Stop me if you’ve heard this before: there’s a cat, a vial of poison, and a Geiger counter all in a box. If the Geiger counter detects a certain particle, it’ll smash the vial of poison and the cat will die. And until you open the box and see the cat, it’ll be alive and dead at the same time.

No, wait, sorry — what?

Ah, Schrödinger’s cat. Reason No. 642 why physics is supposedly unapproachable. But it seems ok! There’s a box, there’s some poison, there’s a cat. Sounds like great television.

Oh, and then the cat exists in a horrible juxtaposition of life and death. Right. That.

It doesn’t make sense! And the thing is, it isn’t supposed to.

Let me explain.

It all started when Einstein wanted to understand light. In that quest for understanding, he discovered that in order for matter to behave the way it does, particles would have to communicate with each other faster than the speed of light, which Einstein’s own theory of relativity absolutely forbids.

To quote Einstein when he heard this, “That is so not Raven.”

Einstein thought that the discovery was part of an incomplete idea — that they only had one part of the puzzle. Enter our hero, Erwin Schrödinger, who stood with Einstein in saying that the theory was incomplete. Being an utter nerd, he set out to derive an equation for this freaky phenomenon. What he got was an illustration of a “wavefunction,” which statistically describes the position of a particle — there’s 30% chance that it’ll be here, 20% chance for there, and 50% chance someplace else.

Well, that didn’t do much for Schrödinger — he and Einstein figured it was just another piece of the incomplete puzzle. However, another smart cookie named Werner Heisenberg (whose elegant Uncertainty Principle practically defined quantum mechanics to this very day — and, yeah, the Breaking Bad connection) came up with the same theory by himself and went to his buddy Neils Bohr, and they thought the theory was the be all and end all — that it was already complete.

Bohr came up with the Copenhagen interpretation of quantum mechanics, which states that, given any particle, that particle can be in multiple places and states at once until you observe it. Let me say that again: until you set your eyes on a particle, it is in many places and in many states simultaneously, and when you do observe it, all those potential places and states “collapse” into just one place and one state — just because you fixed your peepers on it.

Whaaaat?

Which is pretty much what Einstein and Schrödinger said. But, there was some good evidence that Bohr was right — and some good evidence that Einstein was right, too. It came down to interpretation. The debate, headed by Einstein on one side and Bohr on the other, raged for decades.

And, by the way, this wasn’t a question of some silly scientific tidbit that people were splitting hairs over — this would redefine not only science but our perception of reality. Einstein fought for our traditional view of the universe — we saw a particle there because it was always there, not because the power of our own observation made it be there. Bohr was fighting for a radical new interpretation of everything, with far-reaching and deeply disturbing implications — that sh*t was scarier than a Trump rally.

In this war, instead of exchanging bullets, the combatants exchanged paradoxes, thought experiments designed to make their opponents’ argument sound contradictory. One of Einstein’s involved light particles shooting out of a box—they were all a little out there. None more out there, however, than a particular cat, a particular box, and a particular man with a silly-looking “o” in his name.

Oh yes.

In a letter to a friend, Erwin Schrödinger offered a thought experiment to undermine the Copenhagen interpretation: there’s a cat in a box with a Geiger counter connected to a vial of poison. If the Geiger counter detects a certain particle, it’ll smash the vial and the cat will die. If it doesn’t, the vial remains un-smashed and the cat lives on in fuzzy glory.

Now, according to Bohr’s theory, if you were to close the box, that particle that the counter is detecting, since it has not been observed, would be in two states at once—the state that the counter would detect and one that it wouldn’t. So, the counter would both be detecting it and not detecting it, since it would be in both states at once. And since the counter would be detecting it and not detecting it, the poison vial would be both smashed and left alone. And since the poison is both released and not released, the cat would be killed and not killed simultaneously.

Whew.

Schrödinger’s cat, boys and girls.

Schrödinger used this example to show that Bohr’s idea was just darn silly. Funny thing is, though? Despite Einstein’s and Schrödinger’s desperate efforts to preserve the world as we know it, Bohr’s Copenhagen interpretation is now the accepted view of quantum physics. Seriously. And it’s been proven right — there was a study recently that showed that particles only exist once we observe them. That’s some heavy stuff right there.

So that’s the outcome of the great debate — a totally and irreversibly altered view of the universe.

Oh, and a cat in a box.

No animals were simultaneously harmed and not harmed in the making of this post.

Thanks to George Musser’s excellent book Spooky Action at a Distance, published by Scientific American in 2015.

The cover photo was photographed by Dwight Sipler. This photo has been altered from its original state. I do not own this photo. Permission granted to reproduce here by the Creative Commons under the Attribution 2.0 General License. Copyright Dwight Sipler.