David Gelernter’s giant macaw, Ike, has taken a tumble. One moment he was there, offering agreeable squawks as Gelernter spoke, and then, in a flash of lightning, he wasn’t. Ike is fine, the 64-year-old Yale computer scientist assures me, simply stunned. “Luckily he’s as light as a bird. So he can fall great lengths and it doesn’t bother him,” he says.