.
5. In your main function, loop through the program array and send it through writeData.

With this setup, you can now load multi-line programs in a fraction of a second! This can really come in handy with debugging by stress testing your CPU with software. Make sure to test your setup with existing programs you know run reliably. Now that you have your basic setup working, you can add 8 additional lines to read the bus and expand the program to let you read memory locations or even monitor the running of your CPU.
Making an Assembler
The above will serve us well but it's missing a key feature: labels. Labels are invaluable in assembly because they're so versatile. Jumps, subroutines, variables all use labels. The problem is that labels require parsing. Parsing is a fun project on the road to a compiler but not something I wanted to delve into right now--if you're interested, you can learn about Flex and Bison. Instead, I found a custom assembler that lets you define your CPU's instruction set and it'll do everything else for you. Let's get it setup:

1. If you're on Windows, you can use the pre-built binaries. Otherwise, you'll need to install Rust and compile via cargo build.
2. Create a file called 8bit.cpu and define your CPU instructions (source code). For example, LDA would be lda {address} -> 0x01 @ address[7:0]. What's cool is you can also now create the instruction's immediate variant instead of having to call it LDI: lda #{value} -> 0x05 @ value[7:0].
3. You can now write assembly by adding #include "8bit.cpu" to the top of your code. There's a lot of neat features so make sure to read the documentation!
4. Once you've written some assembly, you can generate the machine code using ./customasm yourprogram.s -f hexc -p. This prints out a char array just like our Arduino program used!
5. Copy the char array into your Arduino program and send it to your CPU.

At this stage, you can start creating some pretty complex programs with ease. I would definitely play around with writing some larger programs. I actually found a bug in my hardware that was hidden for a while because my programs were never very complex!

Step 2: Expand the Control Lines (Image)

Before we can expand the CPU any further, we have to address the fact we're running out of control lines. An easy way to do this is to add a 3rd 28C16 ROM and be on your way. If you want something a little more involved but satisfying, read on.
Right now the control lines are one hot encoded. This means that if you have 4 lines, you can encode 4 states. But we know that a 4-bit binary number can encode 16 states. We'll use this principle via 74LS138 decoders, just like Ben used for the step counter.
Choosing the Control Line Combinations
Everything comes with trade-offs. In the case of combining control lines, it means the two control lines we choose to combine can never be activated at the same time. We can ensure this by encoding all the inputs together in the first 74LS138 and all the outputs together in a second 74LS138. We'll keep the remaining control lines directly connected.
Rewiring the Control Lines
If your build is anything like mine, the control lines are a bit of a mess. You'll need to be careful when rewiring to ensure it all comes back together correctly. Let's get to it:

1. Place the two 74LS138 decoders on the far right side of the breadboard with the ROMs. Connect them to power and ground.
2. You'll likely run out of inverters, so place a 74LS04 on the breadboard above your decoders. Connect it to power and ground.
3. Carefully take your inputs (MI, RI, II, AI, BI, J) and wire them to the outputs of the left 74LS138. Do not wire anything to O0 because that's activated by 000 which won't work for us!
4. Carefully take your outputs (RO, CO, AO, EO) and wire them to the outputs of the right 74LS138. Remember, do not wire anything to O0!
5. Now, the 74LS138 outputs are active low, but the ROM outputs were active high. This means you need to swap the wiring on all your existing 74LS04 inverters for the LEDs and control lines to work. Make sure you track which control lines are supposed to be active high vs. active low!
6. Wire E3 to power and E2 to ground. Connect the E1 on both 138s together, then connect it to the same line as OE on your ROMs. This will ensure that the outputs are disabled when you're in program mode. You can actually take off the 1k pull-up resistors from the previous tutorial at this stage, because the 138s actively drive the lines going to the 74LS04 inverters rather than floating like the ROMs.

At this point, you really need to ensure that the massive rewiring job was successful. Connect 3 jumper wires to A0-A2 and test all the combinations manually. Make sure the correct LED lights up and check with a multimeteoscilloscope that you're getting the right signal at each chip. Catching mistakes at this point will save you a lot of headaches! Now that everything is working, let's finish up:

1. Connect A0-A2 of the left 74LS138 to the left ROM's A0-A2.
2. Connect A0-A2 of the right 74LS138 to the right ROM's A0-A2.
3. Distribute the rest of the control signals across the two ROMs.

Changing the ROM Code
This part is easy. We just need to update all of our #define with the new addresses and program the ROMs again. For clarity that we're not using one-hot encoding anymore, I recommend using hex instead of binary. So instead of #define MI 0b0000000100000000, we can use #define MI 0x0100, #define RI 0x0200, and so on.
Testing
Expanding the control lines required physically rewiring a lot of critical stuff, so small mistakes can creep up and make mysterious errors down the road. Write a program that activates each control line at least once and make sure it works properly! With your assembler and Arduino programmer, this should be trivial.
Bonus: Adding B Register Output
With the additional control lines, don't forget you can now add a BO signal easily which lets you fully use the B register.

