- #1
TonyTT
- 4
- 0
If the universe began from the Big Bang, then why is the universe not a spherical shape? I mean, if it expanded from a singularity, then why is it not spherical?
TonyTT said:If the universe began from the Big Bang, then why is the universe not a spherical shape? I mean, if it expanded from a singularity, then why is it not spherical?
"Checking outside" allowed you to determine the topology of the Universe?Last time I checked outside the universe is spherical. What makes you say it is not?
TonyTT said:If the universe began from the Big Bang, then why is the universe not a spherical shape? I mean, if it expanded from a singularity, then why is it not spherical?
Quantumjump said:The issue of what is the shape of the Universe is a consequence of Poincaré's conjecture, and it generalization. This problem has been solved a few years ago by Grigori Perelman.
TonyTT said:If the universe began from the Big Bang, then why is the universe not a spherical shape? I mean, if it expanded from a singularity, then why is it not spherical?
phinds said:I think you need to read up on cosmology. No respected physicists claim to know what the shape of the universe is.
Poincaré conjecture allows to deduce is the shape that is associated to every assumed topological structure.
Quantumjump said:You completely misunderstood my post. Read it again. It's the Poincaré conjecture that has been solved, not the shape of Universe. What Poincaré conjecture allows to deduce is the shape that is associated to every assumed topological structure. This shift the problem to whether a chosen topology for the Universe is better than another. It is more interesting to investigate the question in terms of topology than shapes, as topology allows connection with fields such as quantum field theory and string theory.
Having said that, there was no need to be contemptuous in your reply. I am a theoretical physicist, and I know my stuff.
There isn't any reason to believe that it started with a spherical shape, nor that it is a spherical shape today.TonyTT said:If the universe began from the Big Bang, then why is the universe not a spherical shape? I mean, if it expanded from a singularity, then why is it not spherical?
phinds said:I have reread your post and I cannot see how my interpretation was at all unreasonable. It did not SOUND as though you know your stuff. Still, I regret the misunderstanding, even though I feel that it was the fault of your post more than of my interpretation.
Alex1998 said:The universe does expand spherically. this is just not in 3 dimensional space. if you watch my youtube videos on dimensions and the big bang, I explain a model: "The Pebble and the Pond", this is that the big bang was a pebble being thrown in a pond, this creates a circular shockwave, the circular shockwave is 3 dimensional space, and the movement over water is the passing of time. to us, in 3 dimensional space, it looks like the universe is infinite in every direction, because if you walk around a circle, you could do so infinitely, only, in 4 dimensional space the universe actually is a spherical shape (or actually, a hyper-spherical shape). this also explains the exponential expansion of the universe, because as time (the radius of the circular shockwave) moves constantly, 3 dimensional space (the circumference of the shockwave) expands exponentially.
if you want to see my YouTube videos, my channnel is called "Fathom the Universe"
phinds said:Is this just some theory you made up or is it supported by any solid science? I was not aware that there was any KNOWN shape to the universe.
Alex1998 said:No it is not my personal theory. Maybe my explanation was a bit clumsy, the model I talked about is an analogy used to explain the current big bang theory..I find it easier to scale down hyper-dimensional space to two or three dimensional models for clarification. Also on the question of shape.. there is not really a shape per se, as outside the universe has no meaning in this context. The internal dimensions expand in 4D from the moment of the big bang.
The shape of the universe is a topic that has been debated by scientists for centuries. Currently, the most widely accepted theory is that the universe is flat, meaning it has a Euclidean geometry with no curvature. However, there are other theories that suggest the universe may have a spherical, hyperbolic, or even fractal shape.
The universe is not spherical because of its expansion. When the universe was first formed, it was relatively uniform and could have been spherical in shape. However, as it expanded, it became more and more stretched out, leading to its current flat shape. This is known as the inflationary theory of the universe's shape.
Scientists have been able to determine the shape of the universe through various observational methods, such as studying the cosmic microwave background radiation, measuring the distribution of galaxies, and analyzing the effects of gravity on light. These studies have consistently shown that the universe is flat, providing strong evidence for its shape.
If the universe was spherical, it would mean that space is curved and that parallel lines would eventually meet. This would have significant implications for our understanding of the laws of physics and the evolution of the universe. For example, it could mean that the universe would eventually collapse on itself instead of continuing to expand.
Yes, there are several alternative theories that have been proposed to explain the shape of the universe. These include the Poincaré dodecahedral space, which suggests that the universe may have a dodecahedral shape, and the cosmic crystallography theory, which proposes that the universe has a crystal-like structure. However, these theories have not been widely accepted and require further research and evidence to support them.