Remember all those Star Trek gadgets you wished you had because they looked so cool? Well, it turns out looking cool is about all they'd be good for.
还记得在《星际迷航(Star Trek)》里那些让你想要拥有的看起来酷毙了的小玩意儿吗?呃,实际上,他们也就是看起来酷,仅此而已。

Here's five inventions that will be available some day ... even if nobody wants them.

5.Flying Cars
As seen in:
Blade Runner, The Fifth Element, Back to the Future II, Futurama, The Jetsons ... it's actually kind of difficult to list sci-fi that doesn't feature some variation of the flying car.
《银翼杀手》,《第五元素》, 《回到未来II)》, 《飞出个未来》, 《杰森一家》 ... 实际上,从某种程度上讲,很难能列出来一个单子,说科幻小说里没有出现飞行汽车的——不管什么样的飞行汽车。

Why we thought we wanted them:
First, we don't mean some kind of sissy half-plane, half-car hybrid that some people will try to tell you is a flying car. No, we mean real, float off the ground, how the crap is that happening, Jetsons sort of flying cars. Admit it, when you were 7 years old, there were only two things you were sure of: Transformers fucking rule, and the future would be full of flying goddamn cars.

Of course, once you learned to drive you wanted one even more. Every time you're stuck in traffic, you can picture yourself flipping a switch and swooping into the sky, leaving those honking bastards behind. You'd fly straight to work, free as a bird.

Why we were wrong:
Well, guess what: They're not gonna let you do that. People just flying wherever they want would be a death warrant for every radio tower and power line in the country.

No, you'd have to fly according to a wussified autopilot, along pre-set pathways. Air-roads, in other words. And, once everybody has a flying car ... well, have you ever been driving to work in a city at around, oh, eight or nine in the morning? If so, you'll know exactly how bad traffic can get during rush hour. Now, imagine if there was not just one layer of cars, but there was layer after layer of flying metal death traps over top and below you.

That's not even the worst part. The many people who have tried to invent flying cars over are finding out that every single thing that's bad with cars (cost, safety, etc) is made worse when you try to make the thing fly.

For instance, no matter what kind of engine they invent, a flying car will always burn more fuel than a regular car, especially on short trips (you burn a bunch of gas trying to overcome that gravity thing on takeoff).