Lessons in life and the universe from a cup of tea | Helen Czerski

Physics has its patterns, and you don't even have to leave your kitchen to find them

We live on the edge, perched on the boundary between Earth and the rest of the universe. Every human civilisation has seen the stars, but no one has touched them. Down here it's the opposite: messy, changeable, and full of things we touch every day. This is the place to look if you're interested in how the universe works. The physical world is full of startling variety, caused by the same principles and atoms. But this diversity isn't random. Our world is full of patterns.

If you pour milk into your tea and stir it, you'll see a swirl, a spiral of two fluids circling each other while barely touching. In your teacup, the spiral lasts just a few seconds before the two liquids mix completely, a brief reminder that liquids mix in beautiful swirling patterns and not by merging instantaneously. The same pattern can be seen in other places, too. If you look down on the Earth from space, you will often see very similar swirls in the clouds, made where warm air and cold air waltz around each other instead of mixing directly.