Why does quantum tunnelling lead to a change in the number of observers, and why would that be fatal?
Simple answer the universe is not in its lowest energy configuration the moment one part snapped to the lowest energy configuration collapse would continue out as a bubble of destruction until it encompassed the whole universe.
It is covered in enough detail in
http://en.wikipedia.org/wiki/False_vacuum=> Simply put, the false vacuum is a local minimum, but not the lowest energy state, even though it may remain stable
for some time.
=> For decades, scientific models of our universe have included the possibility that it exists as a long-lived, but not completely stable, sector of space,
which could potentially at some time be destroyed upon 'toppling' into a more stable vacuum state.=> This catastrophic bubble of "true vacuum" (per quantum models) could theoretically occur at any time or place in the universe,
which means (because the bubble of "true vacuum" will expand at the speed of light) the end of such a false vacuum could occur at any time.=>
If a more stable vacuum state were able to arise, then existing particles and forces would no longer arise as they presently do.And so on and so.
The final answer is given in the implications section
If measurements of these particles suggests that our universe lies within a false vacuum of this kind, then it would imply - more than likely in many billions of years that it could cease to exist as we know it, if a true vacuum happened to nucleate.
Under different ways to view QM the removal of an observer means that the quantum electrodynamics don't resolve because to resolve it must include EVERY PATH and so the inability to resolve means the waveform must collapse and that collapse rolls out through the universe. So it's the same result as viewed from the other way above.
Do you see my objection to Ethan's article now he has used QM to make an argument position but then only taken half the story because he doesn't like the other half.
Everett many worlds sidesteps quantum suicide in an interesting way but that is a whole other story.
