Friday, April 30, 2010

Degrees of crazy

I recently read an article in Skeptic Magazine ("Crazy Ideas 101", Vol. 15, No. 1) that began with a simple and thought-provoking question:

Which is more plausible: That aliens are visiting and abducting humans, or that there is some large creature living in the Loch Ness which caused the Loch Ness monster sightings?

I would say that Nessie is more plausible than UFOs.  And I don't just mean that Nessie is a few times more likely, I mean by several orders of magnitude.  Cryptozoology may be wacky and based on sketchy evidence, but UFOlogy requires at least a couple huge and improbable conspiracies.

But based on polls (if I remember the article correctly), roughly equal numbers of people believe in both these things.  Of course, it's old news that public opinion doesn't always reflect reality.  But the larger point is that people don't distinguish between different degrees of crazy.  There's a category of crazy stuff, and a category of non-crazy stuff.

To some extent, it doesn't really matter.  If the likelihood of claim A is 1 in 1010 and the likelihood of claim B is 1 in 1020, well so what?  Claim A may be ten orders of magnitude more likely than claim B, but they're still both effectively impossible.

But it does matter, because there are some things that are slightly more in the gray area.  For example, I think cold fusion (the claim that nuclear fusion can be caused at room temperature through electrolysis of heavy water using palladium electrodes) is almost definitely the result of experimental error and/or fraud.  But if the cold fusion community ever breaches its way into more legitimate scientific literature, and the results become widely replicated, then that's that.  Then I was wrong about cold fusion.  I would be greatly surprised, but I wouldn't feel betrayed by science or skepticism for having mislead me.  Sometimes the evidence can mislead us, despite our best efforts.  That's why science is hard.

On the other hand, if Autodynamics were proven correct, I'd think the world had gone crazy.  Because E is not mc3.  And 3 m/s plus 4 m/s does not add up to 5 m/s.  That's just stupid.

The point is that skeptics may be occasionally wrong.  So when we're wrong, we better have a good idea of which claims we're most likely to be wrong about.  And we should be able to convey this information in any skeptical analysis.  There's no need to rank individual claims, but it's good to keep in mind how much evidence there is opposing each claim.  But you were doing that already, right?

Wednesday, April 28, 2010

Polyomino equations

There is a particular shape that you can build with three copies of the piece on the left, or with 5 copies of the piece on the right.  You may rotate and flip the pieces, but they cannot overlap.  What shape can you build?

These shapes, made up of multiple connected squares are called "polyominoes".  The polyomino on the left is called a U pentomino.  The one on the right is called an I tromino.

If that's too easy, try this one:
The polyomino on the left is called an L pentomino, and the one on the right is called a T tetromino.  Note that unlike in Tetris, you are allowed to flip these pieces.

solution posted

Tuesday, April 27, 2010

Solution to "Fast clock, slow clock"

See the original puzzle

The clock is a digital clock.

Click for image

One of the LCD lights is broken.  So, for example, when it is 8:18, it reads 9:18, an hour fast.  Similarly, at 6:00, it reads 5:00, an hour slow.  In the hours of 2, 10, and 12, the display will not make any sense at all.  But most of the day (14 out of 24 hours), the clock reads correctly.

As a side note, I've just added new graphics to the margins of my blog.  I hope no one minds that I basically spoiled the solution to one of my puzzles, but that was over a year ago, and I like the graphic.

Monday, April 26, 2010

Hemant Mehta visits UCLA

I know I haven't blogged for a week.  I've been busy with important things, which may or may not include partying.  Perhaps I can make it up to you, dear reader, by dazzling you with one of my week's activities.

Hemant Mehta is the chair of the Secular Student Alliance, the blogger of Friendly Atheist, and author of I Sold My Soul on eBay.  Basically, he's the coolest guy ever.  He came to UCLA!
Hemant Mehta (center) and a bunch of BASS members

Hemant Mehta grew up as a Jainist.  Therefore, he didn't have the same experience as many other atheists (eg me) who grew up going to church until they were sick of it.  In the interest of activism and gaining understanding, Hemant Mehta held an auction on eBay, which allowed the winning bidder to send Hemant Mehta to a worship service of their choice.  The winner decided to send Hemant to nine different churches, and his experiences led him to write the book  I Sold My Soul on eBay.

