The cosmic microwave background radiation?

Question

The cosmic microwave background radiation, the remnant of the radiation produced in the original Big Bang explosion, appears to us to be not quite uniform in temperature or intensity in all directions; that is, it is not isotropic. Why is this?

a. The Earth, as part of the solar system and the Milky Way galaxy, is moving through this radiation and the Doppler effect produces this anisotropy.

b. The radiation is hotter and brighter in the direction of the original Big Bang explosion.

c. Cold dust and gas clouds absorb more of this radiation in one direction than another, producing the observed anisotropy.

Answer 1

I don't like any of these answers.

a. is true.  But the CMBR maps we are shown have this effect subtracted out.

c. is true, but the CMBR maps we are shown have these effects subtracted out.  There is some controversy here and there about how well this was done.  It's a particularly harsh problem in the plane of the galaxy.

so only b is totally wrong.

I'm afraid i'd go with a.  But i'd give the question an F.

Answer 2

none of these answers are any good. the observed anisotropy is due to density fluctuations in the early universe.

scintists listen to comic background radiation with special radios and play it at parties. it's really cool.

Answer 3

c.