Astronomers and cosmologists have long ceded the question of "what happened before the Big Bang?" to the world's religions. But now, new discoveries in astrophysics are shedding light on what may have existed before our universe boomed into existence.
A new mathematical model suggests that another universe's collapse probably gave birth to the one we live in today.
Martin Bojowald, assistant professor of physics at Pennsylvania State University, suggests that the behavior of quantum matter affected how the Big Bang happened. Bojowald, and others, calls this new theory the Big Bounce. The theory has been proposed as an alternative to the Big Bang. It goes, more or less, thus: After a big bang, a universe expands for a while before the gravitational attraction of matter forces it to collapse back in on itself; a "bounce" then creates another universe.
According to a Penn State news release, Bojowald's research is exploring the time before the Big Bang using a mathematical "time machine" called loop quantum gravity.
Bojowald's work combines Einstein's Theory of General Relativity with equations of quantum physics that did not exist in Einstein's day; this Big Bounce theory "opens a crack in the barrier that was the Big Bang."
"Einstein's Theory of General Relativity does not include the quantum physics that you must have in order to describe the extremely high energies that dominated our universe during its very early evolution," Bojowald explained, "but we now have loop quantum gravity, a theory that does include the necessary quantum physics."
Loop quantum gravity is now a leading approach to the goal of unifying general relativity with quantum physics.
"Scientists using this theory to trace our universe backward in time have found that its beginning point had a minimum volume that is not zero and a maximum energy that is not infinite. As a result of these limits, the theory's equations continue to produce valid mathematical results past the point of the classical Big Bang, giving scientists a window into the time before the Big Bounce."