As a species, we are tool makers first and foremost. That's why we love to see gadgets in our movies, and to watch our Captain Picards and Batmans and David Hasselhoffs defeat the bad guys with technology we know we'll never own.
But in the course of trying to dazzle us with their fancy spaceships and battle vehicles, sometimes Hollywood forgets to make sense.
6The Imperial Walker
The dreaded Imperial Walker, or All Terrain Armored Transport, is frequently considered the single coolest vehicle in the entire Star Wars universe.
The moment the rebels spotted these things on the horizon in The Empire Strikes Back, the only question was exactly how much of their stuff they could pack before they flew screaming off the planet.
"Fuck it! Leave the porn, leave everything! RUN!"
In addition to being huge battle robots of death, the Imperial Walkers also boast a blind spot in excess of 300 degrees. The thing can't turn its head. Specifically, it can only turn its head this much:
This is not a minor issue. That up there is an AT-AT trying to shoot an enemy ship that's flying past it. That's as far as it gets; it's like a huge, muscular guy who happens to have his head frozen in a neck brace due to a crippling spinal injury. The only difference being that guy could still conceivably punch an enemy by swinging at him wildly. Meanwhile, all of the AT-ATs guns are glued to that non-swiveling head.
"Two targets for the price of one. Nice design, Kuat Drive Yards."
This would not be a problem if, say, the walkers were extremely fast and maneuverable. For instance, in the real world, jet fighters have all of their weapons pointing forward, too. But they also go faster than the speed of sound. These bastards, on the other hand, have the top-speed of a Geo Metro driving across a river. It takes them what looks like an entire day to execute a full U-turn. That's good news for you if you're Luke Skywalker, because if you get within 20 yards of one, it can't hit you to save its life.
Years of additional weapons development actually lead to shittier war machines.
Also, the Empire seems to have constructed the Walkers without considering that most militia battles are not fought thirty stories above ground, so the tank commanders spend the entire day on Hoth with their chins to their chests trying to see what the hell they're supposed to be shooting at.
The only reason the rebels had such trouble with them is because the speeders insisted on using what Luke referred to as "Attack Pattern Delta", which appears to mean, "fly directly at the enemy in the one single spot where they are able to shoot us."
5The DeLorean Time Machine
While Doc Brown may not have been entirely up front about the potential dangers of time travel, it is possible that he simply ironed out the DeLorean's disastrous defects off-screen when be built that steampunk time-train.
Sure, Dr. Brown probably could have invested all that time and effort into solving the world's energy crisis but, fuck, sometimes you gotta make yourself happy.
One of the major plot points of Back to the Future, Part III is how they can't start the DeLorean without some gasoline.
This is not just a case of bad luck. This is pretty much a fatal flaw for any time machine.
The DeLorean DMC-12 was built by douchebags for douchebags, with sleek lines to murder air friction and gull wing doors that flared open like a peacock's tail to attract more douchebags.
We don't know who owns this gold-plated DeLorean,
but we'd be willing to bet they wouldn't look out of place on the cast of Jersey Shore.
It's the kind of car that can only exist in a society with paved roads and a steady supply of the specific kind of refined fuel the engine is capable of burning. Both are things that 99% of the places you would go in a time machine will not have.
A utility vehicle with a diesel engine would have probably been a better choice to attach the Flux Capacitor to, or at the very least a DeLorean with a converted diesel engine. They can take a beating and are capable of running on a huge range of volatile, comparatively crude chemicals from vegetable oil to bathtub gin. Doc, Marty and even Biff could have traveled to just about any point in recorded human history and found (or made) something to run their car on.
Above: the one constant in human history.
Though, all of this just begs the question of why the DeLorean had an internal combustion engine at all. Before Doc Brown went back to the future he spent his first trip tricking out the DeLorean with a hover refit and a Mr. Fusion generator. Great. So why didn't he rig the car up so that the generator turned the wheels, too?
Mr. Fusion could supposedly convert any organic matter into enough raw energy to molest the fabric of time and space. If it can spit out 1.21 gigawatts, it can sure as hell generate enough juice to replace the gas engine. Plus, he'd have had unlimited fuel no matter where he went.
"Look, Marty! I crammed a goddamned dinosaur dick in there!"