Let's rewind the clock. Before humans existed, before Earth formed, before the sun ignited, before galaxies arose, before light could even shine, there was the Big Bang. This happened 13.8 billion years ago.

But what about before that? Many physicists say there is no before that. Time began ticking, they insist, at the instant of the Big Bang, and pondering anything earlier isn't in the realm of science. We'll never understand what pre-Big Bang reality was like, or what it was formed of, or why it exploded to create our universe. Such notions are beyond human understanding.

But a few unconventional scientists disagree. These physicists theorize that, a moment before the Big Bang, all the mass and energy of the nascent