The Physics of Starship Battles: Gravity and Potential Energy

If there's one thing about aliens, there's too gosh darn many of them, and they all want to invade. But what is the best way to proceed? Whereas Hollywood has given us many different views of many different weapons predicting how such an alien invasion would take place, few to none of them have ever used elementary physics to its full advantage. Explaining the Acceleration of Gravity and its use in the concept of Potential Energy, here I use video clips from TV (and a few movies you're sure to recognize) to demonstrate the most dreadful weapon an invading alien force may use against us.

So I guess you might think after watching this that I think Independence Day is a derivative phony cliche, and you' be right. ;) Every movie needs a catalyst, a point where I say "I can make a movie about that." In this case, it was watching ID4 on cable, watching its super weapon kill BARELY a square mile, and remarking on how much smarter Hollywood movies would be if they would only let smart people make them. Holding that point in my head, I also suddenly remembered that one line from Lt Cmdr Data: "They can obliterate you from orbit," and the movie began.
(And ironically, that catalyst line by Data ended up in several different points in the movie before settling on its current spot. At one point it might not have made it in at all, which is what happened to the catalyst point for Lasers and Kinetic Energy.)

So now there's always that problem, is this a HOLLYWOOD movie or a PHYSICS movie? And how best to combine them? Potential Energy seems like an easy thing to explain until you get right down to it and realize how much overlap there is between Kinetic Energy (which I already did), and how much you have to simplify to get the point across. (The acceleration of gravity decreases the further away from a planet you are, and varies from planet to planet, but I cant get nearly technical with that.)

All that in mind, its been a long six months since Lasers and Kinetic Energy hasnt it? ;) Well there were always ideas, but none of them exploded in my head until I remembered that line from Data. I tossed around a radiation movie for a bit (and still might do that), but in all actuality I spent many months researching a novel I want to write (yes I know I said that last year when I made Energy Waves and Sound, but that was nonfiction). And now it looks like I'll actually get it done.
Dont worry, there are always more movies to make, but it might be time for a reinvention, switching to "Hollywood Screw Ups" or something. Remember there was a six month wait between "Laws of Motion" and "Disintegration," and that lead to 4 movies all within a few months of each other. Who knows. The future is young ;)

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• kinetic
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[Myro117]

Why would they even bother with us?

Clearly we are retarded showing film after film of killing "their kind" and being hostile toward them. If they have the ability to build ships they damn well have the ability to watch our broadcasts and see what a nasty species we really are.

If they ever were to come to Earth one of us would surely try and kill them (as hollywood and our xenophobic ways have trained us to do). we kill one of them, they destroy our entire race. (possibly a good thing)

[SpreadingtheMuse]

@Myro117 One reason we've lasted as long as we have is that I think that they DONT care about us. There's so many habitable planets that they cant be bothered to invade every single one

[TaintedMustard]

I have to say, though, I don't think they'd need to even bother with this much. If their technology is so advanced, all they really have to do is study our biology and then develop a biological weapon to destroy us. No damage to the planet itself, but humanity is either completely obliterated or left so devastated that mopping us up will be a breeze.

[TaintedMustard]

I love this little briefing/tongue lashing on mass drivers from Mass Effect 2.

"This, recruits, is a 20-kilo ferrous slug. Feel the weight! Every five seconds, the main gun of an Everest-class dreadnought accelerates one to 1.3 percent of light speed. It impacts with the force of a 38-kiloton bomb. That is three times the yield of the city buster dropped on Hiroshima back on Earth. That means Sir Isaac Newton is the deadliest son-of-a-bitch in space!"

[danyeo]

The bad guys used an Asteroid in The Last Starfighter to blast the Starfighter home base.

[WintersFinalstand]

@aarontaylor94 and liquefy the crust the energy is say light is the constant is dependant on the mass of the object inquestion you can be a atom at the speed of light and not dent a single thing, your a astroid at the same speed and youll annihilate whatever you touch, back to the original, the light photon is the atom and the astroid i mentioned is the other larger object it is. remember E=MC^2 M is mass

[WintersFinalstand]

@aarontaylor94 lets see, take your peble at the speed of light the impact if it occurs avoiding atmospheric burn up would create little change to the south pole and would have its presence soon erased the speed of light remains our current energy, now say you made the pebble a small boulder or large it would create a sizable impact radius, imagine a space ship moving at the speed of light carrying heavy metal balls that would crash into earth then it would make a crater all the way to the core

[MissingMandible]

@SpreadingtheMuse

So, what then? Use many smaller meteorites to wipe us out? Not only is that even more dangerous and expensive to do, but they wouldn't be able to wipe out humanity in it's entirety, lest they do irrevertable damage to Earth.

Therefore, smaller craft and/or vehicles and/or infantry is needed to finish the job.

[MissingMandible]

@SpreadingtheMuse

Then, there is the question about whether or not they want the environment intact. Hardly any planets out there has a developed ecosystem ready to be lived in. Terraforming is expensive. It requires both time and resources.

Therefore, if the aliens want it as a home, they can't afford to use a large meteorite to wipe us out, for it would take millions of years for life to recover.

[MissingMandible]

@SpreadingtheMuse

I find that meteors to be too...inefficient. There is the inherent danger of dragging them out of an astroid belt. They are needed to be slowed down (because they are moving quite fast there), while the ship doing so would be in constant danger of being slammed into by the various other meteorites.

Than there is the problem of bringing it to a planet. Would they spend extra energy to launch it from it's current location, or spend energy bringing it to Earth's pull?