Lets Talk about “The Big Bang Theory.” What conclusive data do they have
to fit that theory?
There are 3 major points of data to support the big bang.
1) All galaxies outside of the local group are receding from us. And specifically the speed they are moving away is directly tied to the distance. Specifically that speed works out to 70Km/s/Mpc +/- 7 (mpc = mega parsec or 3.26 million light years). This was first observed by Edwin Hubble in the 1920’s and has been refined ever since. Actually one of the prime missions of the Hubble space telescope was to refine that number my measuring distances to the galaxies in the Virgo cluster.
2) The Cosmic Microwave Background, This was discovered by Penzias and Wilson at Bell labs in the 1960’s quite by accident. But the entire sky is filled with microwave radiation of a very specific spectrum that indicates that the universe which is now cold was at one point a uniform hot dense gas.
3) The distribution of chemical elements in space. The fact that the universe is about 75% hydrogen, 24% helium and 1% everything else can only be explained by the Big Bang. And the level of Deuterium actually puts some very specific constraints on the details of the model.
There are of course a large number of details of all 3 of those points that I have left out because they are beyond what I can put in a single forum post. If you really care google “Richard Pogge Astronomy 162” and you will find some podcasts that have a bunch more detail but are still understandable to someone who is not an astronomer.