A Survey of the Sciences and Arts
Eric Says:
March 9th, 2008 at 10:25 pm
Tim,
At least 99% of the 10^500 possible vacua are complete garbage and can be ruled out easily. Thus, the regions of the landscape for which realistic vacua may arise is limited. If string theory is the right theory, then at least one of these vacua is our universe and it can be found with a focused effort.
Peter Woit Says:
March 9th, 2008 at 10:30 pm
Eric,
Once you rule out the 99% garbage, you’re left with 10^498 vacua to study….
I would like to state a theorem which at present can not be based upon anything more than upon a faith in the simplicity, i.e., intelligibility, of nature: there are no arbitrary constants ... that is to say, nature is so constituted that it is possible logically to lay down such strongly determined laws that within these laws only rationally completely determined constants occur (not constants, therefore, whose numerical value could be changed without destroying the theory).
Straightforward estimation suggests that empty space should weigh several orders of magnitude of orders of magnitude (no misprint here!) more than it does. It “should” be much denser than a neutron star, for example. The expected energy of empty space acts like dark energy, with negative pressure, but far more is expected than is observed.
The flavor/Higgs sector of the standard model is, by a wide margin, its least satisfactory part. Whether judged by the large number of independent parameters or by the small number of powerful ideas it contains, our theory of this sector does not attain the same level as we’ve reached in the other sectors. This part truly deserves to be called a “model” rather than a “theory”.