Step 3: Add a Stack (Image 1, Image 2)

Adding a stack significantly expands the capability of the CPU. It enables subroutines, recursion, and handling interrupts (with some additional logic). We'll create our stack with an 8-bit stack pointer hard-coded from $0100 to $01FF, just like the 6502.
Wiring up the Stack Pointer
A stack pointer is conceptually similar to a program counter. It stores an address, you can read it and write to it, and it increments. The only difference between a stack pointer and a program counter is that the stack pointer must also decrement. To create our stack pointer, we'll use two 74LS193 4-bit up/down binary counters:

1. Place a 74LS00 NAND gate, 74LS245 transceiver, and two 74LS193 counters in a row next to your output register. Wire up power and ground.
2. Wire the the Carry output of the right 193 to the Count Up input of the left 193. Do the same for the Borrow output and Count Down input.
3. Connect the Clear input between the two 193s and with an active high reset line. The B register has one you can use on its 74LS173s.
4. Connect the Load input between the two 193s and to a new active low control line called SI on your 74LS138 decoder.
5. Connect the QA-QD outputs of the lower counter to A8-A5 and the upper counter to A4-A1. Pay special attention because the output are in a weird order (BACD) and you want to make sure the lower A is connected to A8 and the upper A is connected to A4.
6. Connect the A-D inputs of the lower counter to B8-B5 and the upper counter to B4-B1. Again, the inputs are in a weird order and on both sides of the chip so pay special attention.
7. Connect the B1-B8 outputs of the 74LS245 transceiver to the bus.
8. On the 74LS245 transceiver, connect DIR to power (high) and connect OE to a new active low control line called SO on your 74LS138 decoder.
9. Add 8 LEDs and resistors to the lower part of the 74LS245 transceiver (A1-A8) so you can see what's going on with the stack pointer.

Enabling Increment & Decrement
We've now connected everything but the Count Up and Count Down inputs. The way the 74LS193 works is that if nothing is counting, both inputs are high. If you want to increment, you keep Count Down high and pulse Count Up. To decrement, you do the opposite. We'll use a 74LS00 NAND gate for this:

1. Take the clock from the 74LS08 AND gate and make it an input into two different NAND gates on the 74LS00.
2. Take the output from one NAND gate and wire it to the Count Up input on the lower 74LS193 counter. Take the other output and wire it to the Count Down input.
3. Wire up a new active high control line called SP from your ROM to the NAND gate going into Count Up.
4. Wire up a new active high control line called SM from your ROM to the NAND gate going into Count Down.

At this point, everything should be working. Your counter should be able to reset, input a value, output a value, and increment/decrement. But the issue is it'll be writing to $0000 to $00FF in the RAM! Let's fix that.
Accessing Higher Memory Addresses
We need the stack to be in a different place in memory than our regular program. The problem is, we only have an 8-bit bus, so how do we tell the RAM we want a higher address? We'll use a special control line to do this:

1. Wire up an active high line called SA from the 28C16 ROM to A8 on the Cypress CY7C199 RAM.
2. Add an LED and resistor so you can see when the stack is active.

That's it! Now, whenever we need the stack we can use a combination of the control line and stack pointer to access $0100 to $01FF.
Updating the Instruction Set
All that's left now is to create some instructions that utilize the stack. We'll need to settle some conventions before we begin:

• Empty vs. Full Stack: In our design, the stack pointer points to the next empty slot in memory, just like on the 6502. This is called an "empty stack" convention. ARM processors use a "full stack" convention where the stack points to the last filled slot.
• Ascending vs. Descending Stack: In our design, the stack pointer increases when you add something and decreases when you remove something. This is an "ascending stack" convention. Most processors use a "descending stack", so we're bucking the trend here.

If you want to add a little personal flair to your design, you can change the convention fairly easily. Let's implement push and pop (source code):

1. Define all your new control lines, such as #define SI 0x0700 and #define SO 0x0005.
2. Create two new instructions: PSH (1011) and POP (1100).
3. PSH starts the same as any other for the first two steps: MI|CO and RO|II|CE. The next step is to put the contents of the stack pointer into the address register via MI|SO|SA. Recall that SA is the special control line that tells the memory to access the $01XX bank rather than $00XX.
4. We then take the contents of AO and write it into the RAM. We can also increment the stack pointer at this stage. All of this is done via: AO|RI|SP|SA, followed by TR.
5. POP is pretty similar. Start off with MI|CO and RO|II|CE. We then need to take a cycle and decrement the stack pointer with SM. Like with PSH, we then set the address register with MI|SO|SA.
6. We now just need to output the RAM into our A register with RO|AI|SA and then end the instruction with TR.
7. Updating the assembler is easy since neither instruction has operands. For example, push is just psh -> 0x0B.

And that's it! Write some programs that take advantage of your new 256 byte stack to make sure everything works as expected.

