String theory

[CPL.Luke]

personally I don't like it, but I do have a question on it.

 

I know that there are many many many different versions of string theory, but recently I've heard that it may be possible to construct one to fit any universe, is this science popularization crap or is it true or relatively true?

 

 

Also would it be possible to construct a thought experiment that would show whether string theory could be made to fit our universe? essentially a bell inequality for the string theories.

 

Even if such a though experiment seemed untestable it could eventually lead to an experiment similarly to how the bell inequality eventually led to experimentation.

[Martin]

personally I don't like it' date=' but I do have a question on it.

 

I know that there are many many many different versions of string theory, but recently I've heard that it may be possible to construct one to fit any universe, is this science popularization crap or is it true or relatively true?

[/quote']

 

Science journal is reliable. It has an article on the controversy about string non-predictiveness-----the famous 10⁵⁰⁰ string vacua

aka the Landscape of stringy versions of physics.

 

I will get the link to the Science article. It was from 11 August.

here is the main link

http://susy06.physics.uci.edu/proceedings.html

then you select

A `Landscape' Too Far? [pdf], Science Magazine, 11 August 2006

then you get this PDF

http://susy06.physics.uci.edu/press/susy06_science_naturalness.pdf

 

I mention it because the audience of Science mag is NOT specialist but neither is it general public either. The audience is mostly scientists in other fields. So the writing is not popularization but it still is often comprehensible. And they are fairly responsible. I believe them a lot more than, say, Time magazine! or Discover! but all the coverage is helpful, just have to weigh it.

[CPL.Luke]

hmm so would it be possible to show mathmatically whether or not our universe matches one of those 10^500th string theories?

 

probably not but it would be worth a shot.

[Martin]

hmm so would it be possible to show mathmatically whether or not our universe matches one of those 10^500th string theories?

 

probably not but it would be worth a shot.

 

 

yeah people have been trying to grope around statistically

one person is Michael Douglas. of course 1 followed by 500 zeros is a big number. there was a research effort in this "Landscapeology" area in the years 2003-2005.

there has also been a tendency to give up and say forget trying to find our physics, just apply the anthropic truism and say we are in one of them that permits life, because we are alive.

 

but actually nobody knows if ANY of the string theory vacua describes our world because we dont know if the theory is at all right in the first place.

maybe NONE of its Landscape of solutions actually makes contact with reality.

 

so some people look for more promising ways of unifying QM and GR

to investigate and try out. As Smolin said on the radio just now, there are a half dozen different non-string QG approaches by his count.