I’ve never been able to understand this phenomenon. How is it proof of the Big Bang?
In: 7
When you look out into space you’re also looking back in time.
Light from something a billion light years away took a billion years to get here, so we see it as it was a billion years ago.
This leads to an interesting phenomenon as you look further away: galaxies get increasingly crude, clustered closer together, and filled with increasingly young stars.
Eventually you can’t see anything at all. The ability to “zoom” further back in time stops at the “cosmic microwave background”. This haze of ancient heat and radiation from primordial hot gas appears to be the oldest thing we can see.
In a much older universe you would just expect to see fully formed galaxies forever in every direction, but we don’t see that – we see a baby universe ~14 billion years ago and then nothing beyond that.
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