Step 4: Add Subroutine Instructions (Image)

The last step to complete our stack is to add subroutine instructions. This allows us to write complex programs and paves the way for things like interrupt handling.
Subroutines are like a blend of push/pop instructions and a jump. Basically, when you want to call a subroutine, you save your spot in the program by pushing the program counter onto the stack, then jumping to the subroutine's location in memory. When you're done with the subroutine, you simply pop the program counter value from the stack and jump back into it.
We'll follow 6502 conventions and only save and restore the program counter for subroutines. Other CPUs may choose to save more state, but it's generally left up to the programmer to ensure they're not wiping out states in their subroutines (e.g., push the A register at the start of your subroutine if you're messing with it and restore it before you leave).
Adding an Extra Opcode Line
I've started running low on opcodes at this point. Luckily, we still have two free address lines we can use. To enable 5-bit opcodes, simply wire up the 4Q output of your upper 74LS173 register to A7 of your 28C16 ROM (this assumes your opcodes are at A3-A6).
Updating the ROM Writer
At this point, you simply need to update the Arduino writer to support 32 instructions vs. the current 16. So, for example, UCODE_TEMPLATE[16][8] becomes UCODE_TEMPLATE[32][8] and you fill in the 16 new array elements with nop. The problem is that the Arduino only has so much memory and with the way Ben's code is written to support conditional jumps, it starts to get tight.
I bet the code can be re-written to handle this, but I had a TL866II Plus EEPROM programmer handy from the 6502 build and I felt it would be easier to start using that instead. Converting to a regular C program is really simple (source code):

1. Copy all the #define, global const arrays (don't forget to expand them from 16 to 32), and void initUCode(). Add #include and #include to the top.
2. In your traditional int main (void) C function, after initializing with initUCode(), make two arrays: char ucode_upper[2048] and char ucode_lower[2048].
3. Take your existing loop code that loops through all addresses: for (int address = 0; address < 2048; address++).
4. Modify instruction to be 5-bit with int instruction = (address & 0b00011111000) >> 3;.
5. When writing, just write to the arrays like so: ucode_lower[address] = ucode[flags][instruction][step]; and ucode_upper[address] = ucode[flags][instruction][step] >> 8;.
6. Open a new file with FILE *f = fopen("rom_upper.hex", "wb");, write to it with fwrite(ucode_upper, sizeof(char), sizeof(ucode_upper), f); and close it with fclose(f);. Repeat this with the lower ROM too.
7. Compile your code using gcc (you can use any C compiler), like so: gcc -Wall makerom.c -o makerom.

Running your program will spit out two binary files with the full contents of each ROM. Writing the file via the TL866II Plus requires minipro and the following command: minipro -p CAT28C16A -w rom_upper.hex.
Adding Subroutine Instructions
At this point, I cleaned up my instruction set layout a bit. I made psh and pop 1000 and 1001, respectively. I then created two new instructions: jsr and rts. These allow us to jump to a subroutine and returns from a subroutine. They're relatively simple:

1. For jsr, the first three steps are the same as psh: MI|CO, RO|II|CE, MI|SO|SA.
2. On the next step, instead of AO we use CO to save the program counter to the stack: CO|RI|SP|SA.
3. We then essentially read the 2nd byte to do a jump and terminate: MI|CO, RO|J.
4. For rts, the first four steps are the same as pop: MI|CO, RO|II|CE, SM, MI|SO|SA.
5. On the next step, instead of AI we use J to load the program counter with the contents in stack: RO|J|SA.
6. We're not done! If we just left this as-is, we'd jump to the 2nd byte of jsr which is not an opcode, but a memory address. All hell would break loose! We need to add a CE step to increment the program counter and then terminate.

Once you update the ROM, you should have fully functioning subroutines with 5-bit opcodes. One great way to test them is to create a recursive program to calculate something--just don't go too deep or you'll end up with a stack overflow!

Conclusion

And that's it! Another successful upgrade of your 8-bit CPU. You now have a very capable machine and toolchain. At this point I would have a bunch of fun with the software aspects. In terms of hardware, there's a number of ways to go from here:

1. Interrupts. Interrupts are just special subroutines triggered by an external line. You can make one similar to how Ben did conditional jumps. The only added complexity is the need to load/save the flags register since an interrupt can happen at any time and you don't want to destroy the state. Given this would take more than 8 steps, you'd also need to add another line for the step counter (see below).
2. ROM expansion. At this point, address lines on the ROM are getting tight which limits any expansion possibilities. With the new approach to ROM programming, it's trivial to switch out the 28C16 for the 28C256 that Ben uses in the 6502. These give you 4 additional address lines for flags/interrupts, opcodes, and steps.
3. LCD output. At this point, adding a 16x2 character LCD like Ben uses in the 6502 is very possible.
4. Segment/bank register. It's essentially a 2nd memory address register that lets you access 256-byte segments/banks of RAM using bank switching. This lets you take full advantage of the 32K of RAM in the Cypress chip.
5. Fast increment instructions. Add these to registers by replacing 74LS173s with 74LS193s, allowing you to more quickly increment without going through the ALU. This is used to speed up loops and array operations.

Source
There are several people answering: Paolo Martino is PM, Marco Micheli is MM, Heli Greus is HG, Detlef Koschny is DVK, and Aidan Cowley is AC.

