Stellar Movie Fudges Science

picture of Harry KellerBy Harry Keller
Editor, Science Education

Interstellar is a great story with excellent acting, especially from Matthew McConaughey and Mackenzie Foy. For me, the three hours felt more like a normal two. Like the characters in the movie, I was asking where the time went.

In the not-to-distant future, maybe 20-30 years, the Earth is in real trouble. All efforts are now focused on food. Climate change has destroyed much of our ability to grow crops. National budgets have even eliminated defense spending.

InterstellarCooper, a former NASA test pilot, is now a farmer struggling against ever-increasing problems of drought and blight. He stumbles across strange gravity messages that direct him to the remnants of NASA run by Professor Brand (Michael Caine).

The film revolves around the relationship between Cooper and Murph (Foy and, later, Jessica Chasten, and, even later, Ellen Burstyn). This is the emotional center of the movie and the important love story. Oh, there’s another standard love story as well but one that definitely is not strongly promoted in the story.

Needless to say, there are adventures and sacrifices made, and the intrepid astronauts save the world through a combination of love, luck, and lots of fancy mental gymnastics.

If you’ve seen a trailer, you’ve seen a mountain-size ocean wave approaching people standing in calf-high water. These waves are continual on this odd planet and also are completely unexplained and irrational. What force could have moved so much water — over and over again? This is just the beginning of making this movie exciting while ignoring reality. 

This planet, the one with the monster waves, is near enough to a black hole to cause extreme relativistic time dilation. The tidal forces from the black hole at such near range would tear the planet apart. The problem here is that gravity decreases with distance, a fact that we have known ever since Newton gave us his famous universal theory of gravity. The near side of the planet in such a strong gravitational field would feel a much stronger force than the far side. As a percentage of the gravitational field, it may be modest, but when applied to gravity strong enough to be seriously relativistic, the planet could not survive.

There’s a scene in which the spaceship swings around the black hole in near proximity to the event horizon. To their credit, the movie makers did not show the black hole as black. However, the same tidal forces would have torn the ship apart. The strong, high-energy radiation coming from the matter falling into the black hole would have fried the crew and electronics on their ship as well.

There’s a planet of frozen clouds that you can land on and walk on. How those clouds remain afloat is unclear. They could never have formed in the first place, but they make a clever plot device.

For me the oddest part of the movie was not the unscientific parts but the strange juxtaposition of old and new technologies. Rocket propulsion was totally 20th century, but they have cryogenic sleep capabilities. The farm equipment looks like a few decades ago today, but they are able to construct a gigantic spinning cylinder in space inside of which people can live with farms and baseball fields and all of the rest of normal living conditions. The spinning creates gravity. The blight is gone inside of this cylinder out near Saturn. They must have nearly unlimited power to operate this environment out in such a remote location. Despite this very advanced capability, they cannot save their own planet. It doesn’t fit.

Gerontological medicine has not advanced at all. Lifespans remain the same. They should either have lengthened due to medical innovation or declined due to the environmental damages to the planet. We see children coughing from the omnipresent dust presumably clogging their lungs.

Science teachers: If your students have seen this movie, have them discuss these issues. Just talking about building one of those Rama-like (from Arthur C. Clarke’s books) cylinders involves tons of science and engineering. Can the future influence the past? Could Cooper have sent a message telling people to keep him from the space flight and thus create a time loop paradox?

The story is tough and tender, wonderful and worrying. You should enjoy it, but only if you turn off your fudging-science antennae.

One Response

  1. Time loops and their associated paradoxes cause lots of fuzzy thinking.

    Let’s take the one involving Coop in Interstellar. Because he made the wormhole trip, he was able to return to the past and provide the information necessary for him to make that trip.

    How did this loop begin? It should have begun at the beginning. However, in the ordinary flow of time, he would not have seen the messages and would not go to where he could provide those messages.

    In simplest terms, there is no way to start the time loop. It never could happen because the start depended entirely on the results of the start. No start means no results and no way to get started.

    Once you have a time loop, even though you cannot get one in any ordinary way, you have the problem of using the time loop to break it. Again in simple terms, you can send a message to the past that interrupts the loop and destroys it. However, the broken loop means that the stopping message never could be sent, and the loop was never broken. But not breaking the loop means that it was broken — and so on forever.

    Of course, we can view the past, but changing the past would create impossible situations that would, in effect, bring down the entire space-time structure of the universe. Not going to happen.

    We cannot view the future for the same reasons. Seeing the future means that we can change it. Any glimpse of the future must be probabilistic. That is, we can only see possible futures and never can see a certain future that we have any chance of altering today.

    When you understand how traveling faster than light speed, even using a wormhole, means traveling in time, then you understand that we will not be traveling faster than light — ever.

    I have figured out a way to send messages faster than light — sort of. I’ll be using this concept in my next Martian Music novel to allow real conversations between Earth and Mars in the future. Just know that there’s no free lunch, even in this case. You always pay for what you get.

Leave a comment