Given this links to a Penrose’s Hawking Points based diagram [1], i am constantly wondering why the universe - or its history is always depicted as a cone.
It’s hard to get my head around it since if there was a big bang, you’d expect a spherical visualization.
I am aware of WMAP and even if the reality is a, b or c - it all goes back to the theory of a flat universe, thus space time.
Since everything we see - on earth and through instruments in space - has three dimensions it is hard to understand gravity by showing a warped plane by spheres.
That works when showing the earth and its moon but is hard to follow once you add a galaxy, a cluster, etc…
Does anyone know of any good explanations and above all visual models that might make this more comprehensible?
Cheers and thanks!
[1] https://physicsworld.com/a/inside-penroses-universe/
Edit: Formatting.
By taking a telescope and looking back in time we would be looking at a smaller universe heading towards the big bang in the cone, and hence the redshifted nature of what we see - since the universe is smaller.
If you were to take a slice of the top of the cone, that is your spherical view of the universe today - in 3d. The cone is 4d.