Questions	Answers
Can we really detect any asteroids in space with accuracy and do we have any real means of destroying it?	Yes, we can detect new asteroids when they are still in space. Every night dozens of new asteroids are found, including a few that can come close to the Earth.
	Regarding the second part of the question, the goal would be to deflect them more than destroy them, and it is technologically possible. The Hera/DART mission currently being developed by ESA and NASA will demonstrate exactly this capability.
	MM
I always wanted to ask: what is worse for life on Earth - to be hit by a single coalesced asteroid chunk, or to be hit by a multiple smaller pieces of exploded asteroid, aka disrupted rubble pile scenario?	DVK: This is difficult to answer. If the rubble is small (centimetres to meters) it is better to have lots of small ones – they’d create nice bright meteors. If the rubble pieces are tens of meters it doesn’t help.
Let’s say that hypothetically, an asteroid the size of Rhode Island is coming at us, it will be a direct hit - you’ve had the resources and funding you need, your plan is fully in place, everything you’ve wanted you got. The asteroid will hit in 10 years, what do you do?	DVK: I had to look up how big Rhode Island is – a bit larger than the German Bundesland ‘Saarland’. Ok – this would correspond to an object about 60 km in diameter, right? That’s quite big – we would need a lot of rocket launches, this would be extremely difficult. I would pray. The good news is that we are quite convinced that we know all objects larger than just a few kilometers which come close to our planet. None of them is on a collision course, so we are safe.
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Why are you quite convinced that you know all object of that size? And what is your approach in finding new celestial bodies?	DVK: There was a scientific study done over a few years (published in Icarus 2018, search for Granvik) where they modelled how many objects there are out there. They compared this to the observations we have with the telescopic surveys. This gives us the expected numbers shown here on our infographic: https://www.esa.int/ESA_Multimedia/Images/2018/06/Asteroid_danger_explained
	There are additional studies to estimate the ‘completeness’ – and we think that we know everything above roughly a few km in size.
	To find new objects, we use survey telescopes that scan the night sky every night. The two major ones are Catalina and Pan-STARRS, funded by NASA. ESA is developing the so-called Flyeye telescope to add to this effort https://www.esa.int/ESA_Multimedia/Images/2017/02/Flyeye_telescope.
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Thanks for the answer, that's really interesting! It's also funny that the fist Flyeye deployed is in Sicily, at less than 100km from me, I really had no idea	DVK: Indeed, that's cool. Maybe you can go and visit it one day.
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What about Interstellar objects however, like Oumuamua?	DVK: The two that we have seen - 'Oumuamua and comet Borisov - were much smaller than the Saarland (or Rhode Island ;-) - not sure about Borisov, but 'Oumuamua was a few hundred meters in size. So while they could indeed come as a complete surprise, they are so rare that I wouldn't worry.
Would the public be informed if an impending asteroid event were to happen? And, how would the extinction play out? Bunch of people crushed to death, knocked off our orbit, dust clouds forever?	DVK: We do not keep things secret – all our info is at the web page http://neo.ssa.esa.int. The ‘risky’ objects are in the ‘risk page’. We also put info on really close approaches there. It would also be very difficult to keep things ‘under cover’ – there are many high-quality amateur astronomers out there that would notice.
In 2029 asteroid Apophis will fly really close to Earth, even closer than geostationary satellites. Can we use some of those satellites to observe the asteroid? Is it possible to launch very cheap cube sats to flyby Apophis in 2029?	DVK: Yes an Apophis mission during the flyby in 2029 would be really nice. We even had a special session on that topic at the last Planetary Defense Conference in 2019, and indeed CubeSats were mentioned. This would be a nice university project – get me a close-up of the asteroid with the Earth in the background!
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So you’re saying it was discussed and shelved?	In the conference we just presented ideas. To make them happen needs funding - in the case of ESA the support of our member countries. But having something presented at a conference is the first step. One of the results of the conference was a statement to space agencies to consider embarking on such a mission. See here: https://www.cosmos.esa.int/documents/336356/336472/PDC_2019_Summary_Report_FINAL_FINAL.pdf/341b9451-0ce8-f338-5d68-714a0aada29b?t=1569333739470
	Go to the section 'resolutions'. This is now a statement that scientists can use to present to their funding agencies, demonstrating that it's not just their own idea.
Thanks for doing this AMA! Did we know the Chelyabinsk meteor in 2013 (the one which had some great videos on social media) was coming? Ig not, how comes? Also, as a little side one, have there been any fatalities from impact events in the past 20 years?	Unfortunately, the Chelyabinsk object was not seen in advance, because it came from the direction of the Sun where ground-based telescopes cannot look.
	No known fatalities from impacts have happened in the past 20 years, although the Chelyabinsk event did cause many injuries, fortunately mostly minor.
	MM
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How often do impacts from that direction happen, compared to impacts from visible trajectories?	In terms of fraction of the sky, the area that cannot be easily scanned from the ground is roughly a circle with a radius of 40°-50° around the current position of the Sun, corresponding to ~15% of the total sky. However, there is a slight enhancement of objects coming from that direction, therefore the fraction of objects that may be missed when heading towards us is a bit higher.
	However, this applies only when detecting an asteroid in its "final plunge" towards the Earth. Larger asteroids can be spotted many orbits earlier, when they are farther away and visible in the night side of the sky. Their orbits can then be determined and their possible impacts predicted even years or decades in advance.
	MM
