Thank physics for our lack of futuristic flying machines

According to Doc Brown's calendar, it's officially The Future. So where's our flying everything?

Some of our slow progress is thanks to a regulatory vacuum, but most of it is thanks to plain old physics.

Lexus tested out an early version of the hoverboard this month, which uses nitrogen-cooled superconducting magnets to float, and it can support a person.

The thing about superconducting magnets is they have to stay chilled down to work. And they have to stay above the magnetic track they push off of. That's how Lexus did it, too.

And this board requires a copper-lined hover surface to generate the required magnetic fields.

So true hoverboards are out until we figure out how to free them from their magnetic bases. Sorry, Marty McFly.

Take a look at other tech innovations in this infographic:

Jetpacks are a tall order, too, in that you have to point enough energy to lift a human down at the ground, without setting your legs on fire.

There are fixed-wing jet backpacks, but that's technically using a wing surface to generate lift rather than a true jetpack.

The Martin Jetpack is technically a "ducted-fanpack," but that doesn't roll off the tongue quite the same way.

Pumped-water rocket packs actually use jets of something pointed straight down, but they're altitude-limited.

See more of the jetpack in this video:

Okay, so what about our flying cars?

Concepts are everywhere: Terrafugia started showing off this crazy commuter just last month.

And even DARPA has shown interest in something that might fly as easily as it drives.

But infrastructure and regulation haven't caught up yet, mostly because the government has never had to come up with rules for something that's simultaneously a car and a plane.

Maybe "Back To The Future" was just too far ahead of its time. We'll set the clock for another 26 years.

Take a peek at the hoverboard videos from Lexus below:

More from AOL.com:
This tiny toaster can charge all your mobile devices
There's a reason you're always cold at work
Birth control might be long-term tool against uterine cancer