The direction of water swirl in your sink is determined by the Coriolis effect, which is caused by the rotation of the Earth. This effect is stronger in larger bodies of water, such as oceans, but is too weak to have an impact on the direction of water in a sink. Other factors, such as the shape of the sink and the way water is introduced to it, have a greater influence on the direction of the swirl.
While it is commonly believed that water swirls clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere, this is actually a myth. The Coriolis effect does have an impact on large-scale weather patterns and ocean currents, but its influence on the direction of water in a sink is too weak to be noticeable.
Yes, the shape of the sink and the way water is introduced to it can have a significant impact on the direction of the water swirl. The shape of the sink can create eddies or currents that influence the direction of the swirl, while the way water is introduced (e.g. pouring from a cup vs. turning on the faucet) can also affect the direction of the water.
While it is not possible to control the direction of water swirl with the Coriolis effect, you can influence it by changing the shape of the sink or the way water is introduced. Additionally, external forces such as air currents or objects in the sink can also impact the direction of the swirl.
The direction of water swirl in a sink may be interesting to observe, but it does not have any practical applications. It is simply a result of various factors, including the Coriolis effect, that do not have a significant impact on our daily lives. However, studying the mechanics of water swirl can help scientists better understand fluid dynamics and make advancements in fields such as meteorology and oceanography.