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View Full Version : The Big Bang, a one off event or a cycle?



BrianT
2006-May-03, 09:32 AM
Oohh here'a a nice light question for you first thing in the morning! Seriously though I was browsing this site and reading an answer given by Phil Plait to The Big Bang. I'm not by nature into "deep" metaphysical questions, but this got me thinking about it in the first time time years. Seemigly the Big Bang theory had hit a few stumbling blocks but is still considered correct. Most everyone agrees that the Big Bang happened, and that at one point the universe was a singularity and was infinitely dense. Great, but was this the first Big Bang? Or just one in a cycle? I suppose the answer is still a long way off, but on a more human level, rather than logical one, I find the idea that the Big Bang "just happened", was just a one off event, very hard to grasp. But as someone noted the universe is not only weirder than we imagine but weirder than we can imagine.:lol: Still, the idea of near-googleplex tonnes of matter appearing from one place and one time only just BECAUSE, is to put it in unscientific terms, "extremely weird"

antoniseb
2006-May-03, 10:37 AM
I find the idea that the Big Bang "just happened", was just a one off event, very hard to grasp.

I find the idea that the universe is doing the same thing over and over, and has been here forever in that state also kind of hard to grasp. Neither choice is well modeled by our personal experience.

Blob
2006-May-03, 12:27 PM
Hum,
yeah,
either way, it is still weird.

Personally i would be swayed by the `fine tuned` nature of the universe to say that it must have derived from some sort of `Darwinian` process.

(this current universe is the product of may other universes that have come `before` )

Swift
2006-May-03, 12:44 PM
Hum,
yeah,
either way, it is still weird.

Personally i would be swayed by the `fine tuned` nature of the universe to say that it must have derived from some sort of `Darwinian` process.

(this current universe is the product of may other universes that have come `before` )
There is a science fiction short story by (IIRC) David Brin to that effect. The creation of black holes create new universes which are derivatives of the parent universe (with minor changes in properties and constants). Universes that develop the right "conditions" to create black holes are more likely to have offspring universes.

An interesting idea, but I suspect it will remain science fiction.

Baby_Boom
2006-May-03, 04:17 PM
Hello.I am trying to find someone to interview about a project im doing on the creation of the universe (ie:How was it made etc...) i was wondering if i could interview one of you over the internet via AOL.

Thank you.

ToSeek
2006-May-03, 05:34 PM
Oohh here'a a nice light question for you first thing in the morning! Seriously though I was browsing this site and reading an answer given by Phil Plait to The Big Bang. I'm not by nature into "deep" metaphysical questions, but this got me thinking about it in the first time time years. Seemigly the Big Bang theory had hit a few stumbling blocks but is still considered correct. Most everyone agrees that the Big Bang happened, and that at one point the universe was a singularity and was infinitely dense. Great, but was this the first Big Bang? Or just one in a cycle? I suppose the answer is still a long way off, but on a more human level, rather than logical one, I find the idea that the Big Bang "just happened", was just a one off event, very hard to grasp. But as someone noted the universe is not only weirder than we imagine but weirder than we can imagine.:lol: Still, the idea of near-googleplex tonnes of matter appearing from one place and one time only just BECAUSE, is to put it in unscientific terms, "extremely weird"

There are three possibilities for the fundamental geometry of the universe: closed, flat, or open. Only in the former case will the universe collapse back on itself and (possibly) create another Big Bang. For the other two possibilities, current physics indicates that the universe will continue expanding forever and eventually just fade out.

Ara Pacis
2006-May-03, 07:36 PM
I've also wondered if blackholes create other universes. The activity of matter and energy at a quantum level seems to behave like information in a computer: It can be in one place one moment and transition to something else without any intervening steps like an instantaneous leap (or have they traced electrons transiting between shells since I was in HS?).

I would think that a singularity in this universe is a discontinuity without any frame of reference for scale, so that even one particle leap-transition to it provides enough energy to create a new universe. However, I'm not sure if each particle creates it's own universe or contributes to the same one so that there is only one universe created per blackhole.

A contribution model might explain both the expansion of the universe and changes to the rate of expansion as well as changes in some constants over time by virtue of more input by contributing particles. Conceptually, this could result in a daughter universe composed primarily of one type of matter if mostly that type of matter falls into the parenting black hole (or it may be inversely proportional or some other type of correlation).

What kind of evidence would support this hypothesis? Could there be a correlation between the initial expansion of the universe in the Big Bang and the predicted fluid dynamics of neutronium (or other particle stream) phasing to a singularity at the birth of a singularity? Maybe the the singularity at the center of a surrounding mass of neutronium relies on individual particle dynamics transitioning to a wider and faster vortex type of fluid dynamics over a period of time as they leap the transition between this universe and the next, making room for the next particle to move into position. Of course, each particle would contribute more to the daughter universe in a format that is not known, but could be simply percent (first=100, until the second particle, when each =50% and so on). No matter the actual mechanics, there should be some sort of correlation, after accounting for scale.

I don't know if this is right, but it's worth looking into, for me at least.

jlhredshift
2006-May-03, 08:00 PM
Lee Smolin in his book "Life in the Cosmos;1997" suggested that universes that create black holes, that create additional universes that are predisposed (genectically?) to create universes, with the correct "fine tuning", for propagation of universes that create black holes. And, it is universes that create black holes that have the correct "fine tuning" for our type of life to exist.

Kullat Nunu
2006-May-03, 08:51 PM
Yeah, I've heard of that theory. Though highly speculative, it somehow sounds very logical and interesting.

jlhredshift
2006-May-03, 09:02 PM
But how do you test the predictions of such a theory?

