"Nothing" doesn't exist. Instead, there is "quantum foam"
bigthink.com
Quantum physics shows that there is no such thing as "nothing." Even in a vacuum, particles can blink into and out of existence.
  •  Sas [she/her]   ( @Sas@beehaw.org ) 
    1•1 month ago

    And the cat observes it but that doesn’t mean that the cat is now in a discrete state that is either alive or dead. It is both and will stay both and you’ll only see which version of the cat is in your world. At least according to the many worlds theory which makes sense to me