Expanding on that, the downwash theory is the easiest to understand in my opinion. If you think about the flow of water over the back of a spoon then imagine in

Expanding on that, the downwash theory is the easiest to understand in my opinion. If you think about the flow of water over the back of a spoon then imagine increasing the amount of the water flow and the size of the spoon until you could eventually feel the force pulling your hand opposite the direction the water is deflected.