If you think this universe is bad, you should see some of the others
-Philip K Dick
|Ψuniverse> =∑αi|Ψworldi
You may have read my earlier article about Schrödinger’s equation and that famous cat of his. Well this piece is an attempt to expand that somewhat and go into the direction of the ‘Many-Worlds’ interpretation of quantum mechanics.
Hugh Everett was the first physicist to actually propose this particular and not to mention peculiar interpretation of quantum theory, way back in the banner year of 1957. Although it wasn’t until almost a decade later that it got its current moniker, thanks to the work of Bryce DeWitt. I suppose that its main competition in the quantum theory world is from what is called the Copenhagen interpretation. For reference and comparison, in the Copenhagen version, the various mathematics used allows for the prediction of probabilities of various events happening. When a given event actually occurs it then becomes part of ‘reality’ and alternative possibilities simply do not exist. So when you hear about that cat, it means that until you actually open the box and look inside the cat is both dead and alive at the same time. There is a catch however; only the act of looking realizes one of the two states. It requires an ‘observer’.
Everett’s proposition is radically different from this. Any time that a quantum experiment takes place that has different possible outcomes, all outcomes are obtained, but each in a different world. This is true even if we are only aware of the world with the outcome we have observed. In a way this could explain why a physicist in this world measures an object as a wave, whilst in another, a particle. (Perhaps)
So when you open the box to find the cat dead as a doornail, don’t be sad because in another world she is happily purring and licking her paws.
Those that dabble in the quantum arts will tell you that some of the characteristics of the Many Worlds view are indeed difficult to wrap your mind around (at least in this world; because there is another where you understand with clarity), but indeed probably no stranger than a feline being both dead and alive simultaneously.
In a multi world view…
- There are by definition, multi; in-fact an infinite number of ‘verses’.
- You are not a single person; there are exponentially expanding instances of you.
- It is meaningless to ask yourself the question; “what if I had done ‘such and such’ instead”. Because you did…
- Leads to the conclusion that there must be some unimaginably strange worlds out there.
- Undermines any concept of times linearity, which in turn eliminates any paradoxes associated with time travel. This is my personal favourite.
- In-fact resolves or eliminates all quantum paradoxes.
One way to get a clearer understanding, or proof of something is to determine if it is testable or falsifiable. Either experientially or by a thought experiment. There is some work being done precisely in this area regarding the Many Worlds interpretation. There is also speculation that there may even be tenuous communication channels between parallel universes; perhaps via gravity waves.
There is no definitive answer to the question of whether the Many Worlds view is the one true model, or if the Copenhagen view is correct; or indeed a number of other competing theories. Some of the competition includes:
- de Broglie-Bohm
- Von Neumann
- Many Minds… sort of an extension of the many worlds
- Objective Collapse Theories
- Quantum Informational Theories
The Many Worlds is only one of a handful that does not provide a unique history, but it is also among most in that it does not require an observer. One of the primary reasons for accepting Many Worlds is because it does avoid the pesky collapse of the wave equation. Why is that ‘pesky’ you might ask. For one, it postulates a physical law that differs radically from any known physics. Two, it is random. And three it involves ‘spooky action at a distance’. Both of these last points were anathema to Einstein; although he by no means has final word on the situation.
There are strong adherents and detractors in the various camps. Perhaps it will remain in the realm of the unknowable.
It is probably important to mention that the Copenhagen view is the one favoured by more physicists. Equally notable is that to date there is no actual evidence that exists (in this world) that distinguishes between the validity of various interpretations. The fact remains that quantum theory works. It is self-consistent, and has stood up to all observation and experiment. We only run into issues when we delve into the philosophy of it and ask the question…’what’s it all mean?’
The whole affair is mind-bendingly psychedelic. In some world you can and have rolled snake-eyes 1000 times in a row, or you have free-soloed 5.15c. I suppose if true then there must also be worlds where the Copenhagen interpretation is correct.
Why wait any longer for the world to begin, you can have your cake and eat it too.
-Bob Dylan