Bad news, Big Bang believers … scientists may have discovered something that existed before our universe was born and want to change the name of that singularity from the violent Big Bang to the more playful yet controversial Big Bounce. Did we really bounce out of a past universe?
“The standard inflationary paradigm based on general relativity treats space-time as a smooth continuum. Consider a shirt that appears like a two-dimensional surface, but on closer inspection, you can see that it is woven by densely packed one-dimensional threads. In this way, the fabric of space-time is really woven by quantum threads. In accounting for these threads, loop quantum cosmology allows us to go beyond the continuum described by general relativity where Einstein’s physics breaks down—for example beyond the Big Bang.”
“Loop Quantum Cosmology” sounds like a great name for a prog-rock album, but anything that causes Einstein’s physics to break down is disconcerting in this age where people are not sure what to believe anymore. Abhay Ashtekar -- an Evan Pugh Professor of Physics, holder of the Eberly Family Chair in Physics, and director of the Penn State Institute for Gravitation and the Cosmos (this is why he has an accordion-folded business card) – co-authored the paper published in the journal Physical Review Letters about this Big Bounce theory that future satellite missions may actually be able to test.
"The primordial fluctuations we are talking about occur at the incredibly small Planck scale. A Planck length is about 20 orders of magnitude smaller than the radius of a proton. But corrections to inflation at this unimaginably small scale simultaneously explain two of the anomalies at the largest scales in the universe, in a cosmic tango of the very small and the very large."
The “cosmic tango” co-author Brajesh Gupt refers to in the press release relates to anomalies in the Cosmic Microwave Background (the electromagnetic radiation left after the birth of the universe) which are minuscule primordial fluctuations that were stretched under gravity’s influence and are now visible in the CMB. Instead of a bang, the Big Bounce theory views the creation of the current universe as a double funnel with a previous universe shrinking into the tiny connecting middle, passing through the “bounce” and then expanding again into a new universe. (Apologies to physicists that this simple explanation may offend.)
“The researchers also produced new predictions about a fundamental cosmological parameter and primordial gravitational waves that could be tested during future satellite missions, including LiteBird and Cosmic Origins Explorer, which will continue to improve our understanding of the early universe.”
LiteBIRD will be a small space observatory whose mission is to detect the footprint of the primordial gravitational wave on the cosmic microwave background (CMB) and is hoped to launch in the 2020s. COrE (Cosmic Origins Explorer) would be a full-sky, microwave-band satellite proposed to launch by 2025. Neither are approved, so the Big Bounce theory might help in that process.
Big Bang or Big Bounce? While you’re trying to decide, LiteBird and Cosmic Origins Explorer would both be great names for bands.