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.

In Britain, these swirls come rolling across the Atlantic from the west on a regular basis, causing our changeable weather. They form at the boundary between cold polar air to the north and warm tropical air to the south. The cool and warm air chase each other around in circles, and you can see the pattern clearly on satellite images. We know these swirls as depressions or cyclones, and we experience rapid changes between wind, rain and sunshine as the arms of the spiral spin past.

A rotating storm might seem to have very little in common with a stirred mug of tea, but the similarity in the patterns is more than coincidence. It’s a clue that hints at something more fundamental. Hidden beneath both is a systematic basis for all such formations, one discovered and explored and tested by rigorous experiments carried out by generations of scientists.

Sometimes a pattern is easy to spot in new places. But sometimes the connection goes a little bit deeper and so it’s all the more satisfying when it finally emerges. I studied physics because it explained things that I was interested in, allowing me to see the mechanisms making our everyday world tick. Even though I’m a professional physicist now, lots of the things I’ve worked out for myself haven’t involved laboratories. The most satisfying discoveries have come from random things I was playing with when I wasn’t meant to be doing science at all. Knowing some basic physics turns the world into a toybox.

There is sometimes a bit of snobbery about the science found in kitchens and gardens and city streets. It’s seen as something to occupy children with, a trivial distraction. But that attitude misses something very important: the same physics applies everywhere. A toaster can teach you about some of the most fundamental laws of physics. The advantage of looking at the toaster first is that even if you never get to worry about the temperature of the universe, you still know why your toast is hot. But once you’re familiar with the pattern, you will recognise it in many other places.

There’s another benefit to knowing about how the world works, and it’s one scientists don’t talk about often enough. Seeing what makes the world tick changes your perspective. The world is a mosaic of physical patterns, and once you’re familiar with the basics, you start to see how those patterns fit together. The essence of science is experimenting with the principles for yourself, considering all the evidence available and then reaching your own conclusions. The teacup is only the start.

Storm In A Teacup by Helen Czerski, published by Bantam Press, £18.99, is out now. To order a copy for £15.57 go to bookshop.theguardian.com