Whether you’re in the bath or washing-up in the kitchen, nothing makes a daily chore more fun than bubbles.
No, really. Bubbles are fun. Serious fun.
The science behind bubbles is fascinating, because it relies on the physics of water. We’re so used to water being all around – heck, it falls out of the sky! – that we don’t stop to think about how weird it is. That ice cubes float is amazing, because with almost every other material the solid is more dense than the liquid, so they sink. Whereas ice takes up just a little more space than liquid water, so it floats.
You can get an idea for just how weirdly water behaves even more easily: fill a glass all the way to the brim, then keep going. You’ll see the water bulge upwards, like this. That happens because water molecules interact with each other and with the glass, just a little bit. It’s a very small effect, but it’s enough to cause water to tend to clump together, to flow a little distance up the side of a glass, and to bulge like this.
Gently place an object on the surface – like this rather tatty-looking paperclip we found kicking around in the Think Physics office – and you can see the curve of the water surface around the object. That curve is what provides the force balancing the weight of the object.