Our own Bad Astronomer has a whole big list of stuff like this at his website. Bad Astronomy: Movies.
Concave lenses for nearsightedness look like this in cross-section: )(
Convex lenses for farsightedness look like this in cross-section: ()
There’s no way to reverse the concavity or convexity of those lenses by turning them around.
41 posts, and no one’s mentioned Armageddon?
The best part of the movie was the space station that had artificial gravity. How did they generate this gravity? The station rotated. Slowly. About the axis down which gravity was pointing. And then, a space shuttle docks with the part of the station that is furthest from the axis of rotation.
I would go on about the end of the movie, but I seem to have repressed those memories (thankfully).
I remember reading the book and just assuming the kid was far-sighted (and bad enough that he needed glasses to see anything around him). Was there anything in the book that indicated he was near-sighted?
Yeah, but I think it’s supposed to be one of those things they throw into movies like this to, y’know, anchor the whole thing in reality somehow. They don’t put the School for Gifted Youngsters or whatever it is in some totally fictional place like Bingcrosbia (even though nothing’s stopping them), they put it in Westchester County. When the jet fighters tell the X-Plane to land, they say to fly it to Hanscomb Air Force Base, near Boston, even though they could have called it Willy Wonka Air Force Base and it wouldn’t have made a bit of practical difference. They could have put three-headed wombats in the science exhibit if they felt like it, but they tried to make a realistic-lookiing Science Museum because the X-men are supposed to inhabit our world. That’s what makes it compelling.
Actually, farsighted eyeglass lenses can look like this: ((eye where the outer convex surface has a greater curvature (smaller radius) than the inner concave surface. I believe this kind of lens is known as convex meniscus. The center of the lens is thicker than the edges and it is one type of converging lens. It will act as a converging lens no matter which way light shines through it.
Similarly, nearsighted eyeglass lenses can look like this: ((eye where the inner concave surface has a greater curvature than the outer convex surface. It is called concave meniscus and the center of the lens is thinner than the edges. It will act as a diverging lens no matter which way light shines through it.
You do reverse the concavity/convexity by turning them around, but you don’t reverse the convergence/divergence of these lenses.
One that I like to jump on, because it was otherwise such a good movie: In Deep Impact, the orbit of the comet is determined from only two (to be charitable) observations (Elijah Wood’s and the professional astronomer’s), while in actuality it takes at least three. But when that’s the worst science blunder in a science fiction movie, they’re doing pretty good.
Also, the Starfury fighters from Babylon 5 are one more to add to the sparse list of realistic space maneuvers. They maneuver by means of thrusters mounted on long torque arms, and whenever a Starfury changes orientation, you see the appropriate thrusters firing. You also hear them, of course, but I’m willing to justify that by saying that the microphone is on board the ship (where sound could be transmitted through the structure).
For another mistake, in the recent The Time Machine, whenever you see equations on the blackboard, it’s nonsensical. It’s not just that it’s meaningless; that would be OK. After all, I don’t know how to build a time machine, so it’s reasonable that I wouldn’t recognize the mathematics behind one. The problem, though, is that it does have meaning, but the meaning doesn’t make sense. So you end up with things on the board like “the divergence of six” (in mathematical notation, of course). Which is just a really fancy way of saying “zero”. That movie also had a lot of problems with the time-lapse sequences, but I’m not sure that those qualify for the present discussion.
I seem to recall a discussion here quite a while ago on the same question. Someone pointed out that the lenses, whether converging or diverging, are bowl-shaped as Tangent’s diagram (or ‘digram’ as I originally typed it) suggests. A poster in the previous thread pointed out that filling the bowl with water will make either kind of lens into a converging one. Of course there was no mention of that solution in either the book or the movie.
I’ll admit that is was probably a mistaken understanding of the units. But I like it. It gives background and character to the universe. For example, modern day motorheads will refer to a car’s speed as 10.6 seconds. Obviously that’s a unit of time not speed. It’s known to the people they’re talking to that it’s a 1/4 mile time. It’s a jargon that kind of indicates an understanding, and anybody who has to ask isn’t in the know. Jargon usages among groups are the norm in realistic life, and people who speak in actual scientific terms when in casual conversation, aren’t credible. The clique of space smugglers I would deffinatly expect to speak in tons of jargon.
That’s one of the reasons I love Firefly. The use of language quirks seems natural and more complete.
Do you have a copy of that article? I’d love to read it.
Um, I hate to break it to ya, but that’s not what they do, or how the movie ends.
They did the “blanket over hole” trick, true, but with metal floor paneling over a big water-tank-reservoir-thing that the lab was built over. (It was a hydroponics station, so it kinda makes sense.) They do trick/force the robot into falling into the water, but it only slows the robot down. Kirk Douglass eventually has to tackle/suicide bomb the robot into the same water tank, but it’s about 20 minutes later.
A nitpick…the X-Jet wasn’t near Westchester county when it was intercepted by the F-16s, it was supposed to be near Bobby Drake’s house.
Of course, that doesn’t explain how the Air Force was even able to find the “stealthy” X-Jet in the first place. Or why it wasn’t cruising at mach 2, and away from the major population centers. (Maybe they were low on gas.)
And…I see that someone else has beaten me to the punch about Saturn 3. Sorry. :smack:
And, for a nit of my own…I remember hearing about a time-travel movie a few years ago (Timecop, I think) that had some characters carbon-dating…wait for it…a pile of Gold.
Except for the fact that the Earth was hit square on by the giant rock (even if it was in iddy biddy pieces). I guess the whole kinetic energy thing of the comet strike and/or the ensuing nuclear winter would have made the ending a bit of a downer. In this respect the “science” in Armageddon is better than Deep Impact.
The Core anyone?
Whah? I never said the Jet was in or near Westchester. I said it was near Boston.
Well my glasses for short-sightedness diverge light no matter what way round I put them. When I’m next at work I’ll try the water in the lens thing and see if it’s possible to start a fire.
Oops, forgot to add: Piggy being shortsighted was crucial to the plot, something about him being reliant on Ralph, or helpless without his glasses (like the whole group), and he cleaned them when he was nervous or something like that.
The whole math puzzle thing in the Cube was ridiculously easy to solve.
Naw. I’m pretty sure that (like the black hole thing) was just made up later by the Lucas Cult when people noticed the silly error.
The types of lenses used in eyeglasses are more often referred to as positive and negative meniscus lenses, if that helps any,
I’ll be the first to admit that I know next-to-nothing about physics, but wouldn’t a good portion of the energy of the explosion cancel out the kinetic energy of the rock?
Something like
/\
||
<==BANG==> <==ROCK
||
\/
Course, I guess if the difference is large enough, it wouldn’t matter…