Tuesday, May 31, 2011

An anecdote on obscurantism

You know what I realized earlier?  It's been over a year since I've talked about the ontological arguments for a god.  Perhaps it is because I think the last post I wrote summarizing the flaws in the modal ontological argument is about as clear as I can manage.

In the course of blogging about the ontological arguments for years, I attracted a handful of self-described philosophers who argued with me rather persistently, perhaps because I am one of the few people on the internet who is willing to discuss what is wrong with the ontological arguments in detail, rather than what is wrong with them in the big picture.  Of course, I found out that most of these self-described philosophers were unable to speak of logic without making the most basic of errors, even when it was irrelevant to the argument.

Buried somewhere in the archives, buried in dozens of long comments, buried in jargon and symbols, is a joke I thought so funny that it's stuck with me over a year later.  It starts like this:

What can you do to make an already obscure argument even more difficult to understand?

As I explained before, the basic modal ontological argument has just a few steps:
Premise 1: If God exists, then God necessarily exists.
Lemma: If God possibly exists, then God exists. (proof omitted, as it is irrelevant to this post)
Premise 2: God possibly exists.
Conclusion: God exists.
But what if we were to make this argument instead? The difference is in bold.
Premise 1: If God exists, then God necessarily exists.
Lemma: If God does not exist, then God does not possibly exist.
Premise 2: God possibly exists.
Conclusion: God exists.
It's the same argument, only the lemma has been replaced with its contrapositive.  Every if-then statement has a logically equivalent contrapositive statement.  For example:
If Socrates is a man, then Socrates is mortal.
Contrapositive: If Socrates is not mortal, then Socrates is not a man.
The contrapositive of the contrapositive statement is the original statement.  So whenever we make an if-then statement, we have two choices in how to say it.  Why not choose the one that is most clear and intuitive to lay audiences?  Often times the two statements can each be unclear for different reasons, but that's not the case here.  The lemma as originally stated is shorter, allows the conclusion to use modus ponens rather than modus tollens, not to mention that it flows more naturally from the proof I omitted.  So why replace it with its contrapositive?

That's more or less what one of the philosophers did.  It's a very small thing that hardly matters, but I couldn't help but think... why?  Why take these tiny steps to make an obscure argument just a tiny bit more obscure?  I asked him, and he said it was the simplest way to state the argument.  He also seemed to have trouble understanding whenever I stated the argument the other way.  I found all of this hilarious.

Some might say this is to be expected, since obscurantism is what philosophers are trained to do.  I suspect that the person simply didn't understand the argument well enough to spot a purely unnecessary step that was added in.

Friday, May 27, 2011

Summer research: High-Tc Superconductors

As you know, I am currently working on my physics Ph.D. with a specialization in condensed matter.  I am finally starting research this summer, next week in fact.  My research project is on one of the hottest topics in condensed matter physics, High-Temperature Superconductors.

I've written about superconductors before, but in case you're too lazy to read that...  *clears throat*

Just like many liquids freeze below a certain temperature, there are some materials which change into superconductors below a certain temperature (that temperature is called Tc).  They won't look any different, but they have awesome properties like zero electrical resistance and magnetic levitation (which are used in MRIs and maglev trains respectively).  For the earliest discovered superconductors, Tc was 30 degrees above absolute zero (-243 Celsius), but so-called High-Tc Superconductors have a Tc as high as 135 degrees above absolute zero (-138 Celsius).  Which is still very cold.  Many physicists seek to understand High-Tc Superconductors with the dream of discovering superconductors at room temperature.

More specifically, I will be investigating superconductors through the use of the ARPES method.  ARPES stands for angle-resolved photoemission spectroscopy.  ARPES involves shooting a photon at the material, and looking at the electrons that pop out.  It's a lot like the photoelectric effect experiment which won Einstein his Nobel prize.