Hemant didn't just disappear after that.  He started blogging at, which has proven to be a great source of activism.  Hemant told us some of the highlights of his blogging saga, including the story of Laurie Higgins, who tried to get him fired from his job as a math teacher.  Hey, I remember when that happened!

Apparently I've been reading Friendly Atheist since his first year of blogging, 2006.  Has it really been that long?  At the time, Friendly Atheist was probably no more popular than my blog.  Not that I ever expect to be as popular as he.  I don't think I could handle the fame anyways.

We also got to see Richard Wade, who was originally a guest blogger on Friendly Atheist.  Eventually, people found out that Richard Wade is a really awesome advice columnist, so now he functions as the agony aunt for atheists.  Richard Wade is the kind of guy who can just off-handedly mention that he's doing an astronomy show for kids tomorrow.

Even with my shoddy photography skills, it's still impossible to take a bad picture of Richard Wade

Hemant himself has a few more pictures and comments on his blog.  A voice recording of the talk may appear in the near future.

Tuesday, April 20, 2010

I see Ann Coulter speak

The Bruin Republicans decided to host Ann Coulter in a talk called "Why Liberals are Wrong About Everything".  Of course, I had to go.

In some ways, it was a bit disappointing.  Ann Coulter focused most of her talk on economic conservatism.  It was all, reduce government and spending, health care will be a disaster, etc.  I don't agree with economic conservatism, but I don't strongly disagree with it either.  It's not as fun listening to Ann Coulter when I have no strong feelings about what her statements.

Another disappointment is that Ann Coulter tries to be funny... but about half of her jokes fall flat.  I mean, Bill Clinton's sex scandal is so last decade.  But I did still laugh a few times.  Like when she said that some republican is probably involved in a sex scandal right now, but we're missing it because the media is so focused on Sarah Palin.  Or when she said she lost a bet when a magazine compared Obama to Jesus, because it proved that the democrats have heard of Jesus.  hahahahaha. ha.

The final disappointment was that most of the questioners came from supporters.  One questioner was decidedly hostile, but she was one of those kinds of questioners.  She tried to make commentary rather than ask a question.  This happens at every Q&A session.  Ann Coulter handled it the right way; Coulter cut off the questioner repeatedly until the questioner finally cobbled together a vague question.  Well, that went nowhere.

The highlight for me was the last question: "What do you think about gay people?"  I thought, "Finally, the focus is on social liberalism.  Now I can experience that facepalm moment that I came for!"  Ann Coulter delivers!

Ann Coulter likes gay people.  She has lots of gay friends!  So many gays support her that if you went to West Hollywood and said you didn't like her, all the hair stylists would refuse to cut your hair.  But she doesn't want them to marry.  They don't want to marry, they told her themselves.  They just support gay marriage because it's a nice symbol of public acceptance.  Isn't that the whole point of being gay anyway, that you don't have to marry?  She's not anti-gay, she's just pro-family.  She also opposes single mothers.  Did you know that such and such criminal was raised by a single mother?  Who knows what weird stuff will happen to children raised by gay couples?

Most of that doesn't require comment, except for the part about her gay friends who don't want to marry.  In my experience there is a grain of truth to this.  Not all queers want to get married, and not all of them think marriage is the most important thing to be fighting for now.  As every heterosexual knows, if some people aren't interested in getting same-sex marriages, clearly it should be outlawed for everyone.  Clearly.

Monday, April 19, 2010

Casual conversation

It often comes up in casual conversation that I study physics.  Of course it would come up, since I'm devoting a significant part of my life to the subject.  The common reaction is to express complete ignorance of all that complicated physics stuff.  I must be so smart to be studying this stuff!

I'm not really convinced that you have to be super smart to study physics.  But there I am, the representative of physicists, and I give off an air of intelligence.  What can I say in the face of that kind of evidence?

