G+'er +Jonah Miller pointed out yesterday that Unruh had shown that the radiation predicted by Fulling produced a black body thermal spectrum in the same manner as Hawking radiation. For some reason, I had it in my head that Unruh had actually pointed out prior to Hawking, so I wound up on another search through the research. The necessary papers are usually fairly close at hand since the main thrust of my current theoretical research is looking at the spectrum of particles created, (or not), when an observer is rotating rather than accelerating in a linear fashion, but I digress. Here's the chronology of papers to the extent I was able to work them out today. By they way, Jonah was right!
Fulling was the first to point out that an event horizon coudl muck with your particle creation and annihilation operators producing what might look like particles to the uniformly accelerating observer.
Davies certainly discussed the temperature of the radiation in the same year as Hawking. If it weren't for the following quote from the article, I'd say that Davies preceded Hawking, since his article was submitted in its final form in 1974, but, you'll see
Since Davies does in fact point out Hawking's treatment of the temperature, it looks like the correct attribution of the thermal nature of the produced particles goes to Hawking after all!
Unruh pops in a bit later and points out that the particles produced in Rindler space, (as opposed to the Schwarzschild metric of a black hole), also has a thermal spectrum.
Interestingly, Unruh had looked at the spectrum of particles created in a Rindler metric as early as July of 1974.
Two last interesting papers: Fulling and Davies point out that Hawkings derivation has can be reviewed in terms of their work on radiation from an accelerating mirror.
Picture of the Day:
View along the coast near Dingle, Ireland
1. +Jonah Miller's comment can be found at
2. Fulling on the creation of particles by event horizons in Rindler space
3. Davies on particle production and the temperature of the radiation 1975
4. Hawking on the temperature of the radiation 1975
open access on project Euclid:
5. Unruh on the thermal nature of the created particles
6. Unruh on particle spectrums a bit earlier
7. Fulling and Davies on Hawking
8. Fulling and Davies on particles from mirrors