Multiverse

My exposure is limited to science fiction. Like time travel, it makes my head hurt, too.

I've not read the article that you refer to, but stuff like M-theory, with branes drifting next to each other, is very possible.

Ed, "multiverse" has many possible connotations but I for one tend to disbelieve anything for which there's no evidence

http://en.wikipedia.org/wiki/Multiverse

One version of it is this. The traditional interpretation of quantum mechanics is that a system may not have only one value of a variable, say a system energy, but be in a superposition of several allowed states, each with a certain probability, as long as you don't go and measure the variable, in this case energy. When you measure the variable, you knock it out of the superposition state and force it to choose one and only one value. This is called the Copenhagen Interpretation after Danish physicist Neils Bohr. It's also sometimes referred to as the collapse of the wavefunction. This is the basis for the thought experiment called "Schrodinger's Cat."

In the 1950s, in his PhD dissertation, Hugh Everett proposed a rival interpretation for this probabilistic nature of quantum mechanics. He proposed that what is really going in in this situation is that the universe is splitting into different branches with a different one of the allowed values of the variable occurring in each branch. The practical consequences are the same as with the Copenhagen Interpretation.

When I was a graduate student, I came across this dissertation in the Physics Department reading room. I asked one of my professors whether he had heard of it and what he thought of it. He had heard of it. He said something close to, "Well, it's all very nice I suppose, but if these alternate universes are mutually unobservable, then it's kind of like religion. There's no way to distinguish it from the Copenhagen Interpretation by experiment."

In the years since then, the Many Worlds Interpretation has grown greatly in acceptance. I think the physics community likes the fact that it eliminates the rather magical collapse of the wavefunction. I believe it is now somewhat more popular than the Copenhagen Interpretation among theoretical physicists who specialize in quantum mechanics.

edgar, I have mentioned a festive few times (and some not so festive times I suppose as well) on this site, my belief in the multiverse. On at least 1 occasion I was attacked so viciously that I considered never again clickety clacking out my belief on this site.

So yes, I believe.

Mind you now, there are some inane and even insane theories out there which will make people question the validity of multiverses; however, throughout life and the vast cosmos there will be doubters and they will doubt for any number of reasons and often quite convincingly.


Now, if only we could also discuss Gödel's incompleteness theorems, then I'd be in blissful bliss.

I see no reason to suppose a "multiverse" is impossible...nor any reason to suppose a "multiverse" is required to explain anything...

...so any comment I make on whether or not such a thing exists...

...would be nothing more than a blind guess.

I suspect everyone else here is in that same position.

REALITY is one hell of a thing to contemplate, isn't it!

Some of the pages I was reading seemed sensible to me. But I have not the education some of you have. That's why I have asked opinions, rather than providing one.

Don't sell yourself short edgar. You have an educated background far superior to many, in that you look, read, investigate that which interests you.

As far as understanding the entirety of the multiverse, it is, to place it nicely, a slow process and there are times where there will be seeming contradictions within. Just take a deep breath, relax a little and push onward, it'll seep in a little at a time.

I never seriously accepted multiverse, but as I mentioned, some of what I have read seems pretty sensible. I need to read more.

Here is an article on the subject in layman's language. More at the end of the article.

http://science.howstuffworks.com/what-is-the-multiverse.htm


and some stuff from TED talks:

http://blog.ted.com/2012/02/28/the-multiverse-in-three-parts-brian-greene-at-ted2012/

https://www.ted.com/talks/sean_carroll_distant_time_and_the_hint_of_a_multiverse


And a NOVA documentary

Thanks. I will have to check these links tomorrow.