I read that the Hubble telescope could look 13.2 billion years back in time – what would it see if it turned 180 degrees and looked the other way?
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Because light does not travel instantaneously and has a speed limit (C), no matter which direction you point your telescope, it will always view objects as they were in the past. And the further away you look, the further into the past you are looking.
For instance, when you view the moon at night, you are actually viewing the moon as it was approximately 1.3 seconds in the past. When we view mars through our telescopes or if you spot it in the night sky, we are seeing as it was between a 3-13 minutes in the past, depending on the relative orbits of Earth and Mars. And when viewing the closest star (Proxima Centauri) to our solar system, we are viewing it as it was more than 4 years in the past.
So, you can extrapolate from there, and see, that if you continue to move further away in your observations, you will continuously peer further into the past, irrespective of the direction you are looking.
In fact, if the sun spontaneously exploded or extinguished itself, we wouldn’t even know it happened until 8 minutes after the fact. We would simply look up and see the sun, without noticing any difference whatsoever. Kind of fun.
ELI15: In fact, the latest measurements of the curvature of the universe suggest it is flat (and infinite) and there is no preferential point from which the universe expands. This means the observable universe from earth, the entire universe from our perspective (90+ billion light years diameter, due to inflation), is just one in a likely infinite set of observable universes, all of which, aside from our own, we will never be able to access. And even within our own observable universe, assuming we could travel at light speed, we would still only be able to visit approximately 6% of what we can observe, due to how fast everything is moving away from us.
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