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Was There Only One Big Bang?
goldaryn writes "Physorg.com is running an interesting story about the work of Oxford-based theoretical physicist Roger Penrose. Penrose has been studying CWB radiation and believes it's possible that space and time did not come into being at the Big Bang but that our universe in fact continually cycles through a series of 'aeons.' He believes that he has found evidence supporting his theory that the universe infinitely cycles."
There is a BBC Horizon episode up on youtube called What Happened Before the Big Bang. Interviews with several physicists about different ideas on the topic of what might have preceded our universe.
The Long Now Foundation
According to the article, concentric circles of temperature variation in the cosmic background radiation were caused by successive massive black holes, some of which supposedly predate the big bang.
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Galactus, the sole survivor of the universe existing before the Big Bang, disagrees.
The Doctor already did it last season.
rewriting history since 2109
Basically. You're talking about the critical density of the universe. This is about 1, meaning that the universe is "flat" -- so it's infinite in extent and basically composed of a load of flat sheets rather than saddle shapes or spheres. So far as we can tell it's exactly 1. (It's pretty easy to tell, actually. We can look at the ripples in the universe back from when it was 370,000 years old, and then look at *those same ripples* from when the universe was about 10 billion years old. Those ripples have a particular wavelength, so from that we can tell how much the universe had to expand. It pins things down really quite nicely.)
Our problem comes from counting how much actual normal ("baryonic" though it includes more than just baryons) matter there is, by looking at everything that glows (and also by looking at the amount of hydrogen and helium, which was produced in the first few seconds of the universe's life; the ratio between the two is extremely sensitive to how much baryonic matter there was). It gives us a density parameter of about 0.05. Shit. So we then look at how much clumping matter we need, which would include "dark matter", whatever form that takes. We find that we need about a density parameter of 0.3 -- so 25% of the universe is dark matter.
Shit. We *still* only have 30% of the universe even accounting for dark matter.
So we're forced to add about 70% of the universe in something else. That can't clump and for other reasons it has to act as an "anti-gravity". That's called "dark energy".
Rather surprisingly, this model fits all the available data...
"the theorie of Black Holes gave the idea to the BigBang theory - they just applied time-reversal!."
No 'they' didn't. Black holes are based on inhomogeneous solutions to Einstein's equations -- the first being the Schwarzschild solution describing a spherical, uncharged body embedded in flat spacetime, with Reisser-Nordstrom, Kerr and Kerr-Newman adding in electromagnetic fields, rotation and then both respectively.
Cosmology is based on Friedman-LeMaitre-Robertson-Walker solutions, which impose maximal symmetry on spatial surfaces of constant time. You might be interested to note that no black hole solution can be maximally-symmetric since only three surfaces are -- normal flat space, a (hyper)sphere and a (hyper)saddle.
There really isn't much connection. "Reversing" time on a black hole solution (which happen when you take, for example, a Schwarzschild solution and allow it to exist all the way to the centre of the system instead of cutting it off with a stellar surface partway down, which is what happens in the solar system) gives you a white hole.
Milliseconds, not minutes, but yeah. At about t+4ms, the strong forces came into existence. Before that, the math completely falls apart, and we have no idea what was happening. We don't even know if time itself was constant, and as we percieve it those first 4ms could have taken a billion years or more.
This isn't, by any stretch, a new idea, though. It's very similar to the Hindu/Buddhist cosmologies, which have been around for thousands of years. Sure, the hindus do use the notion of Brahma and the Manus to explain the passing of cycles, but both faiths teach that the universe goes through an infinite cycle of expansion, stability, and collapse, and that time goes off into infinite in either direction from here. This scientist's "new idea"? It's been around for at least 5,000 years.
Sir Roger Penrose is one of the more prominent living physicists. Penrose tilings were named after him (in a nutshell, they generate infinitely complex mosaics with only a few tile types). These tilings later came up in quasicrystals. He also invented twistor theory in the 60's, which is another way to view spacetime. Ed Witten of string theory/M-theory fame--perhaps the second most famous living physicist behind Hawking (my opinion)--applied twistor theory to string theory in 2003. Penrose has controversial views on human consciousness and has suggested our brains must work by a quantum mechanical process. He's written several books on the subject including The Emporer's New Mind . He won the Dirac Medal and Prize in 1989 (Hawking won in 1987; Witten won a similarly-named award in 1985) and has won a laundry list of other awards for theoretical physics. He was knighted in 1994 for his contributions to physics, is an emeritus professor at the University of Oxford, and is 79.
More people are alive today than all humans who have ever died.
That's an urban myth (how you defend it with flawed math probably nicely demonstrates our propensity to attaching to ourselves undue importance). 100+ billion homo sapiens dead already:
http://www.sciam.com/article.cfm?id=fact-or-fiction-living-outnumber-dead
http://www.prb.org/pdf/PT_novdec02.pdf
http://www.prb.org/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx
One that hath name thou can not otter
I saw Penrose speak on this topic at the Perimeter Institute about two years ago. He has been working on this for quite a while.
You captured the essence of his hypothesis. The idea is that in the latter stages of a universe, you eventually get two supermassive black holes orbiting each other - each containing half of the matter in the universe. As they rotate around each other, they're effectively ripping each other apart from the massive gravity wells. His theory is that the point at which they finally coalesce after billions of years of orbit, space and time "reset", and in that same instant the big bang takes place.
His premise is that not all of the energy has been completely contained within the singularity. When the big bang happens, the outlying energy causes rings in the background radiation.
Funny thing was, two days before his talk he got the first results back from the radiation survey. They didn't find rings, they found ovals. And in his words "we have no idea what that means".
It's great to see that he's making progress.
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