I'm always amused when people bring up string theory.  Well, of course you don't understand string theory!  There are layers and layers of other physics you'd need to understand first.  String theory is not basic physics!  I think it's a wonder that string theory gets so much popular media attention when clearly the audience doesn't understand what's going on.  You'd think that would make it uninteresting.

The other day, I was hanging out with a psychology student, making casual conversation with a few other people.  I've decided that people say much sillier things to psychology students than to physics students.  Some people decided that this was an appropriate time to advance their own grand hypothesis about psychology.  How awkward is that?  I'm trying to imagine a physics analogue: upon telling someone that I study physics, they say, "I have this theory that space is not continuous, but comes in tiny little pieces!  What do you think?"  Is there a way to say, "I think you don't understand your own proposition," without coming across as snarky?

And of course, someone at some point has to bring up Freud.  My friend had to explain that psychologists haven't taken Freud seriously in a while.  The person who brought up Freud said, "But wasn't Freud right that people are irrational?"  Well, yeah...  But it's not as if we didn't already know that.  And Freud didn't have the right explanation for why people are irrational.

When skepticism comes up in casual conversation, people generally don't understand what you're talking about.  The best reactions are when people just ask me to explain it.  I explain that it's all about critical thinking, science, and the scientific method.  But that's not clear enough, so I have to rattle off a list of things I disbelieve, like conspiracy theories, alternative medicine, psychics, creationism, and so forth.

I find that one of the best things to bring up are LaRouchians.  Most UCLA students have seen the table set up on campus by the LaRouchePAC, but have no idea who they are.  I just have to mention the picture of Obama with a Hitler moustache, and people's faces light up.  "Oh, them!  Who are they?"  Let me tell you, they're crazy!

In general, talking about crazy people is a good way to gain sympathy for skepticism.  Skepticism does not and should not only focus on the craziest fringes, but this is just casual conversation.  I think it's fair to talk about the most amusing parts of skepticism.

Another common reaction to skepticism is to immediately jump to atheism and agnosticism.  Either they take it for granted that skepticism and atheism are the same thing, or they act like the connection is a novel concept that they just came up with.  It seems like people aren't aware that the relationship between atheism and skepticism is a longstanding topic in the community.  I'm tempted to think of these people as newbies to the debate.  But that's a horribly silly thing to be elitist about, so I listen people out anyways.

Wednesday, April 14, 2010

The basic semiconductor

In the media, there are two kinds of physics which are the most hyped: the physics of the very big, and the physics of the very small.  Namely, cosmology and particle physics.  These fields are really exciting, but what about the physics of everything in the middle?  In the middle, there is Condensed matter physics.  Condensed matter is one of the biggest fields of physics, and also one of the most practical.  Practically every piece of electronics uses it.

In particular, nearly all modern electronics rely on the transistor, considered to be one of the most important inventions of the 20th century.  But I will leave my explanation of the transistor for another day.  For now, I will explain the basic physics of semiconductors, which form an essential component of transistors.

A semiconductor is basically a material whose electrical conductivity is somewhere in the middle between conductors and insulator.  An example of a conductor would be a copper wire, while an example insulator is the rubbery stuff around that wire.  We use conductors for wires because we want want electricity to move as freely as possible through the wires.  We use insulators to cover wires because we don't want the electricity to jump between crossed wires.  An example of a semiconductor is silicon.  Silicon is used in electronic devices because it allows us more control over whether electricity can pass through or not.

Insulators, conductors, and semiconductors are all important for electronics

What makes these materials behave so differently?  The difference comes from what's called the "electronic band structure".

Many of you are familiar with the electron energy levels of atoms.  Electrons are allowed to be at certain energy levels but not others.  There's an energy level 1, and energy level 2, but no electrons can exist between.  Furthermore, each energy level can only contain a certain number of electrons, because by the Pauli Exclusion Principle, no two electrons may be in the exact same state.  After the energy level is filled up with electrons, any additional electrons must occupy higher energy levels.

Of course, the atom doesn't really look like this, but the energy levels are indeed discrete
In order to make a wire or a microchip, we can't just use one atom.  We need thousands of billions of billions of atoms.  When there is such a large collection of atoms, most of the quantum weirdness disappears.  There are still energy levels 1, 2, 3, and so on, but they're so close together that we might as well describe the energy as a continuous spectrum.

