Tuesday, November 30, 2010

Retroactive psi

Over a year ago, I wrote that if quantum mystics can choose the outcomes of measurements, then they can also send messages backwards in time.  In brief, this is because of the EPR paradox.  Normally, the EPR paradox is only an apparent paradox, but quantum mysticism breaks the laws of physics in such a way that it becomes a real paradox.  The end result is that quantum mysticism violates causality.

Dear reader, that was one of those times where I had my tongue in cheek.  I can't use that as a serious argument against quantum mysticism, because I just know that quantum mystics will bite the bullet and agree that they really can violate causality.

I'm amused to see a new study doing just that.  The study shows that "priming" (subliminally showing a word or concept) affects people even if they are primed after being tested.  The author takes this as evidence of psi, and goes on to talk quantum nonsense.
Those who follow contemporary developments in modern physics ... will be aware that several features of quantum phenomena are themselves incompatible with our everyday conception of physical reality
Gee, I do follow modern physics, and I'm pretty that it's incompatible with retroactive psi effects.  Whatever the explanation for the results, this is not it.

For us lay skeptics, the appropriate thing to do here is stop and await replication.  I'm probably not qualified to spot any errors in the study's methodology (and there's no guarantee that they wrote the report in such a way that it's even possible to spot the errors).

But from the comments, I found that part of the study was already replicated--with negative results.  And someone went through the study itself and found some serious flaws in their statistical analysis.  Among other things,* the study ignores the distinction between exploratory and confirmatory research.  Exploratory research is intended to try out many hypotheses to see if any of them might be interesting.  Confirmatory research is meant to look at a specific hypothesis to see if it pans out.  The authors appear to have done exploratory research, but failed to be upfront about it.  That is, they tested so many different hypotheses, that a random data set was bound to confirm at least one of them.  They were data snooping.

*The study also ignores prior probabilities, and the positive results disappear under the more rigorous Bayesian t-test.

This study reminds me of my brief experience with LIGO.  The LIGO collaboration has some pretty zany schemes to prevent bias in data analysis.  Is it too much to ask that psi researchers do the same?

I just thought up a simple scheme they could use!  First, they should simulate every study with a random number generator.  Repeat like a hundred times.  Then, give all the data sets to the data analysts without telling them which is the real data set.  Data analysts must use the same analysis on all data sets.  How much do you want to bet that they find correlations in nearly every data set?

(via freakonomics)

Monday, November 29, 2010

Don't pray for me

Some atheists don't mind when Christians say they'll pray for them.  But I do.  I think it is inappropriate in virtually all contexts.

I feel like I could stop right here already.  I don't like it, therefore it's impolite to pray for atheists.  Nobody needs to know why I don't like it.  They just need to know that I and other atheists don't like it.  If the intended message of prayer is to show that you care, you should show that you care by avoiding praying for people who probably don't like it.  There are secular alternatives ("You're in our thoughts" instead of "You're in our prayers"), or you could just pray privately.

But this being a blog, we'll dig deeper even though we don't need to.

Tangent: This is one of those situations which resembles post-hoc reasoning (ie, starting with a conclusion, and then finding justifications for the predetermined conclusion).  I feel an emotional reaction against people praying for me in front of me.  I can only figure out why I feel irritated by thinking about it afterwards.  Thus, the conclusion ("I feel irritated") comes before the justification ("Why am I irritated?").

But it's not quite post-hoc reasoning, nor is it a fallacious argument from emotion.  I may be using my emotions as evidence, but I am not trying to prove a fact about the external world.  I'm merely trying to prove something about my internal state, that I feel irritated.  And when I talk about reasons for why I feel irritated, this is not supposed to prove the predetermined conclusion that I feel irritated.  We already agree that I feel irritated, and we don't need further evidence for that.  Instead, this is an exploration of what part of prayer I think is most irritating.

