X-Message-Number: 22022 From: Date: Wed, 18 Jun 2003 16:35:10 EDT Subject: Re: CryoNet #22016 Infrared divergence --part1_1ef.b51d049.2c2226fe_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit From: "michaelprice" <>: > > When a charge is accelerated the low-frequency energy of the > Bremsstrahlung radiation emitted is independent of frequency, > so that the number of low energy photons emitted scales with the > inverse of the frequency. Total photon number is obtained by > integration of the inverse function to yield the logarithmic function. > Since log(0) = infinity we have an infinite number of low-energy > or "soft" photons, even though the total energy emitted is finite. > I disagree :-( The real acceleration takes place in a finite time T, Photons with period (inverse of the frequency) far larger than T can't be radiated away. they remain as virtual photons. So, the number of photons, real + virtual is indeed infinite, but the number of real ones is finite. The infinite photon problem is an artifact coming from using a classical idea (instantaneous photon production) in a quantum problem. Yvan Bozzonetti. --part1_1ef.b51d049.2c2226fe_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=22022