Extraordinary Physics
In January Eliezer warned:
Our own eyes can deceive us. People can fool themselves, hallucinate, and even go insane. The controls on publication in major journals are more trustworthy than the very fabric of your brain. If you see with your own eyes that the sky is blue, and Science says it is green, then sir, I advise that you trust in Science.
If you trust the scientific establishment enough, you should explain odd personal experiences via odd arrangements of familiar science, rather than rejecting established science claims. In cosmology today, physicists seem to face a related choice.
For 35 years, the standard model in particle physics has passed every test with flying colors. Yet we see some odd phenomena in cosmology — how willing should physicists be to invoke radically new physics to explain this phenomena, rather than looking to odd arrangements within or close to the standard model? For example:
The flat uniform universe we see, as well as its small initial deviations, could come from adding one more scalar (the simplest possible particle type).
The universe of matter see, with almost no anti-matter, could be explained by a small change to the way the electroweak force violates C and CP symmetries.
Dark matter could be axions, scalar particles predicted by a small change to the standard model introduced to explain how the strong force respects CP, while the electroweak violates it.
Dark energy could be just ordinary large magnetic fields, which stretch as the universe expands.
It is striking to me, and somewhat puzzling, that physicists seem to prefer to explain these odd facts via more radical changes to the standard model, such as string theory with extra dimensions. I understand that radical changes would be more interesting to learn about, but it seems to me that the least radical changes should be the most likely explanations.
Lubos, yes, a statement is not its own evidence, but the fact that a person claims the statement is evidence, even if sometimes weak evidence.
On one hand, it is a very inspiring reading. On the other hand, would you agree that all these statements how much evidence XY requires to make us certain at a UV level can be expressed much more accurately, e.g. in terms of the formulae behind the Bayesian reasoning (which I don't particularly like, but OK)?
I didn't quite understand in what sense a statement itself is its own evidence.
A statement about children who died under some unusual circumstances needs some evidence. Of course, the evidence doesn't have to be directly related to the children and a good track record of someone saying true things can be strong enough.
Well, I can tell you a real story of this kind that happened to me, and what it means. One hour before my PhD defense, I woke up in my former office where I spent a night ;-), got a shower, and found a projector. Half an hour before the defense started, I read an e-mail in Czech. It was 9 a.m. and the e-mail contained an extraordinary statement that one - and 5 minutes later, two - large airplanes crashed into some rather well-known buildings 50 miles from the place where I defended.
It was extraordinary and a priori unlikely but I - probably in agreement with your analysis - immediately knew that the message was almost certain. But this belief was still based on some strong evidence, albeit indirect one: the message seemed to be copied from the Czech Press Agency. It sounded strange that the author would fake such a serious message because this exact kind of tough fake messages wasn't usual with him. And it sounded even more unlikely that the Czech Press Agency would create such a silly black joke. So I immediately decided that it was almost certainly true. And of course, it was.
On the other hand, I received a lot of similar extraordinary messages from some other sources during different days than 9/11/2001 that I didn't believe simply because they were extraordinary while the evidence (of the phenomena themselves or the integrity of the messenger) was not. And I was right.