Look at this. Or don't.

Rage bait, maybe. But I chuckled, and that is good enough for me.

NOT HOW ANY OF IT WORKS

I AGREE WITH YOU!

For anyone wondering what all the yelling is about: https://en.wikipedia.org/wiki/Observer_effect_(physics)

oh boy, here I go banging this drum again:

When physicists say “observe”, they actually mean “measure”. And to measure a photon of light, you have to interact with it somehow, there is no passive way to do so.

The post’s header image implies that the interference pattern goes away just by looking at it. If that were the case, we would never see the interference pattern, never know it was there in the first place! In the actual experiment, they put a sensor at one or both of the slits. But to “sense” a single photon, you have to interact with it in some way. Otherwise you wouldn’t know it was there.

Again, this is where the language trips us up. Rather than “sensor”, would really be more accurate to say they put a photon-touch-er at the slits.

So, what we actually get is “Touching the photon changes the photon’s behavior.” The universe doesn’t magically infer when we happen to be looking at it, there is no spooky action-at-a-distance!

Think of it like this...a photon is both a wave, and the smallest discrete unit of energy

When the wave is absorbed by something, the energy must be transferred. But the smallest unit of energy is the full photon, and so the full amount of energy of the wave is absorbed at a single point, because there's no such thing as partial photons

Or in other words, the wave doesn't turn into a particle, the energy gets spent at a single point in space

Really, I think all of quantum physics works like this. Electrons don't exist as a point in space, they exist in an area. They're fields, they're not necessarily moving fast, which is why atoms don't randomly slip through each other and we can't measure all the properties of it at once

The thing that made it click for me is to realise that particles and waves don't really exist — they're just terms we use to try to understand the world. When we see weird quantum shit happening, it's not actually weird in and of itself, we're just finding that our reductionist (but often useful) models are breaking down and we can't straightforwardly say "that's a particle" or "that's a wave".

I think of it as analogous to statistical averages. If I have a group of 100 people for whom I know the average height (and other summary statistics). Thinking of them in terms of the group is like treating them as a wave. They don't have a precisely defined position (because they're a diffuse blob of people), and although I know their average height, it's clouded by uncertainty. When we do statistics on a group of people, it's almost as if the individuals cease to exist. If all you have are the summary statistics from the group, you can't know the heights of any individuals within the crowd.

I can "zoom in" and pluck a person from the crowd and measure their height, then that's sort of like wave function collapse. Now I can precisely define the position of this person, because they're just one person — if someone says "which person are you talking about?", I can point to them and say "this one here". However, I don't know anything about their surrounding context — whether they're taller or shorter than average. They're basically a particle.

The key to this is how "zooming in" on an individual person gives us a fundamentally different perspective to the zoomed out view of the crowd.

It's simple, just look at the picture and....God damn it.

I don't think anyone figured out the "why" for wave-function collapse yet, the Copenhagen interpretation is obviously flawed. PBS had a good video about it a few months ago, but if you don't get it, that's not weird since the leading theories for WFC are all inelegant.