‘Cosmos’ Tells a Ghost Story Like No Other

Do you believe in ghosts? What about time travel? After seeing the latest episode of ‘Cosmos’, you most certainly will.

These ghosts aren’t the wandering spirits of the human dead, but the pale light of the stars in the night sky. Even though light travels faster than anything else in existence (299,792,458 meters per second, to be precise), it still takes years or centuries or even eons to reach our eyes. That means many of the stars we see died long before life on this planet even began. When we observe the night sky through a telescope, we’re peering back in time. It’s ‘A Sky Full of Ghosts,’ as the title of the episode describes.

But can we peer forward in time? Neil deGrasse Tyson says so. Our sunrise is an illusion. We see a mirage of the sun minutes before it ever actually appears above the horizon (which is itself a mirage, but we won’t go into that here). That’s because our atmosphere bends the already eight-minute-old light of our star, projecting a future image of a sun we’re not physically capable of seeing yet. It’s a fascinating example of space, time, light, and gravity conspiring to create a little magic.

There is another way to see into the future, if scientists’ predictions are correct. Within a black hole, the laws of physics break down, but if you could cross the event horizon—like Tyson can in his Spaceship of the Imagination—you might be able to look out at the cosmos and see its future history play out before you. Unfortunately, even if you could get in, you couldn’t get out; nothing escapes a black hole, not even light.

This sequence, where Tyson drives into the heart of a black hole, and speculated universes beyond (you’ll have to watch him explain that one), is one of the most visually stimulating sequences we’ve seen so far, even in a series packed with gorgeous special effects.

Last week’s episode devoted a great deal of time to animated sequences depicting the efforts of Newton and Halley to unlock the secrets of gravity. It was a very straight-forward story of two geniuses working together to solve a problem. In this episode, William Herschel shares a touching moment with his son in which he explains the ghosts in the sky. These touching segments feel less like a historical drama and more like a moment from our own lives. ‘A Sky Full of Ghosts’ may be the strongest entry into the series yet in terms of balancing human drama with the romance of science.

It’s made all the better by the sense you get from Tyson that he’s having the time of his life. When he’s turning off the gravity on a busy New York street or gripping the arm rest of his captain’s chair as he experiences black hole turbulence, you can’t help but share in his glee. He’s on an adventure, and we’re right there with him. It all feels like a sci-fi epic, but its factual basis makes it that much more exciting.