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At Multiverse Impasse, a New Theory of Scale

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Re: At Multiverse Impasse, a New Theory of Scale

#61

Post by coliveira »

axilmar wrote: post #45
givan wrote: post #20

I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.

I do not think that it is possible. Any physical system that can be described by a set of mathematical laws is bound to have some axioms that simply cannot be proven within its context. Godel's incompleteness theorems prove that. Hence, we will never get to the bottom of the reality of our universe.

This argument is always used to try to reduce the power of mathematics, but the whole fact that mathematics was used to prove this tells me otherwise. There is a huge amount of properties of the universe that can be understood with mathematics despite Goedel's result.

Re: At Multiverse Impasse, a New Theory of Scale

#62

Post by saalweachter »

lutusp wrote: post #34
sampo wrote: post #27

Earlier quoted context omitted.

You should first worry about how we get out of this planet before the Sun turns into a red giant and swallows the Earth after 5–6 billion years from now.

Please have some perspective. Human beings have existed in roughly our present form for 200,000 years. In another 200,000 years, chances are we won't recognize ourselves. And in 5 billion years, which is 25,000 times farther into the future, there will be nothing remotely resembling human beings . We won't be a distant memory, we won't be a memory at all.

Five billion years really is getting up there.

I had a scheme, once, for everyone to be remembered. It started with one nearly impossible scheme, producing a biography for every person ever (starting with the living, with some effort made to recover as many of the deceased as are still remembered today). The problem with that is that being recorded is not the same as being remembered. Being remembered means that someone living knows about you and thinks about you. They occasionally ask themselves what you would think or do.

So you would need a system for everyone's life to be read from the recordings periodically, by at least one person. For the near future -- say a few thousand years -- this could work. For the first few generations, each living person could remember a small handful of the deceased, and all of the deceased would be held in living memory. Once the number of people to be remembered grew too great for that, you could still cycle them in from time to time. Being remembered by one person every thousand years could still be pretty nice.

But five billion years, that dog don't hunt. At current generation lengths, there'd be 200 million generations to be remembered. Unless you are willing to postulate either constant, exponential population growth, dramatic lengthening of generations, or superhuman capacity to remember, you couldn't remember any one person more than once every several million years. It still beats being forgotten, if that's your fear, but not by much.

Re: At Multiverse Impasse, a New Theory of Scale

#64

Post by pfortuny »

protonfish wrote: post #60
givan wrote: post #20

I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.

There is this belief propagated among physicists that smaller scales somehow have more to do with reality. I have never been presented with logic or evidence that convinced me that an electron is somehow more "real" than a molecule or a person or the solar system or the observable universe. I wish the word "reality" would stop being thrown around without justification. "Fundamental" might be a more appropriate term.

I guess you mean "elements." We used to apply the word to earth, air, fire and water. Now it is all about tachions and whatnot. But elements is the word.

Re: At Multiverse Impasse, a New Theory of Scale

#65

Post by pfortuny »

snarfy wrote: post #40
givan wrote: post #20

I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.

"Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for any consistent, effectively generated formal theory that proves certain basic arithmetic truths, there is an arithmetical statement that is true, but not provable in the theory" - Gödel (Kleene)

It is funny because if nature is discrete then Gödel has nothing to say about it. Only our present MODELS fail to deal with finiteness properly.

Re: At Multiverse Impasse, a New Theory of Scale

#66

Post by calinet6 »

mSparks wrote: post #56
calinet6 wrote: post #41

Earlier quoted context omitted.

It "kills it" because it's only really appealing if the universe we're in appears extremely unlikely, like it's the "just right" goldilocks balance of cosmic variables that we can't explain, that happened to be the stable ones that resulted in life evolving eventually. If the universe is actually very likely to occur in the state that it's in, then we don't need to use this "vast multiverse where our universe was the…

But the whole point of the multi verse model is that universe also exists. Multi verse theory afaik is just a mathematical construct of the various dimensions we can observe in a space time framework. The whole http://en.m.wikipedia.org/wiki/Flatland Idea.

You're thinking of parallel or alternate universes, which is based on the "many worlds" interpretation of quantum mechanics, where the universe "forks" at every quantum possibility into an infinite number of universes. That's one type of multiverse.

A "Multiverse" is a superset of that idea—it simply means a condition of many universes existing. They could have arisen in the same way ours did through a "big bang" in some larger space alongside our universe, they could be the many iterations of our one universe expanding and contracting over an infinite time, or they could be overlapping in the "many worlds" sense; we don't know.

The point of a Multiverse set is to explain our universe's existence statistically rather than empirically (as in, with a satisfying observational explanation). It says "we know that the chance of our universe existing is extremely small, so we must be one in an infinite number that had the right combination to result in life."

This is sort of like a car crash, and saying: "whelp, it happens with a probability of 1 per 1000, so it was bound to happen to someone" after a car accident rather than finding out exactly why and what caused the event—"whelp, the brakes didn't work, we should probably look into that."

Just like that car crash, finding out exactly why our universe exists, and how likely it is to have the reality we enjoy, gives us far more information than a simple philosophical statistical conclusion. It doesn't mean that the statistical conclusion isn't correct—there still may be a Multiverse, we may never know—it just means we know more about it than just how often it happens.

But, knowing how likely our universe is to happen is a big step. If it's very likely, then we know a lot more about universes. If it's unlikely, then we could just chalk up our existence to chance and it would be perfectly valid. In the latter case, however, it would be extremely unsatisfying scientifically. We'd love to know more.

Re: At Multiverse Impasse, a New Theory of Scale

#67

Post by antimagic »

lrem wrote: post #38
unfunco wrote: post #37

Earlier quoted context omitted.

"There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable." – from The Restaurant at the end of the Universe.

"There is an accompanying theory that states this has already happened." - same source

I often think about that quote when I'm thinking about the universe as being a simulation in someone's computer somewhere. So imagine us clever little monkeys on the inside, have been probing the behaviour of the simulator by conducting science experiments. We're basically conducting targeting fuzzing of the simulator, which probably results in quite a few bugs going off. At which the compsci student running the simulation sighs, corrects the bug, and launches the simulation again.

Re: At Multiverse Impasse, a New Theory of Scale

#68

Post by fjolthor »

axilmar wrote: post #45
givan wrote: post #20

I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.

I do not think that it is possible. Any physical system that can be described by a set of mathematical laws is bound to have some axioms that simply cannot be proven within its context. Godel's incompleteness theorems prove that. Hence, we will never get to the bottom of the reality of our universe.

I agree with this but for a different reason. No matter how much we discover, everything we find is still something in existence. No matter what force or object you are observing, you can't doubt that it exists at some level, in some way (whichever multiverse or reality it is).

This means that at some point, existence must have been started by something non-existent. Because we only comprehend cause-and-effect, we can't possibly find the origin in a provable way while researching from within existence.

Re: At Multiverse Impasse, a New Theory of Scale

#70

Post by john_b »

axilmar wrote: post #45
givan wrote: post #20

I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.

I do not think that it is possible. Any physical system that can be described by a set of mathematical laws is bound to have some axioms that simply cannot be proven within its context. Godel's incompleteness theorems prove that. Hence, we will never get to the bottom of the reality of our universe.

Godel's incompleteness theorems only place restrictions on deductive systems. In mathematics, you can't perform "experiments" and measure what happens. As long as we can observe and measure physical quantities, even if those quantities are only indirect effects of what physicists are actually trying to measure, incompleteness is not a strong limitation of physics.
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