Plants For Improved Indoor Air Quality

It’s no secret that pollution is pretty bad for you. Thankfully, in most western countries nowadays pollution levels are pretty low. Here’s a neat little website that shows pollution levels all around the world. If you live in a westernized country, chances are you’re in the green with regard to pollution levels. But even if you weren’t, around 90% of time is spent indoors for most people anyways.

So no problem, right? Well, not exactly. Throughout the last several decades there’s been various changes in building designs to improve energy efficiency, mostly in the form of superinsulation and reduced fresh air exchange. In short, contemporary buildings are made much more airtight than older structures.

This isn’t necessarily bad as it drastically cut down energy costs. However, when combined with all the modern synthetic materials used in building materials, fabrics, paints, carpeting, cleaning products, fabrics, etc., a condition known as Sick Building Syndrome can occur. In short, poor ventilation and the outgassing of much of these products can cause residents to suffer from headaches, irritation, dizziness, etc. Indoor air pollutants are often at levels “2 to 5 times higher than typical outdoor concentrations.

Indeed, indoor air can “contain over 900 chemicals, particles and biological materials with potential health effects.” It’s difficult to measure and quantify the risks of indoor air pollution since there is still insufficient data and the research is immature. Likewise, there is great variation in the levels and types of pollutants across different households.

Despite that, it doesn’t seem like it would hurt to look further into this. If there are simple ways to dramatically lower levels of indoor air pollution, then why not? Also, the EPA consider indoor air quality to be one of the top five environmental risks to public health, so it’s probably worth looking into.

My initial thoughts were to use plants. After all, plants are known to produce oxygen, purify the air, and we evolved all around them, so it sounds like a good thing to start with.

But which plants? Darn, if only an independent agency with a focus on scientific research performed a large-scale study on which plants were best for filtering the air of common toxic agents. Oh, thanks NASA. In 1989 NASA was looking for ways to clean air in space stations and tested a bunch of different plants and compiled a list of the best ones for removing compounds like formaldehyde, trichloroethylene, and benzene from the air. Some were especially promising like Peace lilies, Chrysanthemum, and Snake plants.

As a result, we start getting blog posts like this, this, this, and hundreds others disseminating NASA’s results and recommending the best potted plants for scrubbing your home’s indoor air. Some even mention how some of the tested plants “remove up to 90 percent of the toxins in your indoor air.” Alright then, problem solved. Pollution is bad for you and here are the best potted plants for lowering indoor pollution. Buy a couple of them and move on.

If only things were so simple. Let’s begin with dissecting the original NASA study.

NASA designed small, sealed Plexiglas containers where they would seal a plant with an activated carbon soil filter for 24 hours. The experimenters injected a chemical such as formaldehyde or benzene into the chamber and collected air samples immediately, 6 hours later, and 24 hours later.

As for the results, they were quite variable. After 24 hours, depending on the plant and chemical, there could be anywhere between 10% and 90% removal. Here’s a screenshot of the relevant table, showing the most impressive six plants:


However, we must keep in mind several things:

  • As previously mentioned, there are hundreds of chemical pollutants floating around, and this study tested just three. How well does this generalize to other toxins?
  • NASA used charcoal filters that will provide for greater adsorption of toxins.
  • The lab was testing with ideal conditions. The chambers were small (between 15 and 30 cubic feet) and single chemicals were injected once at the start.
  • Imagine an average 150 square foot room with 8 foot ceilings. That would be 1,200 cubic feet, so you’d need around 75 small plants with carbon filters in that room to match NASA’s results. John Girman estimates around 680 plants would replicate the results of NASA’s chamber study in a 1,500 square foot home.
  • Even then, the results wouldn’t match because homes have constant generation of chemicals such as formaldehyde via outgassing.
  • Lastly, the NASA experiment used sealed chambers, whereas modern homes have ventilation and air exchange, further confounding the applicability.

As an aside, it was later shown that the primary contributors to the reduction of volatile organic compounds (VOCs) were rhizosphere microbial activity of plants. That is, the microorganisms in the soil were doing the majority of the work and in some cases the foliage actually inhibited toxin reduction by forming a boundary layer on top of the soil.

Additionally, indoor air streams are fairly still. This study talks about the limitations of using potted plants and suggests ways of using biofiltration via actively exposing the air stream to the rhizosphere of plants. For significant air scrubbing, a method would need to be devised to provide efficient gas exchange between the soil and air. Measures would then need to be taken to prevent the drying out of the soil and the humidification of the ambient air.

Okay, so maybe the results won’t be as impressive as ideal laboratory conditions, but at least it’s something, right? Besides, look at all the benefits of plants:

  • Common potted house plants are cheap, so it’s not a large investment.
  • They’re mostly low-maintenance, with most requiring watering once a week or so.
  • They’ll at least clean some air and make some oxygen.
  • Everyone loves plants! They brighten up the room and are great decoration.
  • There have been studies showing they can be therapeutic, lowering rates of depression and generally just increasing well-being and motivation.

So yeah, why not then? It’s low cost, and may very well be low benefit, but they’re probably still worth it, right?

Maybe. Let’s continue with reviewing the relevant research.

After NASA’s study people were curious of how the effects stack up in the real world, so similar experiments were performed, but this time in homes and offices.

Healthy Buildings International (HBI) designed an experiment in Arlington, Virginia where two identically furnished office floors would be run on separate but identical ventilation systems, with both floors sharing a common outside air intake. The ninth and eleventh floors were chosen, and both floors were asked to give up their plants for a month-long period where baseline measurements were taken. Following this, for the first four months the ninth floor was filled with many plants, and for the last four months, plants were present on both floors. Measurements of VOCs and airborne microbes of both floors were then taken over the duration of the experiment.

The results?


The authors concluded the “levels of VOCs on the ninth floor remained essentially the same as those on the eleventh floor throughout the duration of the study.” So there was practically no difference between the two floors.

Dingle et al. then tried their luck in 2000 in an Australian study where they found some office buildings and added five plants every other day to each room (to a maximum of 20 plants) in the experimental building. They used two adjacent buildings with no plants as controls. At the end of the study the authors concluded there was “no change in formaldehyde concentrations with the addition of 5 or 10 plants in the rooms and only an 11% reduction in formaldehyde concentrations with 20 plants in the room.”

So again, not much, and the paltry 11% may very well just be statistical noise.

Okay, well what about oxygen production? They may not be excellent scrubbers but at least they can help turn some carbon dioxide into oxygen, right? For example, the Snake Plant is recommended to put into your room at night because unlike most plants, it also gives off oxygen at night.

Unfortunately, the amounts are mostly negligible. Consider that air on average contains around 20.95% oxygen and 0.04% carbon dioxide. Even if you filled your home with plants and they converted all the carbon dioxide, the oxygen levels would only increase from 20.95% to 21%, which wouldn’t even be noticeable. Also, decomposing organic matters in many potted plants can cause a net increase in carbon dioxide.

Even if this wasn’t the case, animals and plants both engage in respiration, 24 hours a day. During the night when photosynthesis can’t take place, most plants continue to use oxygen while not releasing any back into the room. However, as previously mentioned, all these amounts are trivial.

Okay, maybe the scrubbing and oxygen generation potential are negligible, but it’s not like plants can do any harm, and they’re still good decoration.

About that..

To summarize, a team at the University of Georgia conducted a study to measure the amounts of VOCs released by common indoor plants (Peace Lily, Snake Plant, Weeping Fig, and Areca Palm). As it turns out, our friendly plants aren’t so innocent after all. They found on average 16 different VOCs released by these plants. The actors responsible?

  • The plants themselves.
  • Micro-organisms in the plant’s soil.
  • The plastic pots containing the plants. Here’s some alternatives.

Additionally, people may be allergic to some plants, and other plants may affect the moisture content in the air, promoting mold growth. Plants may also be grown with fertilizers and pesticides that could have harmful effects on humans. And don’t forget about the possibility of bugs!

So, plants both input and output various VOCs in variable amounts. They may still be a net benefit, but as previously stated, the effects are likely negligible one way or the other.

Alright then, what about this? Some sites have been reporting it. Here’s the abstract:

New University of Technology Sydney (UTS) research made possible by nursery levy voluntary contribution funding has found strong evidence supporting the benefits of office plants for reducing stress and negative mood states in office workers. Plants were found to promote wellbeing, and therefore, potentially performance. Staff who had plants placed in their offices showed reductions in stress levels and negative feelings of a magnitude of 30 to 60%, while those with no plants recorded increases in stress and negativity of 20 to 40%, over the 3-month test period. Importantly, just one office plant was enough to make all the difference. In this Nursery Paper, the researchers involved outline their findings.

The study starts by talking about how significant amounts of studies have shown that potted plants have been effective in reducing VOCs emitted by plastics (furnishings, furniture, computers, etc.) and carbon dioxide in the air. Then, since clear air leads to clear thinking and better cardiovascular health, that perhaps potted plants could also reduce depression and stress and lead to better moods and improved worker performance and productivity.

