Wednesday, May 30, 2012

Correction: Tumblr comments

In a previous post complaining about Tumblr, one of my major points was that Tumblr does not have a comment system.  I am obligated to correct myself.

Tumblr has a few different comment systems, all of which are limited.  As far as I'm aware, there are also questions, replies, and third party comment systems.  Questions and replies are so constrained that I'm not sure they deserve to be called comment systems.  But I did manage to install a third party comment system, Disqus.  The comments work fine, though I don't like that there's no rss feed for me to track comments.

(BTW, I could also install Disqus on this blog, but I probably won't unless anyone gives me a compelling reason for it.)

However, I do not think this calls for a revision of my original conclusion; tumblr is still terrible.  The fact of the matter is that most tumblrs do not bother with third party comment systems.  Reblogging is still the main method of discussion.

Monday, May 28, 2012

Hypothetical fallacies

My boyfriend pointed out these two fallacies, and now I feel like I see them everywhere!

Argument from future majority:  "In a few decades, everyone will look back and see how wrong you were."

Hidden assumptions: Will people in the future in fact see how wrong you were?  Is the majority opinion relevant?  Are future people's opinions necessarily better than present people's opinions?

Combines: appeal to future evidence and argument from majority

Argument from hypothetical hypocrisy: "If she were a Republican, the right-wing would be dismissing this scandal as a distraction."

Hidden assumptions: Would the right-wing in fact do that?  Does that necessarily mean that the right-wing's current actions are wrong, or could it just mean that their hypothetical actions are wrong?  Do hypothetical wrongs of the right-wing justify similar wrongs of the left-wing?

Combines: begging the question and tu quoque

The nature of these arguments is that even if all parties were to agree on the hypothetical, the conclusions are still fallacious.

Thursday, May 24, 2012

I have a tumblr

Here you go.  I quote the introduction:
It’s said that labels are for soup cans.  Never having known an aphorism to be false, I have concluded that I am a soup can.

Labels: asexual, gay, gray-A, atheist, skeptic, physicist

I have this blog Skeptic’s Play, and this is just an extension.  Please follow my blog, not my tumblr.  It’s likely that this extension will mainly focus on asexuality, since only the asexuals have a deficient non-tumblr blogging community.  It’s also likely that I will neglect this tumblr, or use it for commenting only.

More about me?  I’m sometimes called Siggy or miller, and I’m known for doing presentations on asexuality for LGBT audiences.  I am in a long-term relationship with a gay man.  I participate in queer, asexual, and atheist communities online and offline.  I study superconductivity.  I am unenthusiastic about everything, especially things that people say I should be enthusiastic about.
The tumblr itself is empty, and I am satisfied with that for the time being.  It's all part of my clever plan to force people to read my blog rather than my tumblr!

I have no particular attachment to the current title, "Godless asexual".  I'm not really trying to be an outpost for the intersection of asexuality and atheism.  There's not a huge need for it, considering how overrepresented atheists are in the ace community.

Asexuals and queer appropriation

I'm going to dip my toes into one of the interminable flame wars of the asexual tumblverse (hopefully, it will be less terrible when it is off tumblr).  The question is, do asexuals (and in particular, heteroromantic asexuals) have a right to use the word "queer"?  Are they misappropriating a reclaimed pejorative?

Wrong question, right question

Since I'm very practically oriented, I feel like this question is a bit of a red herring.  Heteroromantic asexuals make about 22% of the community, and about 13% of heteroromantics consider themselves part of the LGBT community.*  People are arguing over a relatively small group, and in the mean time pushing away a much larger group who they nominally accept.

*Based on survey results which will be released very soon.  Update: they have been released.

The real question is, are there spaces which asexuals and LGBT people can share?  Should there be?  Does this particular configuration help people?  Language has an effect on this question.  If an asexual thinks of themself as just an ally, they will be less likely to participate or share their own experiences.  Is that what we want?  If an asexual acts homophobic, or an LGBT person hates on aces, do we want to treat it as an attack from the outside, or as ignorance from the inside?

In my mind, the desired community organization should determine language, not the other way around.  I've argued before that the asexual and queer communities benefit from shared spaces, and that's why asexuals are queer.  However, there's no way for me to really know if the combined community works for every individual in all their individual circumstances and preferences.  That's why asexuals are allowed to freely identify as queer or not.  Let each person decide if it works for them.

