Bad Bad Movie Physics

Bad Bad Movie Physics

Bad Bad Movie Physics

Bad Astronomy
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March 16 2008 10:15 PM

Bad Bad Movie Physics

I like the scifi blog io9, I really do. I read it every day, and I get a huge kick out of it (though avoiding the Doctor Who spoilers is tough).

But they had a post recently that kinda, well, blew it epically.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  


The topic was bad physics in movies. You might think that my calling them out on this is just due to insane jealousy on my part because they're getting to be a popular blog and they didn't link to my movie reviews even though I was among the first (if not the first, thankyavurrymuch) to review the science in movies on the web, and of course being an honest man I cannot necessarily dismiss that. Happily, though, my ego has the ability to charge on undeterred.

The io9 folks decided to rate several popular movies on how they treated various topics in physics, like faster-than-light (FTL) travel, communicating with aliens, sound in space, and so on. They did it like a check list, so if a movie abused a given topic, it got a check in that column.

Problem is, they got a whole lot of things wrong in their checklist! For example they only fault the Star Wars movies and The Last Starfighter for having FTL, when nearly every movie on their list has it.

So here is a more complete dissection of their list. Think of it as a check on the io9 checklist, sorted by movie:


1) 2001: They correctly said it didn't have sounds in space, which is good, but then said it had a "weird depiction of exposure to vacuum". Weird? It was actually pretty accurate, and it's rare to this day to have a movie treat this topic even close to correctly.

io9 than gave 2001 a check mark in the "people move in slow motion in zero gravity" category. I would say that's a tough call; people in the movie move carefully in microgravity (a better term for it, though a lot of folks still use "zero-g"), not necessarily slowly. You don't go zipping around in microgravity, you have to move a bit slowly to make sure you don't launch yourself across the cabin.

Finally, they don't rate 2001 as having FTL, but it does! In the end, when Dave Bowman takes The Ultimate Trip, he's flying through the galaxy using wormholes or some such thing.

2) Contact: They don't give it a check mark for FTL, when again that was in the movie. Actually, that was the whole purpose of The Machine, and was the whole point of the ending of the movie when Ellie has to present her science as if it were faith.


3) Armageddon: I am no fan of this movie (which is like saying black holes suck a little, or a supernova is a slightly energetic event), but io9 gave it a check under "Nearby asteroids aren't drawn close by gravity". I was scratching my head over what that meant, but then saw a helpful description at the bottom of their post:

Asteroids or other objects shouldn't be able to float close together without falling into each other's gravity.

Well, that just raises further questions (for you Futurama geeks out there)! I'm not sure precisely what they mean by that, but gravity doesn't works like a crane, reaching out and grabbing stuff and instantly moving it around. Also, and it pains me greatly to say it, as I recall Armageddon doesn't mention the Earth's gravity affecting the orbit of the asteroid; but just because they don't mention it specifically in the script doesn't mean you can give them a demerit.

4) Deep Impact: Once again, we get a check mark in that asteroid category. The only thing I can figure out for this in the movie is that the two chunks of the comet drift apart, and don't fall back together. But the movie had it right! The two chunks separate after the detonation of a nuclear weapon under the surface of the original comet. Each of the two pieces of the comet are far too small to have enough gravity to pull significantly on the other. So they essentially orbit the Sun freely.


Did I miss something here? Any ideas from my BABloggees? I'd ask io9 in a comment but my account there doesn't allowed me to leave comments.

5) Mission to Mars: They forget to note that there was FTL at the end of the movie; Gary Sinise's character uses it to go to the alien homeworld. I would also give the movie a half-check under "Easy communication with aliens" topic, too.

6) Serenity: They give this one check marks under "All planets have Earth gravity" and "All planets have one climate world-wide". There is a narration at the beginning of the movie that specifically discusses terraforming, so you can't fault the movie that. While we don't have the tech now to terraform a planet, we know in principle it can be done. Firefly and Serenity both establish they have artificial gravity, though I suppose you can legitimately call them on that since there isn't anything in well-established physics today that would allow that (though it's impossible to say what will happen in the next few hundred years).

7) Stargate: io9 gave them no check for FTL. Um, what's the title of this movie again?


8) "Alien" franchise: They give it a demerit for having interbreeding between aliens and humans. But that's not really what was happening; humans were hosts, not contributing any DNA. Update: See the comments below the post; I concede that in the last two movies there was a limited form of interbreeding, kinda sorta. It was clear in the movies that the aliens were incredibly tough, resilient, and flexible for different environments. It's not too much to ask that humans could be walking (well, sleeping) incubators for them. Also, the movies had FTL, which again went unchecked.

9) Enemy Mine: io9 didn't have it checked under FTL.

10) They gave Apollo 13 a clean bill of health, which is true enough (though you'll note the astronauts do in fact move slowly in microgravity), but the movie did have other (mostly trivial) accuracy errors, mostly due to combining different things from different Apollo missions for the sake of storytelling, which I'll forgive (especially since it's such an awesome movie).

11) They also gave The Right Stuff a clean bill of health, which is fine. My nitpick isn't with the movie so much as with the book; the author made the astronauts look like posers, and the test pilots the real heroes. I object to that because it's hugely unfair to the astronauts; both parties played their parts in history, and both showed incredible aptitude, bravery, and intelligence.


So there you go. As I learned long ago, nitpicking the science in movies is fun, and makes for a great blog entry, but in my opinion the io9 author in this case missed a lot of stuff, and was arbitrary about others.

I may have missed a few examples, too. The only movie on their list I've never seen is Solaris, so there might be something there too (I never saw Alien 4 either, having learned the franchise was dead and buried with Alien 3, but I assume there's nothing there that wasn't in the first three).

The hard part with all this, I've learned, is to know when a little snark is deserved and when it isn't. I make mistakes too, even in my own areas of expertise, and sometimes I deserve a little teasing and sometimes it's just an honest mistake. I don't mean to be mean to io9, and had they made a few mistakes I wouldn't bother commenting. I think the article would have been vastly improved with some details; specific examples from the movies to elucidate their points. They obviously spent a lot of time researching this (read: watching lots of movies), so that extra step wouldn't have been too hard.

Again, I still love io9 and I won't slow down drinking from their firehose of scifidom. There are lots of scifi blogs on the web, and even with this stumble io9 is among the best I've read.