Unraveling the Big Bang Mystery by Advexon's Workspace The Big Bang was the beginning of the universe as we knowit, most scientists say. But was it the first beginning, and will it be thelast? A popular picture of the early universe imagines a singleBig Bang, after which space blew up quickly like a giant bubble. But another theoryposits that we live in a universe of 11 dimensions, where all particles areactually made of tiny vibrating strings. This could create a universe stuck in acycle of Big Bangs and Big Crunches, due to repeat on loop. Which scenario is closer to the truth remains to be seen, but scientists say new experiments underway could provide more answers soon. According to the BigBang theory, the universe began extremely hot and extremely dense. Around14 billion years ago, space itself expanded and cooled down, eventuallyallowing atoms to form and clump together to build the stars and galaxies wesee today. On this, most scientists are agreed. "I would say that there is 100 percent consensus,really," University of Pennsylvania particle physicist Burt Ovrut said ofthe Big Bang theory. "There is overwhelming evidence ? all of thepredictions are true." For example, this theory predicted that the universe todaywould be filled with pervasive light left over from the Big Bang. This glow,called the cosmic microwave background radiation, was discovered in 1964,almost 20 years after it was forecast. However, what caused the Big Bang, what happened at thatexact moment, and what came immediately after it, are much more open to debate. A giant bubble A dominant idea that connects the dots between the Big Bangand the universe we find today is called inflation. This is the notion thatduring the first roughly 10 to the minus 34 seconds (0.0000000000000000000000000000000001seconds), the universe underwent exponential expansion, doubling in size atleast 90 times. During this early stage, matter was in a much different statethan it is now. This theory could explain some of the main conundrums posed by the Big Bang: Why does the universe appear mostly flat, with roughly the same amount of stuff spread smoothly throughout it in all directions? Neither Big Bang theory nor inflationary theory can describe what happened at that moment. And inflation has other problems, in some people's view. Because of quantum fluctuations, different parts of the universe could inflate at different rates, creating "bubble universes" that are much larger than other regions. Our universe may be just one in a multiverse, where different scales and physical laws reign. "It means everything and anything that can happen, will," Stein hard told SPACE.com. "So basically everything could be a prediction of inflation. This to me is a fundamental problem and we don?t knowhow to get away from it." Others say that while inflation may not be complete yet, it's still the most useful thing we've got to describe the origin of the universe. "Even if all things are possible it could turn out that some things are much more possible than others, and you could still have a prediction," Albrecht said. "The real excitement to me is that there's so much data supporting inflation that it really makes it seem worth thinking about these questions." Cycles and cycles In 2001, Stein hardt and Turok proposed an idea called the cyclic model, based on an earlier concept called the ekpyrotic universe that they'd conceived with Ovrut. In this scenario, the universe undergoes an endless sequence of "bangs" and "crunches" ? i.e. periods of expansion followed by periods of contraction. At each transition, the universe would have some finite temperature and density, rather than the infinity of the singularity, and the expansion and contraction would be relatively slow, a sop posed to the exponentially quick expansion proposed by inflation. The idea is based on M-theory, a version of string theo rywhich suggests that every particle is in fact a tiny loop of string whosevibration pattern determines what type of particle it will be. However,M-theory requires the universe to have 11 dimensions. So far, we can onlydetect four dimensions ? three of space and one of time. But maybe the otherseven are hidden, proponents say. OUTLINE: 00:00:00 Introduction to the Big Bang Theory 00:00:17 The Singularity and the Beginning of Expansion 00:00:37 The Birth of the Universe 00:00:50 The Formation of Atoms and the Cosmic Microwave Background 00:01:10 Predictions and Explanations of the Big Bang Theory 00:01:28 Summary of the Big Bang Theory 00:01:49 The Limitations of the Big Bang Theory 00:02:06 The Beauty of Science and the Universe 00:02:22 Stay Connected to Our Journey Thanks for watching Make sure to subscribe and leave a comment below.