In the late 1980s, a thought experiment was published independently by Hans Moravec in 1987 and Bruno Marchal in 1988 that suggested that if the Many Worlds Interpretation of Quantum mechanics is correct, then every person alive today is immortal.
The logic, in short, is this:
- the universe is infinite in size, either through itself being infinite in size, or through there being infinite universes.
- in an infinite universe, at least one copy of every possible and probable configuration of matter and energy must exist.
- the visible universe you experience is a possible and probable (certain, actually) configuration of matter and energy.
- if there is a chance you will die today and a chance you won’t die today, both of those configurations of universe exist somewhere.
- you cannot experience yourself dying.
- therefore you will only ever be aware of a universe where you are alive, and will continue to live.
While the idea has the name "quantum immortality", it actually works no matter what kind of universe we live in, only depending on the universe being infinite in size or number.
In the following pages, we'll look at a few ways that the universe can be infinite.
We will then recap at the end of the chapter by going a little more in-depth into what it means.