What are 5 reasons why the big bang theory is true?

Answer 1

Take your pick, as all of the following are well within the range predicted by the BB, and several completely exclude alternate explanations:

1) Distant galaxies are all seen as moving away from us, and the rate at which they are receding would be proportional to the distance from us.

2) The calculation of when all galaxies began this expansion -- but working backward to when matter would be lumped together -- is about 13.7 billion years.

3) Microwave radiation with a black-body spectrum of about 3.7 degrees Kelvin is seen coming towards our Earth in a perfect isotropic manner.

4) Old galaxies are not seen at distances greater than a few billion light-years distance.

4) White dwarfs, whose life-span is about 100 trillion years, are not observed older than 13 billion years.

5) The ratio of hydrogen to helium in all parts of our Universe are about four to one.

6) Ratios of hydrogen to deuterium are also within a specific range.

7) Ratios of certain isotopes, whose half-life is in billions of years, are in a narrow, specific range to their decay products.

Answer 2

1. Observations of cosmic microwave background radiation provide strong evidence for the big bang's initial hot and dense state.
2. The abundance of light elements in the universe, such as hydrogen and helium, can be explained by the conditions present in the early universe following the big bang.
3. The redshift of distant galaxies indicates an expanding universe, consistent with the predictions of the big bang theory.
4. The cosmic microwave background radiation exhibits a uniformity and pattern that align with the predictions of big bang models.
5. The evolution of large-scale structures in the universe, such as galaxies and galaxy clusters, can be traced back to the initial conditions of the big bang.