Friday, September 15, 2006

Slate vs. The Wisdom of Crowds

Gregg Easterbrook’s The Trouble With String Theory is running into the same problem his article on autism did. What problem is that?

String Claptrap?

I'm a PhD candidate in astrophysics. I recently went to a lecture on String Theory that began something like,

"It is a bit embarrassing that the first task of String Theory is to explain why one of its basic assumptions, which is manifestly wrong, is in fact not necessarily wrong. I'm talking, of course, about the plainly absurd suggestion that our universe has not 3 spatial dimensions, but 10 or more."

The speaker then went on to describe very quickly the standard story of how there might be other dimensions that we'd never notice, and some of what makes String Theory so exciting and some of the more serious challenges to it.

Look, if Mr. Easterbrook wants to argue that it should be called "String Conjecture", that's fine by me. Plenty of people have worked on the Riemann Hypothesis and the Poincare Conjecture. Plenty of people also worked on Fermat's Last Theorem, which probably would more appropriately have been called Fermat's Well-Tested Conjecture (credit: Douglas Hofstadter). There's nothing wrong with working on a conjecture or a hypothesis.

But what else of content is he saying? He wants physics to get back to actually figuring stuff out. But guess what: With the standard model of particle physics, a lot of people were heralding "The End of Physics!" As in, there was nothing else to figure out. But of course there was -- most prominently, How does gravity work on the smallest scales? Does Easterbrook propose using God Theory to explain quantum gravity?

See, there's a big difference between God Theory and String Theory. String Theory actually does make predictions about our universe that are in principle testable, and many people are working on figuring out various clever ways to test these predictions. Of course, these people are hooded alchemists in Easterbrook's opinion. It's my understanding that String Theory has generated enough interesting mathematics that it will continue to be pursued by mathematicians, even if future observations fail to confirm any of its predictions. But the important thing is that physicists CAN give it up, depending on if our universe is consistent with it or not. There would be no reason ever to give up the single extra explanatory dimension that has no predictive power.

Also, he chides string theorists for failing to predict the observation that the universe's expansion seems to be accelerating. But String Theory is still in its infancy. Heck, Einstein and Newton didn't predict that, either. Let's throw out gravity with the bathwater.

Finally, he says that the last third of the 20th century was not very productive, because people were "hit over the head by the unexpected, such as dark energy," as though that weren't an important discovery by physicists, but rather something that some idiots who were partially blinded by their droopy hoods stubbed their toes on. As though a key feature of important discoveries is that they be predicted in advance. Right. How many physicists were expecting the electron, or quantized light, or that Newtonian gravity is incommensurate with Maxwell's Equations? By that standard, the first third of the 20th century sucked for physics, too. --dslack


But string theory IS testable...

...just not at energy ranges that we have access to. String theory predicts extra dimensions that are curled up so tight that it seems technologically infeasible to construct a particle accelerator capable of probing those length scales. It's tragic that a "science writer" such as Easterbrook does not realize the difference between an inherently untestable belief and a scientific hypothesis. Newton's law of gravitation, which predicts an attractive force between masses that falls off as 1/r^2, was untestable until the 20th century. In Newton's time, it was technologically impossible to prove his theory (even using the timing of tides), but the reason it was so widely accepted was it's elegant ability to describe the world. It is precisely the same situation with string theory. The reason the field is so hot right now is that physicists are currently trying to use it to make predictions. I find it hilarious that Easterbrook didn't bother talking to an actual string theorist before publicly making an ass of himself. --JumboMoss
There’s more, both in the science fray and in the blogotosphere, which is where I find the concise sentiment I’d like to second. For good measure, I’ll throw in a link to the last column by Jacob Weisberg, Slate’s Editor, since he needs to know, and I’m willing to wager he’d sooner read Technorati than Slate’s own reader forum.

Personally, my sense is Slate so political, that they failed to recognize that a good science column doesn’t have to be.


wagtheslate said...

Subject: the problem with string "theory"
From: AyalonValley
Date: Sep 14 2006 12:37PM

I am not a cheerleader of Mr. Easterbrook, many times he writes nonsense IMHO, but this time I have to applaud.

Ever since I started to read about String "theory" 20 years ago I also started to develop unease about modern Physics, which grew as these "theory" grew more preposterous with time. I totally agree with the author, its time to put up, or shut up, and rightly call it String Speculation.

Meet you over at the 25th dimension, anyone?

JohnMcG said...

The deal about Easterbrook is that he (and his editors) apparently think that if he's a good enough writer, and he's really interested in something, he's qualified to write a column on it. Thus, ESPN gives him 4000 words a week to repeat his stuipid criticisms of the blitz, refer to NFL teams with unfunny nicknames, ogle at cheerleaders, report on Indiana UNiversity of Pennsylvania (see, it's called Indiana University, but it's in Pennsylvania. Ain't that a hoot!), and make comment no more informed or insightful than what you would hear at the sports bar down the street.

NOw Slate has given him the "Science" column for Easterbrook to speculate on science.

The weird thing is, Easterbrook was made for blogging. But when his musings are given the authority of a column, it rankles a bit.