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Physics in the Movies
nucal writes "Here's a site rating Insultingly Stupid Movie Physics. A really thorough site with a rating system which ranges from GP (Good Physics) to XP (Obviously physics from an unknown universe)." My vote goes to the helix of M&M's.
God forbid that I attempt to defend Trek physics, but I'm not sure why you believe that the orbital velocity of any spaceship has much of anything to do with the mechanics of doing an EVA or a hull excursion.
Yes, a ship in orbit around a planet is moving at several thousand miles an hour, with the associated inertia. But guess what? As a fringe benefit of being inside the ship during liftoff and orbital insertion, so are you. Your own body's velocity relative to the planet does not suddenly change as a result of stepping out of an airlock. You'll stay close to the ship until you apply some force to push yourself away from it -- hence the little backpack-mounted gas jets that Shuttle astronauts use for EVAs.
As far as the boots are concerned, they didn't strike me as terribly unrealistic. Put an electromagnet in the sole, and a pressure switch inside the top of the boot that switches the magnet off when you apply enough upward pressure on it with your foot. Et voila.
Orbital EVAs are incredibly tricky things; just not for any of the reasons you describe here.
News for Nerds. Stuff that Matters? Like hell.
Umm, if the ship is not accelerating there'd be no such difficulties with walking on the outside no matter how fast it's going. You'd just need a little tug to keep your feet planted. I'm not sure you're grasping how intertia actually works.
And I'm not sure about the rest of what you're bitching about, but if these boots had something like a simple electromagnet and some trivial controls, I don't see what the problem is.
If you are a geek or have geeky friends the green laser's a must-buy. You have to be damn careful with it though; it's much easier to permanently blind someone with the green laser than a standard red one, and it's difficult to look directly at the spot it creates on a surface unless the batteries are almost flat.
I'm still looking for a blue one :-)
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Uninspiring and anal retentive, derisive arrogance without just cause.
I found the site to be entertaining in its derision. And I feel his pain, as a fairly intelligent geek whose intelligence is regularly insulted by the mass media which is dumbed-down for the great unwashed masses.
As Homer lamented before he had Moe hammer the crayon back into his brain to make him a dope again, "I'm a Spalding Gray in a Rick Dees world!"
Sadly, movies are not made for the intelligent minority, they are made for the people who need a "Caution! HOT!" warning on their coffee cups. The Matrix was probably the closest we'll ever get to a thinking man's movie, and I heard somewhere that even that was dumbed down a tad (IIRC, the enslaved humans were originally supposed to be part of a tremendously huge RAID via their unused brain capacity, instead of as an energy source).
~Philly
No. Not at least for US spec ops.
IASER is only used in regular infantry units from what I have seen and then only for night fighting. Prob is they show up bright as day in with PLAIN OLD NOD's. Has the same problem as tracers, they draw line back to the shooter. From what I have seen they are using these to replace tracers to solve the tracer visible line issue. Works great -v- 99% of our lowtec opponents though (who don't have NOD's). Sux just as bad as tracer -v- high tech opponents. Needless to say, this is A BAD THING(tm) if you an actual sniper where concealment is vital.
Snipers I have spotted with all use good old plain scoped crosshair sites, though some like the dotted reflex sites. Key thing with both these is they ARE PASSIVE. This is a key requirement for snipers, you don't need to give you position away. Active snipers are reg. infantry sharpshooters...THEY ARE NOT ACTUAL SNIPERS. (Though they think they are). Giving a guy a rifle and a scope doesn't make you a sniper.
De Oppresso Liber
You've never sighted in a rifle have you. All light, including the light that enters your scope travels in a straight line. Bullets of course follow a parabolic tragectory, and since we know this you simply adjust you sight for the rise or more likely fall of the bullet at the expected range. If you are shooting at distances other than your sighted in range, you have to adjust your aim for the difference in drop.
Scopes can be adjusted for ranges up to several hundered meters, so lasers should be equally good.
Degaussing scares the bad magnetism out of the monitor and fills it with good karma.
Your fluids will still boil and make a mess of your innards.
No, they won't. That in itself is bad physics.
I'm probably posting this way too late for anyone to actually notice, and I'm probably being a pedant for pointing it out, but...
From the article:A load of buckshot hitting a vest can be considered an inelastic collision. This qualifies it as one of the situations which can be analyzed using conservation of momentum.
Momentum is always conserved. An inelastic collision implies that kinetic energy is conserved.
High school physics is fun.
yep and (according to tom clancy) snipers use short impulses of laser to measure the distance to the target and can adjust their equipment exactly. for a good placed shot over a large distance they also measure the wind speed and air pressure and must be careful, that no vein is under their rifle arm.
/. nobody knows, that you're a god.
perhaps some soldier or weapon freak can help solving this problem...
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on
The problem with this is that traditionally laser sights have been bolted directly to the barrel, whereas the scope is on adjustable mountings. There is no reason why the laser can not be mounted in the same mountings as the scope, but the *aser as an aiming point does not add anything over a scope.
You use the *aser to measure distance to accurately sight the distance, however the length of the pulse is so short, that even if you were standing next to the future impact point, and were looking directly at the target, it is unlikely that you would notice the pulse, even if you did manage to see it, it would be unremarkable, (think you are seeing spots) until the first shot is fired.
No one uses the *aser dot as an indicator of where the bullet will land. This adds nothing to traditional crosshairs. On the other hand, assuming the wavelengths were correct, etc, it would allow sharpshooters to designate targets for airstrikes, etc. From considerable distances away. But I wouldn't want to hold the designator still for that length of time.
Also never underestimate the intimination power of a visable laser dot appearing on the forehead of an armed militia leader.
This is sort of right. Laser sights are pretty much only useful for close range fighting, where a soldier would need to "shoot from the hip" while maintaining some semblance of accuracy. Snipers often do use IR lasers, however, they don't use them as laser sights. That's what they have a scope for. The lasers are used as rangefinders, so the sniper can tell how far away his target is and adjust his scope accordingly.
.50 cal rifle) the arc of the bullet is significant. You have to adjust your scope to compensate for the range (thus why you need to know how far away the target is.)
The problem with lasers is that they basically say "Look! Here I am!" And with infrared nightvision available for under $1000, it's not a stretch to assume the enemy has it as well. IR scopes are also not as common as you would assume. Their range is limited compared to a conventional scope, plus they're a lot heavier.
One other thing to note is that extreme distance, a laser would be utterly useless for aim on a rifle anyway. Keep in mind the bullet travels on independent axes, both forward (inertia of the bullet) and DOWN (force of gravity.) At longer ranges, the bullet's path is going to look more like an arc than a straight line. Last I checked, lasers don't arc. This brings me back to the rangefinder. If your target is 1500m away (not inconcievable with say, a
Another use of IASER sights is to have special forces operatives "paint" targets with the laser for use in bomb targeting systems. This is much more effective than painting the target from the plane itself, as the forces on the ground can keep a better hold on the target and there's minimal risk to them, as they're not actually firing any rounds (and thus the enemy isn't looking for them.)
So, essentially, the detriments of using a laser sight on a sniper rifle far outweigh the benefits. The main problem is that it compromises the snipers location (his best weapon) while not being very effective. Rangefinders are only in use for a fraction of a second, and aren't likely to be spotted. Lasers, even IR lasers, are stupid as sights at long range. The only ops who actually use laser sights do so at very close range (say, less than 20 feet.) At that range, your presence is already compromised, the bullets won't arc, and you can get a split-second faster target acquisition. But on sniper rifles they really have no point.