# How is wind a force that is able to move and effect other tangible objects?

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I guess it goes for all “gases” but I have a hard time wrapping my head around how gases moving rapidly have the kinetic energy to move solids and even liquids.

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Because gases are made up of atoms, they have mass just like solids and liquids do. While they have less mass given the same volume, kinetic energy is also about velocity and gas molecules are typically moving faster.

So something fast and small can have just as much kinetic energy as something massive and slow.

It is called “boundary layer effect”… on an atomic level the gas/liquid outer layer interacts with the solids outer layer and creates “drag” a it passes over resulting in motion/transfer of kenetic energy. This is what wind mills, propeller aircraft, and hyro power turbines work off of. Inversely, this is also why your car cannot go 500 MPH.

Wind contributes to two “forces” let’s use a sail on a boat as our example.

Force A is the “push” force. All the particles in the air have kinetic energy and they physically hit the sail just a billiard ball hitting other balls. This results in a net push, in the direction of the flow of the air, into the obstacle. This force would “push” a sail boat around, or be felt by a building as a desire to sway or fall over.

Force B is the “lift” force. When air flows over a special kind of surface, called an “airfoil” it results in a net force *perpendicular* (at a right angle to) to the surface. In the case of an airplane wing this would *lift* the plane into the air. In the case of a sail boat if the sail was aligned in the right direction it would pull the boat to the right or left, sideways, from the centerline of the boat. It’s using lift force that sailboats can sail directly into the wind.

All gases have weight and mass and volume just like you or anything you can visibly see does. Because air is transparent, you can’t see it but your moving through it the same way you would move through water. When you move your actually parting the air out of your way. When you wave your hand really quickly from side to side that slight pressure you feel against your hand is the air not being able to move out the way fast enough.

Because air can be moved, it can be forced into an area. It can even be squeezed into an area that is too small to contain it all. Imagine your sock draw. You have lots of socks so as soon as the draw is full, you try to ram more and more socks in until the sock draw is so full all the socks are compressed tightly. Next time you open the sock draw, all the socks come popping out and flying everywhere, because they were so tightly packed together.

This is what we mean by high pressure when we refer to air. The air is squeezed into a space and there’s more air that there is room to fit, so it wants to get out to where there is room for it. If given a release it will shoot out, and because it has weight, volume and mass, it can push whatever it encounters if it was squeezed tightly enough as it expands.

Think of it as standing in front of a hatch of a 10’000 litre water tank and suddenly that hatch burst or broke. The water has weight, mass and volume so it would probably hit you real hard and send you flying. Air would do the exact same thing if you compress it tightly enough. Though for clarity please don’t compare air pressure and water to each other beyond this as there are critical differences between the two elements (Like water cannot be compressed for example).

So basically, when you pack air tightly enough so the pressure of it is high (Think sock drawer overloaded with socks to bursting), if you give it a release the air wants to go where the pressure is low, i.e. where there is less air. That is basically all that wind is. Higher pressure (More densely packed) air moving to an area where the air pressure is lower (Less densely packed) so it can equalize out.

So when you feel wind when your out and about, it’s basically higher pressure air moving to where there is lower pressure air, except on a planetary scale. Hurricanes and tornados can be so powerful because there is an awful lot of high pressure air with a lot of weight wanting to move to a lower pressure area really, really quickly.

This is also the reason why cars and planes can only go so fast, why things entering the atmosphere from space burn up if they enter too quickly and so forth. The air simply cannot get out of the way in time and it starts to get quite a mass till it builds up to the point it starts to become compressed and if you compress something, you heat it up.

Standard ELI5 Disclaimer applies: Answer skips over a lot of nuances for simplification and doesn’t paint a complete or 100% accurate picture.

We’re swimming in very very thin water. It’s all fluid dynamics. Can’t throw a curve ball in a vacuum