Alright, back to business as usual this week as I answer a question that was anonymously sent to me via the feedback form at the bottom of the column:
In movies like “Sunshine” and “The Core,” could you really use a nuke to restart the earth’s core or the sun?
Great question. I’m gonna be honest, I had never seen either of the two films. I’ve caught some parts of The Core on TV before, but haven’t really seen it in its entirety. So I watched them both. The short of it is: absolutely bloody not.
Sunshine is a great movie and actually scientifically possible, while The Core is the main reason why I wish the Earth’s core would stop moving just so future generations could be spared its atrocity.
For those of you who haven’t seen either of these films- they’re basically the same general concept except one goes up and one goes down. In Sunshine, the sun has stopped its fusion. Mankind sent up a team to restart using the biggest fucking nuclear bomb ever, they went missing. Cillian Murphy heads a second mission. The movie is really more of a psychological introspection than straight-up disaster film. And it really embodies the Science Fiction spirit- humanity meeting the challenges of nature by embracing technology and reason. It’s a wonderful film.
The Core is about the earth’s core halting its rotation, this fucks things up, and Aaron Eckhart goes down with a team of scientists to restart it using a nuclear warhead. It’s hammy, dumbly written, poorly acted, and might just be the movie with the worst grasp of science (though Sunshine has plenty of inaccuracies on its own).
The Core is so scientifically fucked up that I don’t even know where to start. Hollywood scientists lack a key piece of scientific methodology. Something called “scientific modesty.” Scientific modesty is when scientists don’t open their mouths until the data is in and processed. So, when Aaron Eckhart’s character takes five seconds to look at a bunch of dead people before concluding that they all died from failing pacemakers. What he’s lacking is scientific modesty, he’s speculating on the color of socks before looking at their ankles. Maybe he’s a psychic geologist, I don’t know.
Also, when Eckhart discovers that the Earth’s core has stopped rotating and the magnetic field is collapsing, no one else has apparently noticed this. Let me just stop and comment on how preposterous that is: any random boyscout who looked at a magnet would notice something awry when it started going absolutely bat-shit crazy. Eckhart then discusses the possible effects of electromagnetic radiation on the earth by lighting the aerosol from a can of hair spray and burning a peach.
Here’s the thing about all this: electromagnetic radiation doesn’t matter at all. Electromagnetic radiation–such as microwaves–does not interact with a magnetic field. Wanna try an experiment? Grab a flashlight and a magnet and shine the light on the magnet. The light (a form of EM radiation) will not bend around the magnet, it will never bend around any magnet, no matter how strong. Also, the Sun doesn’t really release a whole lot of electromagnetic radiation at all. Electromagnetic radiation would mess with radio waves and cell phone signals- but not really have any serious health effects.
The earth’s magnetic field protects us a little bit from solar wind- bands of charged particles and plasma. Without the magnetic field, earth’s atmosphere would be stripped away. I’ll tell you what WOULDN’T happen, though, a beam of radiation wouldn’t descend from the heavens and boil the sea.
So, our heroes decide to drive a big train into the earth where almost all of them pretty much die. First off, why not just send an unmanned vehicle? That just seems like useless deaths. Second off, nuclear detonations would never work. The largest nuke ever set off was a 100 megaton warhead detonated by the Russians in a test and weighed 30 tons. The largest warhead in the United States arsenal is 9 megatons. In the movie, the team sets off five 200 megaton bombs in succession to start turning the core again. Problem is, the force of the rotation of the solid iron inner core is roughly equivalent to some 340 of those 200 megaton bombs. That’s not to even talk about the much larger molten iron outer core (with a rotational force akin to 32,000 200-megaton bombs), both of which have to be rotating to create the magnetic field.
So the nukes don’t have enough force to start the cores spinning again. But that’s okay, because the vast majority of the force from the explosions wouldn’t even go towards that rotational force. Those explosions would propagate outwards in a sphere, so most of the force would be completely lost.
There is one thing that The Core gets right where most other movies get it wrong. And that’s convection. Things that are hot exude heat some distance away from the actual thing. To put it more simply, getting close to a hot thing makes you hot too. Getting close to lava would be just as dangerous as actually touching lava. Most video games and movies completely ignore convection, The Core does not. In the movie, the lava-train malfunctions and some unlucky schmuck has to go outside and fix it. The problem is that they’re drilling through the mantle and the crawlspace they have to go into is extremely hot. True to reality, the person who goes out there gets burnt to an absolute crisp.
Sunshine is actually pretty much scientifically sound. There are a few minor problems in the film: weightlessness doesn’t work how they protray it, and when the crew is moving from ship to ship, they say that the temperature is -273 °C. This is what’s known as “aboslute zero,” the temperature at which molecules stop moving and there is no thermal energy left in the substance at all. The vacum of space is actually usually a little warmer than that, pretty much nothing could last in absolute zero.
The core mechanic (no pun intended, for once) of the film is actually plausible. They even hired NASA advisers to help with solar physics. Fusion is the process that powers our sun, the intense heat and pressure force two hydrogen molecules together into a helium molecule (and releasing a shitload of energy).
When our sun stops fusing, it’s because it has fused all the hydrogen into helium. Bigger suns have more heat and pressure at their core and are capable of refusing the helium into other elements (that’s where the rest of the periodic table comes from), but our sun is too small. That’s why the team in Sunshine detonates a humungous fusion bomb (the size of Manhattan) to force-start helium fusion. This nuclear detonation would actually work, unlike in The Core, you would not need the explosive force to go in a specific direction. You just need enough force and energy to fuse the helium together in the core.
So, in short The Core is bad science and bad movie. Sunshine is good science and good movie.
Join me next week when I answer another one of your movie science-related questions and be sure to check out my other column, where I review dumb-ass action films every Monday: Mindless Action Mondays
Have a science-related question? Ask it!
If I don’t know the answer, I’ll find someone who does.