There must be a trade-off when targeting asteroids as they get closer to Earth, is there a rule of thumb at what the best time is to reach them, in terms of launch time versus time to reach the asteroid and then distance from Earth?	DVK: Take e.g. a ‘kinetic impactor’ mission, like what DART and Hera are testing. Since we only change the velocity of the asteroid slightly, we need to hit the object early enough so that the object has time to move away from it’s collision course. Finding out when it is possible to launch requires simulations done by our mission analysis team. They take the strength of the launcher into account, also the available fuel for course corrections, and other things. Normally each asteroid has its own best scenario.
Do you also look at protecting the moon from asteroids? Would an impact of a large enough scale potentially have major impacts on the earth?	DVK: There are programmes that monitor the Moon and look for flashes from impacting small asteroids (or meteoroids) - https://neliota.astro.noa.g or the Spanish MIDAS project. We use the data to improve our knowledge about these objects. These programmes just look at what is happening now.
	For now we would not do anything if we predicted a lunar impact. I guess this will change once we have a lunar base in place.
Why aren't there an international organisation comprised of countries focused on the asteroid defence? Imagine like the organisation with multi-billion $ budget and program of action on funding new telescopes, asteroid exploration mission, plans for detection of potentially dangerous NEA, protocols on action after the detection - all international, with heads of states discussing these problems?	DVK: There are international entities in place, mandated by the UN: The International Asteroid Warning Network (http://www.iawn.net) and the Space Mission Planning Advisory Group (http://www.smpag.net). These groups advise the United Nations. That is exactly where we come up with plans and protocols on action. But: They don’t have budget – that needs to come from elsewhere. I am expecting that if we have a real threat, we would get the budget. Right now, we don’t have a multi-billion budget.
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There is no actual risk of any sizable asteroids hitting earth in the foreseeable future. Any preparation for it would just be a waste of money.	DVK: Indeed, as mentioned earlier, we do not expect a large object to hit is in the near future. We are mainly worried about those in the size range of 20 m to 40 m, which happen on average every few tens of years to hundreds of years. And where we only know a percent of them or even less.
President Obama wanted to send a crewed spacecraft to an asteroid - in your opinion is this something that should still be done in the future, would there be any usefulness in having a human being walk/float on an asteroid's surface?	DVK: It would definitely be cool. I would maybe even volunteer to go. Our current missions to asteroids are all robotic, the main reason is that it is much cheaper (but still expensive) to get the same science. But humans will expand further into space, I am sure. If we want to test human exploration activities, doing this at an asteroid would be easier than landing on a planet.
this is another reply	Yes, but I am slightly biased by the fact that I work at the European astronaut centre ;) There exist many similarities to what we currently do for EVA (extra vehicular activities) operations on the International Space Station versus how we would 'float' around an asteroid. Slightly biased again, but using such a mission to test exploration technologies would definitely still have value. Thanks Obama! - AC
I've heard that some asteroids contains large amounts of iron. Is there a possibility that we might have "space mines" in the far away future, if our own supply if iron runs out?	Yes, this is a topic in the field known as space mining, part of what we call Space Resources. In fact, learning how we can process material we might find on asteroids or other planetary bodies is increasingly important, as it opens up the opportunities for sustainable exploration and commercialization. Its a technology we need to master, and asteroids can be a great target for testing how we can create space mines :) - AC
By how much is DART expected to deflect Didymos? Do we have any indication of the largest size of an asteroid we could potentially deflect?	PM: Didymos is a binary asteroid, consisting of a main asteroid Didymos A (~700m) and a smaller asteroid Didymos B (~150m) orbiting around A with a ~12 hours period. DART is expected to impact Didymos B and change its orbital period w.r.t. Didymos A of ~1%. (8 mins)
	The size of Didymos B is the most representative of a potential threat to Earth (the highest combination of probability and consequence of impacts), meaning smaller asteroids hit the Earth more often but have less severe consequences, larger asteroids can have catastrophic consequences but their probability of hitting the earth is very very low.
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Why is there less probability of larger asteroids hitting earth?	DVK: There are less large objects out there. The smaller they are, the more there are.
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Is there any chance that your experiment will backfire and send the asteroid towards earth?	PM: Not at all, or we would not do that :) Actually Dimorphos (the Didymos "moon") will not even leave its orbit around Didymos. It will just slightly change its speed.
I'm sure you've been asked this many times but how realistic is the plot of Armageddon? How likely is it that our fate as a species will rely on (either) Bruce Willis / deep sea oil drillers?	Taking into consideration that Bruce Willis is now 65 and by the time HERA is launched he will be 69, I do not think that we can rely on him this time (although I liked the movie).
	HERA will investigate what method we could use to deflect asteroid and maybe the results will show that we indeed need to call the deep sea oil drillers.
	HG
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So then would it be easier to train oil drillers to become astronauts, or to train astronauts to be oil drillers?	I do not know which one would be easier since I have no training/experience of deep see oil drilling nor becoming an astronaut, but as long as the ones that would go to asteroid have the sufficient skills and training (even Bruce Willis), I would be happy.
	HG
If budget was no object, which asteroid would you most like to send a mission to?	Nice question! For me, I'd be looking at an asteroid we know something about, since I would be interested in using it for testing how we could extract resources from it. So for me, I would choose Itokawa (https://en.wikipedia.org/wiki/25143_Itokawa), which was visited by Hayabusa spacecraft. So we already have some solid prospecting carried out for this 'roid! - AC
