Dance of the tides
This is a partially developed activity description. It is included in the collection because it contains ideas useful for teaching even though it is incomplete.
Summary
Usually it's easy for students to visualize why there is a high tide on the side of the Earth facing the Moon. However, those who are not comfortable with vector addition have trouble understanding why the other high tide is on the opposite side of the Earth, and why the low tides are halfway between. It can be notoriously difficult to explain this to some students. This exercise gets students out of their seats and actively simulating how high tide arises on both sides of the Earth, and appeals to kinesthetic learners.
Context for Use
This activity is best done in class. It was developed for an introductory class on solar system geology/astronomy, but the topic of tides is also commonly found in introductory geology, oceanography, and other classes.
Teaching Notes and Tips
It may still be advisable to give the "standard" vector addition explanation for tides, just to introduce the concept that the demonstration will be comparing the motion of a local water parcel as compared to the motion of the entire solid earth.
Doing the tide dance takes about 15-25 minutes, depending on how well students can follow directions.
Doing the tide dance takes about 15-25 minutes, depending on how well students can follow directions.