Time before Big Bang?
Thread: Time before Big Bang? – 3124 days old
takoja
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Here's the latest from the world of science! Phycisist Penrose & Gurzadyan claim to have found evidence of time before Big Bang.
In general, asking what happened before the Big Bang is not really considered a science question. According to Big Bang theory, time did not even exist before this point roughly 13.7 billion years ago. But now, Oxford University physicist Roger Penrose and Vahe Gurzadyan from the Yerevan Physics Institute in Armenia have found an effect in the cosmic microwave background (CMB) that allows them to "see through" the Big Bang into what came before.
The CMB is the radiation that exists everywhere in the universe, thought to be left over from when the universe was only 300,000 years old. In the early 1990s, scientists discovered that the CMB temperature has anisotropies, meaning that the temperature fluctuates at the level of about 1 part in 100,000. These fluctuations provide one of the strongest pieces of observational evidence for the Big Bang theory, since the tiny fluctuations are thought to have grown into the large-scale structures we see today. Importantly, these fluctuations are considered to be random due to the period of inflation that is thought to have occurred in the fraction of a second after the Big Bang, which made the radiation nearly uniform.
However, Penrose and Gurzadyan have now discovered concentric circles within the CMB in which the temperature variation is much lower than expected, implying that CMB anisotropies are not completely random. The scientists think that these circles stem from the results of collisions between supermassive black holes that released huge, mostly isotropic bursts of energy. The bursts have much more energy than the normal local variations in temperature. The strange part is that the scientists calculated that some of the larger of these nearly isotropic circles must have occurred before the time of the Big Bang.
The discovery doesn't suggest that there wasn't a Big Bang - rather, it supports the idea that there could have been many of them. The scientists explain that the CMB circles support the possibility that we live in a cyclic universe, in which the end of one "aeon" or universe triggers another Big Bang that starts another aeon, and the process repeats indefinitely. The black hole encounters that caused the circles likely occurred within the later stages of the aeon right before ours, according to the scientists.
In the past, Penrose has investigated cyclic cosmology models because he has noticed another shortcoming of the much more widely accepted inflationary theory: it cannot explain why there was such low entropy at the beginning of the universe. The low entropy state (or high degree of order) was essential for making complex matter possible. The cyclic cosmology idea is that, when a universe expands to its full extent, black holes will evaporate and all the information they contain will somehow vanish, removing entropy from the universe. At this point, a new aeon with a low entropy state will begin.
Because of the great significance of these little circles, the scientists will do further work to confirm their existence and see which models can best explain them. Already, Penrose and Gurzadyan used data from two experiments - WMAP and BOOMERanG98 - to detect the circles and eliminate the possibility of an instrumental cause for the effects. But even if the circles really do stem from sources in a pre-Big Bang era, cyclic cosmology may not offer the best explanation for them. Among its challenges, cyclic cosmology still needs to explain the vast shift of scale between aeons, as well as why it requires all particles to lose their mass at some point in the future.
http://www.physorg.com/news/2010-11-...verse-big.html
http://physicsworld.com/cws/article/news/44388
Here's some criticism towards Gurzadyan & Penrose.
No evidence of time before Big Bang
Our view of the early Universe may be full of mysterious circles — and even triangles — but that doesn't mean we're seeing evidence of events that took place before the Big Bang. So says a trio of papers taking aim at a recent claim that concentric rings of uniform temperature within the cosmic microwave background — the radiation left over from the Big Bang — might, in fact, be the signatures of black holes colliding in a previous cosmic 'aeon' that existed before our Universe.
The provocative idea was posited by Vahe Gurzadyan of Yerevan Physics Institute in Armenia and celebrated theoretical physicist Roger Penrose of the University of Oxford, UK. In a recent paper1, posted on the arXiv preprint server, Gurzadyan and Penrose argue that collisions between supermassive black holes from before the Big Bang would generate spherically propagating gravitational waves that would, in turn, leave characteristic circles within the cosmic microwave background.
To verify this claim, Gurzadyan examined seven years' worth of data from NASA's Wilkinson Microwave Anisotropy Probe (WMAP) satellite, calculating the change in temperature variance within progressively larger rings around more than 10,000 points in the microwave sky. And indeed, he identified a number of rings within the WMAP data that had a temperature variance that was markedly lower than that of the surrounding sky.
Cosmic cycle
Most cosmologists believe that the Universe, and with it space and time, exploded into being some 13.7 billion years ago at the Big Bang, and that it has been expanding ever since. A crucial component of the standard cosmological model — needed to explain why the Universe is so uniform — is the idea that a fraction of a second after the Big Bang, the Universe underwent a brief period of extremely rapid expansion known as inflation.
Penrose, however, thinks that the Universe's great uniformity instead originates from before the Big Bang, from the tail end of a previous aeon that saw the Universe expand to become infinitely large and very smooth. That aeon in turn was born in a Big Bang that emerged from the end of a still earlier aeon, and so on, creating a potentially infinite cycle with no beginning and no end.