But the energy isn't entirely continuous.  Sometimes it's continuous, and sometimes there are gaps.

The electronic band structure.  The further an electron is to the right, the more energy it has.  Figure not to scale.

This is what's called the electronic band structure of the material.  There are energy bands where the energy is continuous, but there are also gaps between the energy bands.  No electrons can exist in these band gaps.  Also note that the energy bands can only contain a certain number of electrons.  Once an energy band is filled with electrons, any additional electrons must occupy a higher energy band.

I should mention that there's a reason why there are band gaps, but it's one that requires a much deeper understanding of quantum mechanics than will ever appear on my blog.  Suffice it to say that it is caused by the repeating crystal structure of the material.

The band structure has everything to do with the difference between insulators, conductors, and semiconductors.  First I will explain insulators.

An insulator has exactly enough electrons to fill up to one of the band gaps

In the band structure of an insulator, there are exactly enough electrons that all the energy bands are either completely filled or completely empty.  Let's say we tried to make a wire out of this insulating material.  Any given energy band consists of a specific set of states.  Exactly half of those states are moving forward through the wire, while the other half are moving backwards through the wire.  So if an energy band is completely filled, then half the electrons must be moving forwards while the other half are moving backwards.  The total current through the wire is precisely zero.

If we wanted to push current through the wire, we would have to give some electrons enough energy that they jump up to the next band.  But this is a very large energy barrier!  And that's why it's hard to send current through an insulator.

In a conductor, there is an energy band which partially filled and partially empty.  Or perhaps there are two energy bands which overlap.  In any case, there is no large energy barrier stopping us from sending current through a conductor.  The only thing slowing down the electrons are collisions with atoms and stuff of that sort.

Semiconductors have something rather different going on.  In a semiconductor, the electrons fill up to one of the band gaps, but the band gap is very small.  In particular, the band gap is small enough that thermal fluctuations will overcome the gap.

In a semiconductor, the temperature smears electrons across a band gap

Temperature has the effect of smearing the electron energies across a certain range.  So at high temperatures, electrons don't always fall to the lowest energy available.  So even if there are exactly enough electrons to fill up an energy band, some of those electrons jump up to the next band anyways.  This occurs only if the temperature is high enough and the band gap is small enough.

There are some interesting consequences to the semiconductor's band structure.  One consequence is that the conductivity increases with temperature.  As the temperature increases, the electrons smear over the gap even more, allowing more current.  Contrast to conductors, which decrease in conductivity as the temperature increases.

Another consequence is conduction by "holes" (much like the holes discussed earlier).  Because there is an energy band which is almost, but not quite filled, it's best to describe it with holes.  These holes, unlike electrons, have positive charge, and may have a different mass too.  The current through a semiconductor will be carried by a mix of electrons and holes.

A final consequence that I will briefly discuss is sensitivity to "doping".  If you add certain impurities to a semiconductor (such as arsenic impurities in silicon), it may very slightly increase or decrease the number of electrons.  If the impurity increases the number of electrons, it's called "n-doping".  If the impurity decreases the number of electrons (or increases the number of holes), it's called "p-doping".  This may not seem that exciting, but I mention it because it is tremendously important.  P-type and n-type semiconductors are essential to the transistor, among other things.  But that's outside the scope of this blog post, so I'll just leave it at that.

Friday, April 9, 2010

Plantinga made me cynical of theology

I think there was a time when I had more respect for theology.  I thought that maybe there was a non-trivial chance that there was some really good theological argument for Christianity or God that would convince me.  I just hadn't heard it yet, perhaps because it was too complex to appear in popular discourse.

These days, I have little confidence that theology produces anything valid.  My change of mind was gradual, but one epiphany stands out in my recollection.  It was a couple years ago, when I looked up Albert Plantinga.

Plantinga is one of those names that is thrown around as an example of "great modern theologians" who go far above and beyond the common discourse which we find in blogs and bestsellers.  Since he's so highly praised, I thought maybe there was something to him.  If he was wrong, I figured that he would at least be wrong for very complicated reasons.

