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Li Jiaxuan
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I have a question about cosmos microwave background.
Can we get a relationship between CMB's temperature and redshift z??
THX!
Can we get a relationship between CMB's temperature and redshift z??
THX!
Simon Bridge said:Welcome to PF;
iirc that's one of the ways the Universe gets dated.
As the universe expands, the CMB photons are redshifted, making the radiation's temperature inversely proportional to a parameter called the universe's scale length. The temperature Tr of the CMB as a function of redshift, z, can be shown to be proportional to the temperature of the CMB as observed in the present day (2.725 K or 0.235 meV)...
--- Noterdaeme, P.; Petitjean, P.; Srianand, R.; Ledoux, C.; López, S. (February 2011). "The evolution of the cosmic microwave background temperature. Measurements of TCMB at high redshift from carbon monoxide excitation". Astronomy and Astrophysics 526: L7. arXiv:1012.3164. Bibcode:2011A&A...526L...7N. doi:10.1051/0004-6361/201016140.
George Jones said:Li Jiaxuan, welcome to Physics Forums!
At what level would you like your questions answered? What is your background in physics and mathematics?
Simon Bridge said:That's impressive - it usually takes people another 4-6years of college study to "master" calculus or mechanics ;)
The problem then is to figure out what level of detail the competition would like to see.
Have a skim of that link I gave you and see how much you follow.
You may need a more elementary work.
Li Jiaxuan said:I have a question about cosmos microwave background.
Can we get a relationship between CMB's temperature and redshift z??
THX!
Cosmology is the branch of science that studies the origin, evolution, and structure of the universe as a whole.
Cosmologists use a combination of theoretical models, observations, and experiments to study the universe. They use tools such as telescopes, satellites, and particle accelerators to gather data and test their theories.
The Big Bang theory is the prevailing scientific explanation for the origin of the universe. It states that around 13.8 billion years ago, the universe began as a hot, dense and infinitely small singularity, and has been expanding and cooling ever since.
Dark matter is a form of matter that does not emit, absorb, or reflect light, making it invisible to telescopes. It is thought to make up about 27% of the universe and is responsible for the gravitational effects that hold galaxies together. Dark energy is a mysterious force that is thought to make up about 68% of the universe and is responsible for the accelerating expansion of the universe.
There are a few different theories on the fate of the universe, but the most widely accepted one is the Big Freeze or Heat Death scenario. This theory suggests that the universe will continue to expand and eventually reach a state of maximum entropy, where all energy is evenly distributed and the universe will be cold and dark.