Member-only story

Why is no one taught the one concept in quantum physics which denies reality?

It’s called contextuality and it is the essence of quantum physics

Chris Ferrie
6 min readAug 9, 2021
Photo by Ehud Neuhaus on Unsplash

This morning I had a bowl of plain Greek yoghurt and toasted muesli for breakfast. I could have had a plain bagel with mashed avocado — or, I could have had nothing at all. But I had the yoghurt and muesli. I know, I know, damn millennials and their hipster breakfast food. But, also, who cares what I ate for breakfast? Well, perhaps the universe does.

Imagine that, after breakfast, I dutifully went to the lab to perform some quantum physics experiments. The results of the experiments obviously depend on what I do in the lab. But, they shouldn’t depend on what happens outside of the lab, right? I mean, why should laser light bouncing around through crystals and mirrors care what the current value of the S&P 500 is, let alone what I had for breakfast?

The conditions under which an experiment is performed are called its context. In practice, the contexts we consider are very limited to a few settings on the devices in the lab. But, maybe the temperature of the room is important. Were the lights on? Was the door open? Especially when things go wrong — which is more often than not — the context is where you look for answers. But some parts of the context are…

The author made this story available to Medium members only.
If you’re new to Medium, create a new account to read this story on us.

Or, continue in mobile web

Already have an account? Sign in

Chris Ferrie
Chris Ferrie

Written by Chris Ferrie

Quantum theorist by day, father by night. Occasionally moonlighting as a author. csferrie.com

Responses (162)

Write a response

You do not make a case that quantum theory requires denying reality.
You only make the case that quantum theory requires denying an artificial point of view that you call scientific realism.
Nobody in the history of the human race prior to the early…

Why would we even assume there is some objective reality? Presumably there is no omniscient omniscience and our perception is very much a function of our points of view and the very limited information we extract. Otherwise it would be total…

There is no way to define a reality that is independent of the way we choose to look at it.

I think this is the most succinct and plausible statement of idealism that I’ve ever read, and I’ve read a fair bit on philosophical idealism. Good job!