John R. McCuaig, age 11, of Ne san, B.C., for his question:

Does the earth rotate or revolve?

The earth rotates and it also revolves. Both these words mean to turn around, but when used in relation to the earth they have different meanings. For our old earth is busy turning in several ways at the same time.

The earth rotates on its axis, spinning like a top. Each rotation takes a few minutes less than 24 hours. The speed of rotation at the equator is about 1,000 miles an hour.

The earth revolves around the sun, traveling an almost circular path which takes a little more than 365 days. The orbital path is about 600 million miles and the spend at which the earth revolves is 182 miles a second.

But this is not all. The sun also is moving in an orbit through the Galaxy. The earth and the whole Solar System move with it at the breakneck speed of 170 miles a second. These ideas may make you feel dizzy. But the fact is that we are so used to all this revolving and rotating we just do not notice it.