The Science of Interstellar

Often the discussion would take off in unexpected directions, with the sheet forgotten. It was one of the most interesting and enjoyable conversations I’ve had in a long time! We wandered from the laws of physics, especially quantum physics, to religion and mysticism, to the science of Interstellar, to our families and especially our children, to our philosophies of life, to how we each get inspirations, how our minds work, how we make discoveries. I left, two hours later, in a state of euphoria.

Later I told Lynda about our meeting. “Of course,” she responded. She could have told me what to expect; Interstellar is her third film with McConaughey. I’m glad she didn’t tell me. It was a joy to discover for myself.

The next e-mail, a few weeks later, was from Anne Hathaway, who plays Amelia Brand. “Hi Kip! I hope this e-mail finds you well… . Emma Thomas passed along your e-mail in case I had any questions. Well, the subject matter is pretty dense so I have a few!… would we be able to chat? Thank you very much, Annie.”

We talked by phone, as our schedules couldn’t be meshed for an in-person meeting. She described herself as a bit of a physics geek, and said that her character, Brand, is expected to know the physics cold—and then she launched into a series of surprisingly technical physics questions: What is the relationship of time to gravity? Why do we think there might be higher dimensions? What is the current status of research on quantum gravity? Are there any experimental tests of quantum gravity?… Only at the end did she let us wander off subject, to music, in fact. She played trumpet in high school; I played sax and clarinet.

During the filming of Interstellar, I was on set very, very little. I was not needed. But one morning Emma Thomas toured me through the Endurance set—a full-scale mockup of the Endurance spacecraft’s command and navigation pod, in Stage 30 at Sony Studios.

It was tremendously impressive: 44 feet long, 26 feet wide, 16 feet high, suspended in midair; able to shift from horizontal to nearly vertical; exquisite in detail. It blew me away, and piqued my curiosity.

“Emma, why build these enormous, complex sets, when the same thing could be done with computer graphics?” “It’s not clear which would be cheaper,” she responded. “And computer graphics can’t yet produce the compelling visual details of a real set.” Wherever possible, she and Chris use real sets and real practical effects, except for things that can’t actually be shot that way, like the black hole Gargantua.

On another occasion, I wrote dozens of equations and diagrams on Professor Brand’s blackboards, and watched as Chris filmed in the Professor’s office with Michael Caine as the Professor and Jessica Chastain as Murph.[1] I was astonished by the warm and friendly deference that Caine and Chastain showed me. Despite having no role in the filming, I was notorious as Interstellar’s real scientist, the guy who inspired everyone’s best effort to get the science right for this blockbuster movie.

That notoriety triggered fascinating conversations with Hollywood icons: not just the Nolans, McConaughey, and Hathaway, but also Caine, Chastain, and others. A fun bonus from my creative friendship with Lynda.

Now comes the final phase of Lynda’s and my Interstellar dream. The phase where you, the audience, have become curious about Interstellar’s science and seek explanations for bizarre things you saw in the movie.

The answers are here. That’s why I wrote this book. Enjoy!

I FOUNDATIONS

2 Our Universe in Brief

Our universe is vast. Achingly beautiful. Remarkably simple in some ways, intricately complex in others. From our universe’s great richness, we’ll need only a few basic facts that I’ll now lay bare.

The Big Bang

Our universe was born in a gigantic explosion 13.7 billion years ago. The explosion was given the irreverent name “the big bang” by my friend Fred Hoyle, a cosmologist who at that time (the 1940s) thought it an outrageous, fictional idea.

Fred was proved wrong. We’ve since seen radiation from the explosion, even in just the last week (as I write this) tentative evidence for radiation emitted in the first trillionth of a trillionth of a trillionth of a second after the explosion began![2]

We don’t know what triggered the big bang, nor what, if anything, existed before it. But somehow the universe emerged as a vast sea of ultrahot gas, expanding fast in all directions like the fireball ignited by a nuclear bomb blast or by the explosion of a gas pipeline. Except that the big bang was not destructive (so far as we know). Instead, it created everything in our universe, or rather the seeds for everything.

I would love to write a long chapter about the big bang, but with great force of will I restrain myself. We don’t need it for the rest of this book.

Galaxies