Hurricanes, twisters, cyclones, whirlpools, typhoons, and dust devils all have something in common. They involve rotation or spinning. A more technical name for a rotating fluid is a vortex. One technique used for keeping up with these types of rotational flows involves the "right hand rule." That is, if the fingers of the right hand are curled with the direction of rotation, then the right thumb points in a direction perpendicular to the plane of the flow. This can then be useful in mathematical analysis.

If one considers the rotation of the tires on your forward moving vehicle, the thumb would point to the driver's left, for all four wheels, while for a skidding (rotating) vehicle, the thumb would point upward or downward depending on the direction of the rotational skid.

That means for these hurricanes that have been hitting the U.S., since they rotate counterclockwise, the thumb (using the right hand rule) points up from the eye of the storm away from the earth's surface. Ironically, we would think of that as "a thumbs up," hardly suitable for such horrific windstorms.

AU Astronaut Jim Voss, my former student, has a stunning photo taken from space of a Pacific Ocean typhoon posted on his AU campus office bulletin board. He describes it as being 1,000 miles in diameter. This dwarfs these huge storms that have been hitting Florida with regularity this season. During space flight Jim was able to look right down the wall of the eye.

Not all rotations are bad by any means. Those that are best we usually take for granted; the rotation of the earth about its own axis that gives us our hours of sunlight and hours of darkness, the rotation of the earth around the sun which gives us our seasons, the rotation of the moon about our earth that gives us the beautiful full moon of last night and affects the tides, and more.

Most of the sports we enjoy involve rotations: spiraling footballs, kicks that spin end over end, and baseballs that curve due to pitcher-induced spin just to name three. Our homes are full of rotating devices; mixers, microwave oven turntables, CD and DVD disks, fans in our heating and air conditioning systems, and a host of motors that involve rotation.

Many of our own physical abilities involve rotation; eyeballs, necks, shoulders, knees, elbows, ankles, fingers, and more. These too we so often take for granted unless we have problems that limit their range of motion.

Perhaps the greatest scientist who ever lived, Sir Issac Newton stated (because of its unique capabilities), "In the absence of any other proof, my thumb alone, would convince me of God's existence. " The thumb can perform at least 58 distinct functions. There is a great video that shows most of them, spectacularly synchronized to the music of John Williams. See the link to Music and more on the homepage.

The physical world is full of rotations that we cannot escape. They effect our lives whether we know of them or not, whether we understand them or not. In the non-physical world, perhaps the same is true?

We don't usually think of rotations in the non-physical parts of our world, but there are a few examples. One can be acting in certain bad behavior ways, realize that they are heading us in the wrong direction, then turn and change that behavior. One can even change their thought patterns, turning completely in the opposite direction.

Hurricanes may change their direction of forward travel (even meandering like Jeanne and Ivan recently), but their rotation in the northern hemisphere is always counter-clockwise. It's good that human beings aren't similarly fixed in the way they can turn.

Dr. Malcolm Cutchins is an emeritus professor of engineering of Auburn University and writes a weekly column for The Opelika-Auburn News. Published 9/30/2004.