05/19/2012 06:43 pm ET Updated Jul 19, 2012

5 Reasons the Future Is Better Without Jetpacks or Flying Cars

As you contemplate buying your first hybrid/flex fuel/wind-powered car, the one thing you're probably asking yourself (other than, "Is this the only way to assuage my carbon footprint guilt?") is, "Where are all the flying cars and jetpacks already?"

Well, ask no more, fledgling futurist: we have been to the future, and we have seen both flying cars and jetpacks. And we're here to tell you... it isn't pretty. Scorched legs, bifurcated billboards, aerial collisions, and the elderly at 500 feet -- It may seem neat and orderly in your Asimov novels and Hanna-Barbera cartoons, but the reality is grim and often charred.

Here are five reasons why you should just buy your "environmentally friendly" vehicle of choice and stop holding your breath for a flying future that will never come:

1. Air Traffic
As the late, great George Carlin said, "Have you ever noticed that when you're driving, anyone driving slower than you is an idiot and anyone driving faster than you is a maniac?" It's not only true, it underscores the problem of allowing just about anyone to a operate a two-ton motorized soda can on wheels: people suck at driving. If the texting teenager, the road-rage-addled office worker or the legally blind nursing home patient don't get you, the road and its nebulous traffic laws will.

In 2009, the U.S. Census Bureau recorded 10.8 million traffic accidents of one form or another. There were also 1,477 civil air traffic accidents. It's not unreasonable to extrapolate from this data and conclude that if everyone were driving around in flying cars or personal rocket backpacks, we would all be dead in less than three years.

While dangerous, the roads are at least constructed and controlled. Do you really expect people to follow rules of both the road and common decency without a curb to contain them? Corbin Dallas plummeting through traffic and past skyscrapers is awesome in The Fifth Element, but would be far less awesome if this became the norm.

2. Fire
Imagine all of the sidewalks and bike lanes in your neighborhood. Now imagine all of those sidewalks and bike lanes on fire.

This is just one of the many horrifying realities of jetpacks. To operate one, you're going to need a death wish and a closet full of flame retardant clothing. Currently, the list of viable, fireproof fabrics includes: nothing. That's right: there's no such thing as fireproof fabric.

With a fire bursting from your backside at 1,000 degrees Fahrenheit, this could present a few problems. Flame retardant fabrics are typically measured on a scale known as British Standards, or BS. Using "BS" as a measure of flame retardation is not a coincidence. Even the highest-rated materials, as any firefighter can tell you, do not prevent you from baking inside your suit or sweating so hard you develop lifelong and untreatable hypothermosis.

Even if you do manage to get from home to your office in one drippy piece, everything you pass from point A to point B is a fire hazard. This includes trees, bushes, children, birds, flying cars, other jetpacks, briefcases, the groceries you just picked up, your home, other homes, other buildings, playgrounds, lemonade stands and puppies.
Hope you didn't trade in your bike.

3. Fuel
The traditional assumption for the fuel needed for jetpacks is, of course, jet fuel -- but as was discussed above, that stuff is dangerous, as well as expensive. However, there are a few alternatives to power your jetpack.

Watersports equipment company Jetlev Sports has a water-powered jetpack that's currently available and draws water from lakes and rivers to run. It'll also cost you $139,000, and you won't be using it to get to commute unless you live in Venice, Italy, or work in a beaver dam. A similar water-based propulsion system from Zapata Racing is a little more affordable at $6,600 and a little more akin to Iron Man's jet system -- but you'll still have to strip out of the wetsuit before heading up to the office. Which is, you know, kind of awkward for your coworkers.

If jetpacks are going to become practical, the Martin Jetpack is likely to be the shape of the future. It uses a gasoline engine and two ducted fans to lift the pack and its pilot, and it can go pretty high -- 5,000 feet from a standing take-off. But it's a jetpack that's really neither jet nor pack: the ducted fans are more like helicopter turbines, and the whole contraption remains too big to be easy to throw on as you're kissing the spouse and racing out the door. At least you won't be setting any pedestrians ablaze while using it, however.

4. Takeoff
As for flying cars, well, one would assume they could function as airplanes do today, using some manner of traditional fossil fuels. But on the other hand, flying cars raise a lot of distinct issues. Throw wings on them to make them more like planes and they become too big for ground travel or for most landing areas. Put ducted turbines on them, similar to the Martin Jetpack, and they're still going to be way too big for regular life; forget the parking garage or the compact space. Parallel parking should be easier, though.

Cars that can fly in movies such as Back to the Future or Blade Runner always seem to use some kind of alternate, gravity defying hover technology to get them off the ground. There is, of course, a burgeoning technology called "quantum locking" that could be used in this regard, but it's more like magnetic levitation than true flight. So what's the fuel source for anti-gravity cars? Guess what: There's not one.

5. Idiots
Sure, you can look at a scientist and demand, with your indignant voice and hip cocked out because you've got attitude, "Where's my flying car?" But have you stopped to consider what it takes to make a car fly? Some people have -- and the results have not been so great.

Most of the means through which humans attain flight with vehicles today require lift, which is what wings provide. Lift is basically the pressure of air below a wing being greater than the pressure above the wing, which means the air literally lifts a plane off the ground. It requires speed and aerodynamics; those are things hard to attain with a car.

Wings themselves are kind of a big pain to slap onto a car. The heavier the car, the bigger the wings and the engine needed to provide lift. In 1973, just such a winged car actually resulted in the death of inventor Henry Smolinski, after the Ford Pinto he'd outfitted with wings as a prototype crashed during a test flight.

So making a car that can fly isn't easy. And that's to say nothing about people actually flying them. Remember those statistics we mentioned about how there were 10.8 million motor vehicle accidents in 2009? Not a single one of the people involved in those accidents was also flying. They were just driving on the ground, on regular roads, where they only had to worry about movement in two dimensions.

We're not saying everyone who drives is an idiot, but doubtless there are accidents in that 10.8 million created by people doing something dumb. You want those people also ripping through the air in a metal bullet filled with jet fuel with gravity's hungry claws constantly trying to drag them into the nearest orphanage or city park? We doubt it.

So though it might sound fun and look awesome, local aerial transit is a disaster waiting to happen. But you should wipe that pouty frown off your face: you still get to zip to work in incredible motorized machines, listen to music beamed in from space, shout instructions to a robot who lives in your phone and talk to friends and family halfway around the world without lifting a finger. Okay, maybe one finger. So stop your moaning: the future is amazing even without jetpacks.

Phil Hornshaw & Nick Hurwitch are the authors of So You Created A Wormhole: The Time Traveler's Guide to Time Travel from Berkley Press. Find out more at