this is another reply	Not sure if it counts as an asteroid, but Detlef and myself would probably choose ʻOumuamua, the first discovered interstellar object.
	MM
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Do we even have the capability to catch up to something like that screaming through our solar system? That thing has to have a heck of a velocity to just barrel almost straight through like that.	DVK: Correct, that would be a real challenge. We are preparing for a mission called 'Comet Interceptor' that is meant to fly to an interstellar object or at least a fresh comet - but it will not catch up with it, it will only perform a short flyby.
	https://www.esa.int/Science_Exploration/Space_Science/ESA_s_new_mission_to_intercept_a_comet
After proving to be able to land on one, could an asteroid serve as a viable means to transport goods and or humans throughout the solar system when the orbit of said asteroid proves beneficial. While it is probably quite problematic to land the payload, it could save fuel or am I mistaken?	Neat idea! Wonder if anyone has done the maths on the amount of fuel you would need/save vs certain targets. - AC
	PM: To further complement, the saving is quite marginal indeed because in order to land (softly) on the asteroid you actually need to get into the very same orbit of that asteroid . At that point your orbit remains the same whether you are on the asteroid or not..
can the current anti-ballistic missiles systems intercept a terminal phase earth strike asteroid? or it is better to know beforehand and launch an impacting vehicle into space?	DVK: While I do see presentations on nuclear explosions to deflect asteroids at our professional meetings, I have not seen anybody yet studying how we could use existing missile systems. So it's hard to judge whether existing missiles would do the job. But in general, it is better to know as early as possible about a possible impact and deflect it as early as possible. This will minimize the needed effort.
How much are we prepared against asteroid impacts at this moment?	DVK: 42… :-) Seriously – I am not sure how to quantify ‘preparedness’. We have international working groups in place, mentioned earlier (search for IAWN, SMPAG). We have a Planetary Defence Office at ESA, a Planetary Defense Office at NASA (who spots the difference?), search the sky for asteroids, build space missions… Still we could be doing more. More telescopes to find the object, a space-based telescope to discover those that come from the direction of the Sun. Different test missions would be useful, … So there is always more we could do.
Have you got any data on the NEO coverage? Is there estimations on the percentage of NEOs we have detected and are tracking? How can we improve the coverage? How many times have asteroids been able to enter earths atmosphere without being detected beforehand?	Here’s our recently updated infographics with the fraction of undiscovered NEOs for each size range: https://www.esa.int/ESA_Multimedia/Images/2018/06/Asteroid_danger_explained
	As expected, we are now nearly complete for the large ones, while many of the smaller ones are still unknown.
	In order to improve coverage, we need both to continue the current approach, centered on ground-based telescopes, and probably also launch dedicated telescopes to space, to look at the fraction of the sky that cannot be easily observed from the ground (e.g., towards the Sun).
	Regarding the last part of your question, small asteroids enter the Earth atmosphere very often (the infographics above gives you some numbers), while larger ones are much rarer.
	In the recent past, the largest one to enter our atmosphere was about 20 meters in diameter, and it caused the Chelyabinsk event in 2013. It could not be detected in advance because it came from the direction of the Sun.
	We have however detected a few small ones before impact. The first happened in 2008, when a ~4-meter asteroid was found to be on a collision course less than a day before impact, it was predicted to fall in Northern Sudan, and then actually observed falling precisely where (and when) expected.
	MM
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	DVK: And to add what MM said - Check out http://neo.ssa.esa.int. There is a ‘discovery statistics’ section which provides some of the info you asked about. NASA is providing similar information here https://cneos.jpl.nasa.gov/stats/. To see the sky which is currently covered by the survey telescopes, you need to service of the Minor Planet Center which we all work together with: http://www.minorplanetcenter.org, ‘observers’, ‘sky coverage’. That is a tool we use to plan where we look with our telescopes, so it is a more technical page.
Are there any automatic systems for checking large numbers of asteroids orbits, to see if the asteroid's orbit is coming dangerously close to Earth, or is it done by people individually for every asteroid? I ask it because LSST Rubin is coming online soon and you know it will discover a lot of new asteroids.	Yes, such systems exist, and monitor all known and newly discovered asteroids in order to predict possible future impacts.
	The end result of the process is what we call "risk list": http://neo.ssa.esa.int/risk-page
	It is automatically updated every day once new observational data is processed.
	MM
What are your favourite sci-fi series?	DVK: My favorites are ‘The Expanse’, I also liked watching ‘Salvation’. For the first one I even got my family to give me a new subscription to a known internet streaming service so that I can see the latest episodes. I also loved ‘The Jetsons’ and ‘The Flintstones’ as a kid. Not sure the last one counts as sci-fi though. My long-time favorite was ‘Dark Star’.
this is another reply	Big fan of The Expanse at the moment. Nice, hard sci-fi that has a good impression of being grounded in reality - AC
this is another reply	When I was a kid I liked The Jetsons, when growing up Star Trek, Star wars and I also used to watch with my sister the 'V'.
	HG
When determining the potential threat of a NEA, is the mass of an object a bigger factor or size? I'm asking because I'm curious if a small but massive object (say, with the density of Psyche) could survive atmospheric entry better than a comparatively larger but less massive object.	The mass is indeed what really matters, since it’s directly related with the impact energy.
	And as you said composition also matters, a metal object would survive atmospheric entry better, not just because it’s heavier, but also because of its internal strength.
	MM
