What if the future is as real as the past? Physicists have been suggesting as much since Einstein. It’s all just the space-time continuum. “So in the future, the sister of the past,” thinks young Stephen Dedalus in Ulysses, “I may see myself as I sit here now but by reflection from that which then I shall be.” Twisty! What if you received knowledge of your own tragic future—as a gift, or perhaps a curse?

With the entity formerly known as Twitter vanishing in the rearview mirror, here are two articles from the early days, when we wondered what it was and what it might become. A global conversation? A mosaic of communities and interests? Perhaps you remember.

If you could choose one superpower—to fly, or to be invisible—which would you pick? If you were invisible, what would you do?

Dreams of invisibility in a world of ubiquitous surveillance.

Stephen Hawking surrounded himself with a cloud of myth, made himself into a commercial product and an international brand. The celebrity eclipsed the scientist. There’s a scientific story to tell, and most of Hawking’s later life served to conceal it.