"Long before it's in the papers"
August 23, 2012

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Birth of the universe: “Big Chill” instead of Big Bang?

Aug. 20, 2012
Courtesy of the Uni­vers­ity of Mel­bourne
and World Science staff

The birth of the uni­verse should be en­vi­sioned not as an explosion-like “Big Bang” event, as main­stream phys­ics char­ac­ter­izes it, but more like wa­ter freez­ing, a new study pro­poses.

The­o­ret­i­cal phys­i­cists in­volved in the proj­ect say that in­ves­ti­gat­ing the cracks and crevices com­mon to all crys­tals, in­clud­ing ice, could rev­o­lu­tion­ize our un­der­stand­ing of the cos­mos.

“An­cient Greek phi­loso­phers won­dered what mat­ter was made of: was it made of a con­tin­u­ous sub­stance or was it made of in­di­vid­ual atom­s?” said James Quach of the Uni­vers­ity of Mel­bourne, Aus­tral­ia, the lead re­search­er. “We now know that mat­ter is made of atoms.”

“T­hou­sands of years lat­er, Al­bert Ein­stein as­sumed that space and time were con­tin­u­ous and flowed smooth­ly, but we now be­lieve that this as­sump­tion may not be val­id at very small scales,” he added.

“A new the­o­ry, known as Quan­tum Grav­ity, sug­gests that space may be made up of in­di­vis­i­ble build­ing blocks, like ti­ny atoms. These in­di­vis­i­ble blocks can be thought about as si­m­i­lar to pix­els that make up an im­age on a screen. The chal­lenge has been that these build­ing blocks of space are very small, and so im­pos­si­ble to see di­rect­ly.”

But Quach and col­leagues be­lieve they may have fig­ured out a way to see them in­di­rect­ly. The re­search is pub­lished in the lat­est edi­tion of the jour­nal Phys­i­cal Re­view D.

“Think of the early uni­verse as be­ing like a liq­uid,” Quach said. “Then as the uni­verse cools, it ‘crys­tallis­es’ in­to the three spa­tial and one time di­men­sion that we see to­day. The­o­rised this way, as the Uni­verse cools, we would ex­pect that cracks should form, si­m­i­lar to the way cracks are formed when wa­ter freezes in­to ice.”

Some of these de­fects might be vis­i­ble, added re­search team mem­ber An­drew Green­tree of RMIT Uni­vers­ity, al­so in Mel­bourne. “Light and oth­er par­t­i­cles would bend or re­flect off such de­fects, and there­fore in the­o­ry we should be able to de­tect these ef­fects,” he said.

The team has cal­cu­lat­ed some of these ef­fects and claims that if their pre­dic­tions are ver­i­fied, the ques­tion of wheth­er space is smooth or made of ti­ny in­di­vis­i­ble parts will be solved once and for all.

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The start of the Universe should be envisioned not as an explosion-like “Big Bang” event, as mainstream physics characterizes it, but more like water freezing, a new study proposes. Theoretical physicists involved in the project say that investigating the cracks and crevices common to all crystals, including ice, could revolutionize our understanding of the cosmos. “Ancient Greek philosophers wondered what matter was made of: was it made of a continuous substance or was it made of individual atoms?” said James Quach of the University of Melbourne, Australia, the lead researcher. “We now know that matter is made of atoms.” “Thousands of years later, Albert Einstein assumed that space and time were continuous and flowed smoothly, but we now believe that this assumption may not be valid at very small scales,” he added. “A new theory, known as Quantum Graphity, suggests that space may be made up of indivisible building blocks, like tiny atoms. These indivisible blocks can be thought about as similar to pixels that make up an image on a screen. The challenge has been that these building blocks of space are very small, and so impossible to see directly.” But Quach and colleagues believe they may have figured out a way to see them indirectly. The research is published in the latest edition of the journal Physical Review D. “Think of the early universe as being like a liquid,” Quach said. “Then as the universe cools, it ‘crystallises’ into the three spatial and one time dimension that we see today. Theorised this way, as the Universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice.” Some of these defects might be visible, added research team member Andrew Greentree of RMIT University, also in Melbourne. “Light and other particles would bend or reflect off such defects, and therefore in theory we should be able to detect these effects,” he said. The team has calculated some of these effects and claims that if their predictions are verified, the question of whether space is smooth or made of tiny indivisible parts will be solved once and for all.