What are your thoughts on asteroid mining as portrayed in sci-fi movies? Is it feasible? If so would governments or private space programs be the first to do so?What type of minerals can be found on asteroids that would merit the costs of extraction?	Certainly there is valuable stuff you can find on asteroids. For example, the likely easiest material you can harvest from an asteroid would be volatiles such as H2O. Then you have industrial metals, things like Iron, Nickel, and Platinum group metals. Going further, you can break apart many of the oxide minerals you would find to get oxygen (getting you closer to producing rocket fuel in-situ!). Its feasible, but still needs alot of testing both here on Earth and eventually needs to be tested on a target. It may be that governments, via agencies like ESA or NASA, may do it first, to prove the principles somewhat, but I know many commercial entities are also aggresively working towards space mining. To show you that its definitely possible, I'd like to plug the work of colleagues who have processed lunar regolith (which is similar to what you may find on asteroids) to extract both oxygen and metals. Check it out here: http://www.esa.int/ESA_Multimedia/Images/2019/10/Oxygen_and_metal_from_lunar_regolith
	AC
Will 2020's climax be a really big rock?	DVK: Let's hope not...
Considering NASA, ESA, IAU etc. is working hard to track Earth-grazing asteroids, how come the Chelyabinsk object that airburst over Russia in 2013 came as a total surprise?	The Chelyabinsk object came from the direction of the Sun, where unfortunately ground-based telescopes cannot look at. Therefore, it would not have been possible to discover it in advance with current telescopes. Dedicated space telescopes are needed to detect objects coming from this direction in advance.
	MM
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Is this to say that it was within specific solid angles for the entire time that we could have observed it given its size and speed?	Yes, precisely that. We got unlucky in this case.
	MM
Have any of you read Lucifer's Hammer by Larry Niven? In your opinion, how realistic is his depiction of an asteroid strike on Earth?	DVK: I have – but really long ago, so I don’t remember the details. But I do remember that I really liked the book, and I remember I always wanted to have a Hot Fudge Sundae when reading it.
I was thinking about the asteroid threat as a teen and came up with this ideas (Hint: they are not equally serious, the level of craziness goes up real quick). Could you please comment on their feasibility? 1. Attaching a rocket engine to an asteroid to make it gradually change trajectory, do that long in advance and it will miss Earth by thousands of km 2. Transporting acid onto asteroid (which are mainly metal), attaching a dome-shaped reaction chamber to it, using heat and pressure to then carry out the chemical reaction to disintegrate asteroids 3. This one is even more terrible than a previous one and totally Dan Brown inspired — transporting antimatter on asteroid, impacting and causing annihilation. Thank you for this AMA and your time!	DVK: Well the first one is not so crazy, I have seen it presented... the difficulty is that all asteroids are rotating in one way or another. So if you continuously fire the engine it would not really help. You'd need to switch the engine on and off. Very complex. And landing on an asteroid is challenging too. Just using the 'kinetic impactor' which we will test with DART/Hera (described elsewhere in this chat) is simpler. Another seriously proposed concept is to put a spacecraft next to an asteroid and use an ion engine (like we have on our Mercury mission BepiColombo) to 'push' the asteroid away.
	As for 2 and 3 I think I will not live to see that happening ;-)
What is the process to determine the orbit of a newly discovered asteroid?	The process is mathematically quite complex, but here's a short summary.
	Everything starts with observations, in particular with measurements of the position of an asteroid in the sky, what we call "astrometry". Discovery telescopes extract this information from their discovery images, and make it available to everybody.
	These datapoints are then used to calculate possible trajectories ("orbits") that pass through them. At first, with very few points, many orbits will be possible.
	Using these orbits we can extrapolate where the asteroid will be located during the following nights, use a telescope to observe that part of the sky, and locate the object again.
	From these new observations we can extract new "astrometry", add it to the orbit determination, and see that now only some of the possible orbits will be compatible with the new data. As a result, we now know the trajectory better than before, because a few of the possible orbits are not confirmed by the new data.
	The cycle can then continue, with new predictions, new observations, and a more accurate determination of the object's orbit, until it can be determined with an extremely high level of accuracy.
	MM
What are some asteroids that are on your "watchlist"?	We have exactly that list on our web portal: http://neo.ssa.esa.int/risk-page
	It's called "risk list", and it includes all known asteroids for which we cannot exclude a possible impact over the next century. It is updated every day to include newly discovered asteroids, and remove those that have been excluded as possible impactors thanks to new observations.
	MM
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That's quite a list!! Do you guys ever feel stressed or afraid when you have to add another dangerous candidate (and by dangerous I mean those above 200m) is added to this Risk List?	Yes, when new dangerous ones are added it's important that we immediately do our best to gather more data on them, observing them with telescopes in order to get the information we need to improve our knowledge of their orbit.
	And then the satisfaction of getting the data needed to remove one from the list is even greater!
	MM
What inspired you to go into this field of study?	I was fascinated by astronomy in general since I was a kid, but the actual "trigger" that sparked my interest in NEOs was a wonderful summer course on asteroids organized by a local amateur astronomers association. I immediately decided that I would do my best to turn this passion into my job, and I'm so happy to have been able to make that dream come true.
	MM
this is another reply	DVK: I started observing meteors when I was 14, just by going outside and looking at the night sky. Since then, small bodies in the solar system were always my passion.
