How Relativity say about redshift in terms of curvature?
Well red shift is caused by the expantion of space and the further back in distance and time the more red shift. Now think about this as you go back in time and space the smaller the universe untill the frequency drops to zero at the time of the big bang. So now think about this if you point any direction and could travel faster than light you could go back to a point in time. So IE light curves in space in the 4d of space. Now Relativity says that space is curved by gravity and light will curve in the 3d of normal space and also curve in the 4th dimension of space time. Also if you can only go back to time zero there is no outside of this bottle we are in.
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