tell me about cosmology constant?

Answer 1

General relativity is based on how space is measured locally when matter is introduced. This description is called a "metric". Think of it as a generalization of a hypothetical set of three orthogonal rulers with a clock in the middle, which would suffice for a metric in *special* relativity. Well, what Dr. E did was try to determine the simplest possible description of the whole universe consistent with a GR metric. He decided it should be (on the largest scale) homogeneous (look the same everywhere), isotropic (look the same in every direction), and time invariant (never changing). He got an answer for the first two requirements that was simple and elegant, but getting that last one down (time invariant) required fine tuning a free parameter (lets call C) of the metric (analogous to an integration constant in calculus) that is a function of average density to some value we'll call C0. That's the cosmological constant C. If C>C0, or C

Answer 2

If you mean cosmological constant, it's a mathmatical fudge factor Einstein came up with to keep the universe from collapsing. He needed it because he didn't believe it was expanding.

Answer 3

It is more commonly called the Hubble Constant after Edwin Hubble, Einstein had nothing to do with it, who was calculating the rate at which the universe was expanding or contracting. It is measured in kilometers per second per megaparsec. Currently, the best measurements indicate that 70 kilometers per second per megaparsec. But we are currently trying to find a better value for the Hubble Constant.

Answer 4

truly, no person's assuming the universe is increasing in a relentless fee. the upward thrust is changing its %., and scientists attempt to pin a precise fee on the Hubble consistent. The estimations in regards to the age of the universe come from study of chemistry and the life-cycles of stars, which point out that the oldest stars that is seen via us are 14 billion years previous, so the universe could be a minimum of as previous. no longer you will be bothered to google "redshift universe enhance". And the folk who take technology on faith gain this because of the fact it works. Having experienced technology working for awhile, you could anticipate that's alright to permit circulate and tutor some have confidence. i don't comprehend the exceptional way antibiotics paintings, yet in view that I took them for an infection and did no longer die horribly, i'm able to could besides have confidence them.

Answer 5

It is used to determine the behaviour of the universe.

http://en.wikipedia.org/wiki/Cosmological_constant

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