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Neil Turok: What Caused The Big Bang?



Professor Neil Turok of Cambridge University presents his lecture "What Banged?" which examines the possible causes of The Big Bang, the initial singularity that created our universe.



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Far-Future Astronomers Could Still Deduce the Big Bang

According to Harvard theorist Avi Loeb, clever astronomers in 1 trillion C.E. could still infer the Big Bang and today's leading cosmological theory, known as "lambda-cold dark matter" or LCDM. They will have to use the most distant light source available to them - hypervelocity stars flung from the center of Milkomeda.

"We used to think that observational cosmology wouldn't be feasible a trillion years from now. Now we know this won't be the case. Hypervelocity stars will allow Milkomeda residents to learn about the cosmic expansion and reconstruct the past" - Avi Loeb, who directs the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics.

About once every 100,000 years, a binary-star system wanders too close to the black hole at our galaxy's center and gets ripped apart. One star falls into the black hole while the other is flung outward at a speed greater than 1 million miles per hour - fast enough to be ejected from the galaxy entirely.
Finding these hypervelocity stars is more challenging than spotting a needle in a haystack, but future astronomers would have a good reason to hunt diligently. Once they get far enough from Milkomeda's gravitational pull, these stars will get accelerated by the universe's expansion. Astronomers could measure that acceleration with technologies more advanced than we have today. This would provide a different line of evidence for an expanding universe, similar to Hubble's discovery but more difficult due to the very small effect being measured.

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BBC Horizon 2010 - What Happened Before the Big Bang?



The biggest question that science can possibly ask: where did everything in our universe come from? How did it all begin? For nearly a hundred years, we thought we had the answer: a big bang some 14 billion years ago.

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No evidence of time before Big Bang

A recent study had claimed that concentric rings within the cosmic microwave background could provide evidence of black holes that collided in the past, before our Universe existed but three new independent studies have challenged that claim.
Vahe Gurzadyan of Yerevan Physics Institute in Armenia theoretical physicist Roger Penrose of the University of Oxford, UK, had proposed 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.

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Why the early universe was free of charge

Most of us would find living without electricity almost impossible, but in the early universe electric charge was practically nonexistent. It turns out that the electric charge of fundamental particles could have been close to zero when the universe was fractions of a second old. It's all because of the action of gravity - a discovery that, if confirmed, could help pave the way for a unified description of physical reality.
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Title: Cosmological Models with No Big Bang
Authors: Wun-Yi Shu

In the late 1990s, observations of Type Ia supernovae led to the astounding discovery that the universe is expanding at an accelerating rate. The explanation of this anomalous acceleration has been one of the great problems in physics since that discovery. In this article we propose cosmological models that can explain the cosmic acceleration without introducing a cosmological constant into the standard Einstein field equation, negating the necessity for the existence of dark energy. There are four distinguishing features of these models: 1) the speed of light and the gravitational "constant" are not constant, but vary with the evolution of the universe, 2) time has no beginning and no end, 3) the spatial section of the universe is a 3-sphere, and 4) the universe experiences phases of both acceleration and deceleration. One of these models is selected and tested against current cosmological observations of Type Ia supernovae, and is found to fit the redshift-luminosity distance data quite well.

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Ed ~ This model has some glaring omissions, such as not addressing the observation of the CBR.

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This is the oldest light in the Universe.
This incredible image shows the remains of the fireball out of which our Universe sprang into existence 13.7 billion years ago.
It provides scientists with new insight into the way stars and galaxies form but also tells us how the Universe itself came to life after the Big Bang.
It was produced by a European space telescope called Planck and is the mission's first 'all-sky' image which took six months to create.

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From the story of the Big Bang to the Nobel Prize to the ultimate fate of the universe - John C. Mather's career as a Nasa (National Aeronautics and Space Administration) astronomer couldn't have been more exciting. Reviving his failed PhD thesis idea, he designed and built the first satellite - COBE - to measure cosmic microwave background radiation, which, after its launch in 1989, provided the first conclusive evidence that the Big Bang theory of the origin of universe was right.
Mather's team also tested the idea that the early universe had an exponential expansion called inflation. The only Nasa employee to have won a Nobel Prize, he says his public life has since changed, but not his professional life. His research projects undergo the same internal processes as before. At the 60th Nobel laureates meeting in Lindau, he spoke about some of the milestones before astronomers and physicists that would eventually tell us where the universe is headed.

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Toronto astrophysicists pretty much figured out origins of universe

Approximately 13.7 billion years ago give or take an insignificant 260 million years - the piping hot primordial jambalaya of the original universe began to expand. Physicists now agree we shouldn't have called it the Big Bang. The Big Wheeze would have been more accurate. It happened everywhere at once.
About 13.7 billion years later - in layman's terms, a few weekends ago - 180 of the world's top theoretical astrophysicists gathered at the University of Toronto to congratulate each other on figuring out that number.

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Title: The Big Bang and the Quantum
Authors: Abhay Ashtekar

This short review is addressed to cosmologists.
General relativity predicts that space-time comes to an end and physics comes to a halt at the big-bang. Recent developments in loop quantum cosmology have shown that these predictions cannot be trusted. Quantum geometry effects can resolve singularities, thereby opening new vistas. Examples are: The big bang is replaced by a quantum bounce; the `horizon problem' disappears; immediately after the big bounce, there is a super-inflationary phase with its own phenomenological ramifications; and, in presence of a standard inflaton potential, initial conditions are naturally set for a long, slow roll inflation independently of what happens in the pre-big bang branch.

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