What's Your View on Multi-Universe Theory?

#1

A few days ago, I saw an article on low energy spots in our universe that should not be there (by our physics math and all). This raised the question, once again, of Multi-Universe theory (among other things). So, I thought I’d ask: whats your view on Multi-Universe?

#2

I tend to stick with Occam’s razor for a lot of these new agey out there theories of cosmology or the brain or what have you.  I think a lot of times it’s a case of trying to explain one thing we don’t understand with something else that we don’t understand.  A neuroscience example is Quantum entanglement in the brain.  Most of the time the assertion isn’t really that informative because A) the theory can’t be disproved B) Even if it were true, it doesn’t actually have any predictive power.


Actually another pet peeve of mine is much more mainstream (and this may demonstrate my ignorance) is dark matter.  I’d much rather call it unexplained data.  Basically, when we plug in all of the stuff that we can see in the galaxy into the equations of motion that work on a smaller scale, the numbers don’t work out.  It looks like there’s a lot more stuff out there which isn’t glowing.  To me it seems like a cop-out to invoke invisible stuff to make your theory work.  It seems more likely to me that gravitation doesn’t work the way that we think that it does at very large scales (galaxies).  Granted, no one’s been able to come up with a new theory of gravity which explains the data satisfactorily either, but I’d rather state our ignorance explicitly, “Here is data that we can’t explain!” than invoke something imaginary to explain it.  If I can’t find my keys, I can hypothesize that gremlins moved them.  I can then go about looking for evidence of gremlins.  I wouldn’t call it science though…

I don’t mean to be a downer.  There are some things that science can never explain, prove, or disprove.  For everything else, feel free to believe what you like!  Just don’t expect any proof anytime soon.
#3

Hi balkamm, 


I see your point about Occam’s razor, it is a brilliant logical tool, but in some cases it does not apply. Dark matter does indeed seem like a cop-out, (the invoking of a giant invisible substance to explain away the faults in our equations) but it is in fact precisely the opposite. It is hard to call something a cop-out when it raises more questions than it actually explains.

The explanation of the motion of galaxies using dark matter is just that- an explanation! Scientists have stated their ignorance when we found that our theories of gravity do not work at large scales. But it seems you’re saying that we need not proceed from that point. That is not the way science works. The theory that a form of matter exists that does not interact with ordinary matter through the electromagnetic force, and therefore is not visible, and is is present at six times the amount of normal matter, was not just thought up. It follows directly from evidence. If what we can observe in the universe behaves as if it existed around dark matter, and other theories that try to adjust our current laws of gravity fail spectacularly, then we are forced to conclude that our universe is one that includes dark matter until evidence comes along that disproves that theory. 

To reiterate the point that dark matter is the only current theory that explains the observed data, I have attached a jpg image of a graph that shows the the way large structures are distributed in the observable universe. The red points are the observations made of our universe and the black line is the predictions made by standard cosmology, including normal matter, dark energy, dark matter and general relativity governing them. The dotted blue lines are the predictions made by our classical theories of gravity, and the solid blue lines our best relativistic alterations of gravity without dark matter. I’ll leave it to you to interpret the evidence. 

It is true that what is being discussed is still controversial, and new evidence could come around any day that either proves one theory, or overturns everything we thought we understood, leaving us to start from scratch. These are just the best predictions we can make using the available evidence. Because of this, alternate opinions are expected, and should be encouraged; it is what makes science work so well. 

To be honest the only issue I hold is with your last statement. If it exists in reality, than science can explain it through a method of repeated observations, hypothesis and experimentation. If it is falsifiable, than science can prove it’s existence. Anything that is not falsifiable, and does not exist physically in a state in which it can be observed, then by definition it cannot be proven to exist. Ergo it does not need to be explained by science, for if there is no evidence for something that cannot actually be proven, then it is completely reasonable to say that it does not exist, and the opposite to assume that it does in face of overwhelming evidence to the contrary.

With many regards,
addieye

P.S- I am much to blame for this, my apologies, but I think we should try to move the topic back to the Multi-Universe, as it is a rich idea (and the title of the conversation).
#4

Thanks addieye,


That’s a fine and well written post.  The only point that I would disagree with you on is:
If what we can observe in the universe behaves as if it existed around dark matter, and other theories that try to adjust our current laws of gravity fail spectacularly, then we are forced to conclude that our universe is one that includes dark matter until evidence comes along that disproves that theory. 
Lack of evidence for one theory, or lack of a better theory can’t force us to accept another theory.  Disproving stuff can only rule things out, not rule things in.  We may come up with a better theory tomorrow!

I think the real test of dark matter comes when our particle accelerators explore the higher energy regions where the dark matter might be hiding.  My money is on them not finding anything, but that’s just a wager not a scientific anything.

Getting back to the matter of Multi-universe, my question or challenge would be, If this were the case, what would be the implications for the universe that we live in and experience.  Would there be any observable effects that we could measure?  Maybe @jzcrz123 could share the article with us, we could look at the data and we could see what we think of it?
#5

Hi balkamm,


Thanks a lot for that post. I do believe that you are correct.
The test for dark matter will certainly lie in the findings of high energy particle accelerators. My bet is that we will find out in 2015 when the LHC finishes its first long shutdown and is ready to operate at higher energies of 7tev (tera-electron-volts).
But enough for dark matter.

I myself have come across an article from New Scientist quite a while ago, that discussed the new findings of the Plank space telescope (I think), in regards to the cosmic microwave background radiation (CMBR). Many remarkable discoveries were made which are sure to revolutionise modern cosmology, but among them was an area of space (I do not recall what size- assume massive) that had an unexplained, unpredicted and significant lower energy than the space around it at a surprisingly high gradient. It was thought that this phenomena was the remnants of an interaction between our universe and a parallel one. This idea is still controversial, but interesting.

It is possible that jzcrz123 is referring to this article, in which case I think I may be able to find it. Even if jzcrz123 was not referring to it, I think it may still be useful to the conversation.

addieye