Do you wonder why humanity hasn't advanced much?

[Netyaroze]

@HappySqurriel

Yes some flying car can be made like I said. We can build a mini harrier jet. But this is not the point. The point is a useful technology like shown in Back to the future. You have to stay in air for hours. The ability to fly over things without destroying them. A mini jet would melt the pavements also no level flight were cars can fly over other cars. You would kill anyone to close under the car and its freaking loud. Imagine New York with 100000 jets flying through the streets. Also its freaking harf to fly these vertical jets they are literally death traps and hard to maneuver. Also a car would need another energy source then gas. To have enough energy to stay for a useful amount of time in the air. Nuclear is the only way to go. Even if we could do that in a car sized format. The downsides are too much for every society. Giving everyone a nuclear powered jet is kind of dumb. Also inner city traffic would be impossible. And the damages done on structures are too much also death toll would skyrocket. And a car like this would always be super expensive.

This is what the car needs to do to be Back to the future like:

Relatively quiet
Enough Energy on board to stay in the air for hours.
No propulsion system that damages life forms or things which are under/behind the car.
It has to be energetically relatively cheap.
It has to be reliable.
It has to be relatively easy to control.

This can only be achieved through manipulating gravity. Which would also enable us to do everything.