It is impossible to determine just how much science misinformation audiences retain, but it's safe to say the minuscule amount of good science in the movies is entirely outgunned. After combing through a vast library of science fiction flicks both sublime and ridiculous, your intrepid Bad Astronomer sat down to explain the best and worst of movie science. So grab some popcorn, relax, and be glad that when the lights go back up, the real universe will still be out there for us to enjoy.

This gallery is a sample of content from DISCOVER's special Extreme Universe issue, which is available on newsstands only through March 22, 2010.

Bad Movie #1: The Core

For unexplained reasons (because honestly, it's not possible), Earth's core has stopped spinning, causing our planet's protective magnetic field to collapse. The movie almost gets this one right: Earth's magnetosphere does protect us from blasts of subatomic particles from the sun.

But for some reason the writers chose to say that it protects us from deadly solar microwave radiation. They even show a beam of microwaves cooking the ocean and destroying the Golden Gate Bridge (why don't catastrophes in movies ever happen in the middle of nowhere?).

Two problems: The sun is a very weak emitter of microwaves, and worse, microwaves are not affected by magnetic fields! The feeble glow of microwaves from the sun is absorbed by our air on the way down, anyway, so unless the core somehow also strips off Earth's atmosphere--in which case we have bigger problems than solar radiation--we should be safe enough from microwaves if our planet's center stops spinning. Which it can't.

In this continuation of the Star Wars saga, our hero, Obi-Wan Kenobi, is chasing bad guy Jango Fett, who tries to escape in the thick rings of the planet Geonosis. Fett deploys "seismic charges" to kill Kenobi. When the charges explode, they send out huge shock waves that nearly shake Obi-Wan apart.

It makes for a very cool and exciting scene, except for one small problem: Sound waves can't travel in a vacuum. They need something to move through, like air, water, or rock. Of course, had George Lucas stuck to real science, Fett's gambit would have been silenced, and the movie would have been a lot shorter (not to mention less exciting).

Practically every space movie ever made has sounds in space, so singling out Star Wars may seem unfair. But in this particular case the plot depended on there being sound in space, putting this movie forever on the Bad Science list.

That said, the noisy battle (above) between man and machine on the planet's surface--where there is plenty of air--is acoustically perfect.

Giant robots from space battle it out over the course of this movie and its sequel, causing quite a bit of damage along the way. They're so big, in fact, that just walking around causes the ground to shake! But when these robots are done mixing it up, they snap together and fold their way down to smaller sizes and more manageable weights.

So what happens to their mass? A fundamental rule in the universe is that mass cannot be destroyed, so making something smaller doesn't mean it will be lighter in weight! Any Transformer keeping its mass will therefore become very dense: A 100-foot-tall robot compacting down to a 10-foot car would plunge right through the road and into Earth's crust.

That would be amusing to watch but would make endless sequels unlikely.

An astronaut in deep space is too far from his ship, and his air is running out. To prevent his shipmates from trying to rescue him and dooming themselves before they reach the Red Planet, he opens up his spacesuit helmet. He instantly freezes!

Yeah, well, in reality, not so much. Human bodies store a lot of heat, and in the vacuum of space the only way to dump that heat is to let it radiate away (on Earth, cold air could conduct the heat away more rapidly, but we're in space here). That would take hours.

The real problem with space exposure is the air rushing out of every orifice of your body, causing massive tissue damage and giving you anoxia. So you wouldn't freeze; you'd suffocate. And you certainly wouldn't explode: Humans aren't balloons.

Still, no matter what, you're dead. Best to keep that spacesuit helmet closed.

This 1998 blockbuster was so exquisitely awful that it's hard to pick a single instance of bad science in it, since the movie is essentially 99.44 percent steaming garbage.

The plot is that a Texas-size asteroid is spotted 18 days before it hits Earth. NASA sends a team of wisecracking oil-rig workers (including a grimacing Bruce Willis) to plant a bomb that will split it in half so that the two separating chunks will miss Earth, save the day, and allow the boy to get the girl.

But first of all, there is no asteroid that big. Second, if there were, it would be bright enough for Galileo to have seen it. Third, it would take decades for it to get from the asteroid belt to Earth. Fourth, oil-rig workers?

Fifth, the bomb used to split the asteroid would need to explode with the force of a hundred billion one-megaton bombs, millions of times the total yield of all nuclear weapons ever detonated. I, for one, am glad no such bomb exists.

I just wish the movie had bombed as well. In the United States it was the second highest-grossing movie of 1998 (the much better Deep Impact made it to #8).

In this movie, a comet miles across is headed toward Earth, sure to cause a mass extinction if it hits. Astronauts attempt to blow it up but instead split it in two. One piece a mile across hits our planet and causes devastating damage (which is eerily and nightmarishly accurate). The other piece will still wipe us out, so the astronauts sacrifice themselves to destroy it, shattering it "into millions of pieces of ice and rock, which burned harmlessly in our atmosphere."

