Australians help to "listen" for evidence of Big Bang University of Adelaide researchers are among a large international team of physicists taking part in one of the most challenging scientific endeavours ever undertaken: the attempt to directly detect vibrations in space called gravitational waves. The international team's latest research findings, published tomorrow (Friday 21 August) in the journal Nature, are considered to be a small but significant step forward in the quest to better understand the nature of the universe after the Big Bang.
New computer simulations reveal how the early universe would have appeared 500 million years after the theoretical Big Bang. According to the standard Big Bang model, the universe was born about 13.7 billion years ago in a burst of inflation, growing from something smaller than the size of an electron to about golf-ball size within a fraction of a second. In its early stages, the universe was flooded with energy, which congealed into particles and the lighter atoms. Over time, as the cosmos continued to expand on a vastly greater scale, these atoms clumped together into stars and galaxies.
Glimpse before Big Bang may be possible The universe appears to be lopsided, and a new model that aims to explain this anomaly could offer a glimpse of what happened before the birth of it all.
In what many call a "golden age of cosmology", astronomers can now observe the universe with unprecedented precision, resulting in spectacular progress in the search for the origin of the universe. Yet, for all the impressive progress, fundamental questions remain. What is the mysterious "dark energy" driving space to rapidly expand? What existed before the big bang? Is there an origin of time? Do we live in a multiverse? Our audience joined Science Fridays Ira Flatow in conversation with leading cosmologists Lawrence Krauss, Paul Steinhardt, and Lyman Page, and historian of science Helge Kragh as they discussed and debated new advances that are shaping our understanding of the cosmic order and our place within it.
Caltech Researchers Interpret Asymmetry in Early Universe The Big Bang is widely considered to have obliterated any trace of what came before. Now, astrophysicists at the California Institute of Technology (Caltech) think that their new theoretical interpretation of an imprint from the earliest stages of the universe may also shed light on what came before.
"It's no longer completely crazy to ask what happened before the Big Bang" - Marc Kamionkowski, Caltech's Robinson Professor of Theoretical Physics and Astrophysics.
Kamionkowski joined graduate student Adrienne Erickcek and senior research associate in physics Sean Carroll to propose a mathematical model explaining an anomaly in what is supposed to be a universe of uniformly distributed radiation and matter.
Humans like the comfort of symmetry -- the identical image in the mirror, the matching wings of the baroque mansion, the equal numbers in opposing football teams. So it comes as a bit of a shocker when physicists say the Universe is built on broken symmetry. Creation was not a soothing, balanced event, they say. It was, essentially, a lopsided affair. Had things been symmetrical in the Big Bang 13.7 billion years ago, equal amounts of matter and antimatter should have been formed, rather like the hole you dig in the ground is equal to the mound of earth that comes from the hole.
Now Stephen Hawking at the University of Cambridge, and colleagues, think they are close to perfecting an answer - by treating the early cosmos as a quantum object with a multitude of alternative universes that gradually blend into ours. Quantum mechanics is awash with strange ideas and can shed new light on inflation, which came in the wake of when the universe itself was around the size of an atom. By quantum lore, when a particle of light travels from A to B, it does not take one path but explores every one simultaneously, with the more direct routes being used more heavily. This is called a sum over histories and Prof Hawking and Prof Hertog propose the same thing for the cosmos. In this theory, the early universe can be described by a mathematical object called a wave function and, in a similar way to the light particle, the team proposed two years ago that this means that there was no unique origin to the cosmos: instead the wave function of the universe embraced a multitude of means to develop. This is very counter intuitive: they argued the universe began in just about every way imaginable (and perhaps even some that are not). Out of this profusion of beginnings, like a blend of a God’s eye view of every conceivable kind of creation, the vast majority of the baby universes withered away to leave the mature cosmos that we can see today.
"For this, one needs a theory of the wave function of the universe."
And now the world of cosmology has one. The next step is to find specific predictions that can be put to the test, to validate this new view of how the cosmos came into being.
"In recent years, the search for the fundamental laws of nature has forced us to think about the Big Bang much more deeply. According to our best theories string theory and M theory all of the details of the laws of physics are actually determined by the structure of the universe; specifically, by the arrangement of tiny, curled-up extra dimensions of space. This is a very beautiful picture: particle physics itself is now just another aspect of cosmology. But if you want to understand why the extra dimensions are arranged as they are, you have to understand the Big Bang because that's where everything came from."