Sunday, November 16, 2014

Astrophysical problems with Interstellar movie

The dubious physics of movies like Gravity have gotten attention, but the cosmologists seem much more fired up about Interstellar. I have not seen it yet.

Lee Billings writes in SciAm:
Christopher Nolan’s new film, Interstellar, is a near-future tale of astronauts departing a dying Earth to travel to Saturn, then through a wormhole to another galaxy, all in search of somewhere else humanity could call home. ...

If you watch movies for what they do to your mind rather than to your heart, though, the film may leave you less than starry-eyed. Despite being heavily promoted as hewing close to reality—Caltech physicist Kip Thorne wrote the first version of the story, and served as a consultant and producer on the film—some of the science in Interstellar is laughably wrong. Less lamented but just as damning, some parts of the story having nothing to do with science lack the internal self-consistency to even be wrong. ...

Much has already been written about the film’s scientific faults, pointing out fundamental problems with the astrophysics, planetary science and orbital mechanics that underpin key plot points. Just as much ink has been spilled (or pixels burned) saying that such details shouldn’t get in the way of a good story, that this movie wasn’t made for the edification of scientists but for the entertainment of the general public.
Based on reviews, it sure seems to me that this movie was made for the edification of scientists. They took every peculiar aspect of relativity, and worked it into the plot as well as they could. Time dilation, black hole, wormhole, twin paradox, closed timelike curves, and loss of information in black holes. And probably a couple of more that I might not catch even when I see the movie.

Sure, they could have made a more realistic movie, or a more coherent plot. Or just invented their own science fiction, like Star Trek. No, they made a deliberate decision to pack as much relativity in the movie as they could, and still have a marketable movie.

Does it work? I will form an opinion when I watch. I'll try to view it for what it is: a relativity show on a $150M budget.

Update: NY Times Dennis Overbye says that he had to study the physics and watch the movie a second time to appreciate it:
The second time I saw the movie, clued in by Dr. Thorne’s new book, “The Science of Interstellar,” I enjoyed it more, and I could appreciate that a lot of hard-core 20th- and 21st-century physics, especially string theory, was buried in the story — and that there was a decipherable, if abstruse, logic to the ending. But I wonder if a movie that requires a 324-page book to explicate it can be considered a totally successful work of art. ...

At one point, director Nolan asked for a planet on which the dilation of time because of immensely powerful gravity was so severe that one hour there would correspond to seven years on Earth — an Einsteinian effect that plays a big role in the plot. Dr. Thorne’s first reaction was “no way.” But after thinking about it, he says he found a way, which would require the planet to be very close to a massive black hole spinning at nearly its maximum rate. The hole would spin space around with it, like a mixer swirling thick dough.

The planet could get its heat and light from the disk of heated material swirling around the hole, Dr. Thorne calculated, as long as the hole was not feeding too strongly — a rather carefully tuned but not impossible situation. The black hole itself sprang directly from Dr. Thorne’s equations, and its renderings by the movie’s visual effects supervisor, Paul Franklin, showed details that Dr. Thorne plans to write papers about.

Wormholes are another thing that easily pass the beer test. Einstein himself pointed out that such shortcuts through space-time were at least allowed by his equations, but nobody knows how to make one or to keep it from collapsing, or how to install one near Saturn without its gravitational field’s disrupting the entire solar system.

Ditto the fifth dimension, a logical consequence of various brands of string theory. ...

“So why did they take care with relativity but not even bother with planetary science?” he went on. “Arthur C. Clarke is spinning in his stargate!”
So the relativity is bizarre, but it makes more sense than the rest of the movie.

Update: Kip Thorne has more movie explanations.

1 comment:

  1. Roger,
    Please post your reaction to the movie when you see it. Just remember that just because a movie is incredibly silly does not mean it was meant to be laughed at. I almost got thrown out of Jurassic Park because I couldn't stop giggling at the hapless humans trying so desperately to be eaten by dinosaurs.