“Alone, I often fall down into nothingness. I must push my foot stealthily lest I should fall off the edge of the world into nothingness. I have to bang my head against some hard door to call myself back to the body.” -Virginia Woolf
If you think about the Universe, what it is today, what it contains and what makes it up, it very much is “something” by any way you’ll attempt to define it. Yet every “something” we know of has an origin, and the only ultimate origin for the first “something” is that it must have come from nothing.
Visualization of a quantum field theory calculation showing virtual particles in the quantum vacuum. Image credit: Derek Leinweber.
Yet what do we mean, as physicists, when we talk about nothing? Do we mean empty space; do we mean the quantum vacuum; do we mean the nothingness of our Universe or the Multiverse; do we mean the state from which space and time and the laws of physics first arose? Physicists and philosophers don’t necessarily have a good answer to this, yet that doesn’t mean we don’t have intelligent things about the different types of nothingness to talk about!
The hot Big Bang resulted from the end of cosmological inflation. But that still required the existence of space, time, and a large zero-point energy. Where did all of *that* come from? Image credit: Bock et al. (2006, astro-ph/0604101); modifications by E. Siegel.