What Is Cosmology and How Does It Relate to the Speed of Light?

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    Cosmology Means
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Cosmology is the study of the universe as a unified system, focusing on its origins, structure, and evolution. Key to this field is the Big Bang theory, which posits that all stars were once closer together and have been moving apart since the universe's inception. Observations show that distant stars are receding faster, supporting the idea of an expanding universe. The discussion also touches on the relationship between this expansion and the speed of light, highlighting the implications of relativity. Understanding these concepts is essential for grasping the dynamics of the cosmos.
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Hi.
I just wanted you to tell me does exactly cosmology means?
and about the works done in it.
thanks in advanced.
somy :smile:
 
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Cosmology is the study of the entire universe as a single system.
 
Dear LURCH:
can you explain more about it ?
I mean the results of this assumpsion.
Thanks in advanced :smile:
 
explain more about cosmology?
what do you wish to know?
 
The Big Bang theory is probably the best place to start. You see, in astronomy an observatory may detect that a star is moving away from us (the Earth). The same telescope (or another) might lok in the opposite direction and see that a star over there is miving away from us as well. These are astronomical observations; such and such a star moving at such and such a speed.

When many of these observations are put together to form a single coherent picture of the universe, i.e., "all of the stars are moving away from us, and the more distant ones are moving more rapidly", that is cosmology. From this observation, it was concluded that in the past, all the stars were closer together. The further back in the past we look, the the closer together the stars would be. Therefore, if we look far enough back, all the stars were together in one place. This is the big bang theory, and it is a cosmological model.
 
Thanks LURCH.
Another question:
You talked about the speed of expansion and that, the farther stars expand with a higher speed. can you tell me about the relativity and the limit of light's speed?
Thanks alot.
 
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https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
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