Today, I was thinking about quantum physics, which is often thought of as the physics of the small. I was reflecting on how we help people understand the weird world of the small. I’ve got some ideas I wanted to share with you.
The first hallmark of quantum physics is that nothing is certain. Let’s imagine you are on your way to work. Will you get there? Sure, it might take you some time—depends on the traffic—but you’ll get there eventually. In quantum physics, that’s not the case. Whether you arrive at work is dependent on the roll of a dice, on probability, on chance. This is kind of wild. We don’t know why this is the case; it just seems to be how the universe works at the fundamental level.
The second hallmark of quantum physics is even weirder: what could happen changes what will happen. Let’s again imagine you’re going to work. You’ve got three choices: walking, taking the train, or driving. In everyday life, each of these possibilities is independent and doesn’t affect whether you’ll actually get to work. In the quantum world, that’s not the case. Each way has its say. We describe this as the different pathways “interfering” with each other.
This can lead to a truly bizarre situation. For instance, let’s say you have two roads you could walk down to get to work. The mere existence of these two routes can destructively interfere, meaning it becomes impossible for you to get to work—not now, not ever. That might be great for some people, depends on how much you like your job, but this is the strange world of quantum physics.