The second in a series of posts about what’s wrong in movies with geology-related themes.
Journey to the Center of the Earth
Premise: What if Jules Verne’s story “The Journey to the Center of the Earth” were real?
First things first: This movie clearly was never meant to be scientifically accurate. Once you accept that, it’s actually a fairly fun movie. But if you go into it expecting good science, you’ll be disappointed. What worries me is that there may be people who actually think that the science portrayed in the movie is valid. That’s a problem.
It’s based loosely on the original book by Jules Verne, which was written when nothing was know about the Earth’s interior. I’ve read the book and struggled momentarily to accept that it is the truest kind of fiction and was written with none of the modern knowledge of the Earth.
I accept that this movie (nor the book) are based upon real science. Most everyone knows that the Earth is not hollow, with a habitable cavern near its core. (Well, most anyway.) In the story, there are hypothesized tubes that go past the mantle and into the center of the Earth (this is how our main characters gain access to the big cavern).
There is absolutely no evidence that such a thing could exist. The Earth is solid, with no air spaces or bubbles (habitable or not) anywhere. Part of the core is liquid (molten), but other than that, the whole thing is solid.
OK, wise guy, you think. How can you possibly know that?
Much of our understanding of the interior of the Earth comes from the recoding and interpretation of seismic waves that pass through the planet. Every time there’s an earthquake on Earth, seismic stations (seismographs) pick up the vibrations kicked off. These vibrations can be used to determine where and when an earthquake happened, and is how the geologists can pinpoint earthquake epicenters and also the magnitude of the quakes.
But the seismic waves set off by an earthquake provide much more information than that. There are several different types of waves that occur due to earthquakes. Some only move on the Earth’s surface. Others only pass through the body of the Earth. Some cannot pass through liquids. A seismograph picks up all of these. By looking at seismograms from several stations and seeing which waves show up, we have been able to determine the structure of the interior of the Earth.
The liquid outer core stops some waves – so we know it’s liquid. All seismic waves pass through the mantle just fine, so we know there’s no pockets of liquid or air in there.
Sorry folks. No cavern in the center of the Earth.
So, here’s some more nit-picky things to think about:
1) Veins of Magnesium. These show up a few times in the movie. For one, I’ve never heard of veins of magnesium. For two, when they’re in the lava tube, trying to light the magnesium, it should go crazy because of all the water present. That it’s wet should help things, not hinder the burning.
2) To find rubies, emeralds, feldspars, and diamonds all in one place like they do is really unlikely. Finding feldspars with any of those gems is not really that surprising, since feldspars com in all sorts of varieties, but the conditions to form the other gems are all different from one another.
And the shape of the raw diamonds are all wrong. They looked like plastic to me – not like diamonds at all. You see, minerals grow in specific shapes. Diamonds form little octahedrons, which was clearly missed by the movie prop people.
What made this gaffe a little worse was that the main character (a geologist) said that these minerals and gemstones are common in volcanic tubes. Clearly, this is just a line for the movie (although diamonds can be found sometimes where there have been explosive, deep eruptions called kimberlites).
3) Muscovite is a mineral, not a “thin type of rock formation.” Muscovite is a very important rock-forming mineral. It doesn’t tend to form platforms with open chasms below. The comment that changes in pressure can cause muscovite to shatter is also not true. So as a mineral, they’ve got muscovite wrong. As a plot device, it’s pretty interesting.
4) When the main character tells everyone that those cute little bio-luminescent birds have been extinct on the Earth’s surface for 150 million years, I cringed. There were no modern birds 150 million years ago, only some archaic birds and some dinosaurs. Maybe I’ll just give him the benefit of the doubt that he meant 50 million years. That I could accept (though it’s probably still far-fetched!).
5) The discussion of how magnetic polarity is reversed at the core was kind of strange. I would expect that a compass would be useless near the core only because you’re right next to where the magnetic field is being generated, but that a compass should point South instead of North isn’t right.
6) Speaking of magnetism, how about those floating magnetic rocks? If the magnetic field is strong enough to make the rocks float, I would have expected that the kid’s metal gear would also float, and probably the kid as well. This scene just bugged me as being completely impossible, even when I accepted that the movie is purely fiction. I was even ok with the muscovite problem much more than this.
7) Since I am a paleontologist, I do feel obligated to point out that the dinosaur skull that they used as a raft/sled is all wrong. What they’ve done is combined a dinosaur skull (which is full of holes) with a mammal skull (that has fewer holes), left out all the important openings in the bottom of the skull, and called it a raft.
8) Back to the whole magnesium thing. When they’re stuck in the skull and trying to light the magnesium so that it’ll break the walls and release the water on the other side, which would then fall on the magma and make steam and shoot them out of the lava tube. Well, a) would not the heat from the lava have lit the magnesium? b) there’s no way there’s water on the other side a a lava tube just waiting to get out. Besides, c) the water should have made the magnesium ignite better with the lava in the first place. And, d) wait, how is this magnesium even there (or the water) if they’re stuck in a lava tube that’s had lava in it? This one made me facepalm.
Anyway, the movie was an enjoyable romp, provided one realizes from the very beginning that the ‘science’ portrayed is very much fiction. The highlight for this movie was when, 3/4 of the way through, my 8-year-old son turned to me and asked me if it was real. I assured him that it was not. He seemed relieved.