In 1929, Edwin Hubble calculated the velocity of distant galaxies barely visible through the telescopes at the Mount Wilson Observatory. His observations were the first evidence of a theory that has become a foundation of modern cosmology — the universe is continuously expanding.
If you trace that expansion far enough back in time, you reach a distant point in the past. At this point, the entire universe was squeezed into an unfathomably dense spec filled with molten subatomic particles. This distant point in the past is known colloquially as the hot Big Bang.
So how did this spec expand and form matter as we know it? It’s a point of contention among cosmologists and theoretical physicists. In recent years, a once-fringe theory — dubbed the Big Bounce — has gained traction in cosmological circles. It suggests that the Big Bang may have happened before, and may happen again.
In 1981, ...
