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At the center of a black hole is it the same time as the moment of its formation?
The statistical properties of that last map are horrendous, BTW. The meaningful cosmological measurements put out by the WMAP team are based on simply cutting away regions they think are foreground dominated.
But for the low end of the power spectrum (quadrupole, octopole moments...up to l = ~30) such measurements are almost meaningless.
One question. What effect does the extinction from gas and dust affect your measurements of the background radiation in the areas you can see?
I know you have a great big galaxy, but all parts of the sky are afflicted in some way by the interstellar medium to some degree.
If for example, one part is slightly less affected, then these differences will show up as irregularities in the microwave background radiation.
Scouse Git (2)La Fayette Adam SmithSolomwi and Loinburger will not be forgotten.
"Remember the night we broke the windows in this old house? This is what I wished for..."
2015 APOLYTON FANTASY FOOTBALL CHAMPION!
One question. What effect does the extinction from gas and dust affect your measurements of the background radiation in the areas you can see?
I know you have a great big galaxy, but all parts of the sky are afflicted in some way by the interstellar medium to some degree.
If for example, one part is slightly less affected, then these differences will show up as irregularities in the microwave background radiation.
Turns out that the MFP of light at this wavelength from the surface of last scattering is actually pretty long. Differences in the density along different paths does not make that much of a difference.
Think about it this way: density fluctuations at say l=200 are on the order of 1 part in 10^5. For light not going through our galaxy there may be at most a 1% extinction (I'm pulling this out of my butt, but it's not completely ridiculous). But the fluctuations in extinction are hit by the same 1 part in 10^5 factor, so now the effect of extinction on the anisotropy is only 1 part in 10^7.
Ok thanks. Theoretically, there shouldn't be any variations in the CMB radiation, so I was curious if differences in densities would be one explanations for the assymetries that we do see.
Scouse Git (2)La Fayette Adam SmithSolomwi and Loinburger will not be forgotten.
"Remember the night we broke the windows in this old house? This is what I wished for..."
2015 APOLYTON FANTASY FOOTBALL CHAMPION!
Ben, pay attention: the differences in densities ARE responsible for the existence of CMB anisotropies. But it is differences in the densities at the surface of last scattering, not afterwards (which would be where extinction comes into play).
The theoretical prediction without any further effects than density fluctuations (the source of these is primordial) would be that the power spectrum (reference http://en.wikipedia.org/wiki/Spheric...ctrum_analysis) of anisotropies would be flat. In actuality it looks like this:
The most important effect taking a flat power spectrum to the multipeaked one I attached is the gravitational collapse of density fluctuations leading to the existence of so-called acoustic modes. Reference http://astro.berkeley.edu/~mwhite/rosetta/node6.html
Ahh, ok I misunderstood what you meant by scattering.
Scouse Git (2)La Fayette Adam SmithSolomwi and Loinburger will not be forgotten.
"Remember the night we broke the windows in this old house? This is what I wished for..."
2015 APOLYTON FANTASY FOOTBALL CHAMPION!
The surface of last scattering occurred when nuclei and electrons combined to form atoms. Prior to this they were in thermal equilibrium with the cmb. Afterward they were not (the cross-section of interaction between atomic matter and light is much smaller than between a plasma and light) and this happened very suddenly (on a cosmological timescale). The cmb is therefore a snapshot of the surface of last scattering, mod stuff like the sachs-wolfe effect.
From a GR perspective, I actually don't know what would happen. I've never tried to add angular momentum in to the FRW metric.
IIRC, angular momentum conservation drops out of a metric with asymptotic flatness...
"Beware of the man who works hard to learn something, learns it, and finds himself no wiser than before. He is full of murderous resentment of people who are ignorant without having come by their ignorance the hard way. "
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