Underwater Communications

There is one thing that I simply do not understand about communications with submarines and other underwater devices. Such communication has always been difficult. The radio waves that are used for communication on land do not travel well through water. For details look up "Submarine Communications" at http://www.wikipedia.com/

Efforts have been made to develop blue lasers for underwater communication because blue light is the color (colour) that can travel furthest through water without being absorbed. But this method cannot really be considered as satisfactory because the exact position of the sub must be known. Sound waves travel well through water and this has made sonar the undersea version of radar. The disadavantage of sonar, of course, is that in wartime the sub risks giving away it's position by using it.

I simply do not understand why we do not use the same principle that operates a microwave oven for underwater communications. This just seems so obvious to me. A molecule of water consists of an oxygen atom and two hydrogen atoms. However, this arrangement is not symmetrical and means that there will be a different charge each side of the molecule. In other words, the water molecule is polar.

Yet, a quantity of water is electrically neutral and manifests no electric charge. This can only mean that the water molecules align themselves negative to positive and this is why water molecules cling together in drops.

I believe that water should be our ally, instead of our enemy, in underwater communications. The trouble is that we have approached such communications with a terrestrial mindset, trying to adapt land-based methods of communication to the sea. Now, let's try a different approach.

Polar water molecules line up negative to positive into an equilibrium which the presence of an electric charge will disturb. This means that an alternating electric charge will create electrical waves in the water which can be used for communication. A microwave oven is a development rooted in the so-called "travelling wave tube" used in early radar sets.

In the microwave oven, alternating negative and positive charges are produced by electrons moving along a circular track. This causes water molecules in the food to flip over many times a second, producing the heat that cooks the food from within. The microwave cooking process is based on the electrical polarity of water molecules.

It should be simple to use this microwave principle for communications or range-finding under the water. All we have to do is broadcast the electric waves in the water outward instead of inward onto food.

If a portion of the hull of a submarine or an antenna were given alternating electric charges, waves in the position of the polar water molecules would emanate outward. No heat would be produced because each molecule would shift only once in each wave. The energy would thus go not into heat but into waves moving outward from the source.

Keep in mind that these are not electromagnetic waves that we would produce. They would be waves in the alignment of water molecules based on their electric polarity. This is something that we cannot relate to on land because air is not polar as water is.

Neither is it an electric current through the water. The transmitting antenna would not have electrons travelling from top to bottom and back as would a radio antenna. Rather, it would be an object which would bounce from having a negative charge to positive and back again. This would change the directional alignment of nearby water molecules, which would change the alignment of the molecules further out, and so on, thus creating a wave that can readily be used for communications.