The objects you interact with every day are predictable – you can pick up a box, sit down in a chair without falling to the floor, or open a door without your hand passing through the knob. But if you zoom in on these objects all the way to the quantum level – where you look at the individual atoms – you’ll find that things start to behave somewhat strangely.
The typical size of quantum objects is a nanometer, or one-billionth of a meter. For scale, a human hair is 60,000-100,000 nanometers wide. At the nanoscale level, you cannot know where exactly a particle is in space – you can only calculate a probability of where it might be.
