# What is the evidence for the big bang.

**URL:** <https://boards.straightdope.com/t/what-is-the-evidence-for-the-big-bang/609551>\
**Category:** Great Debates\
**Created:** [January 15, 2012, 12:31am UTC](https://boards.straightdope.com/t/what-is-the-evidence-for-the-big-bang/609551 "2012-01-15T00:31:13Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![Marley23](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Marley23](https://boards.straightdope.com/u/Marley23)\
**Post date:** [January 15, 2012, 1:54am UTC](https://boards.straightdope.com/t/what-is-the-evidence-for-the-big-bang/609551/11 "2012-01-15T01:54:10Z")

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> [@Jon55](#):
>
> Would you prefer me to post my arguments on that page?

You may as well post in your own thread - I was just pointing out that a lot of this was already discussed just a few days ago.

> [@The Big Bang's Trinity?](https://boards.straightdope.com/t/the-big-bangs-trinity/609198/2):
>
> We can see from Dopper shifts that some galaxies are moving away from us, and we can see that galaxies that are farther away are moving away faster. […] the first piece of support for that theory is the cosmic microwave background. The Doppler shifting of light is also a significant piece of evidence.

> [@The Big Bang's Trinity?](https://boards.straightdope.com/t/the-big-bangs-trinity/609198/3):
>
> Erm, no, not according to my understanding. Cosmic inflation (aka big bang) was determined by empirical measurement, via red shifting among other things.

> [@The Big Bang's Trinity?](https://boards.straightdope.com/t/the-big-bangs-trinity/609198/44):
>
> It is an observed fact–not a postulate or a hypothesis or an article of faith or anything like that–that when we measure the distance to far-away galaxies, and then look at the light they emit, we see that they have a red shift proportional to their distance. We know from experiments on Earth (and basic physics) that a red shift can be caused by something receding from the observer.
> 
> That _is_ the evidence, to start with. Later on, they detected radio waves from space–in all directions, any direction you look–called the cosmic background radiation–which was _predicted_ to exist, before anyone actually detected it. It’s considered a very good sign for a hypothesis if it _predicts_ that evidence will be found, and then that evidence is, in fact, found.

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