The experimenters obtained a baseline measure of wellness via a Lifestyle Appraisal Questionnaire. The questionnaire confirmed the staff had physical and mental scores similar to those in their general demographic. They then gave the workers some plants (between one and four, or none if you were in the control group).

They also had them complete other various psychological measure questionnaires: The Profile of Mood States (POMS) and The General Health Questionnaire (GHQ). Most people are familiar with surveys like these-they ask you a question and you respond with how you feel on a four/five-point scale. They then waited three months and had them take the questionnaires again.

Needless to say, they were thorough. Here are the results from the study in table form:


Extremely impressive! With the addition of just a few plants, the researchers were able to provide a significant (and statistically significant!) reduction across the board in all the negative psychological feelings being tested. If this indeed the case, the addition of plants to office environments may very well be the single most cost-effective measures businesses can take to improve worker morale and productivity. The study’s conclusion: “This study shows that just one plant per work space can provide a very large lift to staff spirits, and so promote wellbeing and performance”.

However, I’m a bit skeptical. Here’s why:

  • The placebo effect. If you need any reminding in how powerful it can be, here’s some light reading on the matter. If you take a wellness questionnaire and then you and the entire office immediately receives some plants, you may soon suspect that these plants will be improving the tested feelings, which will then improve those feelings.
  • The addition of plants may show that your employers care about you because they are giving you free plants to try and improve your well-being. Who doesn’t love plants? This may cause you to like your job and superiors more.
  • The existence of the experiment may have caused behavioral changes in the staff working there.
  • Sick building syndrome can often dissipate over time as outgassing is abated or people just plain get used to it.
  • Similarly, over time people can get used to the office environment and have lower levels of daily stress from being familiar with their role and coworkers.
  • This could have coincided with other health interventions. For example, upon being questioned about their psychological health or upon the addition of potted plants, workers may become more cognizant of their mental health and do more to improve it both in and out of the office.
  • The control group is all over the place. A 32% reduction in depression coinciding with a 42% increase in negativity? What gives? The study comes out and says that the control group had a small sample size (9 people..) and thus is not statistically significant.
    • This basically puts the entirety of the study into question. Had the control group been of similar size to the experimental group, we may have very well gotten identical results in both. Now we don’t even know if the plants did anything!
  • Could they do it again? Remember everyone, if you ever need any more reasons to doubt a study’s results, just mention the replication crisis and publication bias!

So, the study results may very well be bupkis. Or maybe not. Who knows?

Anyways, time for the conclusion. My thoughts on the matter are probably the following: unless you live in a nursery, the effects from plants on pollution and oxygen levels in the air are mostly negligible. On the other hand, I wouldn’t be surprised if the placebo effect from plants is strong enough to provide significant effects on physical and psychological health. If that’s the case, oops, reading this article may have harmed your health, but probably not by much.

Lastly, if you actually want to improve air quality significantly, the most practical advice may be to just open some windows or buy some heavy industrial air exchangers with fancy filters.


On Retention Rates Of Competitive Games

This post was difficult to write because when I tried to use various examples from many different games, the essay quickly lost its focus and became bogged down with explanatory context in case you weren’t familiar with them. It takes a great deal of writing space to satisfactorily explain even a single game so this quickly became unwieldy. So, I’ve since decided that I’m just going to mostly stick to a few, well-known examples of popular games and hope you’re somewhat familiar with them.

These games are (mostly) StarCraft II, League of Legends (or any MOBA really), and Overwatch. These are all competitive, multiplayer games that include matchmaking, a ranking system, and are/were somewhat popular.

I’m going to define success as sustained or increased player population growth over time. Of course there’s a variety of reasons for why each game may not achieve success. For example, maybe the game gets old quick, has low production quality, or there’s game breaking bugs that the developers never fix. There’s a multitude of reasons why any game lives or dies. In this post I’m going to try to ignore any obvious, low-hanging fruits that have already been discussed ad-nauseam elsewhere and instead bring focus to more obscure, although arguably just as critical, variables affecting player retention. The list will not be exhaustive and will mostly be psychological aspects that some developers ignore, much to their peril.

I’m interested in why certain games just seem to slowly die off despite having no glaring issues and are otherwise well-crafted and fun games. In this post I will present certain psychological hypotheses that I believe hinder the retention of many competitive multiplayer games.

Let’s begin with StarCraft II. The game is extremely stressful to play. In fact if you google “ladder anxiety” the first result is a guide for how to deal with the anxiety associated with just queuing up for a match in the video game, StarCraft II. This was a real phenomenon that used to be discussed a ton on the forums. Eventually it got so bad that StarCraft II mostly became a spectator sport, where everyone would rather watch pros play on Twitch rather than play the game themselves.

But why was it so bad? Certainly there doesn’t seem to be nearly as much ladder anxiety for other contemporary competitive games. What gives? Here are my main guesses:

  • StarCraft II was 1v1. You had no team to fall back on. It was just you against your opponent. (Other results for ladder anxiety nowadays mostly involve Hearthstone, despite its casualness, slow game speed, and randomness (RNG) factor. Ranked 1v1 games seem to come with ladder anxiety as a package deal.) Also, insert obligatory evopsych remark regarding humans being awful at fighting any animal 1v1 throughout history and evolving to thrive in and prefer group engagements for survival.
  • There was no RNG, other than maybe spawn positions. If you lost, it was entirely your fault. You couldn’t blame it on bad luck.
  • The game was mentally taxing. It was real-time, not turn-based. The only limit was just how fast you could play. Professionals often had hundreds of APM (actions per minute). From the second the game started to the very end you would have to play your very best at all times with no breaks.

I’m honestly surprised the game lasted as long as it did. If not for the thriving spectator culture, the fact that it was created by and backed by Blizzard, and the existence of team-based and custom games, I’m sure it would have met its demise much sooner.

Needless to say, most people like to (or at least they tell themselves) play games to relieve, not induce, stress. When a sizable portion of your player base has to expend considerable amounts of mental effort and willpower just to queue for a match, in the long run there will be fewer and fewer matches and players each day.

Contrast this with other popular competitive, multiplayer games out right now. MOBAs (multiplayer online battle arenas) seem to be a pretty safe formula. Ever since their inception via DotA, there have been numerous spin-offs that are more-or-less all successful: League of Legends, DotA 2, Heroes of Newerth, SMITE, Heroes of the Storm, etc. It’s a hell of a formula considering that most games fail but these games in this category are all quite similar and experience great success and continued growth. Basically, it seems pretty hard to fuck up making a MOBA.

So what sorts of properties do these MOBAs have? Well for one you have four other teammates. This provides a diffusion of responsibility and makes individual contribution difficult to measure. Depending on your skill level you can play more or less important roles and you can always deflect blame to anyone else on your team for the loss. One needs not feel as culpable for the loss and it’s difficult to ascertain your actual skill level. Ignorance certainly is bliss when it comes to personal and teammate skill level in competitive matches. When your teammate performance is transparent, those doing well will be quicker to flame lousy teammates, which leads to increased tension and less desire to play the game.

Most successful games nowadays are team-based, with the sweet spot seeming to be around 4-6 players per team. Any less and there’s too much pressure on you to perform, and any more and it feels like the entire outcome of the game is due to luck since you cannot realistically carry that many players. In other words, your contribution is too diluted. Free for all (FFA) is okay, but it often leads to turtling, unlucky situations (getting ganged up on), and has a lack of camaraderie. On the other hand, there’s not as much pressure compared to a 1v1 since players can fight each other and you can be more selective in your engagements. People also don’t seem to like FFA as much, as evidenced by their lack of market share in popular games. Even Quake Champions is currently trying to promote their team-based mode over the class Quake FFA, most likely due to the above factors.

More importantly, whereas in a game like StarCraft II you may soon feel accurately placed in the matchmaker and give up ranked, in a team-based game you are never truly certain of your own skill level. As a result you will continue to re-queue because it’s plausible that you’re just repeatedly getting poor teammates and actually belong at a higher rank. Maintaining the illusion that you’re not accurately placed is what keeps many people requeuing.

Continuing with our contrastment, MOBAs also require much less mental effort. The first ten minutes or so is usually the laning phase where the players perform a mini-game to get last hits on creeps to collect a bounty. This is reasonably low effort and can be auto-piloted quite effectively. After that you usually group with your team for the rest of the game and repeatedly engage in team fights. These team fights require all your mental effort but they’re short-lived activities that are interspersed by simpler processes like roaming, farming, walking to lane, waiting to respawn, etc.

My point is that the games follow a relatively simple flow chart and require little expenditure of mental energy. The graph of effort would be mostly baseline with the occasional spikes during ganks and team fights. This helps avoid fatigue associated with utilization of maximum mental effort. Games that consist of short-lived matches that are heavily concentrated in effort can still be fun, but it’s rare for players to play them for extended durations.