Since the majority of heteroromantics don't identify as queer, that indicates that the queer identity does not work for them.  I respect that.  I also respect the minority who find the identity useful.  If they identify as queer in the face of some obvious differences from the dominant queer subset (ie gay men), they must have a good reason for it.

Degrees of reclamation

One contention is that "queer" used to be a pejorative used against gay, lesbian, bisexual, and trans people.  Therefore, only gay, lesbian, bisexual, and trans people have a right to reclaim the word.*  I think of this as an extension of rules applied to many other reclaimed slurs.  Gay men occasionally use "fag" to refer to each other, but it's not okay for others to do so.  Black people may occasionally refer to each other as "nigga", but it's not okay for other people.  Same for "dyke", "tranny", "slut" and numerous other words you can find on Wikipedia.

*See two examples of this argument in the wild

 But if you look down the list, it's pretty clear that there are different stages of reclamation.  "Nerd", "geek", "Quaker", and "Mormon" are also reclaimed words.  There are no restrictions on these words because most of us can scarcely remember when they were slurs, and their reclaimed meaning has taken over their original meaning.  At some point, the history of the term becomes irrelevant.

"Queer" is a term that is somewhere in the middle.  I am certainly aware of its history as a slur, but I have never heard it used as a slur in my life.  I am not suggesting that it never gets used pejoratively anymore, but that in at least a few geographical locations and environments, its positive meaning has eclipsed its previous meaning.  The positive meaning that emerged is sort of a synonym for LGBT, with fewer syllables, and more of a liberationist connotation.  It also tends to connote inclusion of people who fall into the cracks between boxes.

However, "queer", in its slur form, was not used to refer to all LGBT people.  It was mainly used for effeminate men (or trans women) who were presumed to take a passive sexual position with other men.  Does this mean that butch top men, lesbians, bisexual women, and trans afab people should not be using the word "queer"?  (No it doesn't.)

Note that many people argue that trans men should not use "tranny", which is a slur mostly used against trans women.  The fact that no one disputes trans men's use of "queer" serves to highlight the different natures of "queer" and "tranny".  Here's a quote:
Reclaiming tr*nny feels like a way to have a history. But that word was never our [trans men's] history. It feels like a way to name and confront those invisible oppressive structures. But it doesn’t do that work, because while the structures that oppress trans women have many elements in common with the ones that oppress us, they’re not the exact same ones.
You can identify as anything you want! But if it is absolutely imperative for you to use that word, and you using that word makes trans women feel unsafe around you, I’m not sure what to tell you. Maybe you should do some work within yourself, trying to discover why you have such an intense need to own a word that makes people feel unsafe.
By contrast, the asexual use of "queer" has nothing to with wanting to revise history, it has to do with the practical need for an umbrella term for sexual minorities.  The use of "queer" as an umbrella term is exclusive to its reclaimed meaning, so I feel that using it this way can only serve to push its days as an insult further into the past.  I don't think queer people really feel threatened by this usage.  It's not like calling a woman "bitch", and then justifying it by saying, "But sometimes women call each other bitches!"  I think they're mostly just bothered by the alleged relative degree of privilege asexuals enjoy over other queer groups.

Sufficiently oppressed

The degree of marginalization experienced by asexuals is obviously a very broad topic which I will surely write about again and again.  Here, I only mention it, since it's the main undercurrent of the "Asexuals are misappropriating the queer identity" argument.  The claim is that asexuals aren't sufficiently systematically oppressed, so we have to take away their queer cards.

Arguments for this claim are basically arguments minimizing the issues that asexuals face.  You can see why even non-hetero asexuals feel pushed away by the exercise, even though it's only supposed to apply to heteroromantic asexuals.  I also feel disappointed on bisexuals' behalf whenever someone says asexuals "just" experience erasure.  Bisexuals also experience erasure, and because of it, they're worse off than gay and lesbian folks.  Clearly, open hate and discrimination aren't the only problems the LGBT community should be paying attention to, erasure is another.

