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. Now where was he? Oh yes, Gelernter was in the middle of telling me about his plans to revolutionize social media—emphasis on revolution.