Cosmologic philosophy: multiverse/string theory die! (Introduction)

by David Turell , Wednesday, August 26, 2015, 20:05 (3377 days ago) @ David Turell

Another review article debates the question of currently unprovable theories, string and multiverse:-http://nautil.us/blog/is-it-time-to-embrace-unverified-theories-“'[Last year], debates in physics circles took a worrying turn,” physicists George Ellis and Joseph Silk wrote in an essay in Nature. “Faced with difficulties in applying fundamental theories to the observed universe, some researchers called for a change in how theoretical physics is done. They began to argue—explicitly—that if a theory is sufficiently elegant and explanatory, it need not be tested experimentally.”-"In other words, some scientists are calling for new rules of the game. They're asking the community to put as much faith in math as they historically have in evidence.-"The challenge arises from two ideas prominent in modern theoretical physics. The first is string theory, in which small, vibrating strings make up subatomic particles such as protons and electrons.* The second is the so-called multiverse, which postulates that the Big Bang created not just one universe, but instead an infinite array of universes. Both ideas are beautiful; neither can, as far as we know, be tested.-***
“'There are two ways a theory can fail. It can fail by predicting something wrong, and it can fail by turning into being an empty idea that predicts nothing,” says Woit. He thinks that both string theory and the multiverse fail in that they predict nothing observable.-"As Ellis and Silk wrote in Nature, “the issue boils down to clarifying one question: What potential observational or experimental evidence is there that would persuade you that the theory is wrong and lead you to abandoning it? If there is none, it is not a scientific theory.”-"Have we reached the point in physics where it's time to abandon string theory and the multiverse? David Albert, a philosopher at Columbia University, argues no. “It's true there are worries about string theory that they'll never make any contact with experience,” says Albert. But it's a little too early to be defeated, or assume that “string theory will never produce anything empirically accessible to us.”-***-"Albert draws on the history of science, arguing that it is “full of situations where people thought that something was going to be difficult to get at with technologies envisioned, and then a certain amount of cleverness finds a back door.” Albert is careful to say, however, that he isn't necessarily optimistic. He acknowledges the kinds of worries felt throughout the entire physics community but remains hopeful that physicists will find a new way, as they've always done.-“'A lot of people claim that you can never empirically test a claim like the multiverse because by definition you can only see what's in our universe,” says Albert. “But I think that's much too quick.” He argues that certain fundamental laws, which we can empirically prove in our own universe, might mathematically predict the existence of other universes. These laws would therefore be indirect, but compelling evidence of the existence of other universes.-"So perhaps it isn't accurate to conclusively say that we can't empirically test these theories. “I think the right thing to say is that we don't know yet how to test them,” says Albert. “People shouldn't be so scared of that.'”-Comment: It is right to remember, these two theories are just that, theories, with probably no resemblance to reality.