Teddy Blamines, age 12, of New Plymouth ,, Idaho, for the question:

Where does the water go when the tide goes out?

On most beaches, the water rises and falls six to eight feet with the changing tides. The thing to remember is that these rising and falling tides affect the seas of the entire world. In mid ocean, the surface of the water rises and falls only two to three feet. Certain coastal formations funnel the moving tides and this makes for unusual conditions. In the Bay of Fundy, the difference between high and low tide may be 50 or 60 feet.

No beach, no bay, no little estuary feels the tides by itself. Each is part of the watery movement which takes place over the entire globe. When the tide ebbs from a beach, extra high tide water is piling up somewhere else, just as when you tip a pail of water the surface rocks back and forth.

A 60 foot tide is an awesome sight. The mountain of water, charging forward and upward seems bent on destruction. But lets consider the size of the entire globe. Its diameter   a line through the middle from side to side   is almost 8,000 miles. A variation of 60 feet is not much. Nevertheless, the water at low tide has to go somewhere.

It seems logical to suppose that the opposite side of the globe has high tide while we are having low tide. Perhaps all our lost water piles up on the opposite side of the earth. But this is not so at all. The fact is, the opposite side of the world has low tide when we do  which still does not explain where the water goes at low tide.

There is, of course, only one place where it can go. It piles up between us and the antipodes   the opposite side of the globe. While the two opposite sides of the globe are having high tide, the sides between them are having low tide.

The tide is high, of course, under the moon   for most of the tidal action is caused by the pull of the moonts gravity. The pile of tidal water under the moon pulls at the ocean waters clear around the globe. It draws from the waters on all sides, making low tide areas half way around the world. This reduces pressure on the waters of the antipodes. It pulls back and piles up in a high tide of its own on the far side of the globe.

The spinning earth faces the moon with first one side, then another. High tide is felt by the side facing the moon and this extra water is drawn from the low tide areas half way around the world. A corresponding high tide piles up on the opposite side of the earth.

As the earth turns, the moon pulls at first one area of the seas, then another. This means that the changing tides   high, low, high, low   follow each other around and around the globe. On ant beach, the tide rises high twice in every 24 hours and sinks to low twice in every 24 hours.