as a fan and as a physicist I've come up with a theory and just forewarning there's gonna be some spoilers

In Stranger Things, one of the characters, Will, gets trapped in this sort of parallel universe

called the Upside Down and when he's trapped there his mom is you know really worried about him

But she figures out that he's not missing and that actually she can communicate with him when he's in this

parallel universe and she does it by

Stringing up some Christmas lights on the wall and under each light bulb she writes a letter and so from this parallel universe

The kid manages to light a light bulb above a letter and spell out a message to his mom

Yeah, basically, and so I was thinking as a physicist

How is this even possible? How does one communicate from a whole other universe to our universe in 1983?

And so I've come up with this theory—this physics fan theory—and I think that this is possible if

this parallel universe called the upside down is quantumly entangled with our universe.

I guess we've got to understand quantum entanglement first. First of all you've got to get rid of everything that you know about the classical world

so in the classical world this

Is a red ball, and it will always be a red ball

similarly, this is a blue ball, and this will always be a blue ball, and if I sort of

Shuffled them around and hold one in either hand

When I say to you you know, which one is the red ball, and which one is the blue ball

We know that one of them is definitely red and one of them is definitely blue and so it's only when I open my hand

And say okay, that was the blue ball

And there was the red ball that we knew all along that this was blue, and this was red

but one of them is always blue and one of them is always red.

If this was the quantum world and you couldn't tell which one was red or which was blue

they would both be red and blue at the same time.

So this is like the Schrodinger's cat example—the cat is both dead and alive at the same time.

[Brady:] They both purple?

They're both purple—yes, they are!

So there's some sort of weird linear superposition of red and blue in the quantum world

and it's only when we again we open the hand and we see that this one is blue

that we know this one is red. But before that, they were both.

So if we have two quantumly entangled particles instead

in this weird quantum mechanical world these can have sort of any properties so what I was doing there was this color was

an analogy for spin, basically

or some property of the particle so spin up and spin down and that is a very fundamental

property of particles and so if we have these

Quantumly entangled particles they don't have any spin yet, they do have spin

It's just that you can't describe one without describing the other okay

So they're in this weird superposition state where they can be both spin up and spin down

But the thing about quantumly entangled particles is that as soon as you measure them and one becomes spin up

the other one immediately becomes spin down

so whatever one of them does, the other one has to do the exact opposite, and that's what quantum entanglement is.

Poor Will trapped in this parallel universe if this entire universe

Was quantumly entangled with our universe then anything that Will does in the parallel universe

has to be reflected in our universe as well: the particles have to do the exact opposite

so say Will could take the light bulb in the parallel universe of the upside down and

Put a battery to it and force the electrons in that light bulb to move around a circuit

he would have given them momentum in a direction and

Therefore the particles in our universe would have to do the exact opposite does that mean they would also have to have momentum

But in the opposite direction and therefore also

Move around a circuit and therefore light up a light bulb so if he lit up a light bulb in his universe the light bulb

Would also light up in our universe

Himself

Wouldn't that when he moves the battery wouldn't the

No this is where this sort of theory is a little bit like we're gonna have to think about this

I mean I'm also assuming

That you know these light bulbs are in parallel you know they're not in series in their in their circuit

They're in parallel. I mean this is 1983. They could be in series

I don't know. This is the kind of thing that you have to achieve all the way you go through this theory

The electrons in his he'll be able to manipulate electrons in the other exactly through quantum entanglement, that's my theory

Would you like to hear how this theory is absolutely rubbish so there are many problems

But so as a scientist. I had to think through these problems and go through them the first question

I had was easy even possible to make a quantum Leontine board universe okay, so that just seems ridiculous in my head

Turned out not so ridiculous

So I actually found a paper quantum entanglement in the multiverse and this is you know a theoretical paper

but they're actually talking about it as if

we could measure whether this has actually happened in our own universe so what they're saying is if