Degrees of marginalization vary wildly depending on individual circumstances.  I myself am immensely privileged, but since I am gay, no one tries to take away my queer card.  I would venture that some heteroromantic asexuals, perhaps the 13% who identify with the LGBT community, are on the opposite end, experiencing marginalization that is within range of their local queer community.  We don't really know how much marginalization individuals experience, and that's why we give people the freedom to choose for themselves.

Monday, May 21, 2012

Tumblr is terrible

One of the biggest developments in the ace community over the past year is the growth of the ace tumblverse, which has been accompanied by the death of the blogosphere.  I'm one of the last blogging holdouts.  Growth is great, but tumblr is terrible and blogger is better.  Here's why:

Tumblr has no comments.  This is what makes me the most angry.  I can't comment on tumblrs without getting my own tumblr.  And not just a tumblr account, I have to start an actual tumblr.  That's such monopolizing bullshit.

In case you're not familiar with tumblr, the comment system is replaced by a reblogging system.  People comment by reposting quotes on their own tumblr, with added comments.  At the bottom of the original post or any rebloggings, you can see all the people who have reblogged the post, with a one-line excerpt of anything they added.

Reblogging is a terrible substitute for comments.  For one thing, you have to visit many many tumblrs just to see what people are saying.  Most people say nothing of importance, and you just wasted a click!  Other people engage in these long comment threads full of nested quotes, and it's a real pain to root the whole thing out.

If you follow any tumblr user that wishes to comment on other tumblrs, it brings their tumblr down to commenting quality or worse.  I comment on a lot of blogs, but you should be happy that the comments don't appear here because it would just be a lot of noise.

There is no comment moderation.  It's said that tumblr is a drama machine, and this is why.  The "comments" do not belong to any particular tumblr, so there is no moderation.  Additionally, if anyone from a far-flung community makes a comment, their whole community sees it as well, leading to these huge community clashes.

There is some value in having diverse perspectives, but when uncontrolled (as is always the case on tumblr), it can also just lead to a lot of unproductive flame wars.  I say this as someone who takes a laissez-faire approach to comments.  Blogs are often derided as "echo chambers", but at least they have relatively controlled conversations.  (And ironically, since reblogging is uncommon, they have less echoing.)

There is a culture of no citations.  Last year I talked about how it is good to cite your opponents.  Because for all we know you're making up opponents, or mischaracterizing your opponents.  Also, some of us may want to respond to your opponents as well?  But on tumblr, I've been shocked at all the blatant omitting of citations.

Since then, I've come to understand why tumblr people don't do citations.  People don't cite because they're afraid they'll attract unwanted attention and start more drama.  Also, tumblr lacks effective search and archive functions and contains a lot of reblogging noise, so it's really hard to find a post that you recall.

There is a culture of memes.   This is obviously a personal preference, but I really hate memes.  I will stop reading a blog if there is too high a density of captioned animals, I am not even kidding.

Blogger is better.  Call me old-fashioned, but I prefer the way blogs connect to each other.  If someone leaves a comment, you can choose to go to their blog if you like what they say.  If you think you have an important response to a blog, you can choose to respond on your own blog.

I suppose one of the major advantages of tumblr is that you can follow a particular tag, while with blogs you basically have to find bloggers who'll track that stuff for you.  But I think the greater effort is worth it to eliminate the noise.

In other news, I was considering starting a tumblr so I can comment on tumblrs.  Good idea, bad idea?

Friday, May 18, 2012

Constructive criticism and division of labor

Massimo Pigliucci wrote in defense of criticism and skepticism:
[Francis] Bacon thought of his inductive method as having two components, which he called the pars destruens (the negative part) and the pars construens (the positive one). The first was concerned with eliminating — as far as possible — error, the second with the business of actually acquiring new knowledge.
People often expect both parts to come together.  They want constructive criticism rather than just criticism.  But Massimo goes on to argue that this is a mistake.  Each part is valuable on its own, and if some people are more skilled at one part vs the other, it's useful to divide the labor.  Massimo draws comparisons to the division of labor between theoretical and experimental physicists (an analogy that I approve of as a physicist).

I think people also believe that eliminating errors is somehow easier than creating new ideas.  So if you're offering new solutions, that's a valuable service, but if you're revealing problems, anyone else could do it just as well.  I think there is some truth to this belief.  I criticize as a hobby, but the generation of new ideas and knowledge is more of a profession to me (ie scientific research).  But most of the time, people just say criticism is too easy as a way of flattering themselves for having come up with an idea, and dismissing anything that could be wrong with their idea.

