Imaginary Time

Stephen Hawking, the famed physicist made an appearance last night on HBO's "Last Week Tonight," and had a deep and meaningful conversation with host John Oliver. Well, at least Hawking's side of the conversation was deep and meaningful.

Oliver asked him what was the one thing he most wanted people to grasp.

Hawking replied: "Imaginary time."

"Imaginary time is like another direction in space," he said. "It's the one bit of my work science fiction writers haven't used."

Imaginary time is a concept derived from

quantum mechanics and is essential in connecting quantum mechanics with statistical mechanics.

Imaginary time can be difficult to visualize. If we imagine "regular time" as a horizontal line running between "past" in one direction and "future" in the other, then imaginary time would run perpendicular to this line as theimaginary numbers run perpendicular to the real numbers in the complex plane. 

Imaginary time is not imaginary in the sense that it is unreal or made-up — it simply runs in a direction different from the type of time we experience. 

In essence, imaginary time is a way of looking at the time dimension as if it were a dimension of space: you can move forward and backward along imaginary time, just like you can move right and left in space.

Honestly, I though that all sci-fi was written merely by adding blood, gore, and sex to the work of scientists. So why haven't sci-fi writers built stories around imaginary time? "They don't understand it," he said.

Most importantly, however, Oliver wanted to know about artificial intelligence. Like so many artificial things, it carries with it the idea that it could be noxious or even deadly.

Hawking was very reassuring: "Artificial intelligence could be a real danger in the not too distant future."

Hawking, though, believes that it might be irrelevant what the nice boys from Google think. For your average robot could simply "design improvements to itself and outsmart us all."

Oliver, channeling his inner 9-year-old, asked: "But why should I not be excited about fighting a robot?"

Hawking offered a very scientific response: "You would lose."

Oliver began to worry that Hawking wasn't talking to him at all. Instead, this could be a computer spouting wisdoms. 

Hawking replied: "You're an idiot."

But isn't this the essence of humanity? 

For all that we believe we know, the one thing we know best -- at least when we're honest with ourselves -- is that we're idiots. 

What we don't know far exceeds what we do.