The Physics of Sailing | KQED QUEST

Watching this video before sailing alone around the world

The physics explanation was half baked. I want to know exactly what each part of the sailboat is doing in a free body diagram.

Was produced in high definition "360" max...

And THIS my fellow sailors, is WHY we NEVER confuse facts with Television.

it's simpler to just figure out a workable route and let the sail dictate the angle of approach, turn away from the wind until the sail starts catching and let the wind push/pull you along. always look to your sail for information, it'll tell you how it wants to work.

I have 3 years of studies left then I'm buying a used sailboat and taken sometime off. For me it's the best thing in the world.

Ok this will be a informative video! “Square rigged sailboats can only go one basic direction.” Nevermind.

Informative video. Don’t be deterred by the negative comments. Worth a watch.

I've always been so fascinated on how sailing ship works!!

watching this while working on my architectural project that is inspired by how sailing boats capture wind to bring this flow into my concept, such an inspiring video.

Hard to take this seriously when the first thing they say is completely wrong. Square-rigged ships can most certainly sail into the wind. It's true that they can't lie as close to the wind as a fore-and-aft rigged ship, but they can tack.There's no way Magellan, Drake etc. could have made it around the world in ships that only sailed with the wind. Getting around Cape Horn from east to west is impossible if you can't sail your ship into the wind.

For those who are astute enough to figure this explanation was incomplete. There is NO SUCH FORCE AS LIFT. ALL wings, propellers, sails, and fans generate THRUST. Think about a wing, or propellor blade. The air on the upper or forward surface creates a pocket of low air pressure. This does NOT ‘suck’ the blade forward, nor the wing upward. The inertia of the plane is too high for this relatively small difference in air pressure. And the wing or sail itself acts as a barrier preventing the high pressure air under the wing from moving into the low pressure above the wing. However, the low pressure air is relatively confined to the space very near the wing, and further up above the wing, or ahead of the sail, is an OCEAN of air at higher pressure and the air molecules have LOW inertia. So as the wing or sail moves forward, it continually generates a low pressure zone, that the higher pressure air further away is continually rushing into. Accelerating as it does so. As it reaches the low pressure zone, the wing or sail has moved out of the way, and the result is a jet of air accelerated in a direction perpendicular to the chord of the wing. Airplanes fly because the wing accelerates a mass of air DOWNWARDS with a thrust that equals or exceeds the weight of the airplane. Action-reaction. This is why EVERY propellor and Fan does NOT create a great deal of force on the sucking side- it creates force on the BLOWING side. The wind coming off the sail is moving FASTER than the rest of the air and being directed at a vector. In a plane the high pressure under the wing can not expand upwards because of the inertia of the plane, but it CAN expand into the lower pressure air further below the wing. This, again, is air accelerating downwards, added to the air coming off the trailing edge of the wing and thereby producing thrust. The same is true of the high pressure air in the belly of the sail. It is accelerating away from the sail, and the reaction to that is added thrust perpendicular to the sail. In this way, under certain conditions and under certain point of sail, a sail can generate a speed that exceeds the speed of the wind, because it accelerates air to a higher speed creating thrust. So, forget about ‘lift’. It’s an imaginary force. Every fan proves to you that wings produce thrust.

I've always been so fascinated on how sailing ship works!!. I've always been so fascinated on how sailing ship works!!.

This is still a good description of the physics behind sailing, irrespective if the ‘into the wind’ debate.

I learned to sail at 16 in San Diego, we stayed at a resort that had sailboats for rent, we went down and said we don't know how to sail, the guy renting the boats said it's simple, if you catch the wind and move forward, you are sailing, if your not moving, your not sailing, it's that simple, that was 55 years ago, nothing has changed

Best analogy about how a boat sails when wind is forward of the beam is "squeezing the seed". The person in this video did mention this, not many know this, most think its only the lift, like aeroplane wings that move the boat.

2:12 Fluid Mechanics Laboratory aka F.M.L.

1:52 I was dying that that jib sheet wasn't being pulled!

1:40 Lift from the sail is perpendicular to the wind. It tries to make the boat plow through the water across the wind, but the keel can only slice through the water edgewise. The water prevents the boat from drifting sideways by pushing on the side of the keel, and that force is partially upwind. 5:40 The force from the keel has no forward component. Only the sail pushes the boat forward. End: You need to explain torques and ballast, heeling and righting moments.

Nice thing about videos like this is they're still current no matter when you watch them!