Consider also that people desire fair matches. If people cannot play your game for a lasting time frame, the matchmaker has less of a player pool to select from and has to compromise by having less equal matchups. Or it can have longer queue times. Both of these result in player dissatisfaction and can make them exit the session. This can also become a negative feedback loop where even more players quit in discontent, worsening the situation even more. Before long the population reaches a critical low and the game dies.

Another important factor is a high skill floor. Take a game like Chess-you can learn the entirety of the rules of the game in under an hour, yet the game’s skill cap is so high that people can spend their entire lives improving and learn something new from every match. This is good because it doesn’t lower the skill ceiling, just the barrier to entry.

Games like Overwatch and League of Legends are likewise easy to learn and hard to master. You can just hop into a game and learn a single hero whose abilities take mere minutes to internalize. Games with a steep learning curve can quickly have population problems because most people find it difficult to invest heavy resources into learning a game when they’re not sure if they’ll later find it fun. When over half of your players never even kill the first boss in your game before quitting, you might want to spend additional resources improving the beginning experience.

This is similar to a trend in fiction-rather than having lengthy expository inundations at the start of fantasy novels explaining all the various minutiae of this universe’s properties, it’ll start in media res. Otherwise people just get bored and put the book down. You have to first prove to the player that the game is fun. Once they’re invested in it you can trickle in additional rules and concepts.

High skill floors not only protects against an immediate exodus of players, but also increases the range of players in the demographic for the game. Overwatch is a fantastic example of this-the majority of FPSes (first person shooters) all require their players to have adept aim. Overwatch instead includes classes that span the entire spectrum with regard to aiming ability required. Some have complete auto aim, others ease of aiming due to their short range and high rate of fire, and some are of course the archetypal snipers and pistol players. As a result, players with different aptitudes (positioning, team coordination, healing, etc.) can all thrive. This grows the possible player base by a significant amount because it can now appeal to many disparate demographics.

Speaking of Overwatch, they do a lot of things right. Let’s take the scoreboard-a lot of players complained that you couldn’t see everyone’s stats like in other FPSes. For example, in a lot of games you can hit TAB and see a breakdown of everyone’s kills, deaths, damage, etc., so why not Overwatch too? It certainly would have been easier to just include a table dump of everyone’s stats compared to their medal and scorecard system they currently have, and many players also request the simpler scoreboard, so what gives?

If I were to guess, I’d say it’s because a scoreboard makes players feel pressured, and makes you think everyone is judging you. With a public scoreboard everyone can see how well or poorly you are performing. If you are playing badly you feel self conscious which leads you play worse, and if you do well you get upset with your team’s performance because you can see how much better you are doing than them. You might ask them to do better which they obviously would already be doing if they could, and it just leads to arguments and flaming.

Similarly, it becomes harder to play with friends. When all stats are public and you see just how poorly you are doing, it makes you feel bad and not want to drag the team down. When this information is hidden, you can play easy knowing that no one can see just how poorly you are doing. More importantly, you may also be ignorant of how poorly you are doing, which doesn’t make you feel like a burden to your friend group and want to leave them.

The medal system is also ideal because an elitist only wants to know he’s doing better than everyone on his team, and the presence of the gold medals do just that. He can’t know how much better he is doing, but the knowledge that he’s at least doing the best is good enough for him. He can’t go as far as to flame his team though, because someone could be right behind him in terms of kills and damage, because that information is hidden.

The scorecards at the end of the game are a bit random too. Even if you did mostly poorly, you might get a card in some obscure category, like “Teleporter Uptime”. There’s then upvoting of each cards, which has literally no effect at all other than making other players feel appreciated. All anonymous, competitive, team-based multiplayer games are going to have a high base rate of toxicity, so all these little things help with curtailing the amounts of rage and frustration in games.

I could go on and on about things Overwatch does right. It really goes to show how the structure of games can heavily influence overall toxicity levels in the community. Competitive anonymous, multiplayer environments always leads to high levels of flaming, but my Overwatch experience generally defies this. Out of all the all the competitive games I’ve played, Overwatch has some of the lowest levels of toxicity I’ve seen, and this is with all chat, voice communication, etc. It’s really quite remarkable how cordial most people are, especially when contrasted with other games like League of Legends, which may very well host the most toxic environment online within its ranked system, despite harsh punishments for even slight infractions. The system put in place by the developers has a huge impact on overall hostility levels in the community.

Speaking of toxicity, Blizzard has had a recent trend in some of their games of removing all chat. That is, you can’t type to the enemy team. I’m beginning to think that Blizzard has some psychologists on payroll. Obviously the technology is there and is trivial to implement, but they choose not to implement it. Why? Well, in 99% of matches, it’s completely unnecessary. Very rare in competitive games is the enemy going to be complimenting you or being cordial to you. People also really don’t like being shit-talked, so the cost analysis becomes easy. That is, while removing all chat has negative utility in the rare case someone wants to positively interact with the other team, it has overwhelming positive utility in the common case of preventing flaming and mocking of the enemy team. The removal of all chat also makes the game feel less competitive and real, in that the opponents seem more like bots than humans, but Blizzard seems to think this downside does not outweigh the benefits, and I think I agree with them.

Another aspect that is important, and this is not just for competitive games, but games in general, is progression. The need isn’t as strong in competitive games because you can always be working towards that next rank up. You see this evidenced by the “gamification” of everything. Every game and activity is getting experience bars, unlockable cosmetics, achievements, levels, etc. Recent competitive games all involve a plethora of skins, loot boxes, levels, etc. Everyone is doing this now because it works.

For example, take a Dungeon Crawl like Binding of Isaac. It involves entering rooms, killing all the enemies, and moving on. Occasionally you’ll find an item to make your character stronger, and there’s bosses at the end of each floor, but if you die, you start over from square one.

Needless to say, if you actually lost everything and made no progress with each failed run, no one would play, or they’d get bored very quickly once they won a few times. Progression is added to the game through the form of achievements, unlockable items that will now spawn in future runs, unlocking new characters to do runs with, various goals (such as killing the final boss 10 times), etc. In almost every run, even if you fail, you at least accomplish something, and if you won, you accomplished even more. People are generally quite loss averse, and will avoid activities where they keep losing without gaining anything.

Fairness and difficulty is very important. People are very antagonistic towards “unfair” scenarios, and rightly so. I think this is a big reason why a lot of open-world PvP (player versus player) games fail. Individual skill can slide the scales a bit, but in most engagements the group with more players will win. As a result, the winning strategy is to typically “zerg” your opponent with larger numbers. Often times these games will have serious death penalties such as the loss of items or experience. Needless to say, combining loss aversion with unfair matchups depresses enjoyment and retention of said games.

Most games now counterbalance this by restricting engagements to equal numbers on both sides in the form of arenas and battlegrounds, with skill rating matching done to ensure relatively equal matchups. This is the case with the aforementioned League of Legends, Overwatch, etc. While everyone’s skill rating is slightly more fluid due to the team-based aspects of these games, the aforementioned psychological benefits outweigh the costs of slightly unfair matchups.

The above factors all contribute to startup costs. That is, the ease with which a player launches the game and queues for a match. Each negative factor plays a part in the final decision of “do I want to play this game?” Put another way, elements such as having a good sized team, fair matches, reasonable amounts of mental effort, etc. all lower the resistance towards the execution of that double click to launch the game. Players may not be consciously aware of all of this, but all the preceding ingredients translate to levels of fun and enjoyment. The aggregation of these collective feelings are realized in total player retention numbers over time.

Glorified Water Wheels

Here’s an interesting list of the electricity breakdown by energy source in the US in 2016, courtesy of the EIA:

  • Natural gas = 33.8%
  • Coal = 30.4%
  • Nuclear = 19.7%
  • Renewables (total) = 14.9%
    • Hydropower = 6.5%
    • Wind = 5.6%
    • Biomass = 1.5%
    • Solar  = 0.9%
    • Geothermal = 0.4%

This is probably obvious to everyone reading this, but I only just recently had the realization that the vast majority (~99%?) of our electricity is produced via glorified water wheels. That is, we either stick a wheel somewhere where’s already a flow (in a river for water or in the air for wind) or we just boil water ourselves to spin our big wheels.

For example, how exactly is wind energy generated? Well, we stick a fan on a big stick and wait for the wind to come by. As the wind passes it spins the turbine and voila, energy!

What about hydropower? Dams are colossal feats of engineering. For example, the Hoover Dam cost over 100 lives, $700 million inflated adjusted dollars, and enough concrete to “pave a road from San Francisco to New York“. It generates electricity when the water passing by flows through turbines and causes them to spin.

Coal plants produces around 30% of our domestic energy. How do they work? Well, first we mine some coal and then dump it into a firebox. Then we pump water through the box. The water gets hot, turned into steam, and then, you guessed it, spins a turbine.

Natural gas and oil works similarly. Sometimes instead of using the produced heat to boil the water to spin the turbines they instead spin the turbines with the byproducts of the ignited gas itself, but it’s all the same idea.

