Copenhagen interpretation

I prefer to call it the ghost in the equations.

It has been sitting like a live grenade in the center of quantum mechanics since Niels Bohr and Werner Heisenberg first argued about the Copenhagen Interpretation in 1927.

I've heard the term Schrodinger equation thrown around a lot.

That is the fundamental math that describes how these quantum probability waves move through space, right?

But before something is measured, we actually don't have a mathematical certainty that that's what it is.

And so the extension into this many worlds interpretation, which is the opposite of that, uh, everything becomes concrete interpretation, that's called the Copenhagen.

You mentioned the Copenhagen interpretation, right, Chuck? The, this multiverse-

You said many worlds.

This-

I'm not so sure it's totally been put to bed, though.

What you're talking about is what used to be called the Copenhagen interpretation, right?

Yeah.

From Niels Bohr and his school.

It's out there still.

It's still an issue.

I think the Copenhagen interpretation and the many worlds interpretation are still out there.

I think decoherent histories is maybe an alternative to both.

You have these brilliant minds, uh, Werner Heisenberg, Pascual Jordan, John von Neumann.

And they were desperately trying to pin down the math of the Copenhagen interpretation.

Heisenberg had this idea of representing physical observables like momentum or position as matrices.

Because in quantum mechanics, things aren't just a single solid number anymore.

But Niels Bohr, one of the brilliant founding fathers of quantum mechanics, looked at the double slit experiment and basically said the universe is playing peekaboo with us.

His interpretation of the math, known as the Copenhagen interpretation, argued that before you measure a particle, it truly does not have a defined property.

It exists only as a fuzzy superposition, a mixture of all possible states.

The act of measurement is what forces reality to exist.

Okay, so they fly apart.

One goes to Earth, one goes to Mars.

According to Bohr in the Copenhagen camp, neither particle has actually chosen a spin direction yet.

Because they haven't been measured, they are both existing in a blurry superposition of being both up and down simultaneously.

The next question is about quantum mechanics.

And in the 1930s, Niels Bohr championed a thing called the Copenhagen model of quantum mechanics, which said that it doesn't matter what the theory says.

If it works, just do it.

The mathematics is all you need.

And that Einstein said, I like to think the moon's there when I'm not looking because...

Bohr said, well, so what? And the answer is, well, the moon's still real, even if you're not looking at it.

But in the Copenhagen model, it isn't necessarily.

Then in the 50s along came another one, the many worlds.

Yeah, that's a great question.

So the machine itself is kind of a takeoff of this popular thought experiment called quantum suicide, which itself is a kind of derivation of the Copenhagen interpretation or the many worlds interpretation of quantum equations, which is that if you look at the math, a valid interpretation of Essentially, you're looking at just a system of equations.

One valid interpretation is that nothing ever happens for real.

It just seems to happen for you.

Indeed, we call this the wave function, first written down by Erwin Schrödinger a hundred years ago.

But the real question is, how does this quantum wave-like state suddenly transition into the more familiar classical particle-like behavior post-measurement? For decades, the dominant view has been the Copenhagen interpretation.

That is that these superposition states persist until they are observed, at which point they collapse down into a single sharp state with a probability given by the Born rule.

That is a probability given by the square of the wave function.

Now, after the critical moment passes, the electron can be described as being in a superposition of both states.

And since the measurement device is entangled with this quantum system, then so too must be the cat existing in a bizarre superposition of being both dead and alive.

Wave function collapse, via the Copenhagen interpretation, at first seems to resolve this paradox, but it comes with many problems.

For example, why is it that the observer, be it a stray photon, or the cat, or indeed we who open the box, are allowed to be considered somehow distinct classical entities, whereas the electron has to be considered quantum? Surely everything deep down is truly quantum.

No, I think that...

Does that make sense? Would this be a paradox resolver? Oh, well, the reason the Copenhagen interpretation pops out weird things is because there's actually some higher dimensional thing that's doing something and we're just seeing the projection of it in lower dimensional space.

Are you asking if that's what they thought? Or are you

asking...