Branwen is an A* pupil who has been offered university places at both Oxford and Cambridge. She’s agonised for days about which one to choose. She’s weighed up all the pros and cons and it’s pretty much 50-50.
She decides to flip a coin. If it comes up heads she will choose Oxford; if it’s tails Cambridge will have the privilege of her attendance.
In a parallel universe a Branwen who is identical in every respect down to the last sub-atomic particle has, of course, exactly the same dilemma, and does, of course, exactly the same thing.
This scenario is not science fiction but is based on theories that are taken very seriously by very serious scientists
The Branwens in both universes flip their respective coins. Remember, they are exactly the same. Every thought, every emotion, every breath is exactly the same for each of them. Since there is not a sub-atomic particle of difference between them they are, in effect, exactly the same person.
The coin spins in the air and clatters to the floor of the little coffee shop where Branwen’s working for the summer holidays. She leans down to look more closely at the coin, supporting the small of her back, it’s still sore after the fall from her bike yesterday.
The coin lands heads side up in one universe and tails side up in the other. Now we have two versions of Branwen. Branwen A heads to Oxford while Branwen B takes up residence in Cambridge.
Branwen B loves Cambridge and settles in straight away. In her third year she meets Joseph, a politics student. They fall in love and get married. Joseph wants to devote himself to a political career. Branwen gives him the emotional and financial support he needs to do it.
Ten years later Joseph becomes a Member of Parliament and over the next twenty years ascends the political ladder until he becomes Prime Minister.
Branwen A can’t settle down in Oxford and drinks too much alcohol for her own good. She skips lectures, neglects her coursework and misses exams. In her third year she is asked to leave.
Branwen A goes back to her home town suffering from a breakdown and lives the rest of her life dependent on medication and benefits. Joseph meanwhile, loses interest in politics and becomes a corporate lawyer.
Now, along the way both Branwens make thousands of choices, for example, whether to get a bus to the market or cycle, or whether to wear the red or the green coat. You could say that every time Branwen makes a decision a parallel universe version of Branwen makes a different decision.
This leads me to conclude that if you’re sitting there with your head in your hands lamenting that you should have gone to Cambridge instead of Oxford, or you should have got the bus that day you cycled to the market and got flattened by that idiot in the taxi, then you should stop fretting. In a parallel universe you did go to Cambridge and your husband’s the Prime minister. (For the sake of balance, in yet another one you are the Emperor of the Galaxy.)
Note: I may come back to this. Actually, in another universe I do come back to this and write the most brilliant philosophical piece that leads to the Nobel Prize and world peace, while you win a hundred million on the lottery.
Sorry it’s not this one.