It's good for you, in that it will make you immortal

This article is a great example of how dumb science reporting can get. A quote:

Coffee-drinking men cut their risk for death by 12 percent after four to five cups of java, according to the study, which was led by the National Institutes of Health's Neal Freedman.

So if I drink 42 cups, I'll cut my risk for death to 0%. Sounds like a good deal to me. Studies such as this one usually define "risk of X" as "risk that X occurs during the duration of the study," which would make the claim that coffee reduces the risk of dying by whatever percent make a lot more sense. But the moron who chose to summarize the study didn't think details like that were important. Next quote:

The report sparked some confusion, too, as coffee drinkers were also puzzlingly more -- yes, more -- likely to die. The reason? Coffee drinkers are also generally smokers. How can coffee drinkers can be both more and less likely to die seems like an arithmetic mystery -- but cut out smoking altogether, and the correlation between coffee and longer lives still stands.

Sure, if you're a dimwit, this could indeed "spark some confusion." So the fact that drinking coffee reduces the risk of death when controlling for smoking, but is correlated with higher risk of death when smoking is not controlled for, "seems like an arithmetic mystery" to you. And you write about science.

Basic principle of science: If something happens, it must be possible

About five years ago I got in the middle of an internet discussion about torture. It took place in the comments section of a blog that strongly opposed legalizing torture as means for national security agencies to gather intelligence in extremely important national security cases, for two reasons: 1) because torture is morally reprehensible and 2) because it's ineffective in terms of providing reliable intelligence due to the fact that torture victims will say anything, come up with any lie to make the pain stop, so that the information they provide is completely unreliable. I wrote a comment agreeing with the first point but disagreeing with the second, and provided a few examples showing that torture can sometimes "work" (i.e. generate truthful, actionable intelligence that could not have been procured otherwise).

I've had many replies, with one consistent theme in most of them: that my examples weren't plausible because everyone knows that torture victims will say anything and come up with any lie they can think of to make the pain stop. I started replying to this theme, my reply being something to the effect of that sometimes there probably are situations such that, even though the torturer doesn't know what the truth is (otherwise why torture anyone in the first place), he nonetheless has some knowledge as to what the truth is not, which means he can tell if his victim is lying to him. As I was drafting this reply, I realized I was full of shit: I didn't have the first clue if that was indeed the reason why torture worked in my examples, or any examples, and that I was basically making it up as I went along. I also realized something more important: that I didn't have to answer this question in the first place, that the argument was already over and I had won it.

You have a clever and a priori very plausible theory as to why event X can't happen. One way for me to disprove your theory is to find an instance of event X having happened. All I need is a counterexample. I don't have to come up with a counter-theory that explains why your theory doesn't work. I don't have to understand why X happens; I can be as mystified and baffled by it as you are. Your theory says X is impossible. I show you that X happened. Since X happened, it is obviously possible, and I don't need to know why it's possible to know that your theory must be wrong.

Try to beat that Hirsch Index

This is one of those things that, when you first read it, your immediate thought is "this can't be true." Here's John D. Cook quoting historian Clifford Truesdell:

… in a listing of all of the mathematics, physics, mechanics, astronomy, and navigation work produced in the 18th century, a full 25% would have been written by Leonard Euler.

Scientific betting markets

As expected, Scott Aronson's bet about the newly published proof that P does not equal NP spurred a heated discussion about the bet and scientific betting in general. Aronson's summary of the discussion runs as follows:

I was hoping for some enlightening discussion about the ethics of scientific betting in general, not more comments on the real or imagined motives behind my bet. However, the actual comments I woke up to have convinced me that the critics of my bet were right. In principle, the bet seemed like a good way to answer the flood of queries about Deolalikar’s paper, and then get back to enjoying my trip. In practice, however, the way people respond to the bet depends entirely on what they think about my motives. If you don’t care about my motives, or consider them benign, then the bet probably provided a useful piece of information or (if you already knew the information) a useful corrective to hype. If, on the other hand, you think I’m arrogant, a media whore, etc., then the bet served no purpose except to confirm your beliefs. Since people (at least taking the commenters on this blog as a representative sample, admittedly a questionable assumption!) generally wish to ascribe the worst motives to me, it follows that the bet was counterproductive.

I have no reason to question Aronson's motives and, as I have said, to me his opinion has been more informative than anything else anyone has said about Delalikar's paper. But that's just me, and Aronson can be right: given the average response of his readers, his bet was indeed counterproductive. This doesn't mean, however, that a scientific betting market would also be counterproductive. As the number of market participants grows, you cannot gain notoriety by joining it, so the motive of an average participant becomes purely to try and make money. The only way to make money on an opinion is to bet on it and be right. I see no reason why such market would not work (or work just as well as other markets work, at any rate).

One of the commenters, a computer scientist Gil Kalai, spells out his reasons to believe prediction markets wouldn't work in science:

In the economics setting of “rational expectations” there is an unknown state of the world on which agents have private information. The market prizes aggregate the private information in a subtle way and reveal the true state of the world.

The principal reason that this is not relevant to scientific questions is that a basic implicit assumption in all these models is that if all the private information of agents about the state of the world will be made public, this will suffice to determine the correct state of the world. (Say with extremely high probability). The behavior of agents in the market (or in other strategic situations) give a way for the private information to aggregate as if it was common knowledge.

But, of course, this is not relevant here. Even if we know the sincere private opinion of all scientists on a question like is factoring in P (and even their opinions about opinions of others, and whatever additional information that we want, and we can even give them time to reconsider their opinions based on pinions of others etc etc…) making this private information public is not sufficient (and usually does not help) to determine the “state of the world”.

Kalai is vague about what he means by "the true state of the world." In the context of Delalikar's proof, is the true state of the world whether or not the proof is correct, or the actual reasons why the proof is correct or not? If the latter, then it's true, a betting market can't help much. But if the former, then a betting market is actually more informative than "making all private information of participants public," for three reasons. First, a betting market allows for expressing beliefs that can't be supported by a rational argument ("I just have a strong hunch"). Second, betting markets convey information more efficiently than public revelation of private knowledge. The amount of all private knowledge relevant to a question as complex as "P versus NP" is so huge that no individual can possibly process all of it. Market prices compress all that information into signals that are much easier to process. An third, a scientific prediction market would offer information about open scientific questions in the form that would be accessible to everyone, not only scientists. As I've said before, to me as a theoretical computer science ignoramus, Aronson's bet is actually much more informative that a detailed refutation of Delalikar's proof, because I have no qualifications to judge the technical details. I have no idea why a proof that shows 3SAT is not in P should fail for problems like 2SAT and XOR-SAT. In fact, I barely know what 3SAT, 2SAT and XOR-SAT even mean. But I do know the exact meaning of $200,000.

The Mechanical Universe online

I'm sure I'm late to the party, but I've just noticed that Caltech's introduction to physics series, The Mechanical Universe, is available to view online for free. It really is quite an amazing series. If it's at all possible to make a popular science series on these topics, not dumb it down, and still make it fun to watch, this is it.