Biomass is only 1.5% but let’s do it anyway. Surprise, we just dump a bunch of wood chips, tree stumps, garbage, or whatever into a pile and burn it to heat water into steam that turns turbines.

Geothermal energy is even less at 0.4% and you can probably guess how this one ends. However, instead of heating the water ourselves we just pipe up already hot water from underground. This water is then piped into a turbine and .. yeah.

What about nuclear power? Now we’re getting to the real shit. This is the result of the collaboration of some of the greatest minds in modern history, all focusing on quite literally splitting the atom to release untold amounts of power and destruction. We are able to use mere milligrams of some of the universe’s heaviest elements to decimate countries. It’s also pretty good at boiling water to turn into steam that spins turbines.

But at least there’s solar power! Our saving grace! It may only be 1%, but at least it’s not the same old boring “hey this burns well; let’s use it to boil water to spin some turbines.” We create solar panels with silicon and then place them in sunny areas with lots of photons flying around. When photons hit these solar cells they excite the electrons within them that causes them to flow through the material. We can then hook up a battery or something to these panels so the electrons flow into that for later consumption.

This seems too good to be true. Who’s this solar guy think he is? We’ve got rules around here-if you want to generate electricity you use turbines! You can just stick a turbine in some water or in the air to catch the water or wind flowing past, but we’d kinda prefer you just stick to boiling water with whatever you’ve got lying around. You think you’re special because you found an alternative to spinning wheels? We demand conformity! Ah, much better.

Unreliable Memories And The Supernatural

Do you remember that show with the talking bears when we were younger? They lived in a big treehouse in Bear Country. There was the Papa Bear, the oafish carpenter, the wise Mama Bear, and their children, Brother Bear, Sister Bear, and Honey Bear. Do you remember the name of this show? The Berenst___ Bears. Fill in the blank.

Now look up the actual name of the show. Were you correct in your spelling? If not, why do you think not?

Moving on, here are some quotations and catchphrases that were never originally said by the characters in various TV shows and movies:

  • “Beam me up, Scotty” by various Star Trek characters
  • “Just the facts, ma’am” by Jack Webb
  • “Elementary, my dear Watson” by Sherlock Holmes
  • “Luke, I am your father” by Darth Vader
  • “Play it again, Sam” by Lisa in Casablanca
  • “Do you feel lucky, punk?” by Harry Callahan in Dirty Harry

There are a lot of these. Here, have some more:

  • The Chappelle’s Show is now “Chappelle’s Show”
  • Looney Toons is now Looney Tunes
  • “Mirror, mirror on the wall” now is “Magic mirror on the wall”
  • Oscar Meyer Wieners is now Oscar Mayer Wieners
  • “Depends” underwear is now just “Depend” underwear
  • “Febreeze” is now just “Febreze”

This phenomenon is known as the Mandela Effect, after many people in the Western world remembering that Nelson Mandela died in prison in the ’80s. However, his actual death was in 2013. This is despite individuals having vivid memories of seeing clips of his funeral on television. The term was invented and then popularized by Fiona Broome, a paranormal consultant.

The intense cognitive dissonance that results from being seemingly wrong about such vivid memories have caused many investigating the phenomenon to conclude that there must have been a timeline split in our world at some point, where we are now living in Universe B instead of Universe A.

Another theory is that we are in some sort of simulation and that there are programming glitches that cause these false memories. That is, the world changed but our memories did not.

However, before we get into all that, are there any likely explanations for why this could be happening? After all, it does seem suspicious that so many people share these faulty memories.

Let’s start off with what we started with: The Berenstain Bears. When I first heard about this, even I thought it was spelled “The Berenstein Bears”. Why? Because the ending “stein” is extremely common. So pervasive was this error that even official packaging had the error. Even people who are shown “The Berenstain Bears” logo for the first time, told to remember the spelling, and then immediately asked about it still think it is spelled with the “stein” ending. Brains are efficient and fill in the gaps with known patterns rather than do needless work.

Similarly, no one who lives in South Africa thinks Nelson Mandela died in prison. He was their first post-apartheid president. How could they? Likewise, no one in Japan thinks their islands used to be where the Philippines are. No one in Canada thinks they have only four provinces. People in Febreze factories don’t think it used to be called “Febreeze.” These effects are always falsified when those close to the subject in question never experience the phenomenon. But what causes this confusion?

Let’s use “Chappelle’s Show” as a demonstrable example.

In this case, it’s not surprising to be confused, because many other shows prefixed their title with “The”. “The Jerry Springer Show”, “The Steve Harvey Show”, “The Chris Rock Show”, “The Dr. Oz Show”, “The Ellen DeGeneres Show”, “The Oprah Winfrey Show”, “The Graham Norton Show”, “The Wendy Williams Show”, etc. People noticed a pattern and filled in the blanks with what sounds right.

Speaking of what sounds right, doesn’t Febreeze sound right? After all, it’s an air freshener that has the sound “breeze” in the name! Also, aren’t they Looney Toons, as in cartoons?

People have a model of reality and how things should look or sound, so it comes at quite a shock to us when something isn’t as it should be. For example, with many of the quotes above, the original is not nearly as pithy as the well-known version. Also, the original often lacks context. If you were at a party and wanted to reference a movie quote, you would say “Luke, I am your father” and not “No, I am your father” to avoid confusion and to provide proper context.

Often times the popularized quotations are made up whole cloth, because they sound like something the character would say, and the new quotation is more memorable than the original.

Occam’s razor is the problem solving heuristic that basically states that the simplest solution is usually the right one. So in this case, what would you consider more likely?

  • A: These are all common misconceptions arising from the convergence of many factors: suggestibility influencing memory, preconceived models and stereotypes being violated, confirmation and other cognitive biases, narcissism, ignorance, etc.
  • B: This is evidence of there being parallel dimensions or alternate timelines.

B is so strange. Why would glitches in the matrix manifest as people remembering brand names incorrectly? Why would the glitch overwrite photographic and video evidence but not memories? Why are only some people affected? Why do so many Mandela Effects have such simple explanations? Why are these glitches in the matrix limited to such benign quirks?

Enough about the Mandela Effect though. What about all those kids who think they’re reincarnated and can explain their past lives? The stories all basically go like this:

  1. Around the age of three, some children start recalling memories of a past life.
  2. These recollections are extremely vivid and detailed.
  3. They ask to be taken somewhere to prove their claims.
  4. They turn out to be accurate.
  5. Much awe is had, but usually by the age of seven their memories fade.

Okay. So, this is clearly extraordinary and can be very convincing if you read the articles. Often times these kids explain in astonishing detail events or places that they never could have known of, and then they turn out to be right. How else could this be happening? Well, I could think of a few ways:

  1. Maybe the parents made the whole thing up and just wanted media attention so they coached the kid on what to say. Maybe they wanted money so they could write a book about it?
  2. Maybe the kids picked up this information somewhere. Maybe they saw this place on the TV, internet, magazine, or whatever, and then they identify so strongly with it that they become convinced it happened to them. It’s not exactly controversial that children are extremely suggestible. You can implant memories in 25% of kids pretty easily.
  3. Maybe the kid overhead the parents talking about this while they didn’t know he or she was there. Then they’re later coaxed along with leading questions similar to how fortune tellers operate.
  4. People have a strong tendency to see meaning where there isn’t any. That is, confirmation bias may cause the parents to rightfully disregard the majority of the child’s ramblings but will latch on to anything that seems vaguely sensical.
  5. Maybe by pure chance this figment of their imagination turned out to be accurate. This sounds ridiculous but consider how many children there are at all times. Is it so unbelievable with all the wacky things kids say that a couple out of a million will strike gold eventually?
  6. Kids don’t understand verb tenses, so when they say something like “when I was your age, I changed your diapers”, they might mean that when they are his age, he or she will perform these actions.
  7. Maybe the child wants to fit in and others around him or her talk of past lives and since the difference between reality and fantasy for children is quite blurred, they may come up with and tell these stories and sincerely believe them.
  8. Maybe the detail wasn’t quite as accurate as the parents initially thought, and the Barnum effect is playing a large role. Think of how all horoscopes all sound extremely accurate to you even though they’re often contradictory with one another.

If you need any further convincing that children can be lead to honestly believe false memories, look no further than here. Around a third of people “who were exposed to a fake print advertisement that described a visit to Disneyland and how they met and shook hands with Bugs Bunny later said they remembered or knew the event happened to them.” This never could have happened because Bugs Bunny belongs to Warner Bros. and could never be featured in any Walt Disney Co. property. Yet a sizable percentage truly believe that this happened to them and can describe in detail the events of the day.

There are also questions that cast further doubt on these claims: if reincarnation is real, how can population sizes grow? Where are all the extra souls coming from? Why has this phenomenon never been documented in a controlled, scientific study? Why does this only happen with some kids and not others, and why are they more likely to be male? Why are they more often memories of kings and generals, and not of commoners? One is a lot more common than the other. You’d think there’d be more memories of dying a poor peasant in China or India, considering their population.

