A Thought About The Big Bang Theory

Just for the sake of this discussion, act like you believe the Big Bang Theory is true.

If all the matter in the universe began as a very small, dense object that exploded and is now expanding. Eventually won't it come back together forming the same small, dense object?

If this is the case, then we have no idea if this explosion and contraction hasn't already happened many times before. Also, how can we prove that this explosion hasn't been exactly the same each time, because if this object contains the exact same matter then what would cause it to explode differently?

In conclusion, is it possible that the earth we live on has already existed? If so, then have we previously existed? Also, would the psychics of our world actually be predicting the "past" rather than the future?

If the big bang theory is true and everything came from a very small and dense little something.. where did the little something come from?

Your idea touches on reincarnation. I think its the Hindu's (not sure) that beleive weve done this all before a thousand times over and over.

In conclusion if you want to get down to it all possibilities are possible since we have seemingly endless amounts of time. And with enough time anything can happen. So yes its very possible that weve done this before. And will do it again...

Interesting thought, but who is to say that if that was true that the matter went back together the same way and formed the same elements etc.? But hey drink a beer or two and ponder what you said and it makes for some interesting brain gravy.

1) Whether or not the universe continues to expand or reaches a limit and contracts depends upon whether the current rate of expansion exceeds the tendency to collapsde due to the gravity within (somewhat like the escape velocity for leaving the gravitational field of earth). It is a function known as Omega, which is the product of cosmology's "Hubble Constant" and "Deceleration Parameter". This is unknown, and looks finely balanced at present.

2) As a universe becomes denser (at the early stages, or as compression leads it to the last stages) the energy density gets greater. At a state well before singularity the density of energy and matter is so high that all known atomic particles particles cease to exist. At very early stages, even fundamtental subatomic particles' existence is in doubt. It is up to you at what level you say that the "matter" is the "same" matter, but my instinct is that it is less meaningful to talk of it being the "same".

3) I do not know a theory of the big bang that mandates that a collapsed universe *will* re-expand to form a new universe. I do not know whether physics has proposed a mechanism for the initial coming into being of the expanding singularity in the first place. All it does is look at what happened once it existed and was expanding.

4) If the big bang theory is correct then time itself was created in the singularity (i.e. all time and all place was the same time and same place at the start). Therefore to speak of universes exisiting by expansion and contraction "before" the big bang is a misnomer.

What interests me most about the spacetime geometry of the big-bang model universe is whether or not we would know if the universe was expanding or contracting. If a contracting universe's time ran backwards we may experience that time the same way as we do the forwards one we think we are in, and not know. Memories running backwards and observations likewise so that everything looked just like a forwards one.

Cheers.

Rob.

Technically if we are the same matter that existed before big bang, we have always existed and always will.

When I was a kid, grade 7 and such, that was a theory I was thinking about. In fact, I named it the Big Crunch just for my own personal referance before I ever saw it in a magazine or book (although the word is pretty much begging to be used - so I doubt I was the first to say it).

The idea is that the mass inside the universe is great enough that eventually universal expansion cedes, and then reverses, ending in a firey death - and possible rebirth - of the universe.

However, that is not necessarily true of THIS universe. Every time this has happened, the laws of physics come into being AFTER the birth of the universe - not before. That means that THIS TIME the universe might expand forever, since perhaps there's a new cosmic force, or a current force has a different value. This is touched upon in one man's study on "11 numbers that allow everything to exist" - where he looks at things like the strong and weak nuclear forces, gravity, decay rates, etc. If nuclear fission took place at just a tinier amount faster, then all the hydrogen and helium in the universe would have long been used up - and stars would burn and die with frightening speed. If it happened slower, then most of the universe would still be made of hydrogen, and life, and maybe even stars, would never have formed.

11 Numbers That Allow Everything To Exist is an amazing read. Really mind blowing stuff set down for everyone to understand it. Everyone should give that book an afternoon or 2.

I am a huge believer in reincarnation- but I never really gave the idea that the universe would collapse and re-expand over and over again because a multitude of different things. But if everything is just a product of yes/no, here/there, 0/1, nothing/something then it is a valid point. It is/isn't possible.

creepy.. way creepy. But that is a great thought experiment to use on yourself or someone else.

no for 1 reason

entropy(chaos theroy) does exist

for example, i am right now drinking a can of coke, if instead i choose to pour this coke onto my computer, setting it on fire, burning down the house, burning down the block, burning down the entire world etc

it was me that made that decsion, it was was happen again, its impossible for EVERYTHING to be the same, and this it true of gas in the very beginning, and consequently of elements, gas has large amounts of entropy, its random.

