The Quantum Origins of Our Universe
How did it all start? How was our Universe created? What were the initial conditions? Were there any conditions at all? Is our observable Universe just one patch of many in a much larger universe beyond our reach? Is our Universe unique? Did it pop out of nowhere? Will it expand forever or come crashing down at some point? Did it bubble forth from a bustling region of minute fluctuations? Has the Universe already been around for an eternity?
Cosmologists have been pondering about such questions for decades. To shed light on their work and get a more solid grasp on the moment when the Universe was being started up, this article digs into their research and spends time with three theoretical frameworks in particular: Chaotic Eternal Inflation, the Cyclic Model, and the No Boundary Proposal.
The Big Bang Conundrum
Classical theories, such as thermodynamics and Albert Einstein’s theory of general relativity, describe the course of physical events in space and time at macroscopic levels — specifically, general relativity tells us that gravity arises as a phenomenon when high energy densities or massive objects bend spacetime. In contrast, when we descend into the microscopic realm, down to the atomic and subatomic echelons of nature, we rather appeal to the laws of quantum mechanics to explain the observed behaviour.