So I ask again, what is more likely?

  • A: These children actually are being reincarnated and this is one of the first proven claims of supernatural activity.
  • B: Any of the above is playing a role in causing these unusual circumstances.

Okay, maybe I’m being a bit unfair and only going after low-hanging fruit. We know by now that human memory is quite fallible and suggestible, so many of these earlier claims can be quickly dismissed. What about stronger memories? Like, say, for example, where you were during the JFK assassination or when the twin towers fell. Do you remember?

These are known as flashbulb memories. They’re called such because they’re a highly detailed and exceptionally vivid ‘snapshot’ of the circumstances of a significant event. They’re some of the best we’ve got. We generally forget what we’ve had for by lunch and most days end up as blurs in the memory banks, but at least these events we know to be true. We have exceptional recall of the entire day’s events and we’re highly confident of even the finest details.

But, as I’m sure you can imagine by the trend so far in this post, these memories too often have dubious accuracy, despite the overwhelming confidence of its adherents. In fact, flashbulb memories are notable for this exact discrepancy: although these memories are experienced with such vividness and confidence, their accuracy is typical of regular memories.

Why is this? Well, memories stick through rehearsal. So either you don’t rehearse the memory and you forget it, or you rehearse it and inevitably some errors sneak their way in, which then become part of the memory. You cannot re-experience the event so errors eventually accumulate without opportunity for correction and rationalizations and other interventions must take place to make sense of the errors. Try to imagine continuously saving a JPEG over and over, losing even more quality and creating more artifacts with each successive save. The individuals have then relived this memory so many times that they are extremely confident in its accuracy, yet are unaware of how much it has shifted and morphed over time.

Now don’t get me wrong – the evidence suggests that flashbulb memories can be quite accurate, depending on personal involvement, proximity, significance, etc. but they are mostly less accurate than the adherents believe.

This is why courts are rightfully becoming increasingly suspicious of eyewitness testimony. Although a group of individuals can be extremely confident in what they saw, they often can all be wrong, and people can be wrongfully convicted. The prior link tells the case of Kirk Bloodsworth (that last name probably didn’t help), a man sentenced to death row for the rape and murder of a nine year old. Five eyewitnesses testified that he had been with the victim, and he was convicted. He was eventually exonerated after nine years of false imprisonment when DNA fingerprinting found the real killer. All of the eyewitnesses were wrong about their shared memory.

A friend of mine is entirely convinced that on rare occasions of sleep deprivation that she has had out of body experiences that led to information otherwise impossible to glean. In her specific case she was lying in bed when the out of body experience began. She then drifted downstairs and listened in on the conversations her parents were having. After the event was over, she amazed her mother with fine details of the private conversation despite being physically absent. How could this happen? What explanations could there be for this? Let’s try some:

  1. Maybe her parents were messing with her, and it was just a prank, although she denies this vehemently.
  2. Maybe she was in a half-dream state and was actually subconsciously listening in on the conversation from upstairs.
  3. Maybe her parents’ predisposition towards mysticism and the occult made them more open to accepting this phenomenon.
  4. Maybe their confirmation bias, pareidolia, or Barnum Effect led them to think her accounts of the conversations were more accurate than they truly were?
  5. Maybe something significant happened in their lives where it would have been a safe bet to assume they had been discussing it.
  6. Along those same lines, surely they discussed many things, and it wouldn’t be too much of a stretch to correctly guess one of the night’s conversations.
  7. Maybe this never actually happened but you heard about it and adopted the memory as your own?

So again, what is more likely?

  • A: My friend has the rare supernatural ability of clairvoyance and can thus obtain information at a distance.
  • B: Any of the above (or even other possible explanations).

Remember that if you choose option A that you will also have to reconcile many other questions. For example, if this were possible, why wouldn’t the military be utilizing this phenomenon to spy? Or if it is, is it then one of the most successful conspiracy theories of all time?

Surely since any individual could stumble on to it by chance that the method would have gotten out by now. Over the course of thousands of years and billions of lives, not one person has once figured this out, replicated it in a scientific study, and then publicized it?

And if it’s just extremely rare and hard to perform, then what gives you the ability to perform it? There has never before been any documented case of some sort of gene giving rise to paranormal ability, so is it not quite unlikely that you are the first? Also, is it not strange that this ability only manifests under times of hallucination? That is, during sleep deprivation and symptoms sounding suspiciously similar to sleep paralysis, which has been known to cause such hallucinatory phenomena?

It is similar to how when you take psychedelic drugs such as LSD, DMT, or mushrooms, that you have out of body experiences. However, we know going in that this is not real and is just part of the hallucination. Is it not then more likely that other out of body experiences are also hallucinations and not real? There are multiple routes to the same destination, and one not need consume psychedelics to achieve such states. Indeed, there are reports of sleep deprivation, intense meditation, and even breathing bringing about such outcomes. Yes, breathing.

At this point I feel I’m being a bit mean. After all, isn’t all this still possible? Yes, it may be unlikely, but it could be true, no?

And to this, I say yes, it could be true. However, this is not how you apply epistemology in any other parts of your life, so why here? For example, let’s say that an event occurred that had two possible explanations, one with a 99.9% chance probability and the other with a 0.1% chance probability. Would you not side with the former rather than the latter?

Another example: there could be an invisible dragon in your garage. However, it is impossible to detect the dragon and it does not interact with the real world in any way. Of course you would not believe in the dragon, because although it is possible that it exists, the claim is not falsifiable and it is extremely unlikely to be true. In all other aspects of life we base our beliefs on the most probable answers, so we should be virtuous and continue that trend here.

Probability matters. Consider that James Randi has offered one million dollars to anyone who can demonstrate supernatural ability. The offer ran for 50 years and although over a thousand people entered, not one person was successful in demonstrating their paranormal ability. If the first 1000 supernatural claims were without merit, is it not hubris to presume your personal 1001st claim will ring true?

Similarly with conspiracy theorists, I think one of the main reasons why people go against their better judgement and hold these beliefs are for two reasons. First, they are intoxicating-you are in the know about this forbidden, taboo knowledge. The world is not nearly as boring as you once suspected and it opens up an entire new world of possibilities.

Second, because it feels real to you. If you saw people’s faces as dragons, then even if you knew it was logically irrational, it’s kind of hard to ignore the dangerous fire-breathing dragon right in front of your face. Similarly with schizophrenia, you can know that it’s not real and that in all probability that your brain is just playing tricks on you and everyone else is normal, but when it’s happening to you it’s kind of hard to ignore how real the voice telling you how worthless you are sounds. If some stranger were making these claims, you’d rightly be much more skeptical, but when it’s all happening within your own head, it’s much harder to discount.

This was a bit of a long post, so I guess I’ll end with some key takeaways.

  • Mental models of how we think the world should be often trump how the world actually is.
  • Confirmation bias and cognitive dissonance are scary, because they can lead us to invalid beliefs and cause us to become even deeper rooted in falsehoods.
  • Likewise, pride can be dangerous, for we invent alternate realities rather than concede that our minds may be fallible.
  • Occam’s razor is a decent heuristic for evaluating the merits of supernatural claims.
  • Memories can be surprisingly unreliable despite overwhelming confidence.
  • The importance of probability assessment in weighing your beliefs.
  • To evade the enticement and draw of holding extraordinary beliefs, and to instead be consistent in your epistemic virtue.

Evangelizing Audiobooks

Growing up, I really didn’t like reading books. It didn’t help that I was conditioned to hate reading by being forced to do it in school all the time, but even now I’ll probably only read a couple books per year. Now don’t get me wrong, I read a lot, but the content is mostly in bite-sized chunks on websites.

I mostly stay away from written books because the process of consuming it is awful to me. Maybe it’s undiagnosed ADHD or something, but my mind constantly wanders where I then have to re-read the whole page. Then my arms get tired as I continuously fail to find a comfortable position. Lastly, the eye strain sets in as you drag your eyes line by line across pages of black on white text. Maybe I’m just terrible at it, but the whole process strikes me as slow and boring.

There has been research into overcoming some of these issues. Recognizing the saccadic nature of eyes, speed reading techniques have been developed. For example, having small enough horizontal line widths so your eyes don’t have to travel as far back upon reaching the right margin. Also, rather than dragging your eyes across the text, to instead utilize your peripheral vision and have your eyes “jump” along the lines and take in chunks at a time.

Then there have also been browser addons developed such as Spritzlet and Spreed where each word flashes at you at a designated WPM (words per minute), so you can completely eliminate the wasteful tracking required by normal reading. Unfortunately, the bottleneck then becomes comprehension. That is, it doesn’t matter if reading is inefficient because even if you were able to read any faster, you would still have to slow down because you aren’t able to process the information quickly enough.

Not only that, but the addons displace the normal sense of rhythm, tone, inflection, and flow of the original sentence-based format. The words continuously flashing at you is quite jarring, as if you’re being shouted at, and it’s difficult to maintain a steady pace if one part confuses you.