Tuesday, May 15, 2012

A new relativity paradox

 Recently, there was an article in PRL called "Trouble with the Lorentz Law of Force: Incompatibility with Special Relativity and Momentum Conservation".  I admit I didn't read the article, because I felt that the summary in Science was sufficient.

Figure from Science, credit P. Huey

The basic paradox is as follows.  You have a charge and a magnetic dipole, motionless with respect to each other.  In the reference frame where they are motionless, they exert no forces on each other.  In the reference frame where they are both moving, there will be an electric dipole in the magnet.  If you think of the magnetic dipole as a loop of current, the electric dipole can be understood as the result of Lorentz contraction (as discussed in an old post).

The positive end of the electric dipole will be repelled by the charge, while the negative end will be attracted.  Therefore, the charge applies a torque on the magnet, causing it to spin.  (The moving charge also applies a magnetic force, but this does not counteract the torque.)  But how can the magnet spin in one frame, but not spin in another?  Therein lies the paradox.

The author of the paper concludes that the Lorentz force law needs to be revised in the presence of polarized or magnetic materials.  However, I do not think this is the correct resolution for the following two reasons:
  1. It is easy to construct the same paradox without any polarized or magnetic material.  Replace the magnet with a loop of current, which functions as a magnet.
  2. It is easy (but tedious) to prove that the Lorentz force law is the same in all reference frames.  Showing that it behaves differently in two frames is akin to proving 1 = 2; the correct conclusion is that you made a mistake somewhere.
But I must admit that I could not figure out where the mistake was.  It's a good paradox!  Instead, I solved the problem using the research method.  I read two responses by Daniel Vanzella and Kirk McDonald (both of which said the same thing).  The resolution to the paradox is tricky, and I will attempt to summarize it for a lay audience.


We need to talk about the momentum of the electromagnetic field itself.  It's well-known that light, a fluctuation in the electromagnetic field, can carry momentum.  But even constant fields can have momentum.  The momentum is proportional to the cross product of the electric and magnetic fields.  When you have an electric charge and magnetic dipole near each other, the momentum of the electromagnetic field is not zero.  But the total momentum of the magnetic dipole must be zero, since it is motionless.  Therefore, there must be some hidden mechanical momentum in the opposite direction.
In this figure, the magnetic dipole is represented by a loop of current.  The magnetic field produced by the current goes through the loop out of the screen.  The electromagnetic momentum is downwards.  The hidden mechanical momentum is upwards.

I claim that there's hidden mechanical momentum, but where does that come from?  I believe that it depends on the precise nature of the magnetic dipole, but we can at least consider a simple example.  In the above figure, we imagine that the magnetic dipole is actually a square loop of counter-clockwise current (with no dissipation).  Charged particles in section A are being slowed down by repulsion from the charge on the left.  Similarly, charged particles in section C are being sped up.  Therefore, the particles in section D are moving faster than the particles in section B.  And recall that in relativity, faster particles are heavier.  Therefore, there is more momentum in D than in B, and the total momentum is upwards

And that's how a loop that is motionless can still have momentum.

It turns out that even when we use a moving reference frame, there is some mechanical momentum upwards.  Torque, which normally causes an object to spin, is really the change in angular momentum around a single pivot point.  The angular momentum is proportional to the cross product of the momentum and the distance from the pivot point.  In the moving reference frame, there is torque on the loop, but this does not cause the momentum to change, or cause the object to spin.  It causes the distance from the pivot point to change (because the loop is moving, while the pivot point is motionless).  Thus the paradox is resolved.

Upon reading this resolution, I was puzzled, because there must be an equal and opposite torque applied somewhere else in the system.  I figured out that an opposite torque is applied to the momentum of the electromagnetic field.


The responses from Vanzella and McDonald appeared before the paper was even officially published.  That might be kind of embarrassing for PRL.  Or maybe not?  Presumably, PRL felt that even if the paper was shot down, it would still generate productive discussion.

Note that there is precedence for revising old textbook equations.  I'm thinking of the Aharanov-Bohm effect (which shows that magnetic field has an effect on particles which go around the field even if they don't go through the field) and Berry's curvature (which modifies the laws of motion for particles within a crystal structure).  In both cases, the fundamental equations were known, but physicists overlooked a few of their strange consequences.

