The latest example? An article from the journal Physics Today, in which researchers from the Laboratory of Hydrodynamics (LadHyX) at France’s École Polytechnique in Paris used a crew of robots to work out how teams of rowers could row more efficiently. The results came close to upsetting centuries of human-honed rowing know-how.
As you’ll be aware if you’ve ever watched rowing before, pretty much every rowing team rows with every team member rowing in time with one another. The reason for this is that it results in the smoothest possible trajectory for the vessel, resulting in the fastest possible row from point A to point B. Right? Well, almost.
In fact, the researchers found something a bit different when they built a tenth-scale racing boat with eight tiny Arduino-controlled robotic rowers. What their analysis showed was that when rowers row together it results in significant acceleration and deceleration periods — with the point between strokes, at which no-one is rowing, causing deceleration of around 20 percent. If, however, rowing is carried out asynchronously — or out of time — then there is 5 percent less friction on a boat’s hull.
When you consider Olympic rowing, that 5 percent could theoretically be the difference between a gold and silver medal. In fact, speed variance with asynchronous rowing is just 2 percent, down from the whopping 12 percent with regular synchronized rowing.
Don’t panic, though: As it turns out, despite this being the smoothest (and most robot-approved) way to row, it’s actually slower than the way that we do things. As the researchers explain:
“In our initial thinking, we failed to take into account that the rowers are not stationary. Indeed, the speed in the synchronized configuration keeps increasing at the beginning of the recovery stroke — that is, after the oars have been lifted from the water. If the velocity keeps increasing when the oars are out of the water, there must be an additional propulsive force that does not depend on oars. In fact, the force results from the motion of the rowers on the boat. When the rowers return together to the stern of the boat during the recovery stroke, they pull the hull beneath them and accelerate the boat. Since the crew of a coxed eight weighs several times what the boat does, the rowers generate a significant force. When they are desynchronized, that inertial boost is reduced.”
So to take all of this wildly out of context, when we all row together we can beat the robots. There’s probably a lesson for Skynet hidden in there somewhere!
