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Before the Big Bang: A Twin Universe?
esocid writes "Until very recently, asking what happened at or before the Big Bang was considered by physicists to be a religious question. General relativity theory just doesn't go there — at T=0, it spews out zeros, infinities, and errors — and so the question didn't make sense from a scientific view. But in the past few years, a new theory called Loop Quantum Gravity (LQG) has emerged. The theory suggests the possibility of a "quantum bounce," where our universe stems from the collapse of a previous universe. This may be similar with beliefs of Physicist Neil Turok of Cambridge University who has theorized about a cyclic universe, constantly expanding and compressing."
he got her really drunk.
I was about to mod this funny, but suddenly I got this feeling that maybe you were serious.
I have no response to that other than, um, sometimes its best to not post your thoughts in public where others can see...
The universe is safe for you and me, but what of Lazarus?
Considering approximately 5% of Physicists in the Unites States are religious I dont think they considered it a religous question.
If the likes of stephen hawking and albert einstein with general reletivity cant work it out how are illiterate goat herders from 2000 years ago supposed to have done it?
So Skulldilocks threw acid on the schoolchildrens' faces, cause somebody from the bible told her to do it!
There were two universes but Manfred drones destroyed the Light Universe. Fortunately, we're already in the Dark Universe.
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
Marvel Comics has been telling us this for years! Decades, even!
Galactus, the Overmind, and the Stranger all came from the previous Universe, by one mechanism or another surviving the Big Crunch and the following Big Bang. There may be other previous universe types, but those 3 are the only ones I picked up on, back in my comic book days. (decades ago, even)
The living have better things to do than to continue hating the dead.
Or Hindu belief...
You are assuming that the scale of space is stable - that the separation of galaxies comes entirely from their material moving apart (at sublight speed) since they were essentially together in the moments after the big bang.
In fact space itself stretches. The separation of the material between pairs of distant (and near) galaxies comes from both their motion through space and the stretching (expansion) of the space between them.
The result is that sufficiently distant galaxies can be much farther apart than they could have traveled - even at the speed of light - through non-expanding space in the time since the big bang.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Sure it is. http://en.wikipedia.org/wiki/CMB
Also, http://xkcd.com/54/
Adams said it best: "The Universe, as has been observed before, is an unsettlingly big place, a fact which for the sake of a quiet life most people tend to ignore."
There's nothing particularly special about loop quantum gravity that makes it possible to avoid having a singularity at the big bang. Loop quantum gravity is just one theory of quantum gravity. The best known theory of quantum gravity is string theory. In pretty much any theory of quantum gravity, the classical picture of the big bang singularity is going to get heavily modified. The conditions of the big bang are pretty much the only conditions under which you really need a theory of quantum gravity (unless you're really clever about finding some other situation, like black hole evaporation, where quantum gravitational effects come in). In all theories of quantum gravity, there's a scale called the Planck scale, and when you go beyond that scale (e.g., the universe is hot enough so that the wavelengths of particles are on the order of the Planck length), mysterious stuff happens. Because of this, it's reasonably plausible that the big bang singularity is eliminated in any theory of quantum gravity.
Old attempts to make a theory of a rebounding big bang (with, e.g., a cyclic universe) had various technical problems, which have been solved in recent years. In a rebounding big bang, there are issues to worry about such as what happens to causality, entropy, and the thermodynamic arrow of time. E.g., you could imagine that a universe cycles through a series of big bangs, and that each cycle is a lot like the one before, or you could imagine that the second law of thermodynamics operates across rebounds, so that each cycle has more entropy than the one before. You could imagine that there could be cause and effect relationships extending across rebounds, or that that could be prevented by the laws of physics. Some people believe that there's an unsolved "entropy problem" in the current standard big bang theory. Here is a good FAQ about cyclic models.
