Re: 1/f spectra (Julius Orion Smith III )

Subject: Re: 1/f spectra
From:    Julius Orion Smith III  <jos(at)CCRMA.STANFORD.EDU>
Date:    Fri, 14 Nov 2003 14:32:47 -0800

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

This message came from the mail archive
maintained by:
DAn Ellis <>
Electrical Engineering Dept., Columbia University