Next to 'The Core', possibly the most physics-impaired movie of all time

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While I agree that fact-based movies shouldn't use "bad science", we have to remember most movies are works of fiction. I don't recall any disclaimers at the beginning of this film that said "Please take notes; we'll be testing you for your Physics degree at the end of the film."

Have you ever heard of "suspension of disbelief"? That's what you are supposed to use when you watch a science-FICTION film...

By the way, before you criticize a movie, make sure you've seen it. If you haven't seen The Core, then you can't say anything about it.

As for both movies, they are reasonably entertaining sci-fi films. Sure, the science is bad, but that's not why people are watching them. Or are we supposed to believe in light sabers and ray guns, but not in cold fusion? ALL sci-fi movies have some element of bad science; they are taking leaps for the sake of making a movie. Most film-makers know that they are making stuff up, but they never claimed to be doing otherwise.

Oh, and before you try to come back with some kind of insult about me taking this position, I will tell you that I am one of those science-geeks you were talking about. I know more about Physics than the next 100 people... combined. I really could have cared less about the bad science in this movie (or in The Core). As I said, that's not why I was watching them...

The reactions in this movie are based off a valid theory. Ultrasonic sounds cause microscopic bubbles to form in water. As the bubbles collapse, they emit very high temperatures and a brilliant light. The theory is that if you lace the water with deuterium, the bubble collapse causes a form of inertial confinement fusion.

The flaw is that this would effectively be a steam engine, it would not release large amounts of hydrogen, it could not create any such explosion, and to stop the reaction, you just turn off the sound source. So consider that at the beginning of the movie, Keanu walks in and unplugs the speaker. Done. Movie over. Real science is so much fun!

As far as Hohmann transfers, no one actually uses those anyway. A Hohmann transfer relies on a single impulse (well two actually), and provides the minimal energy path. While that might be good for initial planning, even chemical rockets fire for minutes at a time. Just using the Hohmann calculations would result in being miles out of orbit. If you have a low power, long duration rocket, like ion or nuclear, the Hohmann equations can't even give you a rough estimate.

Missing the point. It's not a documentary or trying to shed light on a viable alternative.

The premise is a "what if?".. there was a great alternative to oil.

I didn't hear anything in his initial speech which confused fusion with the separation of hydrogen from oxygen. Also, the initial speech wasn't a lecture in some "physics class", it seemed to be a presentation at his university (the one funding the project... not that it matters). I thought the film did a good job of presenting the science in a way that was just enough to capture our imagination. A too-complicated exposition of the Macguffin is a common flaw of filmmakers.

There is no where in the film that fusion is confused with separation, I challenge you to show that.

"...nothing is left of me, each time I see her..." - Catullus

The Core was a tongue-in-cheek movie. It was perfectly acceptable for it to have bad science.

This movie had a political message, and was intended to be serious. The Core did not have any message - it was just a pure thrill ride.

The science was horrendous. The reaction they made produced HYDROGEN GAS. They never said anything about fusion, AFAIK. They produced hydrogen, which they stored in tanks. The movie was about using hydrogen + oxygen for fuel, as far as I could tell. Like I said, I don't remember them mentioning fusion.

Hydrogen requires a lot of energy to produce. You can't just turn water into hydrogen and oxygen and recombine them to get more energy. Doing this is an energy-losing activity. You have to put in more energy to split the water molecules than you get recombining them. That energy will come from regular sources, like oil, coal, solar, wind, etc. That doesn't help anything. We may as well cut out the middleman (hydrogen) and stick with our old fuel sources.

Maybe they were talking about hydrogen fusion. But then where did the tanks of hydrogen come from? Hydrogen gas is not a product of fusion.

Then there was the bit about the teflon-coated armor-piercing bullet. They had this myth in Lethal Weapon too. It's just as stupid as "ceramic handguns that don't show up on x-rays." Coating bullets in teflon does NOT aid in their penetration. It only is used to reduce barrel wear. What makes a bullet armor-piercing is the use of a harder material, such as steel or tungsten. Teflon coatings keep this harder material from damaging the barrel.

I'll elaborate on the "ceramic handguns" now, which they didn't have in the movie, but is in line with the stupidity of the teflon myth. Ceramic guns do NOT exist. The Glock handgun (which, by the way, doesn't cost more than you make in a month unless you work at McDonald's), has about a pound and a half of metal, including the barrel and trigger group. It DOES show up on metal detectors and x-ray machines.

Rant over.

You have it backwards. They weren't trying to fuse anything to form water. They were knocking away a hydrogen molecule in order to produce hydrogen.

Prof. Farnsworth: Oh. A lesson in not changing history from Mr. I'm-My-Own-Grandpa!

I totally agree, but its science fiction movies. Where fantasy and science combine to make some money for entertainment purposes as well to score some left wing zietgest points.