What is quantum gravity? Scientists think it could explain the beginning of our universe

Scientists have redefined gravity to explain the Big Bang and perhaps change our picture of the earliest moments of the cosmos. This new framework of "quantum gravity" may explain aspects of the Big Bang that Albert Einstein's 1915 theory of gravity, general relativity, fails to account for — maybe even doing away with the challenging concept of a singularity existing prior to the dawn of the universe. Proving the concept of quantum gravity is something of a holy grail for physicists, as it would bridge the gap between the explanation we have of the universe on vast cosmic scales ( general relativity ) and on tiny scales ( quantum physics ) . However, general relativity doesn't just fail at small scales; the theory also collapses when trying to explain the extreme high-energy conditions that existed during the universe's first moments. To get around this issue, a team of researchers, led by Niayesh Afshordi, a professor of physics and astronomy at the University of Waterloo and Perimeter Institute, explored a theory called Quadratic Quantum Gravity. As it turns out, this theory seems to work even when explaining the high-density, high-temperature birth of the cosmos. "General relativity works extraordinarily well in many settings, but when we run it back to the Big Bang, and apply it to the inside of black holes, it predicts a singularity: a moment where density, curvature and temperature formally become infinite. …