When it comes to automobiles, the conventional wisdom is you need four wheels or more. So why are there cars driving around with three wheels? We'll take a look at the science (and the economics) of tossing out one of your wheels.

In 1901, Thomas Edison developed the recharcheable nickel-iron battery, a technology he hoped to see implemented in electric cars. But a slow rate of energy output and slower charging time saw it superseded by lead-acid and lithium-ion batteries in standard and electric cars alike.

The United States did not have a good year in 1958, especially when it came to transporting nuclear weapons. There was the incident where a nuclear bomb was dropped on a little girl's playhouse. There was the plane carrying a nuclear warhead that caught fire and burned for seven hours, in Morocco.

To most of us, wheels seem pretty intuitive. You've probably known from an early age, for example, that circular or rounded things roll more easily than boxy or angular things. Knowing this, it's hard to imagine that our earliest ancestors did not come to similar realizations on their own — and yet, the first wheels…

If you're one of those people who's always wondering why the flying car hasn't been invented yet, you're too late. The first flying car was already created back in the 1970s — but don't get too excited. It was literally a huge disaster.