When he takes a seat on a plane, Roger Blandford has a choice to make. If he doesn’t want to talk with his seatmates, he tells them he’s a rocket scientist, which shuts down conversation quickly.
But more typically, he tells the truth—that he’s an astrophysicist—and the floodgates of chatter open. Cosmology and astrophysics, Blandford says, are “very visual” subjects. “People see all these Hubble images and so on, and I think there’s intrinsic fascination. It touches on age-old problems: ‘Where did we come from? Are we alone?’ Stuff like that.”
As director of the new Kavli Institute for Particle Astrophysics and Cosmology at the Stanford Linear Accelerator Center, Blandford oversees research teams that study physics at the smallest scales, using particle accelerators, and also at the largest scales, using the universe as a laboratory. Funded by the University and the federal Department of Energy, and dedicated in March, KIPAC seeks to answer cosmic questions: what powered the Big Bang? What are dark matter and dark energy? What happens around black holes?
Blandford taught theoretical astrophysics at Caltech for more than 25 years before coming to Stanford in 2003. A specialist in black holes, white dwarfs, gamma ray bursts, gravitational lensing and the evolution of the universe, he says today is a fine time to be an astrophysicist. “There are great questions that have been posed that are addressable, largely because of the technology we have. One way to think about it is that if you just look at the visual part of the spectrum, what we see with our eyes, that’s just one octave on a piano. And the whole spectrum that’s available to us is actually 10 pianos’ worth.”
The whiteboard in Blandford’s office at KIPAC is a tableau of his interdisciplinary work. It’s covered with red, blue, green and black equations that describe the growth of perturbations in the universe, magnetic fields and fluid mechanics, plus an incorrect formula for the acceleration of the universe. Writing in Physics Today in April 2005, Blandford noted that, “In recent years, a standard model of a flat, accelerating, underweight universe has been established that has thrown theoretical physics into turmoil.” That’s right, the universe is geometrically flat. “It’s kind of an irony,” Blandford says. “Columbus’s sailors thought the world was flat, and it turned out to be round. We thought the universe was round, and it turned out to be flat.”
By “accelerating,” cosmologists mean that the universe is expanding. “It looks like the universe was decelerating, slowing down, and now it’s speeding up—we slowed down for the traffic lights, and now we’re starting to put our foot on the accelerator.” Finally, Blandford says, the universe is “underweight” because the matter we know about (“the stuff you and I and the table are made of”) accounts for only 5 percent of what’s out there.
Finding the two unknown components—dubbed dark matter and dark energy—that comprise the remaining 95 percent of the universe is the holy grail of astrophysics. “The hope is that over the next three to five years we’ll have some understanding of the dark-matter puzzle,” Blandford says. To that end, he and some of his colleagues at KIPAC have joined two galactic enterprises. The first is the Sloan Digital Sky Survey II, which is using a 2.5-meter telescope to search for giant explosions called supernova. “We use the supernova explosions, the so-called white dwarf supernovas, as a means of measuring the rate of expansion of the universe.” And next August, KIPAC researchers will be part of the team that tracks NASA’s Gamma-ray Large Area Space Telescope satellite on a similar mission, looking for results of decays of the particles thought to comprise dark matter.
Blandford believes there is a “real crisis in science education and literacy in the U.S.,” and hopes that programs like these will “improve the level of appreciation of the triumphs, challenges and limitations of science and technology.” After all, astrophysics is something people want to talk about.