One possible reason prayer could be irritating is simply because of philosophical disagreements.  As a skeptical atheist, I obviously don't believe in any of this prayer stuff.  There's at least one kind of prayer that I disagree with so much that it irritates me to see it: intercessory prayer intended to heal people

Tangent #2: Intercessory prayer, prayer meant to call on the supernatural to intervene on our behalf, is anti-skeptical.  Without going into details, the best studies show that prayer does not make people better.  Many people claim that these studies show nothing because prayer can't be analyzed scientifically.  But if a claim can't be analyzed scientifically, not even by phenomenological studies, that places very tight constraints on the claim, constraints that are completely ignored in practice.  There's no place for this kind of nonsense in matters of health.

In short, people are just making excuses for magical thinking in the face of positive scientific evidence.  Intercessory prayer is the reason why we can't have good things.  Intercessory prayer is the reason why there's a fairly good case against the compatibility of theism and skepticism.  And in the rare case where intercessory prayer is offered as a replacement for real help, that's just adding injury to insult.

But outside of this kind of intercessory prayer, I have more tolerance for disagreement.  If you want to believe that prayer allows a divine being to pat you on the back, I think that's silly.  But I'm not as irritated by it, not so irritated that I would declare it impolite.

The thing is, prayer can make for some very awkward social situations.  If someone starts praying in front of me, what do I say?  I feel like a prayer calls for a certain mood, one of reverence, respect, or sympathy.  But prayer does not put me in any of those moods.  Prayer puts me in a cynical, critical, or apathetic mood.  So I have two choices: either pretend that I'm in the same mood as everyone else, or rudely break the spell.

There are few things in an atheist's experience which are as alienating as being in the middle of a group prayer.  It makes me think of our vast philosophical differences.  It makes me think how I'm experiencing this differently from everyone else in the room.  And if I speak up, that's when all the cultural misunderstandings come out in the open.

This happened in a recent episode of Glee...
I know you don’t believe in God, and you don’t believe in the power of prayer, and that’s okay, to each his own. But you’ve got to believe in something. Something more than you can touch, taste, or see. ‘Cause life is too hard to go through it alone, without something to hold onto and without something that’s sacred.

-Mercedes to Kurt in front of a church
Glee isn't exactly known for its realism, but parts of this episode seemed all too familiar.  Here, Mercedes is naively trying to translate religious concepts into nonreligious ones as if there were a one-to-one correspondence.  That's not even true between different religions, much less religion and atheism.  Kurt doesn't say anything about it, but then, who would say anything in front of a big church praying for your dying father?

Incidentally, I didn't like praying when I was Catholic either.  It wasn't really my cup of tea.  I only ever did it out of religious motivation, not personal motivation.  I've often wondered how common this experience is among Christians, and if such people ever get annoyed by prayer.

Thursday, November 25, 2010

Thanks, where it matters

I'm thankful for the universe for all the ridiculous amounts of math and computation it does.  I'm not sure if all that work was strictly necessary, or if it's just going the extra mile for us, but either way, thank you universe.  It is my hope, that as you calculate the evolution of innumerable particles, wondering if anyone will ever appreciate such small details, if it's worth going on so diligently, that you think of us.  We really appreciate it, it's just that we can't keep track of it all.

I would also like to thank my family for giving me all the support I could hope for.  I want to thank my friends for all the good times and ideas.  I want to thank them for putting up with my egocentrism. I want to thank them, but I also realize that this is nonsensical.  We live in a deterministic world.  People are just products of the initial conditions.  They just keep doing what they're doing and feeling how they're feeling, regardless of what they read or hear.  So what is the point?

Wait, I got that backwards!

Happy Thanksgiving!

Monday, November 22, 2010

Cooking with insulators

Look what I got.

It's a thermal pot!  Also a Kandinsky carpet, but the pot!

It's easy to use. Put all the ingredients in the inner pot, and heat them on a stove. Then put the inner pot into the hot pot, and let it cook.  Then, when you open it again later, the meal is still hot and ready to eat.

 Lentil soup... delicious!

The way it works is simple.  The outer pot is a really good thermal insulator.  The outer pot has two layers, with a vacuum chamber between them.

