Given an infinite amount of time for the Universe to do it’s thing, are all possible events considered inevitable?
When I was younger and was first introduced to physics I used to think about this question very often. The question seems to have profound philosophical implications.
I know that many cosmological theories of the Universe consider it to be effectively bounded in time. Eventually everything will decay away into a homogeneous soup of elementary particles. Having learned a bit about thermodynamics I know that the Universe as it approaches it’s ‘Heat Death’ will continue to tend toward a state of equilibrium. Entropy must always increase after all - at least according to classical physics.
However, one has to wonder whether the remnants of this dead Universe still has the potential to do anything interesting.
If it is possible for the dust to reanimate itself in some way, doesn’t that imply that it will have to, eventually? Doesn’t our current understanding of Quantum Mechanics, assuming it’s a fundamentally correct description of the world, guarantee this?
If that is possible - wouldn’t all other possible events also be considered inevitable?
This book has a chapter, close to the end, about Quantum Resurrection.
Even if there is no such thing, there is the possibility of a multiverse reality with different “laws” of physics across the branes. that would seem to make for many more possibilities.
No, not all things are inevitable. Only possible things. No matter how much time passes, you won’t have a square circle, 2+2 will not equal 5, information will not travel faster than c, and so on.
I’m aware that things that are impossible remain impossible as time goes on. I thought I was careful to acknowledge this in my post - albeit, not in the title.
There’s a huge difference between very, very large and infinite. People toss infinite around lightly, but we know of nothing we can apply it to for certain. Our universe is large but finite we think. No expansion can turn a finite universe into an infinite one. However, there’s nothing to prevent the universe from having been infinite from the beginning. And various conceptions of the multiverse call for an infinite number of universes.
We can do a quick calculation of how many states our universe has been through since the big bang. Using the Planck time, we get 10[sup]60[/sup] units of time and using the Planck length, we get 10[sup]176[/sup] units of volume. That gives 10[sup]236[/sup] states. (I may be off a few powers of ten in rounding and assumptions, but that doesn’t matter for this discussion.)
That’s a number too ridiculously large to put in any human terms. But obviously it is approximately 0% of an infinity of possible larger numbers. If we make the assumption - and it’s currently only an assumption - of a truly infinite number of universes, then there will be an infinite number of universes that have exactly the same 10[sup]236[/sup] states and an infinite number of universes that differ by one state and an infinite number of universes that differ by two states and so on. In fact, any set of states that is physically possible will occur an infinite number of times. So yes, anything possible must occur if infinity is posited.
Which is why so many scientists dislike that assumption. Kinds takes the fun of the game.
The idea was that given that the universe is infinite, many thing that would seem impossible are, in fact, not only possible, but inevitable
I will buy that fact that if you had a card dealing machine going 24/7, a royal flush would come up occasionally.
However, what this program was saying is that somewhere out in the universe, there is not only another planet exactly like earth, but it is populated with people who are identical to the people living right now on our planet (Earth). In other words, there are 2 of you and me! . The program admitted that the odds of this being true are staggering, but claimed that because of the infinite nature of the universe, it was true.
There’s also the order or cardinality of infinity to consider. Time has (I presume) the same cardinality as the set of real numbers; at least it does if time is continuous and doesn’t have weird properties. But “all things” certainly sounds to me like it has a higher cardinality since I’d think of all things as a kind of set of sets idea. But you’d have to be a bit more formal in your definition of “all things” to determine exactly.
If all things does have a higher cardinality, then there is not enough time in “all time” for all things to happen.
Right, this gets at some of the problems of throwing around words like “infinity” and expecting the word to apply to the physical universe.
Like, suppose you chose a random real number between 0 and 1 at random. There are an infinite number of them. Then you chose another real number. Is your first choice equal to your second choice? If not, try again. Now continue trying until you get two matching real numbers in two tries. The odds that any two random real numbers matching is zero. So given an infinite number of tries, is the odds that you’ll get a match 1 or 0?
She is never going to have sex with you. Never. Although possible it ain’t going to happen. Never, no matter if you throw infinite in there. Never. Move on.
Actually, the best guess of most cosmologists is that it really is infinite. Though of course there’s no way to confirm this. And in a truly infinite Universe, one would expect that somewhere, inconceivably far beyond any distance we could ever observe, there really is an exact duplicate of our planet, since even “inconceivably low odds” must pale in the face of infinity.
But that’s for infinite space. Infinite time doesn’t really help. Yes, it’s possible for a quirk of statistics to locally reduce entropy and result in something interesting happening even after the Universe is “dead”. But the probability of that happening is not only inconceivably small, but it gets smaller as time progresses and the Universe grows. Integrate over, say, our entire future light cone out to infinite time, and the net probability of such an event occurring ever is still extremely small.
I think this thought of mine probably developed because of the discussion regarding the multiverse - I, erroneously, attempted to apply the same logic to a single Universe given infinite time.