Our universe is one of many and the multiverse theory holds that there are many many universes then after the Big Bang

Ten to the minus thirty-six seconds after the Big Bang to be precise there was this period of time called inflation where the universe

rapidly

inflated in the space of sort of from ten to the minus

Thirty-six to sort of like ten to the minus thirty-three seconds so a very very short space of time

inflated very rapidly and that has like loads of

consequences on sort of how the universe is today because any sort of teeny tiny fluctuations

And the particles that were created just after the Big Bang were sort of locked in so density

Fluctuations anything like that will then spread out over these huge

Distances and that meant that then some areas of the universe more dense than the others and that's how you ended up getting

galaxies forming their eccentric cetera so they're saying if you have inflation in the multiverse and you're creating sort of child

universes from say our parent universe so lots of

Multiverses are sort of springing off and you have inflation then the same properties are going to be

Imprinted in one universe as in the child universe as well like in identical twins

So that's what inflation would do it would imprint both those things

And if you had two particles that work in these quantum the entanglement state in the beginning

Then they will be quantum entangled in these two separate universes and the really cool thing about this paper is that they suggest that actually?

If this was true in our universe. You'd actually be able to test whether that was true because these kind of quantum entanglement

Fluctuations, that would be imprinted in inflation you'd still be able to see in what's called the Cosmic Microwave Background which is this?

Microwave signal which is a remnant of the bang in the very early stages of the universe?

Where light could first escape from the early stage in the universe so I?

Think that's really exciting and the fact that my crazy fan

Theory could actually you know in our own universe could exist I was like that was that was one point to me

That's one point. There is another problem, and it's something called quantum decoherence

if you have two quantum entangled particles

And you want to send a message between the two of them say you're doing it for like encryption or something and you move

One particle say you know 300 miles away and measure

One thing to have a certain span of momentum and therefore the other one has to do the exact opposite

This is what Einstein was really concerned about you were there for

Sending a message faster than the speed of light because as soon as this one is measured this one

Automatically changes and so that is sort of this spooky action at a distance and we know that things

Can't travel faster than the speed of light people have got around that now by saying well

I had to physically move this 300 miles away first to send that message

And I couldn't have made that travel faster than the speed of light

Therefore the message itself didn't travel faster than the speed of light because if I move that you know

Very very close to the speed of light say 99 percent of the speed of light over here, and then I transfer that message

transfer a message back

Then that has trouble fast in the speed of light

But that's not possible so as soon as I measure this one

Spin up and this one it's been down that is an irreversible process

And the reason for that is you've had to put energy into this system

Okay, so you've had to say okay?

This one has to be sped up this one has to be spin down

And what you've done is you've put energy into the universe this is somehow

Interacted with the environment that it's in and with the universe and you've increased the entropy of the universe

So for those of you who are paying attention in school that should raise a little red flag the second law of thermodynamics

says that you cannot decrease the entropy of the universe so we've increased the entropy by doing that measurement and

Measuring to say that yes, this one has been up and this one has been down

And so you cannot reverse that process because reversing it you would have to decrease the entropy of the universe to do that

so any interaction with your environment breaks quantum entanglement

So what does that mean in terms of my crazy fan? Theory as soon as?

Will has moved the electrons and set up a circuit in one light bulb

He couldn't do it again in that same light bulb so when his mum has strung up the lights

With a single letter under every single light

he won't be able to use the same letter twice so we have to get very creative with his lettering and

in the show he writes the words right here, so he uses e twice and

therefore I don't think my theory holds because

He wouldn't be able to use eat Weiss

Under our understanding of quantum entanglement and quantum decoherence. He always sees an H twice as me

Right here. Yeah, okay, okay? I'll do that again

So I could influence his thoughts for example

How would I influence his thoughts well I'd have to change the biochemistry

I was a biochemistry about it's about electrons so somehow my electrons would have to couple

They'd have to become strongly quantum mechanically entangled with brady's electrons