Sean Carroll

And again, we have good ideas, but there's still work to be done.

Wow.

I'm not sure if I'm quite on board with your explanation there about what's going on.

Well, it's pretty close.

I mean, many worlds is like really down to earth and equation based.

There's the Schrodinger equation of quantum mechanics tells you what set of things happen in the future and which don't.

And it's not because you're making a decision that creates a difference between one world and another.

It's because of entanglement in the underlying quantum structure of reality.

But we do have reason to believe that there are other copies of the universe where things turned out a little bit

different.

If you have an iPhone, you can download an app called Universe Splitter.

I'm a big salesman for this app here.

I don't get any commission or anything, but I think everyone should get it because when you're torn between two decisions...

should I take this job or should I just continue living a life of leisure, you can ask the phone.

You can plug in these two options and it will send a photon down a beam splitter that has a 50-50 chance of saying, you should take the job or you should just stay sitting around.

If you do it, if you obey the instructions, you know there will be a world in which you did the other thing.

Before we even start.

Yeah, the double slit experiment is, of course, a famous thought experiment originally.

They wrote down what it should do long before they ever did it to illustrate the magic of quantum mechanics.

You have a single electron going through two slits.