Do we actually have enough information to perform the integration that you alluded to? Would we have to assume the expansion of the Universe will continue to accelerate at it’s current rate?
I’ve heard interviews with Brian Greene etc. talking about theories of an infinite universe and multiverses and how (if true) all possible combinations of matter must exist and repeat - I don’t claim to really understand the ideas but do they not imply that any and every (physically possible) scenario you can imagine exists out there somewhere (and indeed, exists in infinite variations and repetitions?)
A United States with Adolf Hitler or Snookie as President?
Every Star Wars or Star Trek or other science fiction world?
Anything and everything you or anyone else has ever dreamed or imagined or read in a story or seen in a movie?
An infinite amount of time will be filled mostly with repetitious events. Some common events will occur billions of times. Less common events will happen millions of times. Some rare events might only occur a few thousand times. And some events will never happen at all.
What Little Nemo said. Also, most of space is empty, and nothing really worthy of note is happening there. You need concentrations of matter and energy (well, energy, at least) to support the information that is necessary for an “event.”
This “clumping” of the cosmos, at the highest scale, helps get around the “anything will happen” idea.
(It’s also one of the answers to Olbers’ Paradox. An awful lot of light-sources are blocked by other light sources. It isn’t “THE” answer, but just a supporting answer. “THE” answer is that the cosmos isn’t old enough for light to come from all directions, especially given the “Inflation” idea.)
The various multiverse concepts do away with this. It doesn’t matter how much empty space there is in a universe. If there are infinite universes, then there are infinite universes with enough matter for this to happen, even though there will also be an infinite number of empty universes.
There is a hidden assumption that universes contain random assortments of states. I think this is quite realistic. You can imagine a number between 0 and 1 that contains nothing but 1’s after the decimal point but looking at the entirety of possible numbers gives that an extremely low probability.
Little Nemo is correct that an infinite multiverse would be repetitious. However, none of the repetitions would be finite. They would all be infinite.
It’s bigger than the number of drops in a water bucket (about 100,000). [1] Actually, it’s bigger than the number of drops in an Olympic-sized pool (25 billion). [2] Heck, it’s bigger than the number of drops in the Pacific Ocean (7,113,216,772,388,571,428,566,000 or 7.113216772e24, approximately). [3]
As an aside, the number of atoms in the graphite of a pencil is 25,000,000,000,000,000,000,000 or 2.5e22. Yes, that’s just the pencil lead. [4]
So anyway our host and hostess have a lot of possibilities to deal with. More possibilities than… the number of atoms in… the universe. That would be about 4x10^79 hydrogen atoms, counting only stars, which is most of everything. [4] Our master of ceremonies has to consider a number about 200 times more than that:
Sixty people can seat themselves in 60! different arrangements across 60 seats.
60! = 8.320987113e81 = 8,320,987,112,741,390,144,276,341,183,223,364,380,754,172,606,361,245,952,449,277,696,409,600,000,000,000,000, which is a pretty big number.
From this I conclude that the number of possibilities greatly exceeds the number of actualities, by an unfathomable amount. I didn’t have to use a dinner party as an example: we could arrange 60 bricks on a patio and have the same impossibly huge number, assuming that the 60 bricks are only permitted to fit into 60 fixed positions. More flexible arrangements would give us a still larger number.
At the very least, the number of trivial possibilities is unimaginable.
Parallel universes are a decent science fictional device, but I regret to say that there probably isn’t an opposite universe where Angelic MfM posts on CrookedDopeMessageBoard. The number of possibilities is just far too large to permit such doppelgangers.
[1] Drops per ml of water: about 20.
ml per oz: 29.57
64 oz per gallon.
3.5 gallon bucket
2029.5764*3.5 = 132473.6
or 100,000 drops per bucket (rounded, and say it’s not entirely filled).
[2] Drops per gallon: 2029.5764 = 37849.6
or 38,000 (rounded: note that drop size varies a lot).
Gallons in an Olympic swimming pool: 660,253
Drops in an Olympic swimming pool: 660253 * 38000
= 25,089,614,000 or 25 billion drops.
or 2.5089614e10
[3] Gallons in Pacific Ocean: 187,189,915,062,857,142,857
(from http://hankfiles.pcvsconsole.com/answer.php?file=447 )
Drops in Pacific Ocean
187189915062857142857 * 38000
= 7,113,216,772,388,571,428,566,000
or 7.113216772e24 or 25 digits worth.
And the number of possible arrangements of states I mentioned is 10[sup]236[/sup]!.
There’s no way to express that number since even the base number couldn’t be written out in our universe no matter how small (above the Planck length) you made the zeroes. The permutations are so far beyond that number that some special notation that mathematicians use for huge numbers may not even fit in our universe.
And so what? Compared to other really large numbers, that’s still essentially 0.
That’s the amazing thing about infinity. If you can think of even a theoretical way to express a number, then the number is finite, it’s trivially small, and an infinite number of those number strings can be found.