Saturday, May 12, 2012

Uncertain beginnings

This post continues "A few things wrong about the cosmological argument", a series focusing on lesser wrongs of the cosmological argument.

A waste of time

This is where I tell you that everything earlier in this series may have been a colossal waste of time.  I spent all this time arguing for the possibility of an infinite past, but who cares about the possibility?  In our actual reality, it appears that the universe in fact does not have an infinite past.  This is based on our knowledge of physics, and experimental confirmations of Big Bang theory.  It's based on science.

In my mind, the scientific confirmation of a beginning trumps all the philosophical arguments in the world.  If we had evidence that the universe has no beginning, Christians like William Lane Craig (WLC) would not give up Christianity.  They'd just find a new argument for why a lack of a beginning is consistent with Christianity.  The only reason WLC can't think of an argument now is that he doesn't have the motivation.

That goes for atheists too!  A few atheists will respond to the cosmological argument by saying that the universe does not have a beginning.  But if science all but proved that the universe has a beginning, would these people just concede the cosmological argument?  Nah, they'd find a new reason why it's wrong.

On the basis of scientific evidence, I am totally willing to concede that the universe in fact has a beginning.  That particular premise of the cosmological argument is true.  I spent all that time arguing about infinities not because I believe the universe has no beginning, but because I genuinely believe WLC has infinities all wrong.

I also genuinely believe WLC has the cosmology all wrong.  WLC greatly exaggerates the scientific case for a beginning.  I agree that cosmology argues for a universe with a beginning, but it is by no means assured.  It's arguable, though I would not argue it, that the question of a beginning is still completely up for grabs.

The known and unknown

WLC describes the case for the beginning of the universe using the words of physicists:
The universe began from a state of infinite density. . . . Space and time were created in that event and so was all the matter in the universe. It is not meaningful to ask what happened before the Big Bang; it is like asking what is north of the North Pole. Similarly, it is not sensible to ask where the Big Bang took place. The point-universe was not an object isolated in space; it was the entire universe, and so the answer can only be that the Big Bang happened everywhere.
That is indeed one of the standard narratives cosmologists use to explain the beginning of the universe to popular audiences.  But I have the vague impression that this narrative was popular a generation ago (the quote comes from 1976), but contemporary cosmologists realize that there are alternative narratives which are about as likely to be true.

My field is condensed matter, not cosmology, so I get these impressions from colloquia and buzz among physicists.  If I were willing to put in a lot of effort, I would look through the recent papers on ArXiV and see if there are any discussing alternative narratives for the beginning of the universe.  But that would just lead to he said she said, a battle of the experts.  Instead, let me explain a bit why contemporary cosmologists are unsure about the beginning of the universe, and why you should be too.

The Big Bang theory is the theory that the universe evolved from a very hot and dense state to a sparse and cool state.  It's a prediction of Einstein's theory of General Relativity, which is a theory of gravity.  According to General Relativity, the universe can't really have constant and uniform density, because all that matter will attract.  Instead, the density will change over time in the manner described by General Relativity.

The experimental evidence for the Big Bang theory is many-fold, and stands independently from all the evidence for General Relativity.  There is the redshift of far away galaxies, indicating that they are moving away from us.  There is the cosmic microwave background radiation, which is thermal radiation from when the universe became cool enough that it became transparent.  The observed proportions of elements agrees with the prediction from Big Bang theory.  There are numerous other lines of evidence that I don't have time to name.

But note that all the evidence I cited only shows that the universe expanded from a hot and dense state.  It does not actually tell us what happened at t=0.  As we get to t=0, there are more and more disputes over what happened.

There's Inflationary theory, which says that between 10-36 to 10-33 seconds after t=0, there was a period of really fast expansion.  During that time the universe grew in size by about 78 orders of magnitude.  The primary evidence for inflation comes from agreement with tiny variations in the cosmic microwave background radiation. I would say inflation is part of standard cosmology, but it certainly has its detractors, and it could still turn out to be wrong.  The cause of inflation is unknown and disputed.  The theories I've heard usually posit a new quantum field.

