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The mass of the observable universe is often quoted as 10^50 tonnes or 10^53 kg So was all of this mass somehow condensed inside a space smaller than a bowling
by mentos 6y ago
The mass of the observable universe is often quoted as 10^50 tonnes or 10^53 kg
So was all of this mass somehow condensed inside a space smaller than a bowling ball? Seems theoretically impossible?
Are there any examples of black holes/stars exploding after reaching some critical mass that might resemble the big bang?
Is the big bang effectively just a black hole that creates a massive nuclear bomb that starts a new universe?
- svachalek 6y agoThe Big Bang was not an explosion in the conventional sense. When a bomb explodes, even a nuclear bomb, the energy created causes the atoms in the explosive to move violently in all directions. But in the Big Bang, instead suddenly all of those particles got farther apart without necessarily moving. The only real parallel in our current universe is the way the space between galaxies is expanding; nothing on our planet or even within our galaxy (afaik) behaves this way.
- mentos 6y agoOk thank you, so I guess 'big bang' is the wrong imagery. Really its someone stretching the taffy out that all mass sits on, a 'great expansion'. However and wherever mass came from, the idea that mass exists at all is unfathomable. My only way of rationalizing it is that in some higher dimension things 'just exist' and its only because we perceive things in our three dimensions that we believe there must be a start and end to things.
- opwieurposiu 6y agoThere are a couple of details that make the early universe different then a black hole. The first is that, even though the matter/energy density was higher then the Chandrasekhar limit, space itself was expanding at faster than the speed of light so it could not collapse. The second thing is that gravity has negative energy, and matter has positive energy, so the total energy of the universe was exactly zero. Zero total energy is the only amount compatible with our understanding of thermodynamics.
- politician 6y agoSince gravity is an illusion, did you mean to say that time dilation has negative energy? What does that mean?
- opwieurposiu 6y agoIf you have two apples floating in space, it takes positive energy to pull them apart against the force of gravity. Since energy must balance out, this means the gravitational field has negative energy. https://www.livescience.com/33129-total-energy-universe-zero.html https://www.livescience.com/33129-total-energy-universe-zero... For energy balance it does not make a difference if you think of gravity as a real force or an illusion caused by curved space.
- cygx 6y agoIf you have a positive and a negative charge floating in space, it takes positive energy to pull them apart against the force of electromagnetism. And yet, the energy density of the electromagnetic field is strictly positive.
- politician 6y agoThanks for the explanation.
- simonh 6y agoThere is energy in the curvature of spacetime, in the form of the gravitational stress-energy tensor.
- AnimalMuppet 6y agoOK, but what about before that? Space itself was expanding faster than the speed of light? There had to be a time when that was not true, because as you go back earlier in time, if that continued back far enough it would mean the diameter of the universe was negative. That's clearly absurd. But that leaves you with all this mass, inside the Chandrasekhar limit, but the universe not expanding faster than the speed of light. And then it starts expanding. All this presumes that time can be thought of as extending back before the big bang, which I don't know if that's actually a valid idea. I have heard the claim that the laws of general relativity allow for a white hole as well - a singularity from which things go out, instead of things going in. That may be an accurate picture, or at least a decent model.