There are basically three kinds of heat transfer.  The first is convection, which is when hot atoms physically move into a colder space.  Convection doesn't occur in solids, so it's not a problem for my pot.  The second kind is heat conduction, which is when hot atoms transfer energy to cold atoms, essentially by bumping into them.  Conduction occurs in solids, but it can't occur in a vacuum.  So that's why the thermal pot uses a vacuum.

The last kind of heat transfer is thermal radiation.  Random motion of particles will emit electromagnetic radiation (ie light), which carries energy.  Light travels through a vacuum just fine, so that's how the thermal pot loses energy over time.  In fact, we can calculate how much energy the pot loses through the Stefan-Boltzmann Law.

 This basically says that the rate of energy loss (P) is proportional to the fourth power of temperature (T).  It's also proportional to the the surface area of the pot (A).  σ is just a fundamental constant of nature, called the Stefan-Boltzmann constant.

As for ϵ, that is the emissivity.  It turns out that the emissivity is always equal to the percentage of light that the material absorbs (as opposed to what it reflects).  Absorption and emission are basically the same process, only reversed in time, so it's not surprising that their rates are related.  To make the best insulator, we want low emissivity, and thus low absorption and high reflectivity.

Therefore, what we really want is a highly reflective surface, such as silver.  It's likely that the inner surface of the vacuum chamber is coated with silver, though I couldn't be sure without breaking it open and looking.

I tried calculating the rate of change of temperature, and it's about 15 degrees Celsius (or 27 degrees Farenheit) per hour.  That's an overestimate.*  I expect it's a few times smaller than that.  I often leave soup in there for four hours or more, and it's still piping hot when I open it!

Chicken veggie soup!  At least one animal was harmed in the making of this blog.

*Some details: I took the surface area to be 0.5 square meters, the reflectivity to be 90%, and the heat capacity to be the same as two quarts of water.  The pot inside is 100 degrees Celsius, and the temperature outside is 20 degrees Celsius.  15 degrees per hour is almost certainly an overestimate, since the rate of energy loss would decrease as the pot gets closer to room temperature.

Wednesday, November 17, 2010

Meme skepticism

"Meme" is a word coined by Richard Dawkins in The Selfish Gene.  It's used as an analogy between biological evolution, and the evolution of ideas.  The genes that survive are those that are best able to replicate themselves.  The ideas that survive are also those that are best able to replicate themselves.

It's a useful analogy, helpful for a basic understanding of both biological evolution and culture.  It powerfully conveys the truism that ideas can't survive without winning new minds.  It demonstrates that the basic process of natural selection is just an abstract principle that can apply to many things that replicate.

But I think people are too enamored with the analogy (Daniel Dennett in particular). Does it really work as a theory of social interaction?  The source of the idea also rings skeptical bells.  Just as I don't expect new revolutionary physics to first be published in a book written by an engineer and marketed to popular audiences, I don't expect a new revolutionary theory of social science to first be published in a popular science book about evolutionary biology written by an evolutionary biologist.

When all you have is a hammer, everything looks like a nail.  And perhaps, when you're an evolutionary biologist, everything looks like natural selection.  And since I'm a skeptical blogger, everything looks to me like a claim to be questioned.

I can't really speak to the expert criticisms of meme theory (though a cursory glance at Wikipedia indicates that there are many), but there's at least one flaw in the meme/gene analogy that jumps out at me.  What is the origin of a meme?  While ideas aren't created in a vacuum, it's difficult to describe them as "descendants" of other ideas.  Many ideas just have no traceable source, or they look completely different from their source. As far as biological evolution is concerned, it's extremely important that the offspring look at least a little like their parents.  The traits that improve survivability need to be consistently heritable for evolution to go anywhere.

And many ideas come from more than one source.  There's hardly any speciation of memes, they all just mix and cross-hybridize.  Even in religion (a common example of a meme), syncretism is absolutely commonplace.  Imagine if this were the case in evolutionary biology, we'd have crocodiles reproducing with ducks!

