Lawrence Krauss was introduced as a man “obsessed with nothing” and lived up to the billing.
“Science has demonstrated that a universe from nothing is not only plausible but likely,” he said Wednesday at the Nobel Conference in St. Peter’s Gustavus Adolphus College.
Advances in quantum mechanics have shown that empty space isn’t.
“This is what nothing looks like,” Krauss said, displaying an animation with roiling shapes popping in and out of existence. The particles live and die in fractions of a second but can persist in the presence of gravity.
“Gravity plus quantum mechanics allow space and possibly time to appear from nothing,” he said.
But what about the laws themselves? Where did those come from?
One answer might be an infinite number of universes exist, and we live in one with the sort of physical laws that permit life.
“It could be that every possible law happens, and that’s the same, it seems to me, as having no law,” said Krauss, a cosmologist and professor at Arizona State University in Tempe. But if you can’t monitor other universes, this seems impossible to test experimentally, he acknowledged.
Here, as at other times, Krauss sprinkled in some shots at religion, saying you don’t need “supernatural shenanigans” to explain the seeming contradiction of something coming from nothing.
Earlier, he dismissed biblical explanations for existence.
“Really, if we want to learn about the universe, the way is not to think about a book written before we even knew the Earth orbited the sun, but to ask the universe,” he said.
Krauss, wearing a Gustavus Adolphus College shirt, began his talk by stepping out from behind the podium and speaking while strolling back and forth on the stage.
He began by describing how cosmologists arrived at the modern view of what the universe looks like and how it began. Krauss said Edwin Hubble helped overturn the idea of the unchanging and eternal universe and replaced it with the expanding universe, which “changed everything.”
The next step was to investigate what the universe looks like.
The shape of the universe, Krauss said, largely depends on how much matter is in it.
“Very simply, we have to just weigh the universe,” he said. Using powerful telescopes and Albert Einstein’s general theory of relativity, scientists can weigh clusters of galaxies, the biggest known objects in the universe.
“We can use it (general relativity) to weigh this cluster because you can ask how much mass must there be in that cluster and where it must be distributed in order to get the image we get,” he said.
But there’s a problem.
“We have many good reasons to understand that there’s too much stuff there to be accounted for by all the protons and neutrons in the universe,” he said.
Scientists, “with their great linguistic perspicacity,” have termed that “dark matter.” All that really means is that no one knows what it is. Not the “slightest idea,” he said, twice for emphasis.
And most of the universe’s energy (called “dark energy) resides in “empty” space, and no one knows why it’s there. The universe we can see, all the stars and the galaxies, is only perhaps 1 percent of the total.
“So much for a universe made for us. We’re a little bit of cosmic pollution in a universe made of dark matter and dark energy. And it’s changed everything,” he said.
Krauss’ fellow scientists at the dais, especially Frank Wilczek, expressed skepticism during the question-and-answer session about some of his far-reaching statements about a universe from nothing.
“Once you start talking about the laws being random or no laws at all, you really start from nothing at all, I think that’s going too far,” Wilczek said. “I think it’s really within a specific framework that you can discuss these things.”
Krauss didn’t budge, at least not much. He admitted he couldn’t explain how the universe came to be but said it was enough to show that it’s possible that a universe can come from nothing.
“The rest is semantics,” he said.