Jetpacks and Flying Cars

Every now and then, someone remembers the old predictions of the future. By now we were supposed to have jetpack, rocket belts, or some other form of personal flight. For longer travel were were to have flying cars. Both were featured in the 1960s cartoon the Jetsons.

So what happened? Where are they?

The problem is that both technologies require one or two breakthroughs and neither has happened. In order to get individuals off the ground we need a new means of propulsion or a much more efficient energy source.

While there has been progress on top-end speed, the technology at the bottom end hasn't changed in fifty years. The cheapest way of getting someone off the ground involves a propeller and an airfoil - in other words, an airplane. The next option is the helicopter which is much more complex and takes a lot more energy. In fact, nearly all helicopters are propelled by turbines which are first cousins to jets. A regular internal combustion engine just doesn't have the power to weight ratio to power a helicopter.

On the energy side, the most common fuel continues to be distilled petroleum. None of the other alternatives are new either. This is just too heavy for personal flight.

Here is an example of the problem. Two companies are now offering rocket packs. Flight time is around 30 seconds. A different company is planning to offer a true jetpack in the near future. It is more efficient than the rocket packs so it can offer flight times approaching 20 minutes. While this is long enough to be entertaining, I would not like to depend on that for the morning commute.

We have possibly hit against the limits of physics. We made the easy advances in propulsion and energy storage decades ago and there are no good alternative in sight.

The same thing is happening in computers. There is something called Moore's Law which says that the complexity of computer chips will keep doubling every couple of years. Some people treat this as an iron law but it started out as an observation. Intel's marketing department grabbed a hold of this and pushed the engineers to treat it as a requirement. They started running into the laws of physics with the last generation of chips. Instead of coming up with a new generation that breaks the previous generation's clock speed, they went for dual core. This is a slower chip with two processors. In theory it can process nearly twice as much as the same speed. Future generations are supposed to add additional cores instead of increased speed.

This strategy will probably fail. Multiple processors are not new, even if putting them on the same chip is. But adding a processor requires special software that can split the instructions into tasks that can be executed out of order. In practice, adding a second processor speeds things up by 50% instead of 100%. The gains go down as you add more cores.

All of this will probably keep another of the predictions for the future from happening anytime soon - artificial intelligence. No HAL 9000.