I don’t understand this part of your comment:

“What the hell do you think the black body spectrum observed by COBE is? That, you idiot, is the detection of recombination.”

The original question (that sparked the blog post) asks how we can determine the redshift of the CMB without first assuming that recombination must have happened (although it might have not been explicitly stated, it seems clear from the context). ]]>

In classical physics energy can in fact be infinite, if the system has infinite number of particles, or degrees of freedom, and each has finite energy. This is what happens here – the EM field is understood as infinite set of harmonic oscillators each of which has to have energy kT. So the infinite result is obtained correctly. The problem, of course, is that while infinite energy sounds fine for infinite number of particles of gas, here it does not smell right for infinite number of harmonic oscillators of EM field considered for finite volume of space. The culprit is not some flaw in the reasoning, but in the incorrect assumption (the equipartition theorem does not apply to EM field).

]]>https://thecuriousastronomer.wordpress.com/2016/11/08/do-gps-satellites-move-in-the-sky/

GPS: 20,2 thousand kilometers above earth’s surface -> 22 parts in 10(10) GR time dilation.

https://thecuriousastronomer.wordpress.com/2016/01/28/is-tim-peake-getting-younger-or-older/

ISS: 500 km above earth’s surface -> 1 part in 10(11) GR time dilation.

How is that possible… an object (GPS) 40 times further away with a much higher GR time dilation effect ?

Best regards / Dan (curious philosopher), Sweden

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