wrote:

Remember also that the prediction was not just a temperature, but a spectrum.
Black body spectra are hard to make (since temperatures of different sources
get different red shifts); the observation of not only the temperature but
the spectrum is a very strong confirmation.

This a good and important point. It is a crucial fact about nature,
and verfies that the BB paradigm offers a good approximation for what
is going on in the local Hubble Bubble. I regard the prediction of the
black-body spectrum and approximate temperature of the microwave
background as the best evidence for the BB approximation. I do not
accept that this means that it had to be the whole Universe that went
"pop!", or that even within the Hubble Bubble the physics is quite as
idealized as standard cosmology would have it.

Parenthetically, I have always been fascinated with the speculation
that the background radiation might be a result of the Unruh effect in
QFT, which causes an accelerated observer to observe an isotropic
black-body thermal "bath". See Schultzhold et al, PRL, 97, 121302,
2006. Low acceleration gives a low temperature.
This is a pretty far out idea, but one I am pursuing just for the fun
of it.


You shouls also add a number of other predictions:

-- red shift dependence of CMBR temperature (for observations, well after the
predictions, see Battistelli et al., astro-ph/0208027; Srianand et al.,
astro-ph/0012222; Molaro et al., astro-ph/0111589)

-- Tolman surface brightness test (predicted by Tolman in 1930; observed by
Lubin and Sandage, astro-ph/0106566)

-- time dilation of supernova light curves (predicted by Wilson, Ap. J. 90
(1939) 634; for observations, see Goldhaber et al., astro-ph/0104382)

-- three (and no more) light neutrinos (predicted by Yang et al., Ap. J. 227
(1979) 697; confirmed in accelerator experiments later -- see, e.g., ALEPH
Collaboration, Phys. Lett. B235 (1990) 399)

Ok, but again, the first 3 just verify global expansion within the
Hubble Bubble, and do not say anything more. Personally, I have to
admit that I treat many high-energy results with a wait-and-see
approach because of the numerous false "positives", the complexity of
what they are trying to do (Feyman's: 'It's like smashing two clocks
together, and from what falls out,...) and subtle but severe pressures
to get the "right" answers.

At any rate, let us see a prediction by the BB paradigm about something
that is currently unknown, but knowable in the foreseeable future. Can
the BB paradigm do this, or not?

Rob