But ARPES is a little more sophisticated, because it doesn't just measure the energy of the electrons that come out, it also measures the angle at which they come out.  The angle tells you about the electron's momentum.  And so we can plot graphs of energy vs momentum.  This is a graph of the electronic band structure, which is of such great importance that I don't know how to properly convey it.  One of these days I will write a better explanation for lay people.  For now, remember those energy bands which were so crucial to the understanding of conductors, insulators, and semiconductors?  Those energy bands are merely a simplified form of the electronic band structure.

Note that I haven't yet fully described my research project; ARPES plus Superconductors is way too broad for a single research project.  But that's just as well, as I don't start until next week.  Perhaps I will write more then, and say something about what exactly I'm doing in the lab.

Though, if it's anything like previous summers, I will probably never fully describe my research here, and instead opt for inside jokes.

Monday, May 23, 2011

Why is calling people out hard?

A lot of feminist criticism* follows a certain pattern.  Person A says something horribly wrong.  Person B calls them out on it.  Person A either admits error or becomes really defensive and makes excuses.  All spectators begin to either berate person A or person B.  This whole process is painful, for both sides.

As a concrete example, see here.**  At an atheist conference, a speaker said it was nice to have a "pretty blonde Romanian" vlogger on our side.  Jen called him out for essentially reducing the vlogger to eye candy.  On the spot, the speaker made excuses, but by now he's offered a sincere apology.  This surely wasn't fun for the speaker, and it wasn't fun for Jen either.  Jen says:
Part of me hates blogging about stuff like this, because I don't want to promote in-fighting or tarnish an otherwise successful conference with this issue. But the more we let crap like this slide, the more it's going to get perpetuated.
Skeptics are also in the business of criticism, though a different kind of criticism.  So here's my question: why does skeptical criticism feel so much less painful?  Here are some possible ideas:
  1. It's only a matter of perception.  Skeptical criticism is also really painful, but I'm more used to it.  Or maybe it's much more painful for the opponents of skepticism.  Or maybe I'm just lucky, and most skeptics do find skeptical criticism to be painful.

  2. Feminist criticism is more likely to be targeted at friends and allies.  Like when a feminist skeptic criticizes fellow skeptics for scaring women away from the skeptical movement.  Or when friends or family make upsetting comments in front of you, and the only way to stop them is by confronting them.

    Skepticism is pretty painful too when you're confronting the weird beliefs of a relative.  But in my experience, this is usually avoidable.  Weird beliefs are harmful, but in many cases a relative's beliefs are no more harmful than a stranger's beliefs.  So why not stick to persuading strangers?  It's less painful and has the same effect.

  3. Feminist criticism seems to have more of a moral dimension to it.  When someone calls you out, it feels like they are calling you sexist, even if no one actually says that.  Of course, the purpose isn't to make anyone feel bad, the intention is to stop people from saying wrong things.

    Contrast with skepticism.  If you do or say something worthy of skeptical criticism, it just feels like an innocent mistake.  At worst you feel stupid, which is unpleasant but easier to admit.

  4. Feminists often fight a "fog" of discrimination.  It's not any one specific comment which is problematic, it's a whole series of comments and systematic biases which create an unfriendly climate.  This situation makes most people feel powerless.  How can you criticize a whole climate?

    Sometimes the easiest thing to do is to pull out the worst comment and make an example of it.  But no single example can capture the problem.  The critic feels afraid to make a big deal out of it.  The criticized feels unfairly attacked.  And everyone misses the forest for the trees.
Any other ideas?  Is there any way to alleviate these problems?

*I'm not thinking of just feminists.  A lot of other groups, like queers, ethnic minorities, and religious minorities, have the exact same issue.
**This is not the source of inspiration for this essay, just a convenient and recent example.

Friday, May 20, 2011

How common is belief in the Second Coming?

The idea that the Rapture will occur tomorrow is, of course, extremely silly.  And since I'm in the mood to speak seriously, it's not worth speaking of at all.

Or is it?  If lots of people believe it, that in itself is serious.

I tried searching for statistics, and most numbers I found lacked citations.  For example, this article claimed its numbers came from Pew Research Center, but failed to actually cite the survey.  I couldn't find any such survey fitting the description.  Also, the "return of Jesus Christ" is not equivalent to the Rapture.  FAIL

But I eventually found a relevant study from 2006 produced by Pew Research Center (see page 19-22).

