In nature, water drops can have a large variety of sizes and shapes. Small droplets with diameters of the order of 5 to 10 µm are present in fog and clouds. This is not sufficiently large for gravity to dominate their behavior. In contrast, raindrops typically have sizes of the order of 1 mm, with observed maximum sizes in nature of around 5 mm in…

There are phenomena that seem impossible--at first glance. But some knowledge of physics can often allow us to plan and also perform the seemingly impossible without any magic. Here is a very simple experiment that can be done with a whole group of students. I learned about it from an activity in a science center, where it was posed as a magical…