Big Bang Question

[mcoy]

Ok.....so everybody tells me that the Big Bang theory is the cause of the universe' existence.........

 

Also, the theory tells us that the big bang started with a "bang". So what type of matter is this material that exploded and where exactly is it located??

[Martin]

Ok.....so everybody tells me that the Big Bang theory is the cause of the universe' existence.........

 

Also' date=' the theory tells us that the big bang started with a "bang". So what type of matter is this material that exploded and where exactly is it located?? [/quote']

 

the most cogent explanation I've found is that space when highly curved by gravity (as in the pit of a black hole) can itself "explode"

 

that is highly compressed space undergoes a bounce

(the detailed description of the bounce uses the theory called

loop quantum gravity)

and in that bounce the contraction of space reverts to expansion

 

at that point, under those conditions, what is called "inflation" is

automatic----quantum gravity researchers have proven that it

is generic and happens in pretty much all cases----and inflation

is a rapid expansion phase in which large amounts of mass-energy

appear balanced by negative gravitational energy. I can post some

links to technical articles to confirm these points (Alan Guth,

G. Date, L. Modesto)

 

sorry that it seems so weird

 

weird or not it is the simplest explanation for where things come from that I have seen so far

 

it says basically that in our universe whenever conditions are right to create a black hole and a neutron star collapses, then at the pit of this black hole there is a bounce

space collapsed down to almost nothing, quantum physics of space intervenese, and it reinflates and basically buds off a new universe

 

(that is, there is a big bang at the bottom of every black hole)

 

in this way universes breed universes

and our universe was the result of a black hole forming in a prior universe

 

this is not just a fantasy because (as a quantum gravity researcher named Lee Smolin has discovered) this picture of things leads to predictions about what numbers we will observe----star masses, particle physics parameters, dark energy density. there are things we can measure to TEST whether this is how universes are generated, by this budding process.

 

the testability is a very important part of it and is discussed in a recent article by Smolin (which also sketches out the whole idea) called

"Scientific Alternatives to the Anthropic Principle"

http://arxiv.org/hep-th/0407213

[Martin]

Ok.....so everybody tells me that the Big Bang theory is the cause of the universe' existence.........

 

Also' date=' the theory tells us that the big bang started with a "bang". So what type of matter is this material that exploded and where exactly is it located?? [/quote']

 

so the short answer is

that there is no material that exploded

and that it is not located in any particular spot!

 

the space that was created by the process of expansion is all around us

and there is no center

 

the material or mass-energy that was created during the initial brief inflation is all around us and not centered anywhere either

 

there is a computer animation that somewhat illustrates the expansion of space. It is at Ned Wright's UCLA website, he teaches cosmology and is something of a recognized authority, so you get established viewpoint

 

this animation is of something called the "BALLOON ANALOGY"

http://www.astro.ucla.edu/~wright/balloon0.html

 

the balloon analogy is not quite right, but it is worth getting the idea of it.

 

at the bottom of this page you will see links to Ned Wright's homepage and to his Cosmology Tutorial (easy introduction to cosmology) and to his

Cosmology FAQ. these are worth checking out.

 

his balloon analogy animation has not been updated to include the effect of dark energy which would cause the expansion to continue instead of of

eventually starting to collapse---ignore the collapse part, the expansion part is approximately right

 

in the animation image, notice the galaxies get farther apart and the squiggles of light get redshifted, stretched out. even tho slightly out of date it is very informative

[mcoy]

thanks for the answers....

I just have a few more questions.....

according to answer1 the universe is said to be created (by big bang) probably inside another blackhole from another universe...but if this does happen, many universes, or multiverse as we may call it, should overlap...so what happens when it does overlap???

 

and supposedly big bang happened everywhere, what contained the explosion? should it be empty spaceor just energy? ----tnx

[Martin]

thanks for the answers....

I just have a few more questions.....

according to answer1 the universe is said to be created (by big bang) probably inside another blackhole from another universe...but if this does happen' date=' many universes, or multiverse as we may call it, should overlap...so what happens when it does overlap???

 

and supposedly big bang happened everywhere, what contained the explosion? should it be empty spaceor just energy? ----tnx[/quote']

 

no chance of overlap, mcoy

 

here is something to focus on: when people talk about the "big bang" then first and foremost they are talking about the creation of space, when they talk about the "expansion of the universe" they mean most of all the expansion of space, when they talk about "inflation scenarios" these are primarily scenarios for the very rapid expansion of space----matter is in the picture too but let's focus on the space part of it.

 

 

in 1915 General Relativity which is still the predominant framework for cosmology there is no need for any surrounding space for our space to live in

 

when GR is quantized in the most straightforward way (Loop Quantum Gravity and allied approaches) there still is no surrounding space.

so there is no place for universes to collide or crash or "overlap" in

 

if a neutron star collapses and forms a black hole and at the pit of that black hole there is a bounce and space starts to expand---well it just expands, it does not bump us, it does not need a "room to expand into" because space does not occupy space........it IS space.

 

that is how it is in the simplest spacetime picture, GR, which has worked pretty well since 1915 and been tested a lot to high precision etc.

 

[[[there are also highly speculative theories in which our universe is floating around in some higher dimensional universe---but these theories do not predict numbers. they are fantasy and they are fun for those who enjoy the mathematics. But working cosmologists dont use "colliding braneworld" fantasies because they dont predict stuff, whereas so far GR does and its numbers check out.]]]

 

so the "bang" does not have to be contained (referring back to your post) in any larger space. what they call the "bang" is a rapid expansion of space itself-----not in any pre-existing absolute space---the bang did not happen anywhere it WAS where, it made the where.

 

and if you go by the quantized version, which is pretty recent (loop quantum cosmology replaced the singularity with a bounce in 2001)

then the bang was a bounce---a prior contraction of space reaching a maximum density, temperature, pressure etc (planck density, planck temperature, planck pressure at least roughly speaking, they surmise)

and then turning around---the turnaround is what the loop quantum gravity

equation says happens under those circumstances. so the old 'bang' picture may be gradually evolving into a bounce in peoples minds.

 

and it certainly is something that could happen at the pit of a black hole, without ever once disturbing us or "overlapping" back on us.

thank goodness!