 Graphic comes from Pew.  The survey included 2,003 US adults, but the above graphic only shows statistics for the 1,670 respondents who identified as Christians. [Edit: clarified]

Unfortunately, the survey did not ask about belief in the Rapture, much less Rapture specifically on May 21st.  You can't always get what you want.  I'm not sure, but I think the best proxy is the belief that the world situation will worsen before the second coming.  Pew identifies this belief with "pre-millenialism", which is one of the varieties of Rapture beliefs.

Are these numbers higher or lower than you expected?

Tuesday, May 17, 2011

Forecasting issues of race

I recently presented my asexuality workshop at the Queer and Asian Conference at Berkeley.  Disclosure: I myself am mixed White/Asian, though I've never considered it a strong component of my identity.

And so, last month I was wracking my brains thinking about how I could adjust my workshop to better appeal to the audience at this conference.  Was there any particular asexual issue which might be particularly relevant to Asian Americans?

I was struck by how little I know about this particular intersection.  I've heard quite a bit about the intersection of asexuality and homosexuality, bisexuality, transgender, feminism, disability, kink, polyamory, and even religion.  But race, ethnicity, and class are so rarely discussed.  Hardly anyone talks about it.  And I am not so naive to think that means there is nothing to talk about.

Every other movement I'm involved in follows the same pattern.  Issues of race are there, but they're invisible if you're not paying attention.  They eventually become visible at the conferences.  I think we're a long ways away from ever having an asexuality conference, but let this be my prediction: there will be issues of race.  We better start predicting what precisely those issues are, so we're not taken by surprise.

Perhaps the best way to predict is to look at what issues of race appear in other movements.  So here's my forecast of issues at the intersection of asexual and Asian, mostly based on what I heard and saw at QACon:
  • Nearly all media representations of queer people are white.  As a result, many queer people of color and their families perceive being gay as a white thing.  Says a mother, "We don't have the gays in Sri Lanka."  There are virtually no media representations of asexuality at all, but as more asexuals become visible, we should keep track of any systematic biases in who becomes visible. 

     This is the group that marched in the SF pride parade in 2009.

    It's not anyone's fault that the group above is mostly (entirely?) white.  But lots of problems are no one's fault, yet they are still problems.  In the future, will asexuality be perceived as a white identity?  Only time will tell.

  • Generally speaking, Asian families treat sexuality as more of a private issue.  For queer and Asian people, this can mean long periods of silence and denial in their families, rather than confronting the issue.  Or families might object to the queer person's being "out".  This is true in my own experience.  On the Asian side of my family, I know that news of me being gay has spread all around, but only one person has actually said anything to me about it.  She was very positive, but objected to the fact that I have a blog.

    In that sort of environment, it might be basically impossible to be out as asexual.  To identify as asexual is to put the focus on sex, which among family is inappropriate.  What's more, it may be harder to discover one's own asexuality.  If no one your the family ever talks about it, what's the reference point to determine that something is different about yourself?

  • Asian families also have certain heteronormative expectations.  You know, getting married and having children.  Being asexual, or any flavor of queer, often conflicts with parents' images of how their children's lives should go.  This is probably true of all sorts of families, not just Asian ones, but it may be the case that culturally Asian families have a slightly different set of expectations.

  • Stereotypically, Asian women are hypersexualized and Asian men are desexualized.  Each of these come with their own set of issues for asexuals.  Asian asexual women might be disbelieved because they conflict with the stereotype.  Asian asexual men might be assumed to conform to the stereotype completely, even if the stereotype is actually very different from asexuality in real life.  Also, sometimes people say Asian men are stereotypically asexual, which is bad because it's using the word "asexual" as a pejorative.
Of course, the issues would be different for other ethnicities, some of which bring serious issues of social class along with them.  Let's hope that future asexual conference organizers don't get any nasty surprises.

Tuesday, May 10, 2011

A year of TAing

I just finished a year of TAing an intro physics course for pre-med students.  And how do I feel about that?

