Day 1: Determining Draining Direction

Brief Bio:

My name is Berit, and I am a student at Boston University studying history. I am from Florida and I grew up only minutes away from the beach. I am taking this class not only because because I needed a science course and this one was recommended by a number of people, but also because the topic was one that I thought would be interesting. I've spent my entire life around beaches. I have been fortunate enough to travel to beaches as far east as the Mediterranean Sea and the Dead Sea, and as far west as the beaches of the French Polynesian Islands in the South Pacific. My experiences have strengthened my affinity for the ocean and beaches, and have also shed light on how different various beaches are from each other—or even themselves at different points in time.

Field Trip to the Bathroom:

Today in class we took a field trip to the bathroom to perform an experiment to determine which direction water drains from a sink in the Northern Hemisphere: clockwise or counterclockwise. My group consisted of five people, and we performed the experiment two times. On the first attempt, a few moments after the water drained, we reached a consensus that the water drained clockwise. On the second attempt, we reached a consensus again, that the water drained clockwise. It may have been difficult to properly discern the way the water was draining because we did not fill the sink up entirely during either of our attempts.

Research:

Upon researching the topic, it would appear that our conclusion would have been incorrect because water in the Northern Hemisphere is pulled by the air which causes it to drain in a counterclockwise direction. The Coriolis effect explains why water in the different hemispheres drain in different directions: simply, because of the direction of the earth’s rotation. However, research on the direction water drains from sinks in either hemisphere of the earth is influenced by things other than the Coriolis force; instead, for small-scale bodies of water (e.g. a sink or bathtub), the direction in which water drains is determined more directly by the shape of the sink and of the drain. From what I have gleaned from my internet research, the Coriolis effect is more applicable to large-scale air movements like the direction the air blows from hurricanes, typhoons, an cyclones.

Sources:

http://www.loc.gov/rr/scitech/mysteries/coriolis.html

http://www.scientificamerican.com/article.cfm?id=can-somebody-finally-sett

http://www.aoml.noaa.gov/hrd/tcfaq/D3.html