Olympics, Surfing, Physics, and Future Olympians
The Olympic games feature athletes from around the world competing in many different sporting events. Although competition pits man against man, woman against woman, and country against country, athletes battle nature to skillfully control its forces. Sports are effected by the laws of physics in fluctuating environments. Isabella Issacs-Thomas of PBS wrote a very good article entitled "The not-so-hidden-physics of your favorite Olympic Event".
Examples of science evolving sport is seen in the high jump. For years, competitors used the scissors technique to jump. The old method centered the jumper's body mass over the bar and limited trajectory. Dick Fosbury developed the Fosbury Flop that distributed the center of mass and set new records. The trajectory of a soccer ball can be controlled by spinning the ball with a kick in the right spot. A basketball will drop through a hoop touching only the net, when the right amount of force gives it height and distance to arc in with gravitational pull. In Aquatics, swimmers discovered that opening their fingers increased hand size and power in their strokes. Water cannot move between fingers when the hand accelerates. Speed blocks the flow of fluid through smaller openings, increasing pressure and generating force, Bernoulli's Principle. Surfers can apply this principle in paddling. Many sports require strength and speed, but the victors are those who skillfully navigate the laws of physics.
For the Olympic surfing competition, mother nature delivered good size, powerful breaking waves. As anticipated by Geophysics, a passing Typhoon generated the waves. Unfortunately, it also churned up the ocean which created challenging stormy conditions. Competitors had to master an unpredictable ocean with rips and chops that often caused wipeouts and denied good surfers opportunities to advance. Some waves provided long connecting sections for performance, while most dissipated or shut down on surfers.
The winners Italo Ferreira for the men and Clarissa Moore for the women exercised not only skill, but good wave judgement to succeed. Balancing on surfboard was not the only challenge. The successful and victorious surfers balanced the forces of nature.
Hydrodynamics, one of the many branches of Physics, governs the movement of surfboards through water. At low speeds, an object moves in water by moving water. The object pushes water out of its way and takes the place of displaced water, therefore; this is called displacement. Swimmers and paddlers use their strength to move water. When an objects moves fast, water does not have time to move out of the way. Water needs time to flow and move, displacement requires time. Instead accelerating objects such as surfboards and speed boats are supported on water's surface with water resiastance known as hydronamic lift. Displacement and drag is gradually eliminated with speed, as the forward nose or bow lifts out of water. At planning speed, speed boats and surfboard ride of their aft half. Surfboards with a flat forward underside may suddenly stop if the bow or bottom abruptly hits water. Surfers use skill to prevent this from happening.
In the Olympic Surfing final, Italo Ferreira launched his surfboard through the air into a foaming abyss. He landed flat and hard, his force snapped the surfboard in two pieces. In a hard flat landing, water does move enough to cushion a falling surfboard. Instead it briefly blocks entry and the surfboard absorbs impact. An object falling in water, lands with force, which is mass multiplied by acceleration. Water will resist penetration with force and cushions objects falling from lower heights. Objects falling from great heights are not cushioned and briefly stop on the surface. The increase of speed and force with height does not allow time for water to displace. This is the reason it hurts to fall into water from higher heights. Your body stops momentarily on the surface absorbing the impact before decelerating and sinking.
Surfing has evolved with flight, surfers are flying above the waves and landing hard. Freefall late takeoffs have always been difficult. Today with shorter surfboards surfers are taking off later, under the lip and succeeding. Only the harder flatter nose first landing elude success.
The blocking power of water or hydrodynamic resistance causes catapulting in a pearl dive or nose poke. Resistance is optimized on flat surfaces like the underside of surfboards or a surfer's body. In a nose poke or pearl the surfboard's bent flat underside hits water with speed and great force. Hydrodynamic resistance blocks entry and abruptly stops the surfboard. The surfer is launched or catapulted through the air. His body landing may also be flat, hard and painful. Flat bottom surfboards with high nose rocker are designed to work by keeping the nose out of water at high speed. This is difficult when surfers lose control in flight. The tip may clear the surface, but; the flat unside is exposed to impact.
The next generation of Olympians can break new barriers and set new heights with improved equipment. All experienced surfers have suffered through painful catatpults with hard landings. Many surfers have been injured and two have died. We can reduce the pain and injury to our children and their children. Flat bottom surfboards can evolve with modern aerial surfing. The underside of the nose area on a surfboard must part water when it moves slowly in the displacement mode. This is the bow area where Flat bottoms push water forward consuming momentum at lower speed and stopping at high speed. A Veed or round bottom parts water and pushes it aside; water is parted in a hard landing. The Flatbottom will stop while Veed and round bottoms keep moving. Catapult wipeouts can be reduced. Success is not guaranteed and dependant on skill. We can give future Olympians a chance to be champions.