Sunday, September 24, 2006

Cowboy Question #2

Q2. When the tide is high in the Bay of Fundy is it low on the other side of the world?

A logical question from our prairie visitors!

Actually it is more likely to be high on the other side of the world and low a quarter way round in either direction. This is because the moon produces two tidal bulges somewhere on the Earth through the effects of gravitational attraction. The height of these tidal bulges is controlled by the moon's gravitational force and the Earth's gravity pulling the water back toward the Earth.

At the location on the Earth closest to the moon, seawater is drawn toward the moon because of the greater strength of gravitational attraction. On the opposite side of the Earth, another tidal bulge is produced away from the moon. However, this bulge is due to the fact that at this point on the Earth the force of the moon's gravity is at its weakest.

Considering this information, any given point on the Earth's surface should experience two high tides and two low tides during each tidal period.

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