It's getting harder and harder to tell the difference between science and science fiction.
Imagine a novel that starts like this: A speck of space imbued with a mysterious antigravity substance explodes to humongous size in a tiny fraction of a second and transforms into an entire universe. Sounds ridiculous, right? It seems a little weird even to me, and I write science fiction for a living. If I were to suggest a book like that to my editor, he'd furrow his brow and stare at me for several seconds. Then he'd ask if I could come up with something a bit more plausible.
And yet most cosmologists -- the allegedly reasonable people who study the origin and evolution of our universe -- believe this is how the Big Bang began. Their theory, known as inflation, has been gaining support over the past three decades, and last week it got a huge boost. A team of astronomers led by John Kovac of the Harvard-Smithsonian Center for Astrophysics found new evidence for inflation in the cosmic microwave background, the flood of radiation that has been streaming across the universe for nearly 14 billion years.
Astronomers love to study the cosmic radiation because it was emitted relatively early in the universe's history, only 380,000 years after the Big Bang. (But you don't have to be an astronomer to glimpse this radiation. Just get an old-fashioned analog TV and tune it between two channels. See the static on the screen? About one percent of it comes from the cosmic microwaves.) Kovac's team focused on the microwaves' polarization -- that is, the orientation of their wave oscillations, which can reveal a great deal about how the radiation was produced. The researchers observed swirling patterns of polarization that they believe are relics of the explosive instant of inflation that created our universe.
The mysterious substance that supposedly triggered inflation -- the so-called inflaton field -- will probably sound familiar to science-fiction fans. Although scientists have never observed this field and can only guess how it works, they hypothesize that it exerted an antigravity force, much like the futuristic starships in so many space-opera tales. According to cosmologists, the inflaton field stretched a minuscule region of primeval space into a gaping void, then filled the void with the hot, dense soup of matter and radiation that grew into our universe. The field's powers seem godlike. As Star Trek's Mr. Spock might say, it's a being of pure energy.
The evidence for inflation comes from the subtle traces it apparently left behind. Inflation would have produced slight variations in the density of the primordial soup, which astronomers have detected by measuring temperature differences in the cosmic microwaves. Last week's discovery provided even stronger evidence, though, because the polarization of the radiation seems to have been caused by gravitational waves -- ripples in spacetime, predicted by Albert Einstein but never directly observed before. A gravitational wave stretches and squeezes the space it passes through. If a strong wave hit you, it would make you taller and thinner at one moment, then shorter and wider in the next. (Just think how awesome this would look in a movie. Get the director of Gravity on the phone! I have an idea for a sequel!)
Inflation would have generated enough gravitational waves to stir the primordial soup for hundreds of thousands of years afterward, leaving telltale patterns in the cosmic radiation. Unless further scrutiny shows that the observed polarization was actually caused by space dust or another astrophysical phenomenon, the discovery will solidify the case for inflation and weaken alternative creation scenarios that don't produce gravitational waves. What's more, the new findings specifically bolster the so-called "eternal chaotic inflation" hypothesis, which posits that there are other universes besides our own. According to this theory, inflation is a never-ending process. In an unreachable and unobservable sector of reality, the inflaton field is continuing to trigger Big Bangs and spawn new universes, including some with physical laws that may be completely different from ours.
The idea of multiple universes is another science-fiction staple, of course. There are countless books and movies and TV shows about alternative-history universes and parallel worlds. My favorite example is Star Trek's mirror universe, in which the evil doppelgänger of Mr. Spock commits murder and mayhem while wearing a sinister-looking Van Dyke beard.
But sometimes science is even more fantastical than science fiction. The story of how Kovac's team measured the polarization of the cosmic microwaves would make a cracking good novel. For nearly three years the astronomers scanned a patch of sky using an array of more than 500 detectors propped above the Antarctic ice, less than a mile from the South Pole. The researchers chose this location because the atmosphere above the high Antarctic Plateau is thin, dry and clear, making it ideal for observing microwaves. As Kovac says, "The South Pole is the closest you can get to space and still be on the ground."
I'm imagining an astronomer in a voluminous parka standing beside the detector array as a bitterly cold wind scrapes the ice. She looks up at the night sky that covers this part of our planet for six months at a time. The stars are incredibly bright against the blackness, but she's not looking at the stars. She's staring at the vast dark space between them. She's trying to see the hidden past and the unknowable future. She's trying to glimpse eternity.
Mark Alpert is the author of the science-fiction thriller Extinction and the forthcoming novel The Furies.