I know I've written a lot of posts expressing idiosyncratic disagreements with Dawkins, Harris, and other prominent atheists.  But that's not even what's going on here.  Based on things I've heard Dawkins say, I fully agree with him.  Take this interview from 2004:
When Dawkins introduced the meme concept a couple of decades ago, hopes were raised that the evolution of culture, or even of the human mind, might be explained as a sort of Darwinian competition among memes. But little has come of this project, even if the word "meme" does continue to get tossed around quite a bit by pretentious intellectuals. I asked Dawkins if he had cooled on the meme idea over the years.

"My enthusiasm for it was never, ever as a contribution to the study of human culture," he said. "It was always intended to be a way of dramatizing the idea that a Darwinian replicator doesn't have to be a gene. It can be a computer virus. Or a meme. The point is that a good replicator is just a replicator that spreads, regardless of its material form."
Well, yeah!  Memetic evolution is a powerful tool to explain evolutionary biology to popular audiences.  It's not actually meant to contribute to the study of human culture.  I mean, isn't that what the social sciences are for?  I know we all like to hate on the squishy social sciences, but to take memetic evolution seriously does not strike me as an improvement.

Monday, November 15, 2010

On being between

I'm gay and asexual.  Or, if I'm being precise, I'm between the two.  In the asexual community, the word for people like me is "gray-A", though I generally avoid the term outside the community.  That makes me a gay gray-A, which is cool because it rhymes.

Since this identity is somewhat unusual, even within the asexual community, people are always asking me to explain it, to give my personal experience.  But in fact, explaining and giving my personal experience are two very different things.  If I explained what gray-A meant, a lot of it would be correcting misconceptions, explaining what you don’t know about me.  If I gave my personal experiences it could be misleading.

If I had to choose between explaining something and telling people the personal details of my life, I’d rather do the former.  That’s why I often explain asexuality, identify as between gay and asexual, but rarely go beyond that.  Asexuality 101 is difficult enough, so why should I go further, into territory that could be potentially confusing?

And yet, I still think it’s important to get my experience out there.  So I’ll do it.  But I'll intersperse it with a lot of explanation, because I don't want to mislead.

1. What you don’t know

Some people think it’s all about sex, sex drive, and libido.  They think I identified as asexual because I had a low sex drive.  They get the impression that I identified as gray-A because I tried sex with my first boyfriend and liked it.  What a narrative!  What an ill-informed narrative!

In fact, asexuality has nothing to do with sex drive.  A fairly significant fraction of the asexual community has a sex drive.  That doesn't mean they want to have sex with people they don't find sexually attractive (ie everyone).  A lone man on a deserted island would still have a sex drive; that doesn't mean he is attracted to anyone.

Nor does asexuality have to do with disliking sex.  There are many reasons people like sex, including sexual attraction, sex drive, wanting to please one’s partner, and so forth.  Though many straight people find same-sex sex to be unappealing, I think it’s perfectly possible that some of them can and have enjoyed it.  Likewise, some asexuals can enjoy sex. And non-asexuals can have negative experiences with sex.

By identifying as asexual and gray-A, I haven’t divulged any information about whether I have a sex drive, whether I tried sex, and whether I liked it.  I’d rather keep it that way.  I will say, however, that I knew all along that I had a sex drive.  And I knew that this didn’t have anything to do with whether I was asexual or not.  Therefore, the whole narrative is preposterous from the start.

2. Why my story is misleading

For me, it’s not about the sex at all.  It’s more about the romance.

But before I go on, I must explain that asexuality is not about romance.  Asexuality is about sexual attraction.  Many asexuals experience some sort of romantic attraction to people which is decidedly nonsexual.  They could be romantically attracted to one or more genders, or none at all.  We call this romantic orientation, and it parallels sexual orientation.

Therefore, if I were to explain my experience with romance, you might get the impression that a romantic experience amounts to disproving asexuality.  It doesn’t.