But then I actually looked him up.  Plantinga does indeed make some novel arguments, altogether unlike the most frequent ones (cosmological argument, fine tuning argument, pascal's wager, etc.)  But these arguments are worse than the traditional ones.  They aren't just wrong, they're egregiously wrong.  They're utter crap.

Case in point, consider Plantinga's argument that biological evolution by natural selection defeats philosophical naturalism.  It goes a bit like this:
If our cognitive faculties were selected for survival, not for truth, then how can we have any confidence, for example, that our beliefs about the reality of physical objects are true or that naturalism itself is true? (By contrast, theism says God has designed our cognitive faculties in such a way that, when functioning properly in an appropriate environment, they deliver true beliefs about the world.)
(Concise wording by Lee Strobel and William Lane Craig)

In forming a counterargument, there are so many ways I could go, it's difficult to know where to start.  Let's start with how Plantinga gets evolution completely wrong.

It's true that natural selection selects traits for their survival value, not for their truth-producing value.  But evolution is not some magical philosophical ideal.  It does not simply pick out the most adaptive organism possible, and bring it to life.  Evolution has all sorts of constraints, such as the evolutionary history of an organism, and developmental limitations.

Tell me which of the following you think is a more likely evolutionary path:
  1. Humans evolve to have a multitude of ad hoc beliefs and behaviors to survive in every day life.  For instance, humans might believe that tigers are fun to pet, and that the best way to pet them is to run away from them (Plantinga's example).  Every time humans encounter a new situation (ie poisonous plants, snow, thieving rodents, neighboring tribes, hard-to-crack coconuts, you name it), they evolve a whole new set of ad hoc beliefs and behaviors to help them survive.
  2. In order to survive, humans evolve the ability to interpret observations and adjust their behaviors accordingly.
Path #1 seems rather absurd to me.  It is really hard for me to imagine anything but the broadest of beliefs being encoded into our genes.  It's true that we have some instinctive behaviors, like the fight or flight response to stress, but can you imagine having similar processes to govern every complex human behavior?  And that new instinctive behaviors evolve for every new situation we encounter?

I mean, this is one of the problems with having false beliefs.  They may, by coincidence, be useful in certain situations, but their use doesn't extend to others.

Anyways, what's so adaptive about the belief in philosophical naturalism?  If anything, it seems maladaptive, since in most cultural contexts it's a social disadvantage.  Indeed, most people disbelieve philosophical naturalism, so it's kind of difficult to claim that it's the result of evolution.

Plantinga's argument also shows unfamiliarity with critical thinking.  One of the major components of critical thinking is recognizing all the cognitive biases that humans have.  For example, we're likely to find patterns where there are none, because running away from dried grass is not as bad as failing to run from a tiger.  I'm not strictly certain that this evolutionary explanation is true, but I know from experience that people often find patterns in randomness.

Plantinga is sort of trying to make the same argument that skeptics make about false pattern recognition, but he's incompetent at it.  He simply paints a broad stroke saying that if evolution and naturalism are both true, then everything we know is probably wrong.

I also think that Plantinga's treatment of God is wrong.  Plantinga thinks that if we accept evolution and naturalism, then we must admit our cognitive faculties are unreliable.  But who is to say that a designer God would put us in the clear?  I mean, there are clearly a lot of things that God clearly didn't design to be perfect.  Who is to say that he designed reliable cognitive faculties?

See, there's the problem of evil, which argue that an all-good God is inconsistent with evil.  Someone like Plantinga would reject this argument; an all good God is consistent with evil.  Then how can he argue that an all-good God implies reliable cognitive faculties?

Well, that was a lot of garbage.  Whenever someone endorses Alvin Plantinga, I take it as a strike against their credibility.

Wednesday, April 7, 2010

Asexual stereotypes: Everyone loses

There was a wonderful post on Feminists with Disabilities about the intersection of asexuality and disability.  The main point of essay, I'd say, is that stereotypes of asexuals and disabled persons hurt everyone involved.

