The new movie Interstellar was directed by Christopher Nolan, who has brought us a series of mind-twisting films like Inception. This one revolves around human space travel through wormholes and black holes, and the distortion of time. Einstein’s relativity is so central to the plot that he’s repeatedly mentioned by name: juicy stuff for geeks like me.
Most folks will leave the theater with their heads spinning. Already, astronomers are being asked whether all those plot elements are really true. Let’s take a look.
Well, black holes do exist. And a wormhole, first postulated by Albert Einstein and physicist Nathan Rosen in the 1930s, and originally termed an “Einstein-Rosen bridge,” is theoretically possible. There’s not the slightest observational evidence for them, though. If they do exist, they could indeed be conduits to another part of the universe.
In the film, the astronauts talk about the dangers of landing on a particular planet because its strong gravity would make one hour pass for them while a decade passes back at home. So if they spend just three hours on the surface, 30 years will meanwhile elapse back on Earth and their children would be all grown up. They understandably do not want this to happen, so they try to make their surface adventures very brief.
Naturally, things don’t go as planned, and they ultimately realize that everyone back on Earth must now be much older. Even their crew member who waited behind for them in orbit is now decades older, and resignedly reveals that he has been patiently waiting for them all this time, even though less than an afternoon has elapsed for the still-youthful travelers.
Real science shows us that, yes, a stronger gravity would make your time slow down. Where the movie takes liberties is that if the gravity were only three times stronger than Earth’s – which is what the film’s planet supposedly has – the difference in time would be negligible, meaning that the astronauts would experience one year while back at home people would experience one year plus one second. The amount of gravity required to make time noticeably change its passage would be lethal to humans.
Another issue is that in the movie, certain characters enter a black hole and yet are rescued, with no explanation how it happened. In real life, it would be almost impossible to escape from a black hole. At minimum, the saved science-savvy characters would probably ask their rescuers some serious questions. I wonder if most moviegoers will give that piece of illogic a free pass.
Anyway, even if actual events would not unfold the way the movie depicts, there’s nothing wrong with a little suspension of disbelief. Interstellar is a very different kind of film from last year’s sci-fi blockbuster Gravity. What they share is cool science that is accurate to some degree, but has gaping lapses for the sake of the storyline. I would neither condemn nor recommend either movie on the basis of the science alone.
You’ll probably find Interstellar thought-provoking. As to whether it works for you as entertainment, only you can decide.
[Editor’s note: Congratulations, Skyman Bob, on your favorable review in the November 17 edition of the New York Times titled “Speed Reading: ‘Zoom,’ by Bob Berman, Explains How Things Move :” https://www.nytimes.com/2014/11/18/science/zoom-by-bob-berman-explains-how-things-move.html?_r=0!%5D Want to know more? To read Bob’s previous “Night Sky” columns, visit our Almanac Weekly website at HudsonValleyAlmanacWeekly.com.
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