Event Horizon as the Edge of the Universe

[neutralino]

Hi Neutralino, long time no see... where have you been mate?

I've been busy, busy!

By the way the Universe cannot be unbound if it started from a Big Bang. It need to have a boundary which is expanding... And the Universe is also not expanding into itself, because if it did, then it will start defing a curvature after some time. The Universe as we know is flat..

The universe can be spatially unbound: for example, consider the universe as the surface of a balloon. This is finite yet unbound. You shouldn't think about the big bang as a standard explosion, but rather as a popular term that describes the cosmological theory that says the universe was once, a long time ago, a lot denser and smaller than it is today.

[dipayankar]

Good to see you back. I understand that the Univese was a lot denser and smaller. It started its expansion at some finite time way back. Thats when we say time and space started. It wasnt the same size always. However what was the environment outside the singularity like before it started its journey to expansion...

I've been busy, busy!



The universe can be spatially unbound: for example, consider the universe as the surface of a balloon. This is finite yet unbound. You shouldn't think about the big bang as a standard explosion, but rather as a popular term that describes the cosmological theory that says the universe was once, a long time ago, a lot denser and smaller than it is today.

[neutralino]

Good to see you back. I understand that the Univese was a lot denser and smaller. It started its expansion at some finite time way back. Thats when we say time and space started. It wasnt the same size always. However what was the environment outside the singularity like before it started its journey to expansion...

I would advise dropping the notion of a singularity when discussing the universe. Yes, the current model gives us a singularity as you take the limit t -> 0, but who's to say we can do that? Surely, quantum effects will kick in when the universe gets much smaller, say of order the planck length, so it's highly probable that the singularity simply tells us that our model is not the right one to be using at such times, which wouldn't be a surprise. I would, however, be very surprised if someone showed some physical relevance of the big bang singularity.

If you know anything about GR, you can draw an analogy. In the standard black hole solution (the Schwarzschild solution) there is a "singularity" at r=2M, the event horizon. However, it can be shown that this is what's called a coordinate singularity: that is, the model we're using isn't suitable there, so we need to change into another coordinate system.

[dipayankar]

You are probably right. The singularity of the Universe does not fit into a lot of proven theories. If the Universe was small, there has to be a limit to how small it becomes. It cannot become infinite small.

I would advise dropping the notion of a singularity when discussing the universe. Yes, the current model gives us a singularity as you take the limit t -> 0, but who's to say we can do that? Surely, quantum effects will kick in when the universe gets much smaller, say of order the planck length, so it's highly probable that the singularity simply tells us that our model is not the right one to be using at such times, which wouldn't be a surprise. I would, however, be very surprised if someone showed some physical relevance of the big bang singularity.

If you know anything about GR, you can draw an analogy. In the standard black hole solution (the Schwarzschild solution) there is a "singularity" at r=2M, the event horizon. However, it can be shown that this is what's called a coordinate singularity: that is, the model we're using isn't suitable there, so we need to change into another coordinate system.

[ggullet]

flat universe and an enclosed one

[dipayankar]

Enclosed one? Meaning the Universe has boundaries?

flat universe and an enclosed one

[everymansmedium]

Hello All:
I thought I would give another 2 cents worth of thought.

I agree that in most of the existing models the universe has no boundary as is normally indicative of a boundary. However there are a number of factors that prevent you from reaching, going to, or penetrating the edge that does not exist. The edge moves away at a speed greater than anything will ever be able to go. This is in fact a boundary that is the same distance from every observer with out regard to there position in the universe.

Now if you consider what might be beyond that unreachable and maybe non existent point. We have the possibility of a Bose-Einstien condensation. This is where light can not travel greater than about 15 MPH. This sounds to me to be a relatively solid boundary.
John

[everymansmedium]

Good to see you back. I understand that the Univese was a lot denser and smaller. It started its expansion at some finite time way back. Thats when we say time and space started. It wasnt the same size always. However what was the environment outside the singularity like before it started its journey to expansion...

Hello Dip:
This expansion that is normally indicated as the result of a bang, could also be the result of a continued creation of space at NOW. This also would result with the appearance of a universe that was smaller and maybe denser than today. The continued expansion with creation as its cause. Consider the minimum quantum of time and the minimum quantum of space, then think about what all movement might be. The recreation of space and matter from one quantum place to another with nothing in between. You might also consider what happens at the intersection of time and space if in fact that junction does exist. This would be the many universes that are created by time as the forth dimension. If the math is kept to simple methods that we can all follow it is simply the adding of one to the exponent. When that is done in the lesser dimensions the result is the creation of space. Linear space, square area, then finally volume. Why should the 4th dimension be any different. This expansion could be the result of creation at the point of creation = NOW. This variable remains.
John

[ggullet]

Enclosed one? Meaning the Universe has boundaries?

according to Max, the universe has an edge, which indicates flatness, and at the edge inside, which indicates enclosure, is another universe. as I interpret his theory. Universe is all, there can't be two, and it can't be enclosed

[Cubola Zaruka]

The information entering a black hole leaves later in the form of hawking radiation. The event horizon is a hologram, not the boundary of another universe.
A temporal compression wave is created by any moving object, with the amplitude proportional to the mass multiplied by the velocity and greater and a frequency proportional to the velocity.