Quote:
Originally Posted by Eratosthenes
sjastro,
these variations in the cosmic background radiation, as measured today in an expanding universe were once quantum fluctuations.
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Peter,
Quantum fluctuations are small scale effects and apply to the Universe when it was small enough to behave as a quantum mechanical system.
This occurred at a Planck time of 10^-43 second or less.
Unfortunately there is no Unified Theory to link General Relativity to Quantum mechanics at these scales, hence our understanding of the Universe at the Planck time is very limited.
The CMB as we observe it was formed around 300,000 years after the Big Bang.
The variations in the CMB after subtracting out dipole effects such as the motion of our galaxy relative to the CMB, are caused by the following factors.
(1) Polarization of scattered CMB photons caused by minute temperature variations in the plasma forming the CMB.
(2) Polarization due to Inflation.
(3) Polarization of photons due to gravitation lensing caused by intervening matter between the CMB and observer.
(4) The Sunyaev-Zel'Dovich effect where CMB photons gain energy by being scattered by the intervening matter.
(5) The mechanism as described in this thread which is known as the Integrated Sache Wolfe effect.
Quote:
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great avatar btw, Eulers formula is one freaky formula involving the number 1, zero, pi, e and the imaginary number i. absolutely sublime equation. Says something about mathematics, or logic. Does it say anything about reality though?
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The use of complex numbers "in reality" is common.
Electrical Engineers for example know all about them.
I find it intriguing how the term pi crops up in so many theories in physics.
Regards
Steven