How is the big bang theory based on observations?

Answer 1

The evidences of big bang theory depends upon the facts -

from the very first second our universe continues to expand , the distant galaxies are moving away from each other and redshift is directly proportional to the distance between the galaxies . It is related such that if the equation of state denoted by w ( Ratio between dark energy pressure and energy density ) is less that -1 then our universe is pulled apart , this type of energy is called the phantom energy ( a form of quintessence ) and also cosmic microwave background radiation serves As the landmark of big bang theory and it is related to big bang by this way -

In beginning of this universe it was much smaller and hotter and filled with opaque fog of hydrogen plasma and when universe expand and cools down and electron and protons together forms the neutral atoms, it's No longer absorb thermal radiation and make the universe transparent

Answer 2

Here's more than one:

1) An expanding universe.

2) The Hubble Constant shows a Universe that was almost infinitely dense about 13.7 billion years ago.

3) Cosmic Microwave Background Radiation -- its existence, isotropy, and spectrum.

4) The ratio of hydrogen to helium.

5) Ratios of long-lived isotopes to their decay products show that the former did not start to decay till about 10 billion years ago.

6) No white dwarf star has been found older than about 10 billion years.

7) Quasars are found far from us, but not close.

All of the above are easily explained through our present understanding of Big Bang Cosmology, but impossible to explain with any other hypothesis.

Answer 3

Edwin Hubble, using the Hubble telescope, is credited with the discovery that the distances to far away galaxies were generally proportional to their redshifts (as in the doppler effect); an idea which was originally predicted by Lemaître in 1927. Hubble's observation was taken to indicate that all very distant galaxies and clusters have an apparent velocity directly away from our vantage point: the farther away, the higher the apparent velocity.

Other supportive evidence for the big bang Theory - Cosmic Microwave Background Radiation has been discovered and it is suggested that this has been left over from the Big Bang and galactic clusters are still moving away from each other at an ever increasing acceleration.

Answer 4

The Big Bang theory is based on observations such as the expansion of the universe, the cosmic microwave background radiation, and the abundance of light elements in the universe. These observations support the idea that the universe began as a hot, dense state and has been expanding and cooling ever since.

Answer 5

Observing the fact of background microwave radiation and the fact that galaxies are moving away from one another and they are moving faster away the further out they are.