So yeah, I still haven’t found a good way of reading prolonged pieces of text without the aforementioned issues. But it doesn’t matter, because audiobooks are my one true love, and the rest of this post will be why I think they are underrated and how you can get the most out of them if you suffer from the same afflictions.

I knew about audiobooks for a while, but only recently has there been such a convergence of technological advances that have made them so extremely attractive, so only lately have I been able fully exploit them. Let me explain.

For one, they are now quite ubiquitous. Previously it was not the sort of thing you could entirely transition to, as very few books even had an audio version, and if they did it was probably of poor narrative and sound quality. Not only that but services like Audible and torrents either didn’t exist or were not nearly as pervasive.

Next, there’s the advent of mobile phones and earbuds, which allows you to listen to audiobooks anywhere you go. While commuting, doing chores, unsupervised night shifts at work, whatever. So now not only can you get an audio version of nearly any book in excellent sound quality, but you can listen to it wherever you are.

But what of the merits of audio listening versus textual reading? Dr. Willingham discusses this here and cites studies claiming high correlations of scores on listening and reading comprehension tests, so listening to an audiobook isn’t “cheating”.

At this point I could get a bit evo-psychy and say the audiobooks are the natural forms of receiving stories. Telling tales around a campfire probably predates written language by around a million years, so we are subsequently better equipped and evolved to process it. However, since evolutionary psychology can often be a bit suspect, I won’t bring up this point.

In addition, audiobooks also have several advantages over textual reading that I think most people don’t fully consider. It is extremely useful to be able to adjust the playback speed of media. Personally, I get easily distracted at normal playback speeds because the default narration speed is typically slow so I have worse comprehension at 1x speed than at 2x speed because my mind begins to wander from boredom with the former.

It used to be an issue where playing at fast forward would make the audio incomprehensible, but most modern media playback programs such as VLC have features that allow for the speedup of audio without making everyone sounds like chipmunks. They also prioritize keeping as much speech as possible, choosing instead to eliminate long pauses between words and sentence.


This is huge. A 300 page book is normally around eight hours when in the form of an audiobook. Listening to that at 2x speed allows you to complete it in four hours. I would not recommend going above 3x speed because there start to be diminishing returns. For example, going from 1x to 2x speed makes it four hours shorter, whereas going from 2x to 3x speed only makes it 1.33 hours shorter. Not only that, but 3x speed is almost unintelligible unless you’re intensely focusing. My recommendation is to stay between the range of 1.5x to 2.5x depending on the original speed of the narration, your focus levels, and the relative difficulty of the text.

A common objection to such practices is that surely there is a loss of comprehension when the reading speed is increased so dramatically. However, this doesn’t seem to necessarily be the case. The average speaking speed is around 105 words per minute, but even when that is doubled there doesn’t seem to be any loss in comprehension. Indeed, there is a recent trend in “speed-listening” and many are jumping on the wagon. There are even specialized apps being developed for the practice.

Somewhere along the line I realized that these same strategies would apply just as well to podcasts and YouTube videos, and I highly recommend this as well. For example, sometimes you’ll be surfing the web and see a somewhat interesting documentary or some other type of video posted, but it’s an hour long. Previously I would say, “well, that looks interesting but I don’t really feel like devoting an hour to watching it, so I’ll just skip it or maybe bookmark it and watch it never.” Now I think, “one hour is only 20 minutes at 2.5x speed. I’ll just watch it now. 20 minutes is less than an episode of Seinfeld. That’s easy.”

Speaking of 2.5x speed, this addon has been amazing. This sticks a video speed controller at the top left of all HTML5 players, which are most players on the internet nowadays. So that means YouTube videos, Twitch VODs, TV streaming websites, whatever. Even obscure video players that I don’t think would work usually work. I highly recommend it.

Many people I tell this to often express incredulity over listening to a book or podcast so quickly. Believe me, it is not as difficult as it sounds. The original narration is often deliberately slow, and the modern playback features like time stretching audio and pitch correction make sped up versions quite understandable. As long as you pay attention, you can do it.

The next objection is normally along the lines of “shouldn’t reading be enjoyable? Why are you just trying to get it over with as quickly as possible?” To this I present a reductio ad absurdum-if enjoyment is merely a factor of time spent reading, why don’t you deliberately read twice or even four times as slow? Indeed, as long as you can fully comprehend what is being said, there’s no reason why you should take any longer than necessary to perform a task, especially when there are so many great books and podcasts to listen to.

Likewise, even if I did get less enjoyment out of it, I still consider that better than the alternative of no enjoyment. There is limited time in the day and these practices are the determining factor in whether or not a book gets read at all. Lastly, I refer to a previous point where my mind starts to wander and my comprehension is lowered when the speed is too low, for the information is not coming in quickly enough to properly stimulate me and I get bored.

Another question I often get is if you intend to intensely focus on an audiobook while at home, what do you look at? Do you just stare at a wall? I’ve thought about this a bit, and I think I’ve found a good answer. Sometimes I use and find some mindless stream like a first person shooter. Try not to watch any sort of game with complexity or that which requires strategic thinking. You want to avoid anything that will pull you out of concentrating on the story. Another alternative that I think is decent are just scenic train rides. Here’s one that is around six hours total.

Changing gears, I’d like to return to several of the advantages audiobooks have to textual reading that not a lot of people recognize. For one, there is additional concurrent information presented when listening to audiobooks.

  • Pronunciations of unfamiliar words and names allow you to skip either looking it up or fudging it yourself.
  • Voices give you leniency in how well you have to know the names of characters, for you can recognize their voices instead of having to know their names.
  • Inflections allow you to recognize questions or exclamations before getting to the end of the sentence and realizing there was a relevant punctuation mark and having to re-read the sentence.
  • Similarly, instead of having to wait until the end of the sentence to see “said John” to realize the proper context in which to realize the meaning of the sentence, you can know ahead of time based on voice.
  • The elimination of having to read in all the aforementioned. No longer having to waste time reading “said John”. Rather, you just hear John. Similarly, punctuation need not be deciphered as it instead transformed in to the proper spoken sentence rhythm.

If you want to get even more fancy, they now have things like GraphicAudio, where even more of the text is made audible. For example, instead of the narrator saying “They closed the door and began to walk down the cobblestone path while it lightly rained”, there will be a sound of a door closing and footsteps on cobblestone as it drizzles in the background. The ambiance is incredibly immersive and it eliminates the need to vocalize environmental effects and audible actions.

The stories even sometimes go even further than this. For example, in the Stormlight Archive during the battle scenes (example here), there will be battle music, clanging of swords and shields, fighting in the distance, etc.

Anyways, all this stuff has really changed my life. I’m reading and learning so much more than I used to and can actually consume books at a reasonable rate now. I’ve also been on the lookout for some great podcasts and audiobooks, so if you have any in mind let me know. If you want any recommendations from me, for audiobooks I’ve really liked the aforementioned Stormlight Archive series along with Richard Mathews’ narration of The Count of Monte Cristo. As for podcasts, Dan Carlin’s Hardcore History is pretty captivating and Joe Rogan often has long discussions with some interesting guests on his YouTube channel.

The Death Penalty

The United States is one of the last remaining Western countries to retain the practice of the death penalty as a punishment for capital crimes. I’ve vacillated on my stance towards capital punishment over the years, but recently have become more confident and solidified in the “against the death penalty” position in the debate. However, I’m certainly open to a refutation of any of my forthcoming arguments and am willing to change my stance on this topic. So, without any further ado:

There is always a chance the death penalty would kill an innocent person. Blackstone’s formulation says that “it is better that ten guilty persons escape than that one innocent suffer.” Interestingly, this viewpoint goes back quite a bit. The principle appears in the Bible (Genesis 18:23-32) along with the Islamic Hadiths. The numbers vary quite considerably throughout the centuries as well, with some authoritarians even taking the exact opposite view, where Pol Pot and Bismark say it is better to have innocents suffer than one guilty man escape.

However, I feel as if this is a false dilemma in regard to the death penalty-for we are not letting the guilty escape, for the choice is merely between life in prison and capital punishment. Several times the convicted were later exonerated through additional evidence (DNA, confessions, etc.), and if they had been executed in the interim, then an innocent man would have been put to death. The criminal justice system can get it wrong, and these are only the cases we’re aware of. A somewhat recent study even claims as many as “one in 25 sentenced to death in the U.S. is innocent”. Poor quality defenses can lead to undeserved death sentences as well.

Moving on, my second point is that I don’t want our government to have the power to legally kill its citizens. Societies are made worse when executions and other barbaric acts are normalized within its walls. Human life should be prized above all else, and the continuation of the death penalty lowers its value. This reason is a bit more nebulous than my others, but I’d prefer our government maintain the moral high ground. I also want society to be as sensitized as possible to the government murdering citizen, less we fall victim to the slippery slope of murdering citizens and get another Stalin or Pol Pot. It also worsens our image globally, as American is then seen as a violent, vengeful, backwards nation.

