On a hay-mown crest, dozens of people are crouching in the dark. The Earth has turned away from the sun, and the sky has flowed down a color chart, from light gray to orange to bluish-black. A sliver of a waxing moon has appeared briefly and then slipped below the western horizon, leaving the sky to blinking airplanes rising from La Guardia fifty miles to the south, to satellites gliding in low orbit, to Jupiter and its herd of moons and to the great river of the Milky Way beyond.
The crowd that sits in this chilly field in North Salem, New York, is surrounded by a ring of telescopes. There’s a Dobsonian, a giant barrel-shaped contraption that’s so tall you have to climb a stepladder to look through its eyepiece. Small, squat Newtonian cylinders sit on tripods, rigged to computers that give off a weak lamp-glow from their monitors. A few older men are fussing over the telescopes, but everyone else is huddled on the grass.
“Just get snuggly. There’s nothing wrong with that. Get snuggly.”
The voice is deep and loud–not loud from shouting, but from some strange acoustic property that gives it a conversational boom. It comes from a man who looms in the dark at the edge of the crowd.
“We still have the remnants of what we typically call the Summer Triangle,” he says. “And the Summer Triangle is three stars that are about equally bright. So, one is here–”
“Oh my God,” the crowd murmurs.
The looming figure is Neil Tyson, the director of the Rose Center for Earth and Space at the American Museum of Natural History. He has just put the crowd into a swoon by switching on a laser and pointing it towards the zenith of the sky. The green beam seems to reach up from the field and touch the star.
“And one is here, and here,” he says, sweeping the laser across the sky to mark a stellar triangle. The squatters gasp, swear again, and laugh at themselves. Tyson’s laser is creating an optical illusion: he seems to pull the sky down into a dome that floats close overhead, like an astronomical Sistine Chapel.
“Here we have Deneb,” he says. “Everyone say Deneb!”
“Good. And down here we have Altair.”
“And up here we have Vega.”
“One of the telescopes is actually trained on a star that’s in the middle of this triangle,” Tyson says, moving his laser to a faint dot, called Albireo. “It’s right there. It doesn’t look very interesting at first, but when you whip out a telescope, what you’ll find is that this star is not alone, as a solo star. It has a companion star. Albireo is in fact my favorite star of the night sky. If you look closely, one star is this brilliant, beautiful blue color and the other is gold. And we know from astrophysics what must be true if an object is glowing at one or the other of those colors. Unlike what an artist will tell you, something glowing red-hot is the coolest among all the hots. You get way hotter than red-hot. If you crank the temperature, it becomes white hot. Crank it some more, it then begins to glow blue.”
Tyson moves the laser to other regions of the sky, to the feeble North Star, to Cassiopeia, to Sagittarius. As he talks, the people huddling on the ground blast questions at him. Where is Venus? Is that a satellite? Is that a satellite? Is the Chinese calendar based on the lunar cycle? Tyson stops to answer each question. He twirls his laser in a tight circle midway down the handle of the Big Dipper.
“If you look really carefully at it, you should be able to see two stars there,” he says. “How good is your vision?”
“Awesome!” a boy says.
“I can see it!” says another.
“Okay, who cannot see two stars inside my little circle here?” Tyson asks.
“Me,” says a third.
“Okay, therefore you cannot be drafted into the Roman army,” says Tyson. “That was their eye test. So this pair of stars is called Mizar and Alcor. Mizar is the brighter of the two. Alcor is the dimmer of the two. This is a very loosely bound double-star system. If you take out a telescope and point it on Mizar, that’s a double star. Then if you take the telescope and point it on the brighter of the two stars that is the bright of these two stars, that’s a double star. So what you have here,” Tyson says, “is a double-double-double star system. All in mutual, harmonious orbit around their common center of gravity. Such is the lay-out of this cosmic ballet that we call the universe.”
For most of the people huddling on the ground, tonight is the first time they’ve spent such an extended period looking up at the sky. For three hours, Tyson keeps his audience staring so hard at the heavens he cramps their necks. He speaks of galaxies and the delusions of astrology, how to calculate latitude, the fate of the universe. It is not a lecture. He delivers something more akin to a solo concert. Although he is a card-carrying astrophysicist with a long list of scientific papers in publications like Astrophysical Journal, Tyson has turned himself into a rock-star scientist. He plays to sold-out houses. He appears on the Daily Show with Jon Stewart, on the New York Times bestseller list, on Twitter (@neiltyson, with 242,400 followers as I write this). He is now shooting a remake of Carl Sagan’s classic Cosmos series, which will air on Fox in 2013.
Tyson spreads himself so wide for two reasons. One is that there’s so much in the sky to talk about. The other reason is down here on earth. For all the spectacular advances American science has made over the past century–not just in astrophysics but in biology, engineering, and other disciplines–the best days of American science may be behind us. And as American science declines, so does America. So here, in the dark, under the stars, Tyson is going to try to save the future, one neck cramp at a time.
The profile appears in the new issue of Playboy. It’s not online at their site, but I’ve posted the full story on carlzimmer.com. Check it out.