Nanotechnology. Its one of those words you hear bandied about, but often in a slightly sinister, futuristic, matrix-style context. But what exactly is it?

Well, “nano” comes from the Greek word for “small”. And “technology” is pretty much self-explanatory! So nanotechnology is just the application, science and engineering of the very small. How small? Well, take an average human hair – it has a thickness of about a fifth of a millimetre. Imagine splitting that hair 100,000 times across its width. The piece of hair you’d have left is about one nanometer long.

So a nanometer is just a very small length measurement, and its that size which makes it interesting – on such a small scale, the laws of physics change, which opens up new possibilities for science.

The thing is, nanotechnology isn’t about grey goo – it’s already all around us, in many of the products we buy every day. We’ve been studying it for years, so its not a futuristic as you might think! In fact, Mother Nature got there first – lotus leaves are famously self-cleaning. The secret is that each leaf is covered in billions of nano-bumps, which stop water sticking to the surface. We’ve only just caught up – the roof of St. Pancras Station is made from self-cleaning glass. The sporting industry uses nanotech to produce lightweight, stiff and strong golf clubs and tennis rackets; The beauty industry uses nanoparticles of Vitamin A to disguise our deepest wrinkles; The aerospace industry now uses nanocomposite materials, which are as strong as the traditional stuff, but a whole lot lighter.

One thing nanotechnology hasn’t managed to produce are swarms of self-replicating nanobots which will take over the world. And that’s for one reason – the laws of physics might be different down there, but they still exist. The simple truth is, in the nanoworld, friction doesn’t behave as we expect, so a robot scaled down to nano size would probably just fall apart!

The moral of the story? Size really does matter, especially when it comes to physics.