Teaching is fun sometimes.  But it's also a lot of work.  This is especially true of the class I taught, which involved 8 hours in class each week.  This is probably better than 8 hours grading each week, but the downside is I have to be all energized during those 8 hours.  Good thing they pay me for this.

Yes, one major advantage of the class I was teaching was that there wasn't much grading.  The homework was all automated, so I only needed to grade tests.  I hardly need to say it: grading isn't fun.  Some undergrads think that graders are cackling evilly over every red mark they have opportunity to make.  This is not true.  Sure, I enjoy writing zeros on blank tests.  But I also like giving full points to perfect solutions.  My least favorite situation is when they get things nearly right, but I have to scan their work to find what errors they made and give them partial credit.

It's hard to come out of a class of pre-meds without becoming at least a little cynical about the whole deal.  A lot of these students come in with math-phobia.  And they don't care about the material one bit.  They care about getting a grade so they can fulfill the requirement, pass the MCAT, and get into a good med school.

And what good does it do them?  In my last few discussions, I covered a few "extra" topics like superconductivity and particle physics, and those seem to interest even the pre-meds.  But only a few topics can be fascinating, and those two weren't even part of the official curriculum.  What use will a medical student ever have for the Ampere-Maxwell equation?

Would you want a surgeon who doesn't even know what light is made of?  You know, I think I honestly don't care.

I suspect that it's all part of the ridiculous bottleneck for pre-meds to get into med school.  Throwing a bunch of pointlessly difficult hurdles at the pre-meds might lessen the bottleneck.  (I mean, I think this class is really easy, but the students don't agree.)

On the plus side, the course does go a little ways to curing math-phobia.  By the end of the year, most students seemed comfortable with simple algebra.

I was also very cynical about the effectiveness of the professors.  Every week, the students attend three hours of the professor's lectures, and four hours of lab/discussion with TAs.  The students kept on complaining to me that the lectures were worthless.  I never attended the lectures myself (I'm not paid to do that), but based on the powerpoint slides I'm inclined to side with the students.  Don't tell my students I said that; I'm not supposed to disparage the professors in front of them. 

Mainly, I just wish the professors would invest a little more time communicating with their TAs.  As in, more than zero.  Many students felt they learned more from the discussion than the lectures.  So it would really help if the professors told me what they wanted me to teach!

That said, teaching was a very valuable experience.  And I look forward to next year, when I will not do any teaching at all.

Saturday, May 7, 2011

The confused passenger

Classic puzzle:

An airplane has 100 passengers. But the very first one to get on is missing his ticket! He just takes a random seat, and refuses to move from that spot.

The rest of the passengers board the plane one by one. Each passenger takes the correct seat, unless it's already taken. If their seat is already taken, they sit in a random seat, and refuse to move.

What's the probability that the last passenger gets the correct seat?

(Hint: First try to consider an airplane with 2 or 3 passengers)

Extra Challenge:

It turns out that the first passenger isn't isn't really confused, he's malicious!  He knows where he's supposed to sit, and intentionally sits anywhere but there.  What's the probability that the last passenger gets the correct seat?

see the solution

Friday, May 6, 2011

Solution to the Tiger and the Lake

See the original puzzle

You can swim in two directions: the radial direction (towards the edge), and the tangential direction (around the center).  You need to swim in the radial direction to get out of the lake, but you also need to swim in the tangential direction in order to avoid the tiger.

The problem is, the further you get from the center of the lake, the less effective it is to swim in the tangential direction.  Near the center, you can just swim in little circles, and the tiger running around the edge of the lake will never be able to catch up.  But near the edge, the tiger can catch up.  At one fourth the radius of the lake, you can swim around the center just as fast as the tiger can run around the lake.

So here's the strategy.  Swim partly in the tangential direction and partly in the radial direction such that the tiger is always on the opposite side of the lake.  Eventually this spiral path should reach one fourth the radius, or at least very close.  And then you make a break directly for the edge of the lake.

