00:00Whether or not you realize it, as a surfer, you're a master of complicated physics.
00:13The science of surfing begins as soon as you and your board first hit the water.
00:20The board's size and light construction help it displace a lot of water.
00:25In turn, a buoyant force equal to the weight of the displaced water pushes up,
00:31counteracting you and your board's weight.
00:34This lets you stay afloat while you wait to paddle for a wave.
00:38And what exactly are you waiting for?
00:40The perfect wave, of course.
00:42Like other waves in physics, ocean waves represent a transfer of energy.
00:49Wind blowing across the ocean accelerates water particles near the surface,
00:54leading to the growth of ripples that become waves.
00:58These deviations from the flat surface are acted upon by gravity,
01:02which tries to restore the surface to its original flat state.
01:08As the waves then move through the water, particles push and pull on their neighbors
01:13through the wave-induced pressure.
01:15And this motion propagates energy through the water in unison with the wave motion.
01:21The motion of these particles is much more limited than the overall motion of the waves.
01:27Near the shore, the shallower seafloor constrains the motion of the waves to occur in a more limited region than out at sea,
01:35concentrating the wave energy near the surface.
01:38If the topography of the shoreline is even and smooth, this will refract the waves to become more parallel to the shore as they approach.
01:47This is the crucial moment.
01:50As the wave gets near, you quickly pivot your board in the same direction as the wave and paddle to match its speed.
01:57Your board forms an angle with the water, and this creates a dynamic pressure on the bottom of it,
02:04forcing you and your board out of the water to skim along the surface.
02:09At the same time, your increased forward momentum makes you more stable, allowing you to stand up and surf along the wave.
02:18Now you've caught the wave and are riding along its front face parallel to the shoreline.
02:24Fins on the surfboard allow you to alter your speed and direction by repositioning your weight.
02:30Above you is the wave's crest, where the water particles are undergoing their greatest acceleration.
02:37That forces them to move faster than the underlying wave, so they shoot ahead before falling under gravity's influence.
02:45This forms the wave's characteristic curls, or jets, as they break along the shore.
02:51Sometimes the curl might completely enclose part of the wave, forming a moving tube of water known as the barrel.
02:59Because of irregularities in the seafloor and the swell itself, few barrels last as long as the legendary 27-second ride off the coast of Namibia.
03:09But many who manage to get barreled have said they feel time passing differently inside,
03:15making it one of the most magical experiences a surfer can have.
03:20Of course, not all beaches are created equal.
03:23Offshore underwater canyons or rock formations in certain locations like Nazare, Portugal or Mavericks, California,
03:31refract the incoming wave energy into a single spot, creating massive waves sought by surfers worldwide.
03:39And some of these waves travel for more than a week, with swells originating more than 10,000 kilometers away from shore.
03:48Waves surfed in sunny California may have originated in the stormy seas near New Zealand.
03:55So, while you may not be thinking about weather patterns in the South Pacific, tectonic geology, or fluid mechanics,
04:02the art of catching the perfect wave relies on all these things and more.
04:08And the waves we surf, created by wind,
04:11are just one visible part of the continuous oscillation of energy
04:15that has shaped our universe since its very beginning.
04:19Despite its association with fun and sun,
04:22surfing has a richer, deeper, and much more complicated history than many realize.
04:27Check out this episode to uncover the hidden history of surfing.
04:38The
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