Doppelgängion:
Here we have a number so ludicrously large that it is tricky to compare with any other numbers: 10 to the power of 10 to the power of 68 corresponds to 1 followed by 100 million trillion trillion trillion trillion trillion zeroes.
It is a number I have named the doppelgängion, because it relates to the chances of there being another person like you, a doppelgänger, somewhere else in our universe. To be clear, we aren’t talking about doppelgängers in other universes disconnected from our own, as imagined in the many worlds interpretation of quantum mechanics, or any other multiverse theory. Instead, we are asking about our very own universe and the possibility that your doppelgänger is out there – same nose, same eyes, even the same thoughts. It is an idea that goes back to physicist Max Tegmark at the Massachusetts Institute of Technology.
It might seem absurd. But ultimately it comes down to the probability that there is another bit of space, the same size as the one you occupy, in exactly the same quantum state, encoding the likely arrangements of all the particles that make up you. [“5 mind-bending numbers that could reveal the secrets of the universe,” Antonio Padilla, NewScientist (13 August 2022, paywall)]
For the record, Padilla’s number looks like this: 101068
And HTML renders it properly, too. I had my doubts.
