David Johnson, age 10, of Huntsville, Alabama, for his question:

Does a compass point south in the Southern Hemisphere?

A magnetic compass has a needle and every needle has two ends. The sliver of metal in the compass is drawn into position by the earth's magnetic poles. The two magnetic poles are near the North and South geographic poles. They work like the opposite poles of a small magnet, only on a much grander scale. Each of the earth's magnetic poles draws the opposite pole of the compass needle. Actually, the end that points to the north is the south pole of the magnet. But to avoid confusion, we call it the north pole of the magnet. If we wish to be more particular, we can call it the north seeking pole.

In any case, when the arrow of a compass points north, its opposite end must be pointing south. The equator does not change this one bit. If we take the compass down to the Southern Hemisphere, the north seeking pole continues to point north and the south seeking pole of the compass needle continues to point south.