The rule could be anything, as funny or as serious as you want. The universe will progress in a similar way that it has up until this point, unless your changed rule prevented it from doing so.

Some examples might be:

  • The invention of currency is not allowed.
  • Iron is slightly less stable.
  • The Ancient Greeks are able to cultivate Silphium, which does not go extinct now.
  • @thenextguy
    6•20 days ago

    Isn’t Planck’s? Whose constant is it then?

    • @sprack
      10•20 days ago

      For the next 3.7E-13 zeptoseconds it’s yours. My gift to you.