According to the Big Bang theory of how our universe began, our entire cosmos expanded from an extremely dense and hot state and continues to expand today. The graphic scheme above is an artist’s concept illustrating the expansion of a portion of a flat universe. Image via Wikimedia Commons.

EARTHSKY // SCIENCE WIRE RELEASE DATE: NOV 29, 2012

A new paradigm shift for the infant universe

A new paradigm for understanding the earliest eras in the history of the universe has been developed.

A new paradigm for understanding the earliest eras in the history of the universe has been developed by scientists at Penn State University. Using techniques from an area of modern physics called loop quantum cosmology, developed at Penn State, the scientists now have extended analyses that include quantum physics farther back in time than ever before — all the way to the beginning. The new paradigm of loop quantum origins shows, for the first time, that the large-scale structures we now see in the universe evolved from fundamental fluctuations in the essential quantum nature of “space-time,” which existed even at the very beginning of the universe over 14 billion years ago. The achievement also provides new opportunities for testing competing theories of modern cosmology against breakthrough observations expected from next-generation telescopes. The research will be published on 11 December 2012 as an “Editor’s Suggestion” paper in the scientific journal Physical Review Letters.

“We humans always have yearned to understand more about the origin and evolution of our universe,” said Abhay Ashtekar, the senior author of the paper. “So it is an exciting time in our group right now, as we begin using our new paradigm to understand, in more detail, the dynamics that matter and geometry experienced during the earliest eras of the universe, including at the very beginning.” Ashtekar is the Holder of the Eberly Family Chair in Physics at Penn State and the director of the university’s Institute for Gravitation and the Cosmos. Coauthors of the paper, along with Ashtekar, are postdoctoral fellows Ivan Agullo and William Nelson.

The new paradigm provides a conceptual and mathematical framework for describing the exotic “quantum-mechanical geometry of space-time” in the very early universe. The paradigm shows that, during this early era, the universe was compressed to such unimaginable densities that its behavior was ruled not by the classical physics of Einstein’s general theory of relativity, but by an even more fundamental theory that also incorporates the strange dynamics of quantum mechanics. The density of matter was huge then — 1094 grams per cubic centimeter, as compared with the density of an atomic nucleus today, which is only 1014 grams.

In this bizarre quantum-mechanical environment — where one can speak only of probabilities of events rather than certainties — physical properties naturally would be vastly different from the way we experience them today. Among these differences, Ashtekar said, are the concept of “time,” as well as the changing dynamics of various systems over time as they experience the fabric of quantum geometry itself.

Read more:A New Paradigm Shift for the Infant Universe | Science Wire | EarthSky.

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