Science
Related: About this forumWhy there might be many more Universes than our own
By Philip Ball
21 March 2016
Is our Universe one of many?
The idea of parallel universes, once consigned to science fiction, is now becoming respectable among scientists at least, among physicists, who have a tendency to push ideas to the limits of what is conceivable.
In fact there are almost too many other potential universes. Physicists have proposed several candidate forms of "multiverse", each made possible by a different aspect of the laws of physics.
The trouble is, virtually by definition we probably cannot ever visit these other universes to confirm that they exist. So the question is, can we devise other ways to test for the existence of entire universes that we cannot see or touch?
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http://www.bbc.com/earth/story/20160318-why-there-might-be-many-more-universes-besides-our-own
cpwm17
(3,829 posts)since nature doesn't make things in ones. Plus it is extremely unlikely that we would be here with only one shot at a universe.
Also with only one universe with a finite age, there would have been a time=zero moment where there was absolutely nothing before. That is impossible.
DetlefK
(16,423 posts)Fine-tuned to what?
And we don't need either God or multiverses. There could simply be some law of nature that makes ALL universes like ours. We don't know whether those other universes are different.
cpwm17
(3,829 posts)the chances that you would create a universe with such interesting properties like our own universe (like the ability to create life) are astronomically small.
It is like putting a bunch of random pixels on a computer screen and making an identifiable picture. It's not going to happen in one attempt by purely chance.
DetlefK
(16,423 posts)Why do we have to choose between random and intelligently designed? What about these parameters being the only possible parameters when a universe is created?
You are positing that the laws of probability still work outside of our universe... for which we have no evidence.
cpwm17
(3,829 posts)if the only possible properties of our Universe are the properties that can create planets with life.
DetlefK
(16,423 posts)The universe is as it is. Life could be an accident.
Nobody fine-tuned atmospherical physics and geology to each other to produce lightning-strikes in the ash-clouds of volcanoes. They are just a by-product of something else.
cpwm17
(3,829 posts)we wouldn't be here, nor would there be anything in the Universe as interesting as us. This does need an explanation - shit happens doesn't cut it.
Over time, the more we learn the larger our Universe has gotten. We now know that our planet isn't the only one and our galaxy isn't the only one.
Once we learn nature can create something we have good reason to believe nature can create many of the same something. That is why science works. There is order in nature. Natural processes aren't just limited to one time.
Our large Universe gave nature many attempts to create life in our Universe (many lottery tickets). Still we need an explanation on how our Universe can create life. There is no reason to limit universes to one, and there are multiple reasons to believe there shouldn't be only one.
DetlefK
(16,423 posts)Please remember that we aren't talking about some statistical ensemble where we know that the rules are the same everywhere. We aren't talking about life being created at random on random planets.
We are talking about different universes. Different laws of nature. And the multiverse, with yet other laws of nature.
"What is the probability that out of all possible kinds of universes..."
That argument doesn't make sense for a very simple reason: We have no reason to believe that the multiverse is governed by the laws of stochastics. There is neither empirical nor theoretical evidence for that or against that.
How do you know that something like "all possible kinds of universes" even exists? There could as well be only "one possible kind of universe" in the multiverse and each and every universe in the multiverse is exactly the same. We don't have any evidence on anything of that.
The "fine-tuning" theory and the "multiverse"-theory are both nothing more than empty speculation.
cpwm17
(3,829 posts)and pure chance is not an explanation. The multiverse is the most popular explanation. Direct evidence for the multiverse is currently impossible.
Contemplating my own existence, I believe an explanation (within the realm of scientific possibility) that gives me the greatest odds of existing is likely the best explanation.
With only one universe, the odds of me existing ever, let alone me existing only once and at this very moment, are close to zero. The odds would be greater for me to win every lottery I try this year, if I were to buy a ticket every week.
If there is a huge multiverse with various properties, my chances of existing greatly increase. With a large enough Multiverse with enough variation in the individual universes, my existence might be guaranteed.
Our Universe had a starting point at the Big Bang. With only one universe there would have been a time=zero moment, where something just came from nothing. Since nothing doesn't exist, nothing can't create something. So the Big Bang must have come from an already existing realm with already existing physics.
The idea that this physics that created our Universe didn't create any other universes is far-fetched. On Earth, if something is proven scientifically possible once, that same thing has then been proven to be possible any number of times. If this weren't true, science wouldn't work and nature could never be understood.
Here's Leonard Susskind's version of the multiverse:
This gets into the extremely low odds of a single universe existing that can have life. The video up loader had his own agenda, believing that our "fine-tuned" Universe is evidence for a fine-tuned god. That argument is self-defeating:
qazplm
(3,626 posts)is that the multiverse just moves the problem back one level.
If there is a multiverse, where did it come from?
That problem is always going to be there in almost any theory.
cpwm17
(3,829 posts)Last edited Wed Mar 23, 2016, 03:56 PM - Edit history (1)
There could also be far more beyond the Multiverse.
The Multiverse helps eliminate the "fine-tuned" problem. The Multiverse itself wouldn't necessarily be "fine-tuned", it is just extremely large containing a huge number of universes with a wide range of properties. That is far more believable and likely than there only existing our Universe that is "fine-tuned" on a knife's edge.
Bob41213
(491 posts)For that matter, the odds of everything in your life are pretty much zero.
Flip a coin 100 times and you will get some result. The odds of whatever just happened are one in 2^100 (about 1 followed by 30 zeros). BUT SOMETHING HAS TO HAPPEN. If you try to calculate odds after the fact, you will come to the conclusion that it was impossible.
cpwm17
(3,829 posts)That logic does work when we're talking about evolution, for example. Creationists make the mistake of claiming that the odds that a particular critter could have evolved a particular way are extremely small, so there must be a god. But particular critters aren't the goal of evolution. Evolution is going to evolve critters in some direction.
But the odds that an interesting universe could have developed, such as one that can evolve life, with only one attempt, are extremely small. Not all outcomes are in the same category. Our universe is in the category of a very interesting universe, which would be extremely rare if created by pure chance.
When you see an identifiable pattern on an old analog TV set you know that a signal was sent from some place. That pattern will not be there by pure chance. There are a huge number of ways to create a pattern on a TV (the vast majority of patterns are just static), but an identifiable pattern needs an explanation, unlike pure static.
From my selfish perspective, it is legitimate for me to contemplate what version of reality gives me the best odds of existing: one where my odds of existing are next to zero or a version of reality where my odds of existing are quite good. I think it is obvious that the version of reality where my odds of existing are next to zero can pretty much be eliminated.
Some people seem to have a faith-based version of reality where they accept a certain version of reality, even when shown that their version of reality is virtually impossible, and their version of reality violates everything we know about nature. (nature doesn't make things in ones, for example) Nature is giving us clues. Many of the best scientists believe an explanation is needed.
Brother_Love
(82 posts)This documentary talks a bit about GeV above 145 may indicate a multiverse. http://home.cern/about/updates/2016/02/awakening-acceleration-awakes-plasma-cell-arrives A new plasma cell promises to increase speeds dramatically.
MisterP
(23,730 posts)bvf
(6,604 posts)is still the best reading on this that I've seen.
Highly accessible, and you won't find a single reference to string theory. Great stuff on quantum computing, too.