Reynolds number

The Reynolds Number measures how fast and how big the object is that is moving. It is named after the scientist, Osborne Reynolds. It is used to figure out if an object is moving fast enough to produce something called "turbulence." Turbulence is when a object is moving so fast, it can create ripples or swirls in the air or water. High Reynolds numbers mean there will be more turbulence and low Reynolds numbers mean there will be less turbulence.