Could it be argued that the death penalty is a net good because it could act as a deterrent to criminals considering committing capital crimes? This is certainly a complicated sociological issue to dissect, so I initially defer to authority where 88% of the world’s leading criminologists do not believe the death penalty is an effective deterrent.

My personal, uninformed opinion on the matter is that the effect is probably negligible one way or the other. The economists in the linked study who do think the death penalty is an effective deterrent have varying beliefs in how many homicides are prevented the following year from the death penalty deterrent. In the linked study Mocan claims 5, Rubin 18, and Cloninger around 15. So let’s average them out and say around 13?

This sort of claim seems shaky to me. Let’s try to see it in a better light through an example. Let’s pick a year. Current year minus 10 sounds good because it’s still pretty recent and will also have good data. In 2007 there were an estimated 17,128 homicides in the United States. There were also 42 executions. Thus, around 42 * 13 = 546 homicides should be deterred the next year. So there should be around 16,582 homicides next year, and indeed there were 16,465. Pretty close!

But what about, say, the year 2000? There were 15,586 homicides and 85 executions. So maybe we should have 1,105 fewer homicides the next year, and we had … 16,037. Oh. Is it just me or is this all probably just plain old statistical noise and that it’s extremely doubtful that the majority of the variance in murder rates by year could be explained by how many executions we had the year prior?

Sociology and societal murder in particular are such chaotic systems with probably thousands of different variables influencing yearly murder rates and trend lines that to simplify it to just death penalty rates seems a bit naive. So while it may be a variable, its effect size as a deterrent seems mostly unknowable since it’s muddied by the statistical noise of the multitude of other variables all competing for effect size.

It’s doubtful that the death penalty is largely responsible for the continuing year by year fall in homicides because the homicide rate has been falling in almost every western country over the millennium concurrently with the overall abolition and abatement of capital punishment. Also, there were no executions in the United States between 1967 and 1977, and this is when homicide rates were among the highest.

What about cost? Intuitively the death penalty should be cheaper since killing someone can be done for just the cost of a rope or some bullets. Also, the average annual cost per inmate ranges from $14,000 to $60,000, depending on the state. So isn’t this an open and shut case?

Well, not necessarily. Thankfully the burden of proof for sentencing someone to capital punishment is quite high. No stone is left unturned and all available evidence is intensely examined. There is a considerable increase in defense fees, death row costs, security costs, court costs, appeals costs, etc. Life in prison isn’t considered “as big of a deal” and is more quickly moved along and settled and subsequently has substantially reduced costs. Here’s a lengthy study on “an analysis of the economic costs of seeking the death penalty in Washington state“. It found that on average a single death-penalty case costs around $3 million, and a non-capital case around $2 million. In addition, it is not unusual for an inmate to be on death row for decades. Certainly this all varies and some cases may more clean-cut than others, but unless we are to severely relax the burden of proof for capital punishment, it is likely that the two costs will be comparable in the foreseeable future.

What of the issue of justice? For particularly heinous crimes where grieving families demand death, should we not make an exception? This point is rather philosophical, because in what way is executing the offender grant more justice than life in prison? There are certainly individuals who would prefer the quick release of death to the decades of rotting away in a cell.

But what if they killed someone close to you? Should they not too be killed? Maybe if we were basing our legal framework on the Code of Hammurabi, but I don’t see why such a simple formulation should still be relevant, and didn’t I hear about that sort of thing making the whole world blind? And lest we forget, there will always be doubt, even if it is but a shred, and there is no return from an execution, but there is from imprisonment. Lastly, no amount of justice will bring the victim back-revenge, anger, and bloodlust are normal reactions to such trauma, but can just perpetuate the murder mentality. Healing begins with forgiveness.

On another note, these criminals can still be used. The morality of such is debatable, but many prisoners can choose to work extremely low wage positions (as little as $0.23 per hour) manufacturing goods, and the sales of these items net around $500 million per year.

The more intelligent inmates may be studied for psychological research or make significant contributions to the field of ornithology. However, I do not wish to make the impression I believe that the majority of these inmates are a net good or even close to it, just that the situation is not entirely a deadweight loss.

I will end on a bit of a controversial note. Are our decisions not the combination of our genetics and environment? Are not the entirety of our decisions contained within this three pound slab of tissue in our skulls? Do we have free will? Should we be surprised when an individual with debilitated fetal development, a culture of glorifying crime, lousy education, and poor socioeconomic outlooks ends up committing capital crimes?

How much agency do people really have? Most follow the path of least resistance that was laid down by their respective genetic lotteries, as evidenced by social class generally remaining constant for most individuals. Social mobility may even be getting worse as “nearly 70% of the sons in 1998 had remained either at the same level or were doing worse than their fathers in 1979.”

Personally I’m not sure if anyone can be blamed for their decisions. Of course we should still imprison those whom pose a threat to society for the greater good, but should they be executed? I know compassion for murderers is not a particularly popular opinion, but am I missing some sort of exterior motivating force? If you had an identical brain, body, and upbringing to the murderer in question, would you be able to act any differently?

What of the hundreds of millions of otherwise normal individuals propelled into committing hellish atrocities throughout history? Indeed, I believe most people are capable of committing great evil and have much less agency than they think. So if you agree with the premise that societal pressure can induce individuals into committing murder, is it not wrong for the same society to execute those it conceived?

Three Good Puzzles

The word riddle and puzzle are generally used interchangeably but have slight differences. Riddles have more of a verbal history and connotation. They often intentionally phrase themselves in such a way to have a double meaning and attempt to mislead the victim, er, recipient.

I dislike the majority of riddles because they rarely have applications beyond themselves. Here are some examples:

What is in seasons, seconds, centuries and minutes but not in decades, years or days?
The letter ‘n’.

What has a head, a tail, is brown, and has no legs?
A penny.

What can travel around the world while staying in a corner?
A stamp

They’re fun little things but have limited applicability. The knowledge rarely transfers and you quickly forget about each one. After getting each answer you understand why it’s correct, but it’s not like you now know how to travel the world while staying in a corner.

Puzzles on the other hand are usually a bit more fair. They are generally solved by logical reasoning where each piece, when put together, leads to final answer. They test your ingenuity and knowledge and often grant some sort of insight into the world, and the solutions can be generalized and applied to various disparate problems. Here are three of some of my favorite puzzles. I’ll post some more in the future. You can highlight the area in black following each riddle to reveal the answer.

  1. Suppose you are shooting free throws and each shot has a 60% chance of going in (there is no “learning” effect and “depreciation” effect, all have the some probability no matter how many shots you take). Now there are three scenarios where you can win $1000.
    A: Make at least 2 out of 3.
    B: Make at least 4 out of 6.
    C: Make at least 20 out of 30.Which do you choose?

    You would choose “A: Make at least 2 out of 3.” Indeed, all the probabilities reduce to the same amount of 2/3, so why should this be the case? The answer is linked to the Law of large numbers. Try to imagine that instead of shooting 3 free throws that you instead shoot 1,000,000. Since each one has a 60% chance of going in, you’ll probably get around 600,000 in. However, you need to get 666,667 in (2/3). After 1,000,000 shots, each with a 60% chance of going in, it is extremely unlikely that you’d get an additional 66,667 above the average.

    As a more extreme example, can you imagine flipping a coin 1,000,000 times and getting heads 750,000 times? No, after a large enough amount of trials the variance will be minimal and the expected and actual amount of successes will be quite close. However, with a small amount of trials, you can just get plain lucky and beat the odds. There will be high variance with a small number of trials, and this gives you the greatest chance of winning. So where else would this apply? Well, if you’re gambling and the house always wins in the long term, the optimal strategy is to “go big or go home” and minimize the number of bets, because in the short-term variance will be much greater and you can beat the expected long-term returns.
  2. Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations. Which is more probable?A: Linda is a bank teller.
    B: Linda is a bank teller and is active in the feminist movement.

    The answer is A, although most people choose B. This is known as the Conjunction fallacy. The probability of two events occurring together is always going to be less than (or equal to) the probability of either one occurring alone. Let’s say the probability of Linda being a bank teller is 5% and the probability of her being a feminist is 99%. The probability of A would just be 5% and the probability of B would be .99 * .5 = .495, or 4.95%, still less than 5%. The linked Wikipedia article has additional examples and ways you can debias yourself in these sorts of situations.
  3. A king has 1,000 barrels of wine stored in his cellar. Unfortunately the guards found an assassin that had snuck in last night and poisoned exactly one of the barrels. Even 1 drop of poisoned wine would be enough to kill a man, but the poison takes 30 days before becoming fatal, plus or minus a few hours. The poison is colorless, odorless, and victims show exactly 0 signs of being poisoned in the 30 days prior to dying. There is absolutely no way to detect the poison.In 31 days time, there will be a grand feast in which the king will need as much of the wine as possible. He has 10 prisoners on which to test the wine. His first idea is to give each prisoner a drop from 100 barrels of wine, and then when 1 prisoner dies, throw out all 100 barrels of which the dead prisoner drank from. However his jester speaks up and explains a solution that will pinpoint exactly which barrel is poisoned using only the 10 prisoners.What was the jester’s solution?

