So I Googled “multiple universes” and it led me to the Wikipedia entry for the many-worlds interpretation. This is the first sentence:
The many-worlds interpretation is an interpretation of quantum mechanics that asserts the objective reality of the universal wavefunction and denies the actuality of wavefunction collapse.
I had no idea what that meant, but I have the internet, so I decided to see if I could understand it. And, with the internet, I can also write about it relentlessly to people who will disagree with me.
I am deeply envious of people who “understand” quantum mechanics. I put quotes around “understand” because honestly, I wonder if there’s more that’s not understood than actually is. One thing I am certain of is that it’s beautiful. Whether or not quantum mechanics is describing reality doesn’t matter to me, what matters is the way it goes about describing things in the first place.
Conceptually, quantum mechanics is like a very bad date for my mind. I meet her and am unsure if she’s even attractive or not. Exotic, sure, but pretty? That might take further review. Her eyes are too big. Cheekbones just a bit too prominent. Hair just a little too short. Or not? This is weird; let’s sit down and order drinks while I avoid the darkness in her gaze.
Conversation is slow. There’s a very clear disconnect – she’s using words out of order, phrases that sound like they have meaning, but I’m left wondering what she actually just said. I nod politely. Really going to need another drink on this one.
She talks about waveforms, eigenstates, and particles. She said she has a wonderful, healthy cat, but the poor cat is dead. I ask her which is it and she says it’s both. I’m uncomfortable and things are still awkward, but at least now I’m intrigued. She shows me pictures on her phone, pictures where she sees one thing, then I take a look and see another.
Over dessert she explains how she has a twin on the other side of the world mimicking her every movement as if they were right next to each other. What the hell is this woman on about?
I’m frustrated. She seems like she’s annoyed, like she’s not getting through. Uncomfortable silence. She sinks into her phone. I don’t even bother, I just sit there and wait for the waiter to bring me back my card.
As we head back out into the night I am relieved to say goodbye. She smiles slightly, shrugs, then says “You know we left ourselves back there.”
“Come again?” I ask.
“We’re fighting still – it’s going to get ugly. And we’re also figuring out who wants to sleep over at who’s place.”
I shake my head, make a face, and walk away. What a weirdo. Terrible date and yet, the next day, I think about her and realize those exotic features are much prettier than I first thought.
That’s probably far too silly of an analogy, but I’ve been on this date before, a number of times, and I never learn. It’s always the same, although if I’ve learned anything, it’s that it should be both the same and not the same, all at once.
So yes, the grand picture of quantum mechanics will always escape me, just as it escapes most people. There is, however, one aspect that I’m always drawn to, and it’s the last thing my very bad date said to me. She described two states of existence that hadn’t actually occurred, although the implication was that perhaps they actually had and that they would continue to occur into the future. If the many-worlds interpretation is true, she was probably right.
“The many-worlds interpretation is an interpretation of quantum mechanics that asserts the objective reality of the universal wavefunction and denies the actuality of wavefunction collapse.”
The universal wavefunction exists as reality, independent of our minds and perceptions, and that wavefunction never collapses. In quantum mechanics, a wavefunction collapse occurs upon observation; all the states that a particle could exist in previously, referred to as its wavefunction, collapse into one state, which ends up being what you observe.
If the universal wavefunction – all of reality – does not collapse upon observation, then the different states continue on independent of each other. This is a fun way of saying that at the point of decision, the universe continues on in a different reality that considers each decision you could’ve made in that moment. This is also true of the past. There exists an infinite number of events in the past that both led up to where you are now and created different universes that will pass you by – without you even knowing.
I don’t know how you would look at it, but I see it as a bittersweet notion that somewhere out there you’re happier than you are. You’ve had more success, enjoyed more things, been to more places. You could be an entirely different person, you could be much older, much younger, there’s a universe where you’ve yet to be born and one in which you’re already long dead.
There are an infinite number of universes where everything is exactly the same as it is in this one, only you’ve worn a slightly different colored shirt on Wednesday of last week. There are an infinite number of universes where you’re a crazy person in the woods.
There are an infinite number of universes where maybe you didn’t struggle with mental illness for over a decade. A timeline where you turn left and another version of you goes right. Over time, with enough changes, you each die as completely different people on exactly the same day.
There are an infinite number of universes where you’re sad. Where you’re happy. Your best friend in one is your enemy in another. You are your wife or your wife is a princess in another country. Your dog is a lion and still lives in your house with a turtle named Tom (maybe that’s going a bit too far – Tom the turtle? Not likely).
It’s still feels like pure fantasy. That there’s a basis for this in quantum theory is a beautiful thing, as magical as it is terrifying. Infinite universes. Like infinite monkeys at infinite typewriters. The idea that given enough time everything that was ever written will be written again, backwards to front, in Greek, in pig-latin, by an endless room full of monkeys.
The only remaining question is, would you really want to be in any of those other universes? You wouldn’t know if you had it any better or worse, after all. Maybe this is the best option for each of us.
The waveform never collapses.
Anyway, that’s how I understand it. I’ve only been trying to figure it out for a few hours. I like what I think I understand and, of course, there’s a universe where I’ve mastered this already and can’t be bothered to explain it to anyone.