And then there's the big dispute--quantum gravity.  The only reason we believe that the expansion continues all the way to t=0 is that General Relativity predicts it, but General Relativity is not a complete theory.  It's a classical theory, yet to be converted to a quantum theory.  Very early in the universe,* the universe was dense enough that quantum effects would definitely come into play.  We're not just lacking evidence regarding the very early universe, we're lacking reliable theoretical predictions.  We need a theory of quantum gravity to make predictions.  The major candidate theory is String Theory, which is famously controversial.  There are also a lot of other candidates like Quantum Loop gravity, and lots of other stuff I don't understand.

*I don't know exactly how early, because I couldn't find a reference.  Sorry.

Alternate beginnings

Besides the beginning-as-north-pole narrative, there are actually a lot of possibilities for the history of the universe.  WLC mentions one, the oscillating universe, which he quickly dismisses.
As the late Professor Tinsley of Yale explains, in oscillating models "even though the mathematics say that the universe oscillates, there is no known physics to reverse the collapse and bounce back to a new expansion. The physics seems to say that those models start from the Big Bang, expand, collapse, then end." In order for the oscillating model to be correct, it would seem that the known laws of physics would have to be revised.
This may be correct, but it's misleading.  The known laws of physics have to be revised regardless, because we need a theory of quantum gravity to make any predictions.  There is no known physics to reverse a collapse, but the same could be said of any early universe scenario.  There is no known physics to explain inflation, even though we think inflation exists.  All that's known is that classical physics predicts a beginning (I believe this is also in dispute), and that classical physics doesn't apply.

I believe the oscillating universe hypothesis has fallen out of favor, but a lot of new speculations have come into favor as well.  Based on Inflationary theory, there are a lot of speculations about universes budding from each other.  Perhaps there are certain conditions under which a small volume of an older universe will suddenly inflate and become its own universe.  Or perhaps inflation is the normal state of things, but every so often a tiny bit of this infinitely inflating universe stops inflating and becomes a slowly expanding universe.  I've also heard speculations coming from string theory.  Maybe the Big Bang was a collision of branes that exist in a realm of higher dimensions.  So on and so forth.

I call them speculations, because that's what they are.  Probably none of them are correct.  It's probably something we haven't even thought of.  The point is that the Big Bang as the beginning isn't the only possibility, nor is it the only possibility we can imagine.

WLC also uses the Second Law of thermodynamics as another scientific argument, but this is getting too long, so I'll save it for next time.

"A few things wrong about the cosmological argument"
1. Actual and potential infinities
2. Actual infinities in physics
3. What is real?
4. The "absurdity" of Hilbert's Hotel
5. Interlude: God is infinite
6. Forming Infinity, one by one
7. Uncertain beginnings
8. Entropy: The unsolved problem  
9. Kalam as an inductive argument
10. Getting from First Cause to God  

Wednesday, May 9, 2012

Who speaks?

I'm interested in the reframing ideas from social justice as skeptical ideas.  It's a fresh spin on fallacies and biases!

One of the things we talk about in social justice is who speaks, and who gets spoken for. Within any group, the loudest voices tend to belong to the most powerful subsets of that group.  U.S. presidents tend to be old, white, male, and Protestant.  Prominent atheists tend to be old, white, and male.  Prominent LGBT activists tend to be gay rather than bisexual or trans.

We explain these imbalances by calling it "privilege", but it's really not an explanation at all.  "Privilege" is just short-hand for a bunch of different processes--better access to resources, greater encouragement to develop as a leader, greater sympathy from the public, etc.--and we don't really know which processes are more or less important.  But no matter the cause, we have to deal with the result: the loudest voices are systematically non-representative.

On some level, it doesn't matter who expresses an idea.  In California voter guides, they always attack propositions by saying some wealthy guy supports it, but as critical thinkers, we know that's just ad hominem.  If a wealthy person makes an argument, their wealth has no bearing on whether their argument is correct or not.  Some of my best friends are wealthy people who have correct arguments.

And yet, it is a very naive sort of critical thinking that ignores who is speaking.  When it comes to the minutiae of an argument, it doesn't matter who says what.  But in most arguments, we don't support every assertion with hard evidence.  A lot of things we say are opinions based on personal experiences and impressions.  In particular, we all have a bunch of personal impressions about what arguments other people make, what things other people believe, what sort of problems are most important to talk about.

