Physicist spins latest theories for UD crowd
By VICTOR GRETO
You could either feel awe-inspired or small, listening to Max Tegmark's lecture at the University of Delaware on Wednesday afternoon on the probability of the existence of parallel universes mimicking or diverging from our own.
Tegmark, a professor of physics and astronomy at the University of Pennsylvania, discussed the multiverse (more than one "uni-" verse) with a standing-room-only group of more than 50 budding physicists and assorted philosophy, biology and science majors at a UD Department of Physics and Astronomy lecture.
Of course, your reaction depends upon your point of view.
If you're still reeling from the counter-intuitive fact that the Earth is not located at the center of the universe - let alone the solar system; that our solar system is tucked away in some obscure outer arm of a milky swirl of stars; and that our galaxy is but one of a lot more hurtling at enormous speeds through icy and indifferent space - Tegmark's theories that multiple versions of yourself probably exist out there, somewhere, makes old-fashioned common sense seem even more irrelevant.
"There may be at least a thousand parallel universes out there," Tegmark told his audience, and it's all based on the latest measuring capabilities and mathematical equations devised by physicists in the past few years.
Tegmark has published many articles about the subject in academic periodicals and more mainstream magazines, including "Scientific American." Born in Sweden, he earned a doctorate from the University of California at Berkeley and post-doctorate degrees in Europe and at Princeton.
According to Tegmark, the most popular and simplest cosmological model today predicts that there is another you not a short distance from us doing - exactly or approximately, depending on those unpre- dictable quantum mechanics - what you're doing now: eating breakfast, riding in a carpool, or wrinkling your brow and rolling your eyes.
Your alter ego thinks he or she's your true self, of course, just like you do. Hearing that eerie "Twilight Zone" theme music yet?
As Tegmark argued, if space is infinite and the distribution of matter is relatively uniform, then even the most unlikely events must take place somewhere.
In other words, there are an infinite number of inhabited planets with people who not only look like you, but have nearly the same sort of experiences.
That idea intrigued junior Stephanie Smith, 20, a physics major who wants to work for NASA devising space travel technology.
"I always wanted to be a child prodigy," she said, after the lecture. "If there's another 20-year-old Stephanie out there, she may be a scientific child prodigy because, maybe, she got the right toys when she was a kid."
We "know" that the universe is infinite and relatively uniform, Tegmark said, because cosmic microwave background experiments have ruled out old ideas that the universe is like a four-dimensional sphere or doughnut, implying that it's actually rather simple and infinite. Maps of galaxy distribution also have shown a uniformity in the distribution of matter.
So, evidently, the universe just goes on and on and on.
These are the kinds of ideas that got people killed just a few hundred years ago, and not just because they are personally disconcerting. In 1600, theologian-philosopher Giordano Bruno was burned at the stake in Italy for heresy; among his ideas was a claim that there were more worlds out there than anyone could imagine.
Last night, when he was done, instead of getting roasted alive, Tegmark was applauded. After all, the mathematical elegance of the possibility of a multiverse can be inspiring.
"I don't understand a lot of it," said Lauren McCulley, 18, also a physics major. "It's the different possibilities that make it awe-inspiring."
There are at least three other possibilities, Tegmark said.
How about an infinite number of inflating bubble-like universes, theorized to help explain why certain phenomena, predicted by physics to occur just after the Big Bang (the boom that started our version of reality), didn't occur.
Or how about a quantum theory view that the multiverse evolves from a "wave function," without any split; it's us, inside the wave function, who see only a tiny fraction of reality.
Or how about a multiverse of infinite mathematical structures?
"There has to be other universes," McCulley said. "It makes sense mathematically."
But pragmatically, none of this may make a difference to you. You may be like the 18th-century critic Dr. Samuel Johnson, who responded to one philosopher's theory on the nonexistence of matter by kicking a large stone and shouting, "I refute it, thus."
But it's not just metaphysics, Tegmark said. It's based on testable criteria.
"If there's one thing you get out of this," Tegmark told the students, "is that a theory can be eminently testable even if it contains unobservable entities within it."
Kicking a rock just isn't enough anymore.