It turns out you can reach the shore before the tiger catches up to you.  However, it turns out that you can't outrun the tiger after you reach the shore.  Also, in real life, tigers can swim.  So you can't really escape safely.

If you're curious what the spiral path looks like exactly, you're in luck!  This is exactly the kind of problem that physicists are good at solving.  It turns out that the correct spiral path is a semi-circle.  And you can actually reach one fourth the radius exactly.  See spoiler image

Wednesday, May 4, 2011

Panel on diversity in the atheist movement

The panel features Jennifer McCreight, Debbie Goddard, Greta Christina.  You must watch it.

Monday, May 2, 2011

One: the universe's favorite digit

Out of all the digits, from zero to nine, one is the most common.  This has to do with the log scale.

The log scale captures an important fact that is true of many quantities in life.  Take money for instance.  If you have one dollar, then earning another dollar is great because you've doubled your money!  If you have a million dollars, earning another dollar does not make much of a difference.  Small changes matter less the more you already have.

This is true on a log scale too.  On a log scale, 1 is the same distance from 2 as 100 is from 200.  The higher you go up, the more the numbers all get smooshed together.  What does that mean for the digits from zero to nine?

In the above picture, I show a log scale.  And on that scale, I highlighted in blue all the regions where 1 is the first digit of the number.  You should see that the blue regions cover more than one tenth of the log scale.  In fact, they cover about 30%.  And so, if we pick numbers randomly on the log scale, about 30% of those numbers will have 1 as their first digit.

Just for fun, let's apply this concept on the fundamental constants of nature.  I will compare two hypotheses:
  1. The fundamental constants of nature are distributed on a log scale.  About 30% of the constants will have 1 as their first digit, 18% will have 2 as their first digit, and so on.
  2. Each digit from 1 to 9 is equally likely to be the first digit of the fundamental constants of nature.
Of course, it could be that both hypotheses are wrong.  It's difficult to say that these constants are really random.  To talk about randomness, we'd need a whole collection of universes with different sets of fundamental constants so we can do some statistical analysis.  But clearly we have only one universe.  Luckily this one universe has 26 fundamental constants (as far as we know), which may be a big enough collection of numbers to do some statistical analysis.

The caveat is that there is more than one way to choose our 26 fundamental constants!  For instance, the mass of the u quark in planck units could be considered a fundamental constant.  But instead of this constant, we could use a different constant: the ratio of the mass of the u quark to the mass of the electron.  It's possible I could bias my results by "choosing" the fundamental constants that confirm my hypothesis.

Therefore, I will not choose which constants to use.  I will simply use the list compiled by John Baez and David Black.*  Note that 6 of the constants are unknown, so we'll have to make do with the remaining 20.

*Baez offers two sets of equivalent constants for the CKM matrix.  I just used the first set.


The frequency of first digits more resembles hypothesis 1 than hypothesis 2.  I also tried doing some Bayesian analysis.  If our prior belief is that the likelihood of each hypothesis is 1:1, then this evidence increases the ratio to 15.8:1.  In other words, if we previously thought they were equally likely, then after seeing this evidence, hypothesis 1 is almost 16 times as likely.  As far as evidence goes, this is fairly weak evidence, but you're not going to get much better with only 20 fundamental constants.

Does this really mean fundamental constants are randomly distributed on a log scale?  Gee, I don't know.  Probably not really.  What's your interpretation?

Sunday, May 1, 2011

Carnival of Aces

There's a brand new asexual blogging carnival: A Carnival of Aces.  A blogging carnival is a periodic event that collects posts from various bloggers on a single topic.  The theme of the inaugural edition is "coming out", which I hope is something even non-asexuals find interesting.

If I were to highlight two posts in the carnival, I'd pick Elizabeth's and Pippin's (which has comics!).

This carnival reminds me of back in the day when I used to participate in the Carnival of the Godless and Skeptic's Circle.  At some point I lost interest, or I lost the confidence required to submit.  Now both of these carnivals are dead.  Not sure what happened there.  I suspect it might be because the skeptical and atheist blogospheres got so big that they outgrew the carnivals.  Here's to hoping the same eventually happens here.