Thursday, January 18, 2018

S. M. Carroll goes beyond falsifiability

Peter Woit writes:
Sean Carroll has a new paper out defending the Multiverse and attacking the naive Popperazi, entitled Beyond Falsifiability: Normal Science in a Multiverse. He also has a Beyond Falsifiability blog post here.

Much of the problem with the paper and blog post is that Carroll is arguing against a straw man, while ignoring the serious arguments about the problems with multiverse research.
Here is Carroll's argument that the multiverse is better than the Freudian-Marxist-crap that Popper was criticizing:
Popper was offering an alternative to the intuitive idea that we garner support for ideas by verifying or confirming them. In particular, he was concerned that theories such as the psychoanalysis of Freud and Adler, or Marxist historical analysis, made no definite predictions; no matter what evidence was obtained from patients or from history, one could come up with a story within the appropriate theory that seemed to fit all of the evidence. Falsifiability was meant as a corrective to the claims of such theories to scientific status.

On the face of it, the case of the multiverse seems quite different than the theories Popper was directly concerned with. There is no doubt that any particular multiverse scenario makes very definite claims about what is true. Such claims could conceivably be falsified, if we allow ourselves to count as "conceivable" observations made outside our light cone. (We can't actually make such observations in practice, but we can conceive of them.) So whatever one's stance toward the multiverse, its potential problems are of a different sort than those raised (in Popper's view) by psychoanalysis or Marxist history.

More broadly, falsifiability doesn't actually work as a solution to the demarcation problem, for reasons that have been discussed at great length by philosophers of science.
Got that? Just redefine "conceivable" to include observations that could never be done!

While Woit rejects string and multiverse theory, he is not sure about quantum computers:
I am no expert on quantum computing, but I do have quite a bit of experience with recognizing hype, and the Friedman piece appears to be well-loaded with it.
I'll give a hint here -- scientists don't need all the crazy hype if they have real results to brag about.

1 comment:

  1. The problem with Mr. Caroll's argument about needing a multiverse is that he can't even tell when he himself is lying. The line from his own mouth that sums that lie up is "...even if evaluating them can be difficult in practice."
    There is no 'difficult in practice', that's the lie right there, as there is no 'in practice' whatsoever (as far as an actual measurement or experiment goes) to be evaluated in the first place. There are also far more than the originally estimated 10^500 vacua to be considered even for sake of the 'landscape' problem now. The number of possible vacua is now passing 10^272,000 .
    Entirely speculated estimates for the number of atoms in the known universe is around 10^78 to 10^82 for comparison of scale.