Have you ever heard that water drains in different directions depending on whether you’re in the Northern or Southern Hemisphere? This idea has been shown in TV shows like *The Simpsons*. To find out if it’s true, friends Derek and Destin did some experiments to see if the direction of water swirl is really affected by where you are on Earth.
Derek lives in Sydney, Australia, and Destin is in Huntsville, Alabama. They wanted to test the swirling water theory in a controlled way. They synchronized their experiments so people could see both at the same time. However, they realized this might be tricky for people watching on mobile devices, so they made a combined video instead.
Destin mentioned that many documentaries claim the hemisphere affects water swirl direction. But Derek explained that this is a misconception. In Alabama, toilets sometimes swirl clockwise and sometimes counterclockwise, showing that the toilet’s design is more important than the hemisphere. Derek noted that any container of water has some motion, and this motion, not the hemisphere, decides the swirl direction. So, the idea that crossing the equator changes the swirl direction is just a myth.
To dig deeper, Derek and Destin set up a controlled experiment using a kiddie pool. They wanted to remove any existing motion in the water. Derek filled the pool in a clockwise direction, while Destin filled it counterclockwise, making sure the filling method didn’t affect the motion. After letting the water settle for 24 hours, they drained the pool using a valve to avoid adding any extra motion. They added food coloring to see the water’s movement clearly.
As the water drained, they saw a clear counterclockwise rotation, even though the pool was filled clockwise. This seemed to show the Earth’s rotation affecting the water, demonstrating the Coriolis Effect. However, Derek pointed out that this effect is very small and wouldn’t be noticeable in everyday situations like bathtubs or sinks, where other factors hide the Coriolis Effect.
Derek and Destin explained how the Coriolis Effect works. Imagine a pool at the poles, where the Earth’s rotation affects the water’s movement. The outer edge of the pool, closer to the equator, moves faster than the inner edge, which is nearer to the pole. When the pool is drained, the faster-moving water from the equator side rushes ahead, while the slower-moving water from the pole side lags behind. This speed difference causes a swirling motion as the water drains.
Derek and Destin’s experiments show that while the Coriolis Effect is real, it doesn’t really affect everyday water drainage. The direction of water swirl is mostly determined by the design of the drainage system, not the hemisphere. This exploration not only busts a popular myth but also shows the interesting connection between physics and everyday life.
Discuss with your classmates whether you have ever heard about the water swirl myth. Share your thoughts on why you think this myth is so widespread. Consider how media, like TV shows, can influence our understanding of scientific concepts. Reflect on how this experiment helps clarify the truth about the Coriolis Effect.
Conduct your own water swirl experiment at home. Use a sink or a bathtub, and try to observe the direction of the water swirl. Record your observations and compare them with your classmates. Discuss what factors might influence the direction of the swirl in your experiment.
Use an online simulation to explore the Coriolis Effect. Observe how the rotation of the Earth affects the movement of objects. Discuss with your classmates how this effect is different at various points on Earth, such as the equator and the poles. Consider how this relates to the experiment conducted by Derek and Destin.
Work in groups to design a controlled experiment similar to Derek and Destin’s. Plan how you would eliminate external factors that could influence the water’s motion. Present your experimental design to the class and explain how it would help isolate the Coriolis Effect.
Write a short story from the perspective of a water molecule experiencing the Coriolis Effect. Describe its journey as it moves through different environments, such as a bathtub, a kiddie pool, and the ocean. Use your understanding of the Coriolis Effect to make the story scientifically accurate and engaging.
Water – A transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth’s streams, lakes, and oceans, and the fluids of most living organisms. – Water is essential for life and plays a crucial role in many scientific experiments.
Swirl – To move in a twisting or spiraling pattern, often used to describe the motion of fluids or gases. – When you pour cream into coffee, you can see it swirl around before it mixes completely.
Hemisphere – Half of a spherical or roughly spherical body, often used in reference to the Earth or celestial bodies. – The Coriolis effect causes winds to rotate differently in each hemisphere.
Experiment – A scientific procedure undertaken to test a hypothesis by collecting data under controlled conditions. – In our science class, we conducted an experiment to see how different surfaces affect the speed of a rolling ball.
Motion – The action or process of moving or being moved, often described in terms of speed, velocity, and acceleration. – Newton’s laws of motion help us understand how objects behave when forces act upon them.
Coriolis Effect – The apparent deflection of moving objects when viewed in a rotating reference frame, such as the rotation of Earth affecting wind patterns. – The Coriolis effect is why hurricanes spin counterclockwise in the Northern Hemisphere.
Design – The process of planning and creating something with a specific function or intention, often used in engineering and scientific experiments. – We need to design an experiment that accurately measures the effect of temperature on plant growth.
Drainage – The process by which water or other liquids flow away from a surface or area, often used in environmental science. – Proper drainage is important to prevent flooding and soil erosion in agricultural fields.
Observations – The action or process of closely monitoring or examining something to gather data, often used in scientific research. – Our observations of the night sky helped us identify several constellations.
Myth – A widely held but false belief or idea, often debunked through scientific investigation. – The myth that water drains in different directions in each hemisphere has been disproven by scientists.
