Re: 1/f spectra

[Julius Orion Smith III <jos@xxxxxxxxxxxxxxxxxx>]

Yesterday, Steven Weinberg (who received the Nobel prize in physics for
unifying the electromagnetic weak nuclear forces) happened to mention in
his address to the Acoustical Society of America that 1/f spectra have the
unique distinction of being "scale invariant" in the sense that the energy
in an interval df is proportional to df/f.  He noted that any other law
would require some choice of units.  As a result, the 1/f nature of the
angular spectrum of the cosmic background radiation (recently verified by
observation) was predicted by cosmic inflation theory.  All this was in the
context of a talk about the relevance of acoustics to the first 380,000
years of the expanding universe, before the point at which the universe
became transparent to photons. -- jos