There is a crisis in physics today, but Adam Frank sees it as an opportunity rather than a threat. Frank, a professor of astrophysics at the University of Rochester and co-founder of NPR’s 13.7 Cosmos and Culture blog, gave a talk last week at the University of Washington titled, “Beyond the Big Bang: Cosmology and Ultimate Questions.” Frank, who earned his master’s and doctoral degrees at the UW, was back on campus for the last in a series of lectures titled The Big Bang and Beyond, which was sponsored by the university’s alumni association as part of the celebration of the 50th anniversary of the Department of Astronomy.
Frank called the Big Bang a bit of “modern mythology,” an origin narrative that puts us into a cosmic context and gives the universe meaning.
“Science tells us that there is no meaning,” Frank noted. “We can argue about that. But even not having a meaning is meaning. In that sense the Big Bang is a powerful origin myth for our culture.”
While he called it an origin narrative, Frank pointed out that many people have a misconception about the Big Bang Theory.
“It is not a theory of the beginning,” he pointed out. “The Big Bang never tells you why it’s there.”
It gets close; within about 10-32 seconds of the start.
“We can do a pretty good job of telling you in detail what the history of the universe had been going back to some tiny fraction of a second after the Big Bang,” Frank said.
That tiny fraction of a second is where some weighty riddles reside. For the Big Bang to work, we have to assume that the initial conditions were the same as they are now. There’s a lengthy list of constants in the math that describes the universe, such as the speed of light and the gravitational constant. All of them have to be just so.
“You change one of those numbers by just a tiny amount and life could never form,” Frank noted. So how did we end up in a universe that is perfectly fine tuned for us to arrive on the scene?
“If you’re an intelligent design person you say, ‘Oh, it’s God that did it,’” Frank said. “If you’re a physicist, that’s not going to work very well for you. What you want as a physicist is a theory that predicts these.”
“People often talk about cosmology as being the place where science butts up against theology, but physicists don’t want that to be the case,” he continued. “They want to have coherent physical explanations for something like where the Big Bang came from.”
Coherent is in the mind of the beholder, but it may well be that such an explanation has yet to emerge. Frank refers to the most prominient ideas so far as the “standard crazy” and the “alternative crazy.” And it’s from these crazy ideas that the crisis emerges.
The first standard crazy idea is that of multiverses. With an infinite number of universes popping up all over, fine tuning is no longer an issue. There’s bound to be a universe with our exact conditions, and that’s the one we live in.
Then there is string theory, which arose out of the search for a quantum theory of gravity. String theory can reproduce standard-model particles, and it includes a gravity particle. People got pretty excited about a “theory of everything.”
There are problems within the standard crazy. Unobservable multiverses. Hidden dimensions. The existence of 10500 universes. And it all may lie beyond possible experimentation.
“People are really starting to push back on multiverse and string theory—these ‘standard crazy’ ideas—saying these things may be untestable,” Frank said. “If they’re untestable they’re not science, and if they’re not science it’s time for people to stop talking about them.”
“All of the work that was done on string theory and the multiverse may, in the end, turn out to be, in some sense, a wrong direction,” he added.
Other far-out ideas have been proposed. British physicist Julian Barbour puts forward the notion that time doesn’t exist, and that every moment is a distinct and separate now. Lee Smolin suggests that we reboot cosmology entirely, and consider that our “timeless” laws are anything but; that physical laws may in fact be evolving.
“It could be totally wrong, but it’s illustrative of the difference of where you have to go to try and think about going beyond and before the Big Bang without getting into the conceptual problems that string theory and the multiverse lead to,” Frank said.
A good crisis
Frank sees this crisis in physics as an opportunity.
“The crisis in phyics is great because what it’s going to mean is that we’re going to have to come up with even different ideas,” he said. “We’re going to have to probe our understanding of reality even deeper, and what we’re slowly heading toward is some kind of truth. It may not be the ultimate truth, but we’ve been approaching a better understanding of the world since science has begun.”
Frank said that, with a seemingly endless stream of terrible headlines in the news, he sees the search for this ultimate reality as an example of what we do best.
“Humanity is capable of such incredible stupidity and horror, and yet we’re also capable of such compassion, and such wonder, and the ability to experience such awe,” Frank said. “The quest for ultimate reality is a fundamental expression of human goodness and hope.”
- NY Times op-ed: A Crisis at the Edge of Physics
- Lee Smolin says time is real, our post about his talk in Seattle in 2013
- Adam Frank website
Books by Adam Frank