The universe might not only be expanding, but also ringing at the same time, according to two physicists at the University of Southern Mississippi.
It is popularly believed that the cosmos began with the Big Bang before it expanded to the size it is today. Astronomers Arno Penzias and Robert Wilson received the Nobel prize for their discovery of the Cosmic Microwave Background (CMB), the relic radiation that serves as evidence for the event that brought the universe into existence.
Later in 1998, it was found that the universe was not only expanding, but speeding up. “[The discovery] was a shock when it was uncovered,” says Lawrence Mead of the University of Southern Mississippi. “A new form of matter, dark energy, repulsive in nature, was responsible for the speed-up. The teams led by Paul Perlmutter, Adam Riess and Brian Schmidt won the 2011 Nobel Prize in Physics for that discovery.”
According to Mead, the change from slowing down to speeding up took place around six to seven billion years ago. A vast amount of data has verified this theory to very good accuracy.
“The new finding suggests that the universe has slowed down and speeded up, not just once, but seven times in the last 13.8 billion years, on average emulating dark matter in the process,” says Mead, who with his colleague Ringermacher made their discovery accidentally when modelling the dark matter found in galaxies. “The ringing has been decaying and is now very small – much like striking a crystal glass and hearing it ring down.”