What’s going on here is that attraction is really complicated.  Attraction is a single name for many things.  Many people experience different kinds of attraction all at once, and so there is no point in distinguishing them.  And when you tell someone else about your experience of attraction, it’s like trying to explain how something smells or taste.  Our language just isn’t sufficient.  So it’s really hard to tell whether you’re experiencing the same thing as everyone else or not.  So we sort of lump all these experiences together under a single label, “attraction”.

In the asexual community, people spend a lot of time trying to tease apart different kinds of attraction.  Romantic attraction and sexual attraction are just the most widely used labels.  There’s also sensual attraction, aesthetic attraction, platonic attraction, primary and secondary attraction, and so on.  I treat these categories like I treat the descriptions on the back of wine bottles.  They’re rather subjective.  And as far as my personal experience goes, some of the distinctions are meaningless.

In particular, the romantic/sexual distinction is meaningless.  Sure, here’s romance, and there’s sex, and I can tell the difference.  I just don’t see why I would want to have one without the other.  I considered myself asexual because I didn’t experience romantic attraction, which as far as I’m concerned, is a prerequisite for sexual attraction.  So when I experienced a little romantic attraction, it made more sense for me to shift to gray-A rather than merely gray-romantic asexual.

In general, it would be inappropriate to generalize my experience to anyone else. But you knew that already, right?

3. What it’s like to be me

I can’t scope out a room.  I can’t go to a bar and say, hey, that guy looks cute.  He’s just some guy.  Maybe he’s well-dressed.  Maybe his face reminds me of an old friend.  Maybe he looks like he’s enjoying himself.  But it doesn’t occur to me to think of people as attractive based on looks.  You point out an attractive person to me, I’ll say, “Who? What?”  And then I’ll think, “Oh, right, most people can tell if someone is attractive just by looking at them.”  I’m still not entirely sure how that works.

And yet, I did spend many months looking at people passing by, to see if I had any feelings about how people look.  At first I tried with women, with no success.  Then I tried with men.  So I found that seeing certain guys gives me a slight rush.  Finally, I’ve figured out what people have been talking about my whole life, and it’s… it’s so weak and useless!  It doesn’t actually make me like the guy or want to be with him or anything. It doesn't last any appreciable length of time either.

What I’m describing here is what’s known as aesthetic attraction, liking the way someone looks.  I’m keenly aware that it is not necessarily related to sexual attraction. And though it does not constitute asexuality, it’s one of the most notable aspects of my own experience.

Some people say that they’re attracted to personality rather than looks, but that’s not the case for me either.  There are certain personalities I like.  I like serious, nerdy, honest, and eccentric people.  And if I had a partner, it’s probably important that they have a personality I like.  But just because someone has a likeable personality doesn’t mean I’m attracted to them in any sort of romantic or sexual way.  It means I like them as a person, or as a friend.

In summary, I am never attracted to anyone under any ordinary social circumstances.  Not when I look at them, not when I find that they have a great personality, not when I find that they are great people to be with.  How is it that I’m ever attracted to anyone at all?  I'm not entirely sure. I think reciprocation and physical touch are fairly important, but I might give a different answer tomorrow.

How did I ever end up dating anyone?  I may like the idea of a long term relationship, but this is a rather emotionally distant motivator to dating. It doesn't actually carry any weight in ordinary social situations when I see a bunch of people, none of whom are attractive. Both times I've started dating, the other guy asked me out.  Unfortunately, I can’t think of a better way to do it.

But once I started dating, I found that things proceeded almost normally.  I’ve liked kissing, cuddling.  I’ve wanted to hold their hands in public (despite the oppressive social conventions against it).  I’ve wanted to just be with the person, to share moments with them.  To lose track of time with them.

I’ve also had bouts of doubt.  When, sometimes, my instinct is to treat them just as a friend.  When, after a date, I sense that something was artificial.  The worst is when I think that I have something to offer, but it just isn’t enough.  See, it’s not the romantic/aromantic distinction that matters.  What really matters is the distinction between being capable and incapable of functioning in a relationship.

But I’m cautiously optimistic about it.  I’m careful about calling it "optimism" though, because I want to accept all possibilities.  If it works out eventually with someone, that’s cool.  If it just never works out, that’s cool too.  They're very different options, but they both have their upsides.

