The Science of Interstellar

But one thing seems clear. Murph must have figured out how to reduce Newton’s gravitational constant G inside the Earth. Recall (Chapter 25) that the Earth’s gravitational pull is given by Newton’s inverse square law: g = Gm/r², where r² is the squared distance from the Earth’s center, m is the mass of the Earth, and G is Newton’s gravitational constant. Cut Newton’s G in half and you reduce the Earth’s gravity by two. Cut G by a thousand and you reduce the Earth’s gravity by a thousand.

In my interpretation, with Newton’s G reduced inside the Earth to, say, a thousandth its normal value for, say, an hour, rocket engines could lift the enormous colonies into space.

As a byproduct, in my interpretation the Earth’s core—no longer compressed by the enormous weight of the planet above—must have sprung outward, pushing the Earth’s surface upward. Gigantic earthquakes and tsunamis must have followed, wreaking havoc on Earth as the colonies soared into space, a terrible price for the Earth to pay on top of its blight-driven catastrophe. When Newton’s G was restored to normal strength, the Earth must have shrunk back to its normal size, wreaking more earthquake and tsunami havoc.

But humanity was saved. And Cooper and ninety-four-year-old Murph were reunited. Then Cooper set out in search of Amelia Brand in the far reaches of the universe.

Some Parting Thoughts

Every time I watch Interstellar and browse back through this book, I’m amazed at the enormous variety of science they contain. And the richness and beauty of that science.

More than anything, I’m moved by Interstellar’s underlying, optimistic message: We live in a universe governed by physical laws. By laws that we humans are capable of discovering, deciphering, mastering, and using to control our own fate. Even without bulk beings to help us, we humans are capable of dealing with most any catastrophe the universe may throw at us, and even those catastrophes we throw at ourselves—from climate change to biological and nuclear catastrophes.

But doing so, controlling our own fate, requires that a large fraction of us understand and appreciate science: How it operates. What it teaches us about the universe, the Earth, and life. What it can achieve. What its limitations are, due to inadequate knowledge or technology. How those limitations may be overcome. How we transition from speculation to educated guess to truth. How extremely rare are revolutions in which our perceived truth changes, yet how very important.

I hope this book contributes to that understanding.

WHERE CAN YOU LEARN MORE?

Chapter 1. A Scientist in Hollywood: The Genesis of Interstellar

For readers interested in the culture of Hollywood and the shifting sands of moviemaking, I highly recommend two books by my partner, Lynda Obst: Hello, He Lied: & Other Truths from the Hollywood Trenches (Obst 1996) and Sleepless in Hollywood: Tales from the New Abnormal in the Movie Business (Obst 2013).

Chapter 2. Our Universe in Brief

For an overview of our entire universe with lots of great pictures, and with connections to what you can see in the night sky with your naked eye, binoculars, and telescopes, see Universe: The Definitive Visual Guide (Rees 2005). Many good books have been written about what happened in our universe’s earliest moments, its big-bang origin, and how the big bang may have gotten started. I particularly like The Inflationary Universe (Guth 1997); Big Bang: The Origin of the Universe (Singh 2004); Many Worlds in One: The Search for Other Universes (Vilenkin 2006); The Book of Universes: Exploring the Limits of the Cosmos (Barrow 2011); and Chapters 3, 14, and 16 of From Eternity to Here: The Quest for the Ultimate Theory of Time (Carroll 2011). For current research on the big bang, see the blog by Sean Carroll, Preposterous Universe (Carroll 2014) at http://www.preposterousuniverse.com/blog/.

Chapter 3. The Laws That Control the Universe