However, the problem remains: Those pieces would still kill us all! The impact energy of a comet depends on its mass and velocity, neither of which changes when you blow it to smithereens. All those comet bits burning up would lay waste to our planet. Instead of hitting in one piece, you get a bazillion little pieces dumping their energy into our air, which if anything spreads the joy around even more; some scientists argue that letting a big rock hit intact may be better! But honestly, either way--especially with a rock 5 or more miles across--it doesn't matter if it hits intact or in pieces. Dead is dead.

A better solution would be to push the whole comet gently out of the way, but that makes for a dull movie climax. Sometimes real life isn't as exciting as cinema. Thank goodness!

I know what you're thinking: Why is this one in both the Bad and the Good sections? While the movie did blow it--literally--at the very end, there was a lot of good science in it.

The comet is discovered by an amateur, which until recently was how most comets were discovered. When the astronauts go to the comet, they can't land on it due to its weak gravity, so instead they tether themselves to it (I literally cheered when I saw that scene in the theater). And when a mile-wide comet fragment plummets to Earth and creates a 600-mph tsunami, the scene was very accurate, except for only a few small details.

This fictional display of the raw, destructive power of gigatons of rock and ice slamming into Earth was a wake-up call. We do need to be concerned about cosmic debris.

The thing about space is that it's big. Really big. You might consider this to be its defining characteristic. Even our fastest rockets are agonizingly slow when faced with the gulf of interplanetary space.

Most movies get around that by using warp drive, hyperspace, stargates, or whatever. But 2001 got this right--not surprisingly, since it was penned by the great science fiction writer Arthur C. Clarke. In the movie, the trip to Jupiter takes years. Some of the crew are in suspended animation during the journey to save on resources. A spinning centrifuge provides artificial gravity for the astronauts who man the ship.

And everything happens very slowly--which, to be honest, makes for something of a dull movie, but quite a realistic one. The slo-mo of bodies moving in zero-g (as seen at right) is also eerily depicted. In fact, most scientists consider 2001 to be the most scientifically accurate movie ever made.

In the opening scene of 2009's Star Trek movie reboot, the Federation starship USS Kelvin is under attack by the Romulans. We hear explosions, bulkheads are torn apart, there are screams... and then a torpedo rips open the hull and a crew member is blown out into space. The camera follows her as she tumbles out, and when we pass through the hull breach into space there is sudden silence.

Hooray! I mean, it's too bad about the crew member, but it is rare indeed for a movie to show silence in space (see the entry for Star Wars--though television's Firefly gets it right). And in the case of Trek, scientific accuracy is used for good dramatic effect, as the sudden silence during the battle is unnerving.

Like 2001, which came out 18 years later, Destination Moon is an accurate depiction of space travel--at least accurate for its time. While other 1950s movies had their rockets zooming to Venus or Mars without a care for time elapsed, fuel, or other matters of basic physics, the fundamental science of space travel is critical to this movie's plot.

When the rocket lands on our nearest astronomical neighbor, the astronauts realize they don't have enough fuel for the trip home. They try to lighten their load but conclude that they have to leave one person behind. Other, finer points of space travel are there as well: the depiction of acceleration, the need for air locks when entering and exiting the ship, and more. The rocket uses a nuclear engine, a technology that was under serious investigation for a long time (and may yet see its day in space).

Interestingly, the movie's premise is that private industry would build the first rockets to the moon, with the government leasing them for use. That's not too far off from NASA's current plans. While it's not the most riveting movie, Destination Moon was a big departure from the giant insect movies and tales of alien rocket ships that followed it for years. And again, like 2001, it had a towering science fiction writer as its adviser: Robert Heinlein, one of the fathers of modern sci-fi.

In this movie, a signal from deep space is discovered, and when decoded it is found to include blueprints for a machine. That machine, when constructed, creates an artificial wormhole that allows Jodie Foster's character to travel to the center of our galaxy and talk to advanced aliens--who tell her that they didn't build the wormhole tunnels; an ancient race did.

Given that Carl Sagan helped to write the screenplay, it's no surprise that it is well grounded in real ideas. The galaxy is old, far older than Earth by 8 or 9 billion years, so if there are alien civilizations out there, it's likely they are millions or even billions of years ahead of us. Look how far we've gotten in just a few millennia! Any intelligent aliens we meet could be so far advanced we might have a hard time even recognizing them as being life-forms at all.

And the traveling through wormholes? While that's all theoretical, it was based on actual physics done by Albert Einstein and his colleague Nathan Rosen. Along with 2001, Contact is considered one of the most scientifically accurate movies ever made.