4. What people say, but shouldn’t

Some people say my experiences just sound like they’re in the normal range.  Well, yeah!  Asexual and gray-A are as much part of the “normal range” as being gay.

I think what they mean, though is that they think there are a lot of gay people out there with the same experiences and who do not identify as gray-A or have to talk about it ever.  If that’s true, then good for them!  It doesn’t really bother me that two people can have similar experiences yet identify as half an orientation apart.

Other people say I should be open to new sexual and romantic experiences.  For some reason, they never suggest being open to new asexual or aromantic experiences.  In any case, of course I’m open to both!  It’s practically a requirement of identifying as gray-A.  I already have some experiences that I share with asexuals, and some I share with sexuals, and I accept both.

I also understand that, being in the gray zone, it doesn't take much to nudge me into one category or the other.  I could be just a little wrong.  Or my experiences could shift over time.  Or I could just slightly shift the definition of asexual.  I identify as gray-A because I don't like having to play this game of jumping back and forth over an invisible line.

Friday, November 12, 2010

I see Sam Harris

I saw Sam Harris speak on his new book, The Moral Landscape: How Science can Determine Human Values.  I've already disagreed with Sam Harris on this topic, but how does he fare on second glance?

At these talks, I always try to come up with a good brief question to ask the speaker.  I never actually ask the question, because I lack the confidence.  I don't know why I'm afraid, when so many of the other questions tend to be terrible and long-winded can-you-get-to-the-question questions.  But there you go, confidence is irrational.

Question to Sam Harris:  "The subtitle of your book suggests that your main claim is about meta-ethics.  Your talk suggests that you don't really care about meta-ethics.  Which is it?"

Meta-ethics, by the way, is the philosophy concerning the nature of ethics (rather than the nitty gritty).  Meta-ethics is to ethics as philosophy of science is to science.  Knowing philosophy of science is neither necessary nor sufficient to being good at science, though it might be interesting and might suggest certain scientific practices.

The reason I'd ask this question of Sam Harris is because it seems to me like Sam Harris only cares about meta-ethics to the extent that he can use it (abuse it?) to reach his goals.

At least his goals are fairly respectable.  He spent most of the talk highlighting egregious evils caused by religion, and the way that people tend to give it a free pass through some sort of moral relativism.  He's also advancing the idea that some cultures are morally better or worse than others (and in particular, some religions create better cultures than others).  That I can agree with.  Pretty much all of social activism is premised on the idea that we can improve culture.

At first I was bothered that he'd only talk about the most extreme examples of moral relativism.  It's making straw men.  But, you know what?  Attacking the egregiously wrong is a respectable thing to do.  It may not be the most intellectually deep exercise, but if people actually believe these things, then the stupidest beliefs are also the most harmful.  This is also why the atheist movement is right to focus on the egregiously wrong beliefs of the people rather than the merely wrong beliefs of theologians.

So I largely agree with Sam Harris' major points and goals.  But in his arguments, he's using meta-ethics, and Sam Harris sucks at meta-ethics.  I'm not saying this from an ivory tower perspective; I'm not saying that you have to be a professional philosopher to say anything about ethics or meta-ethics.  All I'm saying is that if Sam Harris is good at meta-ethics, then so is Ayn Rand. (Burn!)

Sam Harris thinks that there is objective moral truth, it's just that it's really hard to determine.  Just like how economics is really hard, but must have some underlying truth.  He argues this by coming up with extreme hypotheticals, saying that they are certainly morally undesirable.  I think the conclusion he wants to draw is that the set of all possible outcomes can in principle be uniquely ordered by moral desirability.  How he gets from here to there is kind of sketchy to me.

But, to use a recent example on my blog, I think moral truth is like the question of nature vs nurture.  If you ask, "How much of a given human trait caused by genetics?" that is an ill-defined question.  Science produces an answer to this bad question by subtly replacing it with a good question.  Similarly, if you ask, "What is good and bad?" as far as science is concerned, that's a bad question.  Science can only answer this bad question by subtly replacing with another one.  Sam Harris replaced it with, "What produces the most well-being?"

