For a long while, the standard, so-called Copenhagen interpretation of quantum mechanics struggled to explain why quantum wave functions suddenly collapse. The superposition of quantum states — like a cat in a box being both dead and alive at the same time — resolves to one definitive outcome when we make an observation.
Some ground was reclaimed when the idea of decoherence was fleshed out in the 70s and 80s. When an isolated quantum system comes into contact with the environment, that environment makes an ‘observation’ in a sense and what was an isolated quantum system becomes entangled with its environment. Thus the superposed quantum system ‘collapses’ to the sort of single outcome we’re more familiar with in the classical world.
However, there is an interpretation of quantum mechanics called the Many Worlds Interpretation or just MWI for brevity. I promise you this is a genuine interpretation used by some physicists. What it says is there’s no wave function collapse at all and each component of a superposition is realised in a different universe. Every superposed quantum event splits the universe when an observation is made: in one universe the cat in the box lives and in another the cat in the box dies.
Thus there are countless copies of you, your cat, the Earth and the entire universe. Some people find this concept troubling and feel the vast number of alternative realities is too much of an overhead to make the Many Worlds Interpretation palatable. But once you get past that, it is one of the simplest interpretations of quantum mechanics around and that’s the reason it has the support of a good number of physicists.
That’s all background to bring me onto the Universe Splitter app.
This app claims to use quantum mechanics to help you make binary decisions. You enter two options for the decision you want to make and then press a button. The app then connects to a ‘Quantis’ quantum device in Switzerland. This device then emits a superposed photon that decoheres and splits the universe into two. The app then tells you which universe you’re in and hence which decision was made, and you can proceed on that basis, safe in the knowledge that another you is exploring the other option in a parallel universe.
The app also keeps a track of all your decisions and tells you how many new universes your decisions have created as you continue to use it.
I may make all my decisions this way in future. It would struggle to work out worse than some of the decisions I make in life anyway. Purchasing the app is certainly the wisest use of £1.99 I’ve made in the last hour and I’m giving it 5 stars because, when all said and done, how many other apps allow you to create new universes?
(Or at least I’m giving it 5 stars in this universe — consult other universes for alternative ratings).