‘Golden Age’ of Astrophysics Yields Flood of Data
“We know they’re not Klingons.”
Way back in 1997, that was one of the few things Caltech astrophysicist Shri Kulkarni could say with confidence about the stupendous bursts of gamma rays picked up by newly launched satellites. Just three years later, Kulkarni reported at the recent Texas Symposium on Relativistic Astrophysics that astronomers have tracked down and studied nearly two dozen of the bursts, pinning down their locations (unimaginably far away) and probably their sources (the last gasps of massive stars).
And that’s only the smallest drop from a flood of data now raining down from the skies on astrophysicists.
“We use the term Golden Age,” said University of Chicago’s Michael Turner at the meeting in Austin. Never have so many sets of eyes fixed on the sky come upon so much that’s entirely unexpected. Seeing stars is the least of it.
Consider, for example, the preliminary results announced at the meeting from the Sloan Digital Sky Survey, an ongoing census of more than a million galaxies designed to create a map of the universe at large. With barely 2% of the data in, the astronomers have already harvested thousands of new distant quasars, in addition to strange phenomena like highly magnetic white dwarfs.
What’s more, they’ve found stars lying so far out on the fringes of our Milky Way galaxy that they are 8 to 10 times beyond where the galaxy was previously thought to end. “It’s very confusing,” said Bruce Margon of University of Washington. “What are they doing out there? They’re absurdly beyond any stars in the normal galaxy.”
And it’s not just a few. It’s dozens. “We found two or three last night,” he said.
Even the Hubble Space Telescope, an old standard by now, continues to turn up new things under the sun--and way beyond it. University of Texas astronomer Craig Wheeler used Hubble to take a more careful look at the star that exploded recently in our own (cosmic scale) backyard, known as Supernova 1987A. Instead of spreading out in a spherical pattern, the material from the star seems to have squirted out in two narrow jets, producing a fat pancake in the center. Wheeler demonstrated this effect at a news conference at the symposium using a bread stick (the jets) inserted into a bagel.
And if his interpretation is right, it would mean that the traditional picture of how these stars explode “is substantially and importantly wrong,” Wheeler said.
Meanwhile, theorists are still struggling to make sense of the discovery two years ago that distant galaxies appear to be accelerating right off the edge of the visible universe--as if some kind of repulsive gravity were at work.
“That was a surprise,” said Princeton’s Paul Steinhardt. “It was something we were forced to consider, due to observations.” The explanation he favors for the strange force is something called quintessence, a field that varies over space and time something like a very slowly changing magnetic field; it would be just now revving up to take over the universe (don’t worry; it’ll take a few billion years).
The theory is tentative, to say the least. In fact, the landscape is changing so fast, says Turner, that “Everything that anybody says is wrong.”
The flood is pouring, not just from telescopes, but from an eclectic array of new and planned instruments: balloon-borne experiments, satellites measuring everything from the echoes of the Big Bang to X-rays from black holes, gravity wave telescopes, and detectors poised deep underground to trap the elusive “dark matter” particles that make up most of the universe.
Even particle accelerators are getting into the act, trying to find the same dark matter particles in the debris of subatomic collisions. With luck, the accelerators could soon be seeing even more exotic stuff--signs of extra dimensions of space, for example, or vibrating bits of “vacuum.”
“These are things that would have been considered metaphysics when I was in grad school,” said Mike Witherell, director of the Fermi National Accelerator Laboratory near Chicago.
All in all, Steinhardt said, “it makes for an incredible period. We’re seeing stuff we never imagined.”
Of course, no one imagined gamma ray bursts before they were detected by accident in the early 1970s. The “telescopes” that first picked them up were military satellites spying for evidence of secret Soviet nuclear blasts.
“That’s what you always hope,” said Fermilab physicist Al Goshaw recently. “That you’re going to be surprised.”
If so, next week should mark the beginning of a very good year for physics. And an even better millennium.
*
Cole can be reached at kc.cole@latimes.com.
