Publicly, Lawrence M. Krauss, Arizona State University's Foundation Professor, is well known for making science cooler than science fiction in his book The Physics of Star Trek (Basic Books, 2007). But scientifically, Krauss is better known for asking the ultimate question: why is there something rather than nothing?
The universe, Krauss says, sprang from nothing. That makes us uncomfortable, in part because it's a vast departure from what we used to think. But "the universe doesn't exist to make us happy."
So remember when you’re feeling small and insecure,
How amazingly unlikely is your birth,
And pray there’s intelligent life somewhere out in space
‘Cause there’s bugger all down here on Earth.
The strains of Monty Python’s Galaxy Song, an ironic take on the significance of human existence, ring through the lecture hall in Radcliffe Gymnasium. The lines make a fitting prelude to the lecture we’re about to hear from Arizona State University’s Foundation Professor Lawrence Krauss. The brilliant and sardonic cosmologist answers the fundamental questions—where do we come from and where are we going—with one word: nothing.
Those questions, and their answer, are of interest to Harvard astronomy professor and former Radcliffe science advisor Dimitar Sasselov. As he introduces Krauss, Sasselov notes their shared interests in our beginnings: both professors direct multidisciplinary initiatives to understand our cosmic and chemical origins, Harvard’s Origins of Life Initiative and Arizona State’s Origins Project.
From Nothing and to Nothing
Just 100 years ago, we thought we lived in a lone galaxy surrounded by a vast, eternal cosmic void. But the discovery of galaxies outside our own soon showed the universe was expanding, suggesting an origin. And a universe with an origin might very well have an end.
“The central question of 20th century cosmology then became, will the universe end with a bang or a whimper?” Krauss explains. Cosmologists’ attempts to answer that question only begot more mysteries, such as dark energy, a repulsive force that pervades the universe and causes it to expand ever more quickly.
Dark energy, it turns out, comes from the void. The uncertainties of quantum mechanics turn the so-called empty space between galaxies into a “boiling, bubbling brew of virtual particles that pop into and out of existence on timescales so short, you never see them,” Krauss explains.
The same concept applies to the universe. Out of a truly empty void, whole universes could randomly pop into and out of existence, rendering even the fundamental laws of physics accidental. We just happen to live in a universe with the right set of laws to support human life—we wouldn’t exist otherwise.
So how will it all end? As it began—in nothing. Long after all its stars and galaxies fade away, the universe will continue to expand, cold and empty. “The answer to the question, why is there something rather than nothing, is really quite simple,” Krauss says. “Just wait, there won’t be for long.”
With the kind of humor Monty Python fans might appreciate, Krauss closes by looking on the bright side of life: “Instead of being depressed by our insignificance and our miserable future, let’s enjoy our brief moment in the Sun.”
Monica Young is the web editor of Sky & Telescope magazine.