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But CMB fills the entire universe, it doesn't come from one localized area. See the part of his post:
What you want is a specific "point" at which the big bang happened. That's not the case. When it happened - it WAS the universe - ie it was every single point at once. As the universe expands - anywhere you look from or to you'll be able to see this background radiation. Of course there will be fluctuations if the expansion of the universe isn't completely uniform - and why should it be? Matter distorts space and time, contributing to this non-uniformity.
Seven puppies were harmed during the making of this post.
Though coming from very different directions, both LQG pioneer Lee Smolin and Stephen Wolfram, who needs no introduction here, have opined that the best candidate as the fundamental level of a discrete physics (i.e. where the appearance of being continuous is emergent) is a graph theoretic network of nodes and links where it ceases to make sense to ask what they are made of. (This is also explored in Greg Egan's Schild's Ladder .) The basic idea is that there is some simple enough but cosmologically consistent transformation rule which produces the next local state of the graph from the current local state, supposedly at the Planck scale (of order 10^43 times per second).
A likely scenario is that "somewhere" long unreachable beyond our event horizons, there was a region of network sustaining chaotic inflationary expansion in which a bubble of more conservative physics emerged. Our conservative bubble only exhibits polynomial (near cubic) growth but that was enough to separate it from the exponentially growing seed graph.
My current betting is that Type 1a Supernovae, or at least some more precise analogue thereof in our parent cosmos, seed new outbreaks of chaotic inflation in which a new generation of more conservative bubble cosmoses arise, the whole process being susceptible to selection for fecundity and constrained only by the need for a viable history to some initial conditions simple enough to have just happened, presumably for no better reason than because nothing is unstable.
-- Our systemic servants do not good masters make.
the explanation I have heard from a couple physicists and astronomers goes more like this:
Imagine space as a slightly inflated rubber balloon. Imagine two dots on the outside of that balloon. Then add air to the balloon, inflating it further.
What you get is two dots that are farther apart, more real distance between them but the same balloon.
Consider having two probes going away from Earth at 60%-lightspeed in opposite directions, and they want to communicate with each other. At 120%-c speeds, you might think it's impossible. But each of them could communicate back and forth with Earth at mere 60%-c speeds. If you do the actual math you work out that they appear to each other as moving away at something-like-80%c (that figure is totally made up, but you should get the idea anyway).
The World Wide Web is dying. Soon, we shall have only the Internet.
So it would be safe to say that if nothing can travel faster than the speed of light, we could witness objects distancing themselves at almost 3 times the speed of light, considering the addition of each: ...
Nope. You can't observe objects whose effective speed in your reference frame - combining inflation with velocity - is greater than C. The light from them never reaches you and light from you can never reach them. From your point of view they're "off the edge". It's as if you and they were each below the event horizon of a black hole relative to each other.
(And sorry about an error in my previous post. The correct buzzword for the stretching of space is "inflation".)
Or at least that's how I understand it. IANAP(hysicist)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
To use your analogy, draw a grid on the balloon. When you inflate the balloon, the grid squares grow. But one unit is still one unit. If you had to measure around the balloon, it would be x squares, regardless the size. This is because we are IN the balloon so that is our frame of reference. You are measuring it outside of the universe, and it just doesn't work like that.
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
If object B looked back at object A, B would see A moving away from it slower than the speed of light due to time dilation. Time isn't actually any different for A than for B or for you in the center because you're not supposed to say that any one of them is actually the one that's moving. So if you're sitting in the center waving your hand at second intervals, B and A would see you waving very quickly. Likewise if I'm at B waving my hand at 1 second intervals you in the center would see my waving as quicker than your own! (I might have mixed up who sees who as waving slower).
It makes no sense, but it's OK because the theory never allows us to loop past each other like on a donut and simultaneously notice that the other person is a lot older than we are.