And that's a fine replacement.  It's good enough to condemn Islam, anyways.  However, I'm skeptical that this perspective is of much use to, say, a working ethicist.

Wednesday, November 10, 2010

My first crank mail

One of the perks of being a physicist is that you occasionally get letters from cranks.  See, physicists are the great arbiters of truth, and therefore best able to recognize a good idea when a lone genius sends them one.  How flattering!

I just got my first e-mail from a crank!  (To be fair, I got a few of these when I was running a secular student group.)
When a professor gives a lecture to a classroom full of students, the students learn new things.

The changes in the neural wiring of the student's brain while he's learning aren't caused simply by the low-level electro-chemical signals resulting from the sound waves of the professor’s voice. Instead, the intelligence is located at the interpreted level of the professor’s words. Otherwise the professor could expect the student to learn the same lesson whether he spoke to the student in English or Chinese, since the same intelligence would be located in both sets of auditory signal data. 

In conclusion, thoughts exert the physical forces needed to change the neural wiring in a person’s brain when he’s learning new things. Since new forces emerge at the thought level and add into the net sum of all forces, they affect the path of reality and therefore reality isn’t determined solely by the four fundamental forces of physics, as required by the theory of predeterminism.

Emergent living forces are caused by subcomponent forces, but the living forces aren’t determined by those subcomponent forces because the living forces exist in a different field, and forces located in different fields don’t add directly with one another.
I wonder what he thinks of voice recognition software.  Wait, why am I wasting logical arguments on this?  Let's try again.

Clearly, living forces cannot arise from subcomponent forces, because the dimensions are wrong!  Living forces are three-dimensional, and normal forces are two-dimensional (a product of infinite largeness and infinite potential).  Furthermore, the changes in neural wiring are already explained by the fact that reality has two axes, as explained in the Book of Isaiah.  Anyways, there is no point in fighting the theory of predeterminism because it's all a scam knowingly created by physicists who misinterpreted the words of Einstein.

Monday, November 8, 2010

Acute dissections

Take a 45-45-90 triangle, and cut it into acute triangle pieces.  That means each triangle piece must have angles that are strictly less than 90 degrees.  Try to do this with as few pieces as possible.

Afterwards, try the same with a square.

You may send solutions to skepticsplay at gmail dot com.

[Note: this is not an original puzzle.]

solutions posted

Thursday, November 4, 2010

Nature/nurture and causality

We intuitively understand that things can have many causes.  For example, what caused the election of Obama in 2008?  Obviously, it was a combination of factors, including public disapproval of the war, the disaster of hurricane Katrina, Obama's popular election campaign, and so forth.  Now I ask, what percentage of the victory was caused by McCain's choice of Palin as running mate?

To answer this question, we could perform a thought experiment where McCain chooses someone else, and then we predict how well Obama would have done.  Divide the change in votes by the total number of votes and we have a percentage.  But even supposing we could perfectly predict the outcome of this thought experiment, this answer is problematic.  Wouldn't it depend on who McCain chose instead of Palin?

Furthermore, if we did the same thought experiment for all sorts of different causes, the total percentage would be much greater than 100%, which just doesn't make any sense.

I think this is because the question simply isn't well-defined enough that it can have a definite percentage as an answer.

And yet, when it comes to human biological traits, we ask the same question and expect a definite answer.

What percentage of a given human trait is caused by genetics rather than environment?

This question is problematic, because it's unclear how exactly we would do the thought experiment.  How much do we vary genetics in our thought experiment?  How much do we vary the environment?  And you can't just say that we vary genetics and environment by the same amount.  Given a certain variety of genes, how much is an equivalent variation in environment?  There simply isn't an answer to these questions, because they are bad questions.

But even though it's a bad question, scientists still deliver!  Scientists talk about measuring the "heritability" of a human trait, which is just a number between 0 and 1 that can be experimentally observed.  How do scientists answer the impossible?