    The easiest way to understand this answer is through binary. If you’re not already familiar, it’s rather quick to learn and all you need to know is how to count in it, so take some time for that first and continue here afterwards.
    The answer is to assign each prisoner a position in a 10 digit binary number. So, in the binary number 00000 00000, the first 0 refers to prisoner 1, the second 0 to prisoner 2, the third 0 to prisoner 3, etc. Next, you number each of the 1000 barrels, and convert each barrel to its binary equivalent. For example, barrel #5 would be 00000 00101, because 5 in binary is that number. So for this barrel you have prisoners #8 and #10 drink. You do this for each of the 1000 barrels and at the end of the 30 days, depending on the combination of dead prisoners you will know exactly which barrel is poisoned. For example, if the poisoned barrel was #5, then only prisoners #8 and #10 would be dead.
    The reason why this is one of my favorite riddles is because of how clean it is. It works because there’s exactly 10 prisoners and exactly 1,000 barrels. Because 2^10 is 1024, if there were 1025 barrels then you would not have enough prisoners to be sure. The numbers 10 and 1,000 just look like clean numbers that were chosen somewhat arbitrarily but are actually quite fine-tuned. Also, this combinatorial solution can be applied to other problems and represents an extremely dense way of conveying information.

Spaced Repetition

Spaced repetition is a practice I only just recently learned about. Don’t worry if you don’t know what it is because I’m about to explain it in depth. This is something that I wish I had known about long ago and I’m still surprised how obscure it is. None of my friends or family had ever heard about it which is a shame because it’s extremely useful and easy (and not nearly as boring as it sounds, I promise!)

But first, a picture:


This image shows your chances of remembering something later after learning it. You can recall the information trivially after immediately learning it, but this memory rapidly decays, to the point where after a day you have a mere 33% retention rate.

This is terrible! We spend all this time learning and forget 80% of it by a month. If only there was a better way.. Well, there are many better ways. For example, in the book “Moonwalking with Einstein”, the author discusses various ways of using mnemonics to encode information efficiently in your brain. For example, immediately upon learning the Memory Palace technique, you will be able to store a list of 50 words in your head without much effort, and remember them for weeks to come.

The problem with these techniques is that they are often optimized for specific forms of information. As just mentioned, the memory palace is very good for remembering lists. The Mnemonic major system is very good at memorizing numbers. Then there are various ad hoc types of mnemonics for individualized pieces of information (e.g. ROY G BIV for remembering the colors of the rainbow and a jingle for memorizing the alphabet). (A future post will likely be dedicated to the various types of mnemonics.)

Another problem with these devices are the high startup costs. Which type of mnemonic is appropriate for this sort of information? Can I make it rhyme in any way? Maybe the first letter of each word spells out something intelligible? Oh, maybe I can associate it with an image! Make sure to add some smells and slimy textures to it to make it extra impactful! Try not to think about how silly this all is or question how weird it is that forcing yourself to remember extra information allows you to remember the thing you care about more easily.

Eventually you may begin to wonder the point of using all this cognitive energy to memorize shopping lists and years of famous battles when you can just look it all up in your phone. Also, exactly which mnemonic technique should I be using to memorize these five paragraphs of this legal case for my Law final..? Surely there’s got to be a better and more general method? And yes, there is! Have another picture:


This image shows how you can avoid the usual rapid memory decay (dashed line) by occasionally reinforcing the information (solid red line). Eventually it gets to the point where the memory retention rate will stick to around 80% for months or even years after first reviewing it several times at spaced intervals.

This is the spaced repetition that the title of this post refers to. Research has found that the ideal time to review something is right before you are about to forget it. Through this technique one can maintain excellent retention even years down the line!

However, isn’t this all obvious? Everyone already knows that spacing out your studying is better than cramming it all in if you want to remember something long term. Also, how exactly are you supposed to remember to review something right as you’re about to forget it? It’s almost paradoxical! Lastly, some things are easier to remember than others. What, are you supposed to keep track of each item’s individual difficulty and manually set alarms to review based on their difficulty? This sounds just as difficult as the aforementioned mnemonics!

Thankfully, all of these issues are completely addressed. There exist software programs (such as Mnemosyne and Anki) that have taken decades of research on spaced repetition (creation and storage of information cards, ideal times to review, denoting individual difficulty, etc.) and internalized it all within a single software package. As a result, these programs can prompt you to review a piece of information right as you were about to forget it, leading to ideal retention!

I’ll give an example of how it generally works. You first launch the program and then create a new flash card. A prompt appears that asks you for the front and back of the card. On the front you type “abrogate” and on the back you type “revoke formally.” Later on when you check the program it will remind you to review the card. The front appears:

Card Front: “Abrogate”


At this point you are supposed to think of the answer because you can’t yet see the back of the flash card. Memory researchers find this form of active recall to be extremely efficient and effective for learning. After you think you have the answer or give up, you click the button to show the back of the card.

Card Back: “revoke formally”


There are then usually around five buttons you can click, respectively labeled 0 through 5. You click 0 if you couldn’t think of it at all and you click 5 if it was the easiest thing in the world and you doubt you’ll ever forget it. Likewise, I’m sure you can imagine what 1, 2, 3, and 4 correspond to. Then, the next review time will be algorithmically calculated based on how many prior reviews you had of this card, the difficulty you denoted, and the average human memory decay rate.

The reason why I’m so excited by this is because it is quite rare for the solution to a problem (remembering information long term) to be the most simple, easy, efficient and most effective solution. Also, this sort of solution had been unavailable for the majority of human history, only made recently made possible by the advent of computers. Lastly, due to the spacing effect, even if one has a card database of tens of thousands of cards, you may very well only need to review 30 or so per day because many will be scheduled for review months down the line.

In doing this, for the majority of people it will only take a couple minutes per day to maintain maximum retention of all the information they care to commit to their database of cards. It is also quite pleasing to occasionally scroll through this personal knowledge library, each item bringing back memories of the context under which you added that item to your knowledge pool. Most programs also allow you to tag your cards so you can instantly access all your accumulated knowledge in whatever subject.

However, what about when I said earlier that this sort of remembering is pointless because you can just look anything up nowadays? At this point this post turns a bit philosophical because this is true to an extent. However, it is not the full story. How many times would a piece of knowledge you had forgotten been an appropriate response to a situation? How would you know? You don’t know what you don’t know.

As a reductio ad absurdum, try imagining your life if you couldn’t form any new memories. Would it not matter much because you could just look everything up anyway? Memories allow us to make connections to disparate topics real-time with whomever or whatever we are interacting with. Spaced repetition gives you access to a larger repertoire and range of relevant responses in reaction to recognition of statements, patterns, and situations.

Okay, but if spaced repetition truly is a panacea, why does hardly anyone use it (other than people who set Jeopardy records)? Why has no one heard of it? It’s because while it may be optimal in long-term, cramming still wins out in the short-term. In this trade-off you get a strong memory now for a weak memory later, thus the old adage about forgetting everything after a test. And since school tests generally consist primarily of new information, this strategy pays off.

Also, since spaced repetition involves proper time management and discipline at a distance, cramming is typically the inevitable outcome for most students. Also, as previously mentioned, forgetting something is tautologically the exact opposite of something you notice. It is difficult to students and teachers to notice the rapid decay of all this knowledge since the system is designed around measuring performance in an environment conducive to cramming.

People I explain this to often ask me what sort of cards they should even make. “How do I know what is important enough to make a card? What sorts of topics should be made cards?” My advice is not to think too hard about it. Making a card takes around 20 seconds usually, and reviewing it around the same amount of time. If I’m surfing the internet and learn something new and interesting and feel like it, I’ll make a card for it. Basically if something interests you and want to increase your chances at bringing it back up in relevant situations in the future, just make a card for it. You can always delete it later if it turns out you don’t actually care about it that much or think that it’s the sort of thing you think you’d know to look up if necessary and you don’t mind doing so.

Well, I think that’s about it for now. Personally I use Mnemosyne because I prefer simple, but Anki is probably better and more feature-complete. I’m interested in seeing what kinds of cards you all come up with.


Here are the reasons I’m starting a blog:

  • The act of putting a concept or theory into words helps learn it.
  • Teaching and writing is an effective way of remembering a concept.
  • This gives me an archive of many of the interesting things I’ve found over the years.
  • When I post something incorrect commenters can point it out and I can rectify my beliefs.
  • It’d be neat to look back on this one day to see how my thoughts have changed.

For the topics I currently plan to write about, it’s mostly anything I’m interested in at the time. Here are some examples from my current list:

  • Biases and cognition in general
  • Psychology and persuasion
  • Riddles and thought experiments
  • Philosophy
  • Science, biology, and all their various studies
  • Memory and Learning
  • Statistics
  • Optimization
  • Technology and the future

I hope you enjoy!