Now Gurzadyan and Penrose's idea is being challenged by three independent studies, all posted on the arXiv server within the past few days, by Ingunn Wehus and Hans Kristian Eriksen of the University of Oslo2; Adam Moss, Douglas Scott and James Zibin of the University of British Columbia3 in Vancouver, Canada; and Amir Hajian of the Canadian Institute for Theoretical Astrophysics in Toronto, Ontario4.
All three groups reproduced Gurzadyan's analysis of the WMAP data and all agree that the data do contain low-variance circles. Where they part company with the earlier work is in the significance that they attribute to these circles.
http://www.nature.com/news/2010/1012....2010.665.html
G & P:s answer to criticism
To gauge this significance, Gurzadyan compared the observed circles with a simulation of the cosmic microwave background in which temperature fluctuations were completely scale invariant, meaning that their abundance was independent of their size. In doing so, he found that there ought not to be any patterns. But the groups who are critical of his work say that this is not what the cosmic microwave background is like.
They point out that the WMAP data clearly show that there are far more hot and cold spots at smaller angular scales, and that it is therefore wrong to assume that the microwave sky is isotropic. All three groups searched for circular variance patterns in simulations of the cosmic microwave background that assume the basic properties of the inflationary Universe, and all found circles that are very similar to the ones in the WMAP data.
Moss and his colleagues even carried out a slight variation of the exercise and found that both the observational data and the inflationary simulations also contain concentric regions of low variance in the shape of equilateral triangles. "The result obtained by Gurzadyan and Penrose does not in any way provide evidence for Penrose's cyclical model of the Universe over standard inflation," says Zibin.
Gurzadyan dismisses the critical analyses as "absolutely trivial", arguing that there is bound to be agreement between the standard cosmological model and the WMAP data "at some confidence level" but that a different model, such as Penrose's, might fit the data "even better" " — a point he makes in a response to the three critical papers also posted on arXiv5. However, he is not prepared to state that the circles constitute evidence of Penrose's model. "We have found some signatures that carry properties predicted by the model," he says
Two groups [3,4] have confirmed the results of our paper concerning the actual existence of low variance circles in the cosmic microwave background (CMB) sky. They also point out that the effect does not contradict the LCDM model - a matter which is not in dispute. We point out two discrepancies between their treatment and ours, however, one technical, the other having to do with the very understanding of what constitutes a Gaussian random signal. Both groups simulate maps using the CMB power spectrum for LCDM, while we simulate a pure Gaussian sky plus the WMAP's noise, which points out the contradiction with a common statement [3] that "CMB signal is random noise of Gaussian nature". For as it was shown in [5], the random component is a minor one in the CMB signal, namely, about 0.2. Accordingly, the circles we saw are a real structure of the CMB sky and they are not of a random Gaussian nature. Although the structures studied certainly cannot contradict the power spectrum, which is well fitted by LCDM model, we particularly emphasize that the low variance circles occur in concentric families, and this key fact cannot be explained as a purely random effect. It is, however a clear prediction of conformal cyclic cosmology.
I understand little of this, but the idea of a cyclic universe is quite intriguing. But is it valid, what do you think?
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Zabersus
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If entropy reached its zenith, how could an energetic event such as the Big Bang take place?
Last edited by Zabersus; 2010-12-28 at 12:36.
I2a1b1
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Nordid, Dalofaelid
I can't understand how supermassive black holes could exist before the Big Bang. They are suppose to be the product of the accretion of a number of smaller black holes which are created by collapsing massive stars. If the stars have not been formed yet (since the universe has not been created yet) then how can the black holes exist??? These isotropic rings in the CMB must be made by dark matter or dark energy IMO.
Ok enough said...I am going to turn on my TV and go to a frequency to look at some CMB....maybe something will inspire me to a solution to this cosmic conundrum.
Probably off-topic, but ill post it anyways.
About entropy and the universe.
This happens when all available energy (such as from a hot source) has moved to places of less energy (such as a colder source). Once this has happened, no more work can be extracted from the universe. Since heat ceases to flow, no more work can be acquired from heat transfer. This same kind of equilibrium state will also happen with all other forms of energy (mechanical, electrical, etc.). Since no more work can be extracted from the universe at that point, it is effectively dead, especially for the purposes of humankind.
They_Shimmer
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Nordid
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Divide and conquer
Originally Posted by Zabersus
Obviously it isn't right then.
The longer a particle holds onto an energy change the less energy is available to transfer onto other particles. Creating this ordered state, were the particles are not excited and do not start whizzing around creating more disorder.
So when this happens, you can't start something by adding a kick to get it going. Coz you cant find an energy source that is suitable. It still has energy, just nothing to discern it.
Jooma
R1a1a1g2
Democratic Right
Originally Posted by rogers
Agree, most importantly cosmic microwave background (CMB) did not exist before so called Big Bang, therefore it cannot carry any imprints of any pre-existing black holes.
This is a total desperation and a pity that it applies to a such great mind of Penrose.
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