Inflationary Cosmology

Could not the whole universe have come from exactly NOTHING?If equal amounts of positive and negative matter were to come into being at the same time then there is no limit to the total amount of either one of them is there.On a sub atomic level, a single particle can "decay" into several others provided a number of rules are followed, some of which include the following.
1 The total mass of all of the particles must remain the same as that of the original particle
2 Someting about strangeness having to remain the same also
3 Well actually I can't remember all the others. College physics was a long way back and I was a Chemistry major anyway.Anyway, the gist of it is that an electron can "decay" into a proton, an anti-proton and another electron. In essense, the two new particles have just sprung into being from nothing.
Imagine this on an enormous scale and you have a VERY big bang.PY

Inflationary cosmology seems to indicate that our universe could have come from an earlyer universe. an Inflaton feild mines energy from gravity so that it produces extra matter.Ironicly this doesn't go against thermodynamics becase overall entropy still increases. So in effect our universe could have sprung into exixtance from a "proto universe" that was just as chotic and full of entropy as our own is now. all you need is a quantum fluxuation that produces an inflaton feild near in the same place as a singularity and BOOM new universe.

quoting dread: "all you need is a quantum fluxuation that produces an inflaton feild near in the same place as a singularity and BOOM new universe."dread, i think the problem with this idea is that you need space to exist before you can have a quantum fluctuation "near" something. "near" implies distance which implies space. are you suggesting that space existed first? also, time would have to exist simultaneously here unless both the singularity and the quantum fluctuation were created and interacted instantly. which brings to mind the question, "what created them?".-ncahill
ps. feild is spelled field.

Yes, you are correct. In the examples given here the singularity and the field both exsist in a prior universe with it's own space.Srtictly speaking inflationary cosmology only adresses the big bang and not the universe that proceeded it however brane theory (using inflationary cosmology) posits that perhaps the universe was created when two negboring branes collided.So we haven't yet answered why there is something rather than nothing. Because we don't know about the prior universe or the neihboring branes.

dread: So we haven't yet answered why there is something rather than nothing. Because we don't know about the prior universe or the neihboring branes.you can't know about the previous universe, if it existed, because before photon decoupling information about the universe in the form of light could not be transmitted. unless you suggest that we learn about the previous universe in another manner.also, just a side thought. if there was a previous universe, do you think it still exists outside our visible universe? what existed where our big bang took place would surely have been annihilated and/or displaced by the expansion. any thoughts?

It's true that we could not know much (if anything) about the prior universe, but I don't know what you mean about "photon decoupleing" are you talking about entaglement? If so I do not see the connection.If the 2 branes theory is correct we might be able to detect the nehboring brane. If gravity is capable of leaving our brane we might detect faint gravity waves in regions of our space where we do not detect matter. String theory predicts that perhaps gravity is so weak because it radiates out in more dimentions than, say, light. So it is theoreticaly possible to know some things about our neighboring brane (if it exsists).My initial feeling is that the prior universe would be distroyed or "pushed out of the way" by the new universe, but this is just speculation.

photon decoupling is the stage in the "early" universe, about 300,000 yrs after the BB, when the atoms had expanded and cooled enough to allow photons to move without interacting with atoms' electrons. before this time, photons could not move far before interacting with electrons, preventing any information of the time before decoupling to be transmitted. afterwards, the universe was "transparent" to photons and they could then travel long distances without interaction.entanglement is connecting two particles using their quantum properties i think.quote: String theory predicts that perhaps gravity is so weak because it radiates out in more dimentions than, say, light.i think string theory states that everything exists in all dimensions from light to frogs. we only perceive 3 spatially because after the big bang the other 8 dimensions collapsed do to their unique properties. i think that's what brain greene was trying to say anyway. hehe.

Well strings vibrate in the three extended dimentions plus the small ones. But what I was talking about with gravity is that most forms are "stuck" to our brane. Gravitons, on the other hand, seem to be free to leave our brane. Meaning they could radiate out to neigboring branes. I think you've got it backwards, our three primary spacial dimentions expanded. The other spacial dimentions didn't, they always stayed small.The only thing unique about the extra dimentions is their size, close to the plank scale. The three "extended" dimentions are either realy large, or realy small, depending on how you look at it (We can get into why if you want in future posts). The smaller dimentions stayed small and can be thought of as "normal." Our three larger spacial dimentions were the ones altered in the big bang.