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Universe: Finite or Infinite?

by mattex
Tags: finite, infinite, universe
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DevilsAvocado
#91
Nov26-09, 08:16 AM
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Quote Quote by Dmitry67 View Post
1
As a proponent of Mathematic Universe Hypotesis,
http://arxiv.org/abs/0704.0646
- this is very good reading,
I don't see any difference between physical and mathematical.

2
For that reason Newtonians gravity theory was not valid, because when applied to the infinite Universe, you got infinities. In General Realitivity you dont run into infinities even for the infinite Universe.

3
If a theory is a) self-consistent, b) is compatible with the observations I don't see reason to cry all the time "wow, but wait, the whole Universe is hanging in the nothingness! or wow, but it is infinite!" :)

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1) I love Max Tegmark , he is a brave man and the Grand Master of Mind-Blowing Theories!
  • TOE - Theory of Everything
  • ERH - External Reality Hypothesis
  • MUH - Mathematical Universe Hypothesis
  • CUH - Computable Universe Hypothesis
Tegmark probably has more intelligence in his left pinky TOE than I have in my whole brain, and obviously I cannot comprehend all of his Mathematic Universe Hypotesis.

But then again, I am the DevilsAvocado and I did complete my course at the Argument Clinic , and therefore I naturally gonna have objections about this.

"If a future physics textbook contains the TOE, then its equations are the complete description of the mathematical structure that is the external physical reality. We write is rather than corresponds to here, because if two structures are isomorphic, then there is no meaningful sense in which they are not one and the same."

Huum, isn't this 'maneuver' a little bit too easy to 'replace' the physical reality with math? Isomorphic is mainly a mathematical 'tool' (right?) for mapping between objects... isn't that 'cheating'?

Example: If you have a complete technical drawing of a house, and make a complementation with all scientific knowledge about the material, down to quarks - then Tegmark could call the technical drawing and the physical building isomorphic, right? But can Tegmark take his family and move in to that Technical Drawing?? I say no.

"Wigner argued that 'the enormous usefulness of mathematics in the natural sciences is something bordering on the mysterious', and that 'there is no rational explanation for it'."

I DO admire all people who use extremely advanced mathematics to investigate and explore the world. They are my heroes!

At the same time, I think there is a little risk of losing perspective and getting 'lost in translation', and fall in love with the 'pure magic' of the tools you are working intensely with. For me, as layman, it feels extremely awkward that the physical world doesn't really exist - it's just equations...

In Erwin Schrödinger's book - What Is Life - from 1944 (old stuff I know! ) he wrote as a section header in Chapter 1:

PHYSICAL LAWS REST ON ATOMIC STATISTICS AND ARE THEREFORE ONLY APPROXIMATE

And if I'm not wrong; there is NOT today ANY mathematical equation that can describe what really goes on in the QM-world. All we calculate are probabilities, right? And Heisenberg's uncertainty principle doesn't give us much hope of ever getting rid of this 'trauma', right? So, how can (mathematic) approximations ever be the real physical world we live in??

Another side of this coin could be the EPR paradox, and the fact that Alain Aspect 1982 (almost?) performed a validation of Bell's theorem (Bell inequality). The world is random by nature. As far as I know, mathematics is NOT random by nature?

Tegmark's solution to banish randomness:
" ... so that the final state is a superposition of observers obtaining all outcomes, then in the limit of infinitely many bits, almost all observers will find their bit strings to appear perfectly random and conclude that the conventional quantum probability rules hold."

Huum, "a superposition of observers obtaining all outcomes" = Many-worlds interpretation ...??

If so, I not like...

The final objection is completely homemade, and feel free to laugh out loud!
What's the most natural geometric shape in the universe? Yes, circles/spheres. Not quadrates/triangles. What is the natural mathematic tool for handling circles and spheres?

3.14159265358979323846264338327950288 ... ... ... ... ... ... ... ...

Just a layman 'feeling' - but shouldn't ∏ be more 'exact/natural', if the Mathematical Universe Hypothesis is correct...??


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2) Is the reason for NOT running into infinities even for the infinite Universe, the fact that we can never get out of our local light-cone (event-horizon)? Or is this 'embedded' more 'fundamentally' in GR?


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3) "b) is compatible with the observations"... Hehe, this is the Holy Grail of avoiding difficult questions! Business as usual, everything (observable) works, without any help of the turtles!
DevilsAvocado
#92
Nov26-09, 10:19 AM
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Quote Quote by Dmitry67 View Post
Yes, it can, without any help of the turtles :)
Turtles all the way down
I think I've found the solution... The last turtle is not that big, and he has all the information at the fingertip!

DevilsAvocado
#93
Nov26-09, 10:27 AM
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Quote Quote by Dmitry67 View Post
DevilsAdvocado, regarding the QM ManyWorlds you are a victum of popular junk about the MWI.

1. There are no 'MANY' universes in MWI - everything happens in the same universe, just some parts of the omnium (almost) loses an ability to communicate forming 'branches'
2. When I make an experiment with different outcomes, I dont 'split' the whole Unvierse. The effect propagates at speed of light (or slower) via experimentally observed process called 'Qunatum Decoherence'
3. MWI does not make any additional assumptions expect we already have in QM. In that sense it is minimalistic. It does not even postulate the existence of the other branches: all that is derived using the standard QM stuff + Quantum Decoherence

Okay, thanks for info.