Also, there is Linde's variant "Multiverse"

Ara Pacis
2006-May-04, 03:59 AM
Whose theory? Smolin's or my hypothesis?

Blob
2006-May-04, 01:29 PM
...universes that create black holes, that create additional universes that are predisposed (genectically?) to create universes, with the correct "fine tuning"...

Hum,
of course there are some who think that when the universe becomes empty enough, the conditions are `reset` to allow another bigbang event to be created.

As i mentioned here a while ago, Roger Penrose proposed an idea that at the end of the universe, when all forms of matter decay into photons, that the conditions are reset to create another Big Bang.
The direction of Time for example would become meaningless, and would cease to function, when there are no massive particles or when they are separated from each other (in their own observable universe).

No blackholes or `spacetime budding` needed.

Blob
2006-May-04, 06:51 PM
Hum,
just as i was about to nail the `big crunch` coffin closed, i happened to come across this strange article...

Physicists Paul Steinhardt at Princeton University, in New Jersey, US, and Neil Turok at Cambridge University in the UK, are resurrecting the idea of a cyclic universe (http://www.physics.princeton.edu/~steinh/cyclicFAQS/index.html), which bounces through a series of big bangs and "big crunches". They point out that if time stretches back beyond the big bang, the problem of the cosmological constant could be solved. At that is just what they are predicting by using their cyclic model of the universe – an alternative to the Standard Big Bang theory – which the pair first developed in 2002.
According to Steinhardt and Turok, today's universe is part of an endless cycle of big bangs and big crunches, with each cycle lasting about a trillion years. At every big bang, the amount of matter and radiation in the universe is reset, but the cosmological constant is not. Instead, the cosmological constant gradually diminishes over many cycles to the small value observed today.

The cosmological constant represents the energy of empty space, and is thought to be the most likely explanation for the observed speeding up of the expansion of the universe. But its measured value is a googol (1 followed by 100 zeroes) times smaller than that predicted by particle physics theories.


However, there are other cosmic coincidences that their cyclic model cannot explain, like why the size of the cosmological constant is so similar to the density of matter in the universe today.

And of course, a big crunch scenario is ruled out by current observations of expansion rates.

Source (http://www.newscientistspace.com/article.ns?id=dn9114)

dvb
2006-May-04, 08:28 PM
As far as we can tell, the expansion of the universe is accelerating, so I'm not sure how a cyclic model could be predicted, or even be validated.

Now about black holes creating new universes. Isn't matter that falls into a black hole released through Hawking radiation? Meaning, that the matter doesn't just disappear, but is released back into our universe, making such a model unlikely as well?

Ara Pacis
2006-May-05, 03:48 AM
Hum,
of course there are some who think that when the universe becomes empty enough, the conditions are `reset` to allow another bigbang event to be created.

As i mentioned here a while ago, Roger Penrose proposed an idea that at the end of the universe, when all forms of matter decay into photons, that the conditions are reset to create another Big Bang.
The direction of Time for example would become meaningless, and would cease to function, when there are no massive particles or when they are separated from each other (in their own observable universe).

No blackholes or `spacetime budding` needed.

I had wondered about this too, but I was not sure if heat death meant there would be matter that was simply non-luminous and at maximum entropy. But I may have misunderstood it. If all matter eventually tranforms to photons then I would not expect gravity to continue to exist. Maybe the flattening out of mass-energy at the end of the universe would basically develop an equi-potentiality across the entire universe, even if that was essentially zero. If gravity ceased to exist because there was no more mass (per my blackhole hypothesis) then the universe simply loses it's frame of reference, and any potentiality can render itself at maximum density in an undefined space.

Just a hypothesis.

Blob
2006-May-05, 11:51 AM
Hum,
Indeed it's just a theory.

However it's quite beautiful how it `resets` the conditions back to something what we suppose can create quantum fluctuations to release some energy* to create a new universe with its own space-time (this universe may or may not be swallowed up by the new universe).


*
Simply, if we suppose there is an infinite amount of energy locked up in every point in space-time then it is just a case of `un-renormalizing` the space-time `energy level ` to a new energy level below this, thus releasing the energy needed to cause inflation and the creation of a new space-time (ie a new big bang).

http://static.flickr.com/45/140788801_33660d1f97_o.gif

Ara Pacis
2006-May-05, 03:08 PM
I was thinking that the universe energy-to-volume ratio over the duration would be asymptotic, but that the volume of space created by it is only relative to it's starting point and only that frame of reference. Thus, I would not expect energy to lessen at each go around, negating the need for infinite energy. I am thinking that any energy in an undefined volume (read infinitesimal) represents an infinite potential.

It's just something I thought of after reading Douglas Adams;s Hitchhikers Guide to the Galaxy. He wrote that the population of the universe is none because finity divided into infinity essentially equals zero. I am thinking the flip would be any population (of mass) in an infinitesimal (zero) volume would essentially equal infinity.

Blob
2006-May-05, 04:15 PM
Hum,
Indeed.

i imagine, it would be relative to a new space time (one that is not connected to our space-time).
For all intents and purposes, as you say, the new the new space-time would still have an infinite amount energy.

(But, for anyone living in the new universe, they would be living at a lower energy level to us, but they wouldn't know.
As far as the new big bang sums go, their universes total energy is still essentially zero - a free lunch.)

This too would explain why the cosmological constant, which represents the energy of empty space, would be a lot smaller than that predicted by current theories.

i won't go into details, but a simple test to verify this would be to measure fossil gravity waves from the early universe. In a few years time this may be a reality.

http://science.hq.nasa.gov/universe/science/bang.html