Does size matter? It’s an age-old question in all sorts of areas. Is it always “the bigger the better”? (If you think so, you might like Texas!) Or, can small prevail over tall (like a David v. Goliath type beat)? Honestly, the answer to this debate varies person-to-person.

We constantly make observations about our macroscale world, which we can luckily explore whenever we want. But in the past century, scientists have started taking things up a notch, or more accurately, down a notch. They started zooming in on the world to see where all the mysterious and interesting things happen on the micro and nanoscale.

This is the basis of nanotechnology, which is the study of how we can manipulate matter on an atomic and molecular scale. Unlike your side-view mirror, objects here are much smaller than they appear (in your mind).

That evil piece of paper that gave you a nasty paper cut? 100,000 nanometers thick. The ant you (hopefully accidentally) stepped on? A million nanometers long. Get this, the ratio of a meter to a nanometer (which is a billion) is approximately the ratio of a marble to the Earth. So yes, nano is (na)no joke.

Where did this not-so-miniscule idea even come from? Most scientists agree that the acclaimed physicist Richard Feynman first introduced the idea of nanotechnology in his lecture, “There’s Plenty of Room at the Bottom.” (Whose title, at first glance, seems like a pessimistic worldview.) In this speech, Feynman remarked on the possibilities of miniaturized machines and encoding large amounts of data in tiny spaces, which seemed almost unfathomable at the time–which is what makes nanotechnology so exciting.

Because the nanoscale is so incredibly small (around 1 to 100 nanometers), manipulating matter in this world isn’t too easy. It’d be super cool if we could boss a bunch of individual atoms around, from telling them when to “turn” on and off to store information or lighting them up with different colors (in what would be a fantastic glow show), or just directing them in some way. This isn’t quite currently possible, but don’t despair–we have the next best thing: quantum dots!

Quant-um…what?
Quantum dots, often called artificial atoms, are tiny crystals that range in size from 2–10 nanometers. They’re so small that we can basically think of them as a concentrated single point, which is why they are often called zero-dimensional. Quantum dots are made from semiconductor material (like silicon)–they aren’t really a conductor or an insulator, but can be chemically treated to behave like either.

Quantum dots are proof that you don’t have to be big to be interesting, so it seems that size indeed doesn’t matter…or does it?

Quantum dots are able to absorb light, so when you shine a light on them, they release this absorbed energy as distinctive and precise colors that depend on the quantum dot’s size, shape, and material. Talk about shining in the spotlight!