And then there's the fallacy of omission.  If, for instance, a news article tells me of a study linking vaccinations and autism, there's just no way for me to know by looking at the article whether they omitted some important information, like the failure to replicate the study.  There has to be some degree of trust that the journalists have the investigative ability to dig up such details.  When someone is speaking, I have to trust that they are honest, and that their personal experience is broad enough to uncover any important details.

But if the loudest voices tend to come from people with privileged backgrounds, then their personal experiences are less broad for it.  Even if they make technically correct arguments, but they could be systematically missing multiple elephants in the room.

And there's a moral dimension to this.  What kind of elephants in the room are privileged people likely to miss?  (Answer: the kind of elephants that most hurt disadvantaged people.)

Monday, May 7, 2012

No fault lines

Build a rectangle with multiple 2x1 bricks such that the rectangle has no "fault lines".  A fault line is a straight line through the rectangle that does not cut through any of the bricks.

For example, the following rectangle fails because of the fault line indicated in red.
What's the smallest rectangle you can make without fault lines?  You may send solutions to skepticsplay at gmail dot com.

Can you do the same with 3x1 bricks?

This puzzle is taken from Polyominoes: Puzzles, Patterns, Problems, and Packings, by Solomon W. Golomb.

See solutions

Thursday, May 3, 2012

Entangled minds

Sometimes people use quantum entanglement as an explanation for psychic communication between minds.  The idea is that my neurons are entangled with yours, and whatever my neurons see would be the same as yours.

Being a physicist, I know that's wrong.  Even if psychic communication exists, quantum entanglement would utterly fail to explain it.  But at the same time, as a physicist, I feel compelled to get the technicalities right.  There's a nagging technicality here: Yes, our neurons are in fact entangled.  But that doesn't mean what you think it means.

Most people are told that entanglement is about correlations over large distances.  What someone measures here will be the same as what someone measures over there.  But what you may not have known is that entanglement is also about anti-correlations over large distances.  What someone measures here could be the opposite of what someone measures over there.

So suppose that I feel a twinge of sadness.  I interpret this to mean that you are experiencing sadness right now, because my sad neuron must be correlated with your sad neuron.  Except, maybe they're anti-correlated.  Maybe you are feeling the exact opposite way, and your neuron is happy or whatever?

Or suppose that I think happy thoughts.  Surely happy thoughts are correlated with happy things in the world via entanglement, so if I think positive thoughts I will attract good things to me.  Except, maybe my happy thoughts are correlated with the opposite, and are actually attracting bad things to me?

So if we have two neurons, are they correlated or anti-correlated?  Under carefully-controlled experimental conditions, involving small numbers of particles (ie much fewer than the number of particles in a neuron), and isolating those particles from the random interactions with the outside world, physicists can produce things that are definitely correlated or anti-correlated.  But under any less-controlled conditions, it's essentially random.  There's no way to know.  Every time it happens, it will be different.  It will be completely unpredictable.  On average there will be no correlation at all.  We say that the neurons are decoherent.

(Because there is no observable correlation, some physicists would say that the neurons are not entangled.  This appears to contradict what I said, that the neurons are entangled but decoherent.  We're not really saying different things, we're just using different words to communicate the same ideas.)

Trying to explain psychic ability by quantum mechanics is no better than trying to explain it by thermodynamics.  Thermodynamics is all about the random motion of molecules.  Thermodynamics says that there is a miniscule chance that the molecules in my neuron will just happen to move in the same way as molecules in your neuron!  But out of all the ways molecules could move, why should we single out this particular way, except that it makes us feel fuzzy inside?

Some other gross simplifications I've made:

1. To speak of "same" and "opposite" results presumes that there are only two possible configurations.  I'm sure that neurons are complicated enough that they have a very large number of configurations.  If each neuron has three possible configurations, then we have nine total possible combinations.  Because the neurons are entangled, some of these combinations are more likely than others, but all the probabilities themselves are essentially random.

2. There's no reason to think that entanglement should only involve two things.  In general, entanglement involves every possible configuration of everything.  But imagine that we have just three things: two neurons and my aunt's left foot.  And imagine that each of these has two possible configurations.  Now there are 8 possible combinations.  Some are more likely than others, but the probabilities themselves are essentially random.