Question: Do you believe that alternate realities are scientifically possible? Or like an alternate universe? For example if the Big Bang happened couldn't another universe have been made at the same time and it would be antimatter vs matter. Like is that scientifically/mathematically possible?

Ben Cropper answered on 9 Mar 2020: last edited 9 Mar 2020 4:08 pm

The most likely one of these ideas is the many worlds interpretation of quantum mechanics.

When something happens with really small stuff, it works with probabilities. For example, if you check whether a nucleus has radioactively decayed after a certain amount of time, either it has or it hasn’t, and that is random (the longer the leave it, the more likely it is to decay, but you can still never definitely know until you look).

One possibility is that each of these possibilities (the nucleus has decayed or not decayed) splits off into parallel universes, and this happens for every one of this near infinite number of possibilities (in the history of the Universe). Cool stuff!