They do it by being tricky.  In fact, heritability is the answer to a different question.  If you're a non-scientist, now you are put in the odd situation of having a number for an answer, but not knowing what the original question was.

Google knows all the answers

But enough suspense.  Heritability answers the following question:

How much of the variation in a given human trait is due to genetic variation between individuals of a population?

The question sounds almost the same, but perhaps that's just because I couldn't word it more precisely in a single sentence.*  This question calls for a thought experiment where we take a large population, and hold all environmental conditions constant.  We vary just one factor, genes, and we vary it by the amount we see in the real world.  What percentage of the trait's variation in the population remains?  Alternatively, we can try a thought experiment where we take a large population, and leave their environment as is.  But we change the population's genes, making them all genetically identical.  By what percentage does this decrease the trait's variation in the population?

*The more precise definition has to do with variance, which is a statistical concept that I won't attempt to explain.

 This is a convenient definition because we no longer have to rely on thought experiments to vary the genes and environment.  Now we can look at the real world, and use the real world variation in genes and environment.  The primary difficulty is isolating the two factors.  This is usually done using studies of identical and fraternal twins.  It's by no means a straightforward experiment, and there are all sorts of methodological difficulties, but it's possible.

But even if we can measure heritability perfectly, there are some rather strange consequences of the definition:
  1. Heritability increases as the genetic diversity of a population increases.
  2. Heritability decreases if a population is exposed to a wider variety of environments.
  3. Thus, heritability depends on which population we consider, and what point in history.
  4. Heritability does not tell you how hard it is to change a trait by changing environment.
I should re-emphasize that last point, because it undercuts a lot of political abuse of heritability.  For example, let's consider a people that doesn't get any schooling.  How much variation in literacy is due to variation in schooling?  None, because there is no variation in schooling.  But that's not the same as saying that increased schooling will fail to increase literacy.  What it really means is that being a privileged member of this population gets you nowhere because not even the privileged go to school.

Even if heritability is close to 1, it might still be possible to change the trait by changing the environment.  You just have to change the environment by more than is typical for the population.  This could be easy or hard, depending on specifics.

Further difficulties are caused by the fact that genetics and environment are not exhaustive categories, unless you define environment to be everything that isn't genetic.  For example, what about random developmental factors in the womb?  Technically, this is an environmental factor.  But just like genetics, it's just a bunch of chemicals bouncing around in a way that we have no control over.

And we haven't even gotten into gene-environment interaction.  For instance, what if there's a gene that simply increases human receptiveness to environment?  Is that variation due to environment or genetics?  Nature/nurture is a false dichotomy.

Other posts in this mini-series:
Colds and Causality
Women and Causality
Responsibility and Causality
Nature/nurture and Causality
Physics and Causality 
Math and Causality 

Tuesday, November 2, 2010

Vote vote vote!

Tomorrow Today is Election Day!  I am celebrating Election Eve by finally taking a look at this California voters guide here.
Oh, geez, I don't really have an opinion on most of this stuff.  And of course the stuff I do have an opinion on, I could never hope to say anything interesting about.

For example, I understand that Prop 23 basically prevents cap and trade from going into effect... so no on Prop 23.  Prop 19 legalizes marijuana under state law... so yes on 19.  Wow, I will never persuade anyone on these and my opinions are basically worthless.  Well, they're worth one vote I guess.

I think Prop 27 is pro-gerrymandering and prop 20 is anti-gerrymandering.  I, uh, don't really understand the pros of gerrymandering.  But, uh, several of the voters guides I'm looking at support 27 over 20, so maybe I don't really understand what's going on.

You'd think my skeptical knowledge would prepare me to sort through all this nonsense, but my feeling now is that it really doesn't.  It's not like they're using complicated arguments or anything.  It's just a bunch of one-step arguments that sound like bullshit.  The rebuttals in the official voters guide can't even be bothered to mention the opposing arguments much less address them.

I have only understood a small fraction of the decisions here, and then my internet went out for a few hours.  Clearly I am a terrible American with terrible internet service.  Now it is Election Day already.