A common stereotype of disabled people is that they're asexual.  This stereotype is offensive, because it deprives disabled people of their sexual agency.  There is a parallel stereotype that a person's asexuality is due to autism, hormonal problems, or some other disability.  This stereotype is offensive because it is an attack on the validity of asexuality.

The great irony is that the stereotype hurts most of all the people who are disabled and asexual.  The stereotype might superficially describe them, but just a scratch underneath, it's all offensive nonsense.  The author gave the following example: the stereotype is used to justify giving disabled people less sex education... but even asexuals need sex ed!

What's worse is that people in the asexual community and the disabled community see the person as affirming stereotypes.  So they get hit by ableism in the asexual community, and asexohate in the disabled community.

I myself am non-disabled, but it occurred to me that I have a similar experience with another stereotype.

The stereotype that hurts me the most: Asexuals are simply closeted gays.*  This stereotype hurts many asexuals because it is completely false for them.  I think it hurts me even more, because it is superficially true.  A little over a year ago, I identified as straight.  Then for many months, I identified as asexual.  Now I identify as gay and asexual.  Yes, indeed, it was "just a phase".  But let's go just a bit under the surface, and see how accurate the stereotype really is.

*You have to wonder where these stereotypes come from, since it's not like asexuality is well-known enough to be common in public discussion.  Nonetheless, many people seem to start with the same wrong ideas.

The first inaccuracy, in my case, is that I currently place myself in the middle ground between gay and asexual.  I am not completely rejecting my previous identity.  My identity as asexual was based on a life full of experiences: always being confused by popular enthusiasm for sex, being entirely left out of relationship dramas, etc.  Those past experiences never change, and should not be rejected.  I can only add new experiences to the collection.

Some people have the expectation that people like me will suddenly switch to the opposite extreme, hypersexuality.  Why?  There's no rhyme or reason to it.  If someone mistakenly identifies as fully asexual, they were probably not too far off the mark.  If someone experiences a shift away from asexuality, they will probably always be more asexual than average.

Another aspect of the stereotype says that I was afraid to identify as gay.  But there's a fundamental flaw in this narrative.  It's much easier to be out gay than out asexual!  I speak with some authority on this matter, because I've outed myself both ways a number of times in different contexts.  If I say that I'm asexual, most people don't know what that means.  Some people react by quizzing me.  I have to make sure, before I out myself, that I am in a good position and the right mood to answer questions.  I also end up playing the role of the sole representative of asexuals, however atypical I may be.

Other people don't quiz me.  This can be just as bad, because I don't know whether they understood what I meant.

And of course, there are the people who react with denial.  Some people are just unwilling to accept asexuality.  Sometimes they are willing to accept asexuality, but unwilling to accept my asexuality.  These people are the exception rather than the rule, but I have know way of knowing who will react this way.  Politics are not a predictor.

Also, on Facebook, there's a place to indicate gayness, but not asexuality.

Most of my friends know I'm gay, but fewer know I'm asexual.  Look at me, I'm contributing to asexual invisibility.

According to the stereotypical narrative, not only am I afraid to be out as gay, but I'm also afraid to admit gayness to myself.  But at least in my case, I was far more afraid of admitting asexuality than admitting homosexuality.  Simply being attracted to a different gender is not as radical as being attracted to no gender whatsoever.  At least, that's how it seemed to me.

When I've identified as asexual, some people have said to me, "Maybe you're gay.  You should look into that."  Well, duh, I should look into it.  As if the thought never crossed my mind.  People think they're encouraging self-exploration, but they are not coming from a position of understanding.  Why is the very first reaction to asexuality to suggest alternative explanations?  It's tantamount to denial.  I mean, forget about politeness, it's just plain ignorant.  I did look into it, and I am gay, but not in the way that you think, thank you very much.

ETA: Hat tip to Asexual Curiosities for finding the original article on asexuality and disability.

Sunday, April 4, 2010

Exacto knife beats paper

Here's a quick puzzle.  What is the significance of this photo?

Unless you're reading this through a rss subscription, the answer is probably obvious.  It's related to the new banner I put up.  I cut out little letters from paper, and threw them on a carpet.  I don't feel particularly great about the result, but I've wanted a new banner since forever.  Tell me what you think.