As a layperson, I still think using nuclear weapons against asteroids is the coolest method despite better methods generally being available. Do you still consider the nuclear option the cool option, or has your expertise in the field combined with the real-life impracticalities made it into a laughable/silly/cliche option?	DVK: We indeed still study the nuclear option. There are legal aspects though, the ‘outer space treaty’ forbids nuclear explosions in space. But for a large object or one we discover very late it could be useful. That’s why we have to focus on discovering all the objects out there as early as possible – then we have time enough to use more conventional deflection methods, like the kinetic impactor (the DART/Hera scenario).
It seems like doing this well would require international cooperation, particularly with Russia. Have you ever reached out to Russia in your work? Do you have a counterpart organization there that has a similar mission?	DVK: Indeed international cooperation is important - asteroids don't know about our borders! We work with a Russian team to perform follow-up observations of recently discovered NEOs. Russia is also involved in the UN-endorsed working groups that we have, IAWN and SMPAG (explained in another answer).
how much can experts tell from a video of a fireball or meteor? Can you work out what it's made of and where it came from? https://www.reddit.com/space/comments/hdf3xe/footage_of_a_meteor_at_barrow_island_australia/?utm_source=share&utm_medium=web2x	If multiple videos or pictures, taken from different locations, are available, then it's possible to reconstruct the trajectory, and extrapolate where the object came from.
	Regarding the composition, it's a bit more difficult if nothing survives to the ground, but some information can be obtained indirectly from the fireball's color, or its fragmentation behavior. If a spectral analysis of the light can be made, it's then possible to infer the chemical composition in much greater detail.
	MM
I've always wanted to know what the best meteorite buying site is and what their average price is??	DVK: Serious dealers will be registered with the 'International Meteorite Collectors Association (IMCA)' - https://www.imca.cc/. They should provide a 'certificate of authenticity' where it says that they are member there. If you are in doubt, you can contact the association and check. Normally there are rough prices for different meteorite types per gram. Rare meteorites will of course be much more expensive than more common ones. Check the IMCA web page to find a dealer close to you.
Just read through Aidans link to the basaltic rock being used as a printing material for lunar habitation. There is a company called Roxul that does stone woven insulation that may be able to shed some light on the research they have done to minimize their similarity to asbestos as potentially carcinogenic materials deemed safe for use in commercial and residential applications. As the interior surfaces will essentially be 3D printed lunar regolith what are the current plans to coat or dampen the affinity for the structure to essentially be death traps for respiratory illness?	At least initially, many of these 3d printed regolith structures would not be facing into pressurised sections, but would rather be elements placed outside and around our pressure vessels. Such structures would be things like radiation shields, landing pads or roadways, etc. In the future, if we move towards forming hermetically sealed structures, then your point is a good one. Looking into terrestrial solutions to this problem would be a great start! - AC
What kind of career path does it take to work in the asteroid hunting field?	It's probably different for each of us, but here's a short summary of my own path.
	I became interested in asteroids, and near-Earth objects in particular, thanks to a wonderful summer course organized by a local amateur astronomers association. Amateur astronomers play a great role in introducing people, and young kids in particular, to these topics.
	Then I took physics as my undergrad degree (in Italy), followed by a Ph.D. in astronomy in the US (Hawaii in particular, a great place for astronomers thanks to the exceptional telescopes hosted there).
	After finishing the Ph.D. I started my current job at ESA's NEO Coordination Centre, which allowed me to realize my dream of working in this field.
	MM
this is another reply	DVK: Almost all of us have a Master's degree either in aerospace engineering, mathematics, physics/astronomy/planetary science, or computer science. Some of us - as MM - have a Ph.D. too. But that's not really a requirement. This is true for our team at ESA, but also for other teams in other countries.
What is the likelihood of an asteroid hitting the Earth In the next 200 years?	It depends on the size, large ones are rare, while small ones are much more common. You can check this infographics to get the numbers for each size class: https://www.esa.int/ESA_Multimedia/Images/2018/06/Asteroid_danger_explained
	MM
Have you played the Earth Defence Force games and if you have, which one is your favourite?	No I have not played the Earth Defence Force games, but I just looked it up and I think I would liked it. Which one would you recommend?
	HG
How close is too close to earth? Space is a SUPER vast void so is 1,000,000 miles close, 10,000,000? And if an asteroid is big enough can it throw earth off its orbit?	DVK: Too close for my taste is when we compute an impact probability > 0 for the object. That means the flyby distance is zero :-) Those are the objects on our risk page http://neo.ssa.esa.int/risk-page.
	If an object can alter the orbit of another one, we would call it planet. So unless we have a rogue planet coming from another solar system (verrry unlikely) we are safe from that.
How can I join you when I'm older?	DVK: Somebody was asking about our career paths... Study aerospace engineering or math or physics or computer science, get a Masters. Possibly a Ph.D. Then apply for my position when I retire. Check here for how to apply at ESA: https://www.esa.int/About_Us/Careers_at_ESA/Frequently_asked_questions2#HR1
How much is too much?	DVK: 42 again
Are you aware of any asteroids that are theoretically within our reach, or will be within our reach at some point, that are carrying a large quantity of shungite? If you're not aware, shungite is like a 2 billion year old like, rock stone that protects against frequencies and unwanted frequencies that may be traveling in the air. I bought a whole bunch of the stuff. Put them around the la casa. Little pyramids, stuff like that.	DVK: If I remember my geology properly, Shungite forms in water sedimental deposits. This requires liquid water, i.e. a larger planet. So I don't think there is a high chance to see that on asteroids.