What could be beyond the boundaries of our seemingly infinite universe?

[Deepak Kapur]

Huge concentration of energy!

1.It's told that before the big bang everything was comressed in a very small space (as small as an atom, some say as small as a coin).

My point is even if matter was not created at that time, there should be some limit to the concentration of energy (or whatever was present then).

Is there such a limit?


2. If everything was concentrated in a small space, what was outside it?



3. Isn't it possible that at extremely high concentration of energy, it can turn into matter/
If yes? how can matter be constricted to such a small space.

 

[Shootist]

1.It's told that before the big bang everything was comressed in a very small space (as small as an atom, some say as small as a coin).

My point is even if matter was not created at that time, there should be some limit to the concentration of energy (or whatever was present then).

Is there such a limit?2. If everything was concentrated in a small space, what was outside it?
3. Isn't it possible that at extremely high concentration of energy, it can turn into matter/
If yes? how can matter be constricted to such a small space.

Matter is condensed energy. Energy, after all, equals Mass times the speed of light squared. And how far can matter be compressed? Until it falls out of the Universe (singularity). And we're back, in a Schwarzschild kind of way, to the state before the Big Bang.

 

[tensorbundle]

1.It's told that before the big bang everything was comressed in a very small space (as small as an atom, some say as small as a coin).

My point is even if matter was not created at that time, there should be some limit to the concentration of energy (or whatever was present then).

Is there such a limit?


2. If everything was concentrated in a small space, what was outside it?



3. Isn't it possible that at extremely high concentration of energy, it can turn into matter/
If yes? how can matter be constricted to such a small space.

Modern physics never says anything before big bang. Physics only discusses the aftermath of big bang.So the question of outside region of the tiny point is meaningless. We can't point anywhere in space and say here big bang happened. It is considered that big bang happened everywhere. And the space itself was created after bigbang. So the word 'outside' has no meaning before big bang. The earliest time at which we can say anything meaningful is 10^-43 seconds after big bang. At present pre-big bang physics is at an infant level. So many hypotheses but scarcity of evidences.

how can matter be constricted to such a small space

Edwin Hubble discovered around 1930s that the universe is expanding. It means the universe was smaller yesterday than today. It was smaller 10 years ago than yesterday. In this way if we go backward in time we find that 13.7 billions years ago the universe was like a tiny atom. That's how we concluded that there was a time when the universe was like the size of an atom

Isn't it possible that at extremely high concentration of energy, it can turn into matter

Matter was created after bigbang. Anything of that sort is not possible. Even all four fundamental forces were together initially after big bang. Then gravity withdrew it self from the other three. And later the three were also separated. Atoms which are the constituents of matter were formed after some time of big bang.

 

[matwiz]

It's all speculation !

There may be no big bang.

Because the universe is expanding today, doesn't mean it was always expanding in the past until some singular point is reached looking back.

It could very well be like a spring: oscillating.

Maybe the universe always existed, always just expanding and contracting between two definite sizes, far from being ever a singularity at one end.

However, in the singularity big bang, the idea is that "space, time, and matter" all came into being together at that singularity; time didn't exist before, space was not, and matter non-existant, only energy, whatever that means.

Besides, who knows what physics is like beyond the experimental domain? We look at a few instruments on earth, and from what we see, we project out to the ends of macro and micro space and limits of time, what should be, yet physics cannot be "tested" there.

 

[marcos54]

If the universe isn't creating space and time, this portion of space has manifestly evolved in volume over time (See, e.g., the distribution of metal baryons, the Hubble constant, etc. etc. etc). If that's been going on in a preexisting space, there goes the cosmological principle. In that case, it's a bummer we're not located near enough to the perimeter of our part of space to look outside- somebody is or could be. In fact, given the large-scale isotropy of the CBR (or whatever that is, if not a relic of creation), we're located damn near the precise center of our ginormous little miniverse.