What would happen next is debatable even in scientific circles. In The Core, radioactive particles and microwave radiation literally cooks the planet. In one scene they even slice the Golden Gate Bridge in half.
"I don't want to diminish enthusiasm for the movie, but I don't think anybody would notice if the magnetic field disappeared," said Jack Connerney, a planetary scientist at Goddard Space Flight Center, in Greenbelt, Maryland.
"The ionosphere and atmosphere would keep out much of the solar wind and radiation," said Connerney, so although the radiation would increase slightly, life on Earth would not fry.
Connerney also doubts that huge electrical storms would be instantly generated. Both Venus and Mars lack global magnetic fields, he said. "We don't see strange electrical phenomena happening there."
Earth's Core A Natural Nuclear Reactor?
"Its hard to know what the effects on life will be. They've got to be devastating," said Marvin Herndon, a geophysicist based at the Transdyne Corporation in San Diego, California, another consultant for the movie. "It will short-circuit satellites, we'll have no ability to communicate with radio communications, and currents will be induced not only in electrical transmission lines but railroad trains, bridges, gas pipelines."
As for what the "terranauts" encounter inside the earth, the moviemakers get little guidance from science.
"If you were to ask yourself which is the quickest way to the unknown, very clearly its straight down," said Terrile. "We know a lot more about almost everything else in the universe than we do about what's just a few miles below our feet."
To date, scientists have only been able to peer deep into the Earth indirectly, primarily by detecting the way sound bounces around during earthquakesanalogous to taking a giant CT scan of the planet.
The first really good image came from a massive earthquake in Chile in 1960.
"It was one of the biggest earthquakes on record and it really rang the core like a bell. A lot of understanding came from that earthquake," said Terrile.
But there is nothing to say that our understanding won't change. Earlier this month, Herndon published a radical new theory in Proceedings of the National Academy of Sciences that finds the Earth's inner core isn't just a giant iron-nickel ball as is commonly thought, but contains a ball of uranium only five miles (eight kilometers) in diametera natural nuclear reactor.
Herndon believes that this reactor will burn out sometime, be it in the next century or 1 billion years from now, killing the magnetic field.
"I think it could be worse than the movie portrays," Herndon said.
So as you munch your popcorn thinking that there is no way that this can happen, consider this: there is no guarantee that it won't.
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