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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.
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
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.