Wednesday, September 21, 2011

Simple Questions You Won't Believe Science Can't Answer - How a bicycle works



Bicycles have been around since the early 19th century, and its basic design has actually changed relatively little for almost 200 years. You always had two wheels, a frame to connect them and a handlebar for steering, and you required a person completely devoid of shame to ride on it.
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It turns out skintight short-shorts are an improvement in bicycle fashion.
At the very least, you'd think that the guy who invented the damn thing knew what he was doing, but after more than a century of research, science has been forced to conclude that he was probably some kind of sorcerer. The first bicycles were invented, not through any kind of scientific procedure, but by dumb old trial and error. Even modern bike design schools admit that it's not engineering or computer knowledge that make a good bike designer, but instead "intuition and experience."
So, what happens when you ask scientists exactly what makes a bicycle stable? Or what keeps it going? Or how people ride them? Well, odds are they'll either nervously tell you that they have cookies in the oven and run out on you, or if they're honest, they'll give you a pretty big shrug. In fact, top bike researchers admit that, even though some people have come up with equations on how to ride a bike or how they think bikes work, those equations are pretty much fancy icing on top of a cake of cluelessness. One Cornell researcher even says that absolutely nobody has ever come to an intuitive understanding of what makes a bicycle do its thing.
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Science: "We've narrowed it down to either spoke fairies or wheel fairies."
For ages, scientists assumed that the gyroscopic effect (the force that keeps a spinning top from falling over) was the key for a bike's balance. But nope! In the '70s, a scientist disproved that theory.
So then, scientists thought that the principal factor for a bike's stability was something called the caster effect, or trail (something to do with the front wheel's angle away from the frame). But just this year, top bikeologists from Cornell and other universities formed an angry scientific mob, then torched and pitchforked that theory as well. They did this by building a goofy-looking bike that has no gyroscopic effect and no trail, but manages to stay upright nonetheless.
Sam Rentmeester/FMAX
"Look, Ma! No physics!"
So scientists are essentially back at square one, as things such as steering geometry and the physics of stability are all going back to the drawing board. At least you can be secure in the knowledge that the humiliation you feel when you ride a bike is akin to the humiliation science feels when it's asked how a bike stays up.

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