I like to see scientific principles at work in everyday activities. Here are a few videos that illustrate this. Enjoy the weekend!

Galileo postulated that objects fall at the same speed in a vacuum, regardless of their weight. When we got to the moon, they did this experiment on live TV:

Here’s a bar trick that involves simple density physics:

Another bar trick involves simple dimension estimations:

Handling molten glass is an art and science onto itself. Molding it into shape, whether by blowing into it or by using tools, while it’s still white hot, takes knowledge about materials, temperatures, talent and a lot of hard work. It looks easy in this video, but it isn’t.

The Aardvark is designed to take out land mines. Its action is simple. It rotates chains with attached deadweights at high speed, combing through the ground. When it hits a landmine, they go off. The vehicle is heavily plated, and incurs no damage. It’s really cool to see physics and chemistry in action. Can you spot the different forces at work?

This next video shows what happens when water freezes: it expands. Because in this particular location the water is surrounded by rocks, the extra volume of ice has no place to go but up. It’s an unsettling sight, but it’s just a simple natural phenomenon.

The ferrofluid sculpture you’re about to see made the rounds a while ago. It’s a crowd pleaser, but it works based on magnetic forces. The fluid is filled with iron particles, which are magnetized. Electricity is likely used to create a magnetic field which varies in size and force, allowing the artist or a programmable chip to control the fluid’s movement.