You see s13viper, I have to say yes and no to you. On one hand, processes can't be dublicated, so that's yes.

But, if the Supraverse exists (a universe where every possible quantum possibility occurs, and has a seperate universe just for it) then there will be many, many universes where the entropy for the particles in the gas were exactly the same. If the Supraverse collapsed in on itself and started again, then there would still be a repetition of this specific and exact entropy, since all quantum possibilities would still happen.

good point BUT

in chaos theroy, order is very important, even if every possible quantum action occurs it will still be different. It comes down to choice...this is what makes the universe a possibility in the 1st place, the randomness for lack of a better word.

"then there would still be a repetition of this specific and exact entropy"

this quote in itself is not possible, there is no such thing as specific and exact entropy

I think we have a confusion of terms then . By the same account, we cannot precisely predict where an electron is/will be - but we can give a probability of it being within a certain region. That's quantum physics. So in these other quantum universes, there will be something which occurs in the exact same way. Sure there's a 99.99% chance of the random chance doing one thing, but there's a 0.01% chance that it will happen the same way - and there would be a universe for just that occassion, as many times as it is necessary for the rest of that quantum universe to be the same and only that to be different.


On another note, I just got Seasons 1 and 2 of the TV series "Sliders" for Christmas! EEEEH! I'm so happy! It's practically the exact thing we're talking about (thought some of their technicalities are off since they didn't know as much when making the show). For example, Quin's test to see if they are home is to open the front door of their fenced-in lawn. If it squeks, they're home. If it doesn't (as it appears to be in most times they check it), then they're not home. However, they have visited quantum realities where the squek still exists - even though it's not the right reality. While improbable, in a supraverse where everything that can happen, will happen, then anything, no matter how improbable or close to impossible it is, has to happen.

I love breaking standard physics

There is a great sci-fi book which deals with an alternate universe where the laws of physics are different. It is Raft by Stephen Baxter.



It is the first of the books in Baxters Xeelee sequence, although I think it actually is the last in the timeline. If you're interested in reading about what a universe may be like with different laws of physics, read it. The rest of the Xeelee books are awesome as well

exactly, since we cant know both the position and speed of a electron at a specific time, how can we predit anything with 100% certaintity. and i think its much worse than 99.99 lol...probably closer to 99.99999999999999999% or more....the fact remains is, there will be differences

Why would there be differences?

If its the exact same "matter" that's causing this explosion then where's the proof that it has to be different? Because if the base of this explosion is the same everytime, and the explosion is the same everytime, then why must it be different?

I know the possibility of this is slim to none but if it consists of the same material then why can't the occurences be the same?

The big bang was not an explosion of "matter". The big bang was a point of infinite energy-density contained within an infinitely curved spacetime geometry. What is expanding is not matter but spacetime itself. The galaxies do not get further apart becuase the matter making them is flying away from an origin through space, but becuase spacetime itself is expanding, making the distances between galaxies increase.

The original point of infinite energy-density is not made of "matter". As spacetime expanded, the energy-density likewise became less, until a point was reached where energy "crystallised" into matter (Einstein has shown the mathematical relationship between the two). The same process is duplicated in high-energy particle accelerators, where mutual annihiliation of particles leads to production of high energies, which in turn then crystallise out into new particles (matter). The process and detail of this crystallisation is an essentially random process. One might like to think macroscopically of the fact that no two snowflakes are the same.

Cheers.

Rob.

[edit on 27-12-2005 by d60944]

Not according to current conventional wisdom. Apparently due to the expanding nature of our Universe(and it's getting faster as well) our universe may be destined for a very bleak/lonely and dark universe where the only stars you'll see will be those of the local Galactic Cluster. Some say a Big Rip may happen as the fabric of spacetime gets stretched out to the limit. Space doesn't seem all the elastic if you know what I mean.



In M-Theory there is a object called a Brane which is our universe. M-Theory states that the big Bang(s)(some claim there was more then one due to the non-uniformity of the cosmos) were created when two mind bogglingly huge Branes collided with each other and more resembled a Big Splat rather then a bang, and from that collision our universe was born. When our brane peters out and all energy comes to rest again, our brane will have to have another collision in order to spawn another explosion and possibly universe teeming with life.



Previously? Naw. Simultaniously? Maybe. Alternate realities may exist with a universe similiar or nearly exactly like ours. Who knows. There is more to the Big Bang(s) then we know right now.



Well if what they are seeing is past incarnations of similiar universes I guess so, it would explain why they are wrong so often, but I chose to believe the simplest explanation is the best one, and that they are mostly kooks or money grubbers.