Do whirlpools spin in opposite directions on opposite sides of the equator?

Answer 1

Some will. The Coriolis effect, however, only has absolute effect on large scale motion, and small changes in conditions can cause circulation in either direction in either hemisphere.

Many people believe that toilets in Australia flush clockwise (i.e. the opposite way of those in the northern hemisphere, e.g in the US). This is untrue, as the forces involved are too weak to influence flow on such a small scale. The direction of such flow in toilets and bathtubs is more-or-less random, influenced by perturbing factors in the system.

Moving fluids do tend to flow in the opposite direction on opposite sides of the Equator due to the Coriolis effect, an effect of the Earth's rotation. Water in (large) whirlpools and atmospheric flows around low-pressure areas (cyclonic storms like hurricanes or typhoons) turn clockwise in the Southern Hemisphere and anti-clockwise in the Northern Hemisphere.

Also, from the standpoint of locations on a sphere (the Earth) clockwise in the north *is* counter-clockwise in the south. If a clear window were set into the Earth, people looking down at the opposite side would see the motion proceeding in the opposite direction.