Newton Rules Biology
More than a decade ago I was pointed at a new book written by Colin Pennycuick: Newton rules Biology. It must have been in my first or second year as a biology student. I reminded this because 2009 is the celebration of the Origin of Species and the 200th birthday of Charles Darwin. We had a discussion about who was a greater scientist Newton or Darwin? And as I was to become a biologist of course I voted for Darwin. Especially because Darwin’s ideas were transformed into social ideas, so called Social Darwinism. Either wrong or right, Darwinism had a huge impact on society. Ok, Newton’s laws were useful when you had to build a bridge, send spaceships to the moon. But I couldn’t think of any examples how Newtonianism had influenced politics at that time. So when a friend of mine held an enthusiastic lecture about how Newton rules biology, we reacted like we’re stung by a bee. This was pure heresy!
After the initial unrest had flooded away our fallen biologist continued and with a smile on his face he even stated that we biologist should learn from those lazy physicists. Were biologist have to travel around the world to come up with an idea (like Darwin) physicist do not have to get up from their comfortable chairs to describe to universe. And were biologist are stuck between the molecular level and the biosphere (I leave the idea whether extra terrestrial life does exist up to the reader) the old time physicists have no problem describing the world from the atomic level up to that of the universe! Nature, he continued is ruled by Newton’s laws. Scale for instance. Compared with humans a flee can jump several meters far. That is if you leave scale out of the equation. If you could scale up a flee to human proportions it would crush under its own weight. The legs to support such a body wouldn’t be able to function properly. The huge amount of muscle tissue is not capable of the short energy explosion to make a jump. That’s one of the reasons why you’ll never find an elephant jumping around like a kangaroo. It’s just a matter of mass and forces, and that’s what one of Newton’s laws is all about (F = m*a) .
But what about the bumblebee then? This animal is too heavy to be able to fly, according to the Newton laws it’s wings are too short to lift the insect up in the air. For centuries this animal defied Newton! Hurrah for biology! Hurrah indeed, until the Wright brothers flew their Flyer for a dozen of second through the air. It was the birth of aerodynamics and the end of the miracle of the bumblebee… The wings of a bumblebee are not stiff as opposed to those from an airplane for example. While in flight they wings bent, creating tiny little whirlwinds, which are responsible for the necessary lift. And guess what… Aerodynamics would not have existed if Newton didn’t wrote down its ground rules.