I'll admit that I don't know what he's talking about. But it's not really a unique theory, in that there are other "fate of the universe" theories that predict that an end of one universe will bring the beginning of another. Or something along those lines. I had a lecture recently, where the professor talked about some of the wildly speculative theories of the future of the universe. It goes something like the following:
The common view now is that the expansion of the universe is accelerating. As the universe ages, galaxies will be spread further away, and the amount of hydrogen and helium in any given galaxy will start to decrease to the point that it would be difficult to produce any stars. Galaxies will be full of brown dwarfs, white dwarfs, and black holes. Over a long time frame, galaxies will start shedding some of their stars, and black holes will decay via the process of Hawking radiation. Eventually, about a googol years from now, protons will start to decay. As the universe runs out of ways to generate energy, there will be parts of the universe, starting with the large empty gaps left behind by the expansion, that will undergo a phase transition. Once some pockets of the universe undergo phase transition, they will act as seeds that spread the transition to other parts of the universe (like the process of water turning into ice). When the phase transition is complete, the laws of physics will change drastically, and there may be a new seed for a new universe.
As I mentioned earlier, it's WILDLY speculative, so don't take this comment as anything definitive. I just wanted to illustrate one of the many theories out there that share some of the most basic premises of the one in the story.
Read this off http://en.wikipedia.org/wiki/Cosmogony the other day. Kinda similar idea in ways:
What if the big bang was just the explosion of all the crap that was in the event horizon of a black hole from a parent universe?
Questions I have are:
-How could there be such a massive black hole in a parent universe that our universe originated from? Subsequent universes would have smaller and smaller total mass/energy so it couldn't go on forever, and that would mean there was a starting point?
-Wtf is the collapsing of a black hole? I thought they evaporated...
Yeah, but then again, you're assuming he actually believes the stuff he spouts off, b/c in this universe, he refuses to debate ANYONE on the facts, and he owns the companies he buys 'carbon credits' from... weird, huh?
Beer, now there's a temporary solution -- Homer Jay S.
http://en.wikipedia.org/wiki/Velocity-addition_formula or something?
You are pointing to imperfections in an analogy and claiming they are flaws in the concept the analogy is meant to describe. The balloon analogy is not a premise supporting expansion. It's just a visual aid.
This is because we are IN the balloon so that is our frame of reference.
No, we are on the balloon. The surface of the balloon is a 2D representation of our 3D space. Talking about the inside of the balloon is nonsensical.
"I'm curious about this" ironically becomes "I CAT" in an acronym.
You can see objects whose effective speed is greater than c _now_, but wasnt when the light was emitted. We can see objects with a redshift equal to that of an object travelling twice or more the speed of light. (Redshift of about 6 ish)
No, we are on the balloon. The surface of the balloon is a 2D representation of our 3D space.
You are trying to oversimplifying it and it is getting in the way. The balloon is our universe. Drawing a grid on the outside would be akin to cubing up a block of cheese. Get past the fact that it is drawn on a 2d surface. This represents cubes of space/time within our universe.
In the end, the change in distance is offset by the change in time, which makes it a non-issue.
An unrelated, but equally technical postulation would be, imagine that everything in the universe was growing! Everything is also moving away from each other at a proportional ratio to how fast it is growing. Use any numbers you want. When it comes down to it, IT DOESN'T MATTER, because everything would be the same in our frame of reference. It would only be different to someone outside of our universe, who isn't affected.
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
Everyone here is apparently rather stupid.
If I leave your house traveling at the speed of light, and look back an hour later, I'll see your house exactly as I left it. (Pretending that time would actually pass enough for me to 'see' anything.)
So, 'relatively', anyone who also left at the same time, in any direction, at any speed, looks like they're 'relatively' an hour away! Because they're standing at my starting point motionless!
Of course, as no one can actually do anything at the speed of light, even assuming they could reach it, this concept is rather stupid.
Which is why all this discussion is rather stupid. The original poster apparently doesn't realize that when scientists talk about seeing things farther away than the age of the universe, they're actually talking about where they are now, not where they are when the light that is now reaching us left them.
If corporations are people, aren't stockholders guilty of slavery?