And how do we relate Qunatum Decoherence to Tegmark's:
"a superposition of observers obtaining all outcomes"

To me it sounds like every observer is gonna have their own bit...??
Dmitry67
#94
Nov26-09, 10:31 AM
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DevilsAdvocado, regarding your objections, how do you know if you are living in the virtual reality or real reality? "complete technical drawing of a house" is not a good example for "virtual reality". So you cant live there.

The second part of your objections are rather constatation of fact that we don't know the 'Ultimate', TOE equations. Yes, this is true. But we hope we'll learn them soon.

And precise and deterministic laws of physics can lead to the appearence of randomness (MWI, BM)
Dmitry67
#95
Nov26-09, 10:34 AM
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Quote Quote by DevilsAvocado View Post
Okay, thanks for info.

And how do we relate Qunatum Decoherence to Tegmark's:
"a superposition of observers obtaining all outcomes"

To me it sounds like every observer is gonna have their own bit...??
It depends on how you define the "observer"
After the schoedinger cat experiment:

You + closed box with 1/2 dead cat + 1/2 alive cat

So you can never see the superposition of cats
you get decoherenced with the box literally after you exchange few photons, and the system evolves into

1/2 Happy you observing alive cat + 1/2 Sad you observing dead cat
DevilsAvocado
#96
Nov26-09, 02:52 PM
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Quote Quote by Dmitry67 View Post
DevilsAdvocado, regarding your objections, how do you know if you are living in the virtual reality or real reality? "complete technical drawing of a house" is not a good example for "virtual reality". So you cant live there.

The second part of your objections are rather constatation of fact that we don't know the 'Ultimate', TOE equations. Yes, this is true. But we hope we'll learn them soon.

And precise and deterministic laws of physics can lead to the appearence of randomness (MWI, BM)

Thanks. Virtual reality is cool, and could be one explanation for the "turtle problem". Can we be absolutely sure about the vastness of our universe in that case? I mean, is there any way to tell for sure (CMB, etc)?

TOE is very thrilling. I can't wait.

A deterministic law of physics sounds a little 'disturbing'. I like my free will...
DevilsAvocado
#97
Nov26-09, 02:55 PM
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Quote Quote by Dmitry67 View Post
It depends on how you define the "observer"
After the schoedinger cat experiment:

You + closed box with 1/2 dead cat + 1/2 alive cat

So you can never see the superposition of cats
you get decoherenced with the box literally after you exchange few photons, and the system evolves into

1/2 Happy you observing alive cat + 1/2 Sad you observing dead cat

Yes, but then again Tegmark's MUH has a problem to banish the randomness in the Geiger counter?
Or, Curiosity Killed The Cat??

Dmitry67
#98
Nov26-09, 03:14 PM
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In MWI free will is compatible with determinism.

Virtual reality is cool, but this is not what Max meant. The idea of Matrix is too popular, but what he is saying is much deeper.

Let me ask you - how you can tell the mathematical system from a physical one?
Dmitry67
#99
Nov26-09, 03:16 PM
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Quote Quote by DevilsAvocado View Post
Yes, but then again Tegmark's MUH has a problem to banish the randomness in the Geiger counter?
MUH is unrelated to Schroedinger cat problem
MWI is.
Randomness is an illusion.
Both branches (deterministically) exist
Observer is each branch thinks that the outcome was random.
DevilsAvocado
#100
Nov26-09, 05:56 PM
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Quote Quote by Dmitry67 View Post
In MWI free will is compatible with determinism.

Virtual reality is cool, but this is not what Max meant. The idea of Matrix is too popular, but what he is saying is much deeper.

Let me ask you - how you can tell the mathematical system from a physical one?

Well, I guess if we accept the possibility that we and the universe are a running simulation, then the mathematical system setting the rules, must be more real than the actual simulation!?

And I guess there is NO way to find out if we are real real, or simulated real, i.e. if the 'programmer' did his job.

If this is true; how can we ever find TOE?? The 'programmer' must be an idiot if he programmed his own 'weakness'?

If we are not simulated, then I say my Technical Drawing is a pretty good indicator.

Another (old) question that pops up in my head; Nick Bostrom is almost sure we are in a simulated reality, and that it's impossible to tell the difference between real reality and simulated reality.

Hence the (mathematical) simulation system/rules/programming must be 'govern' from outside the simulation, right? How can the 'simulation governors' (and here goes my turtles again! ) be absolutely sure they are not simulated as well?? And so on, and so forth, in all eternity... (And, does this make any 'real' difference...??)


Finally a new nut for you to crack:
If we are in a simulated reality - how you can tell a 'real' mathematical system that works, from a simulated mathematical system that is simulated to work?
DevilsAvocado
#101
Nov26-09, 05:59 PM
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Quote Quote by Dmitry67 View Post
MUH is unrelated to Schroedinger cat problem
Both branches (deterministically) exist
Observer is each branch thinks that the outcome was random.
So "observer in each branch" is not the same as splitting observer worlds?

(I must be stupid )
Dmitry67
#102
Nov27-09, 01:17 AM
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You're right, there is NO way to find out if we are PEFFECTLY simpulated. Then it is IRRELEVANT if we are simulated or not.And MAx suggests not to talk about the simulation.

For the same reason there is no difference between physical and mathematical - beings in the mathematical structure feel it perfectly physical and real.
Dmitry67
#103
Nov27-09, 01:20 AM
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Quote Quote by DevilsAvocado View Post
So "observer in each branch" is not the same as splitting observer worlds?

(I must be stupid )
You are split.
In order to split an observer in Andromeda Galaxy, that observer must look in the telesope and receive enough photons so there will be difference (even if he is not aware of it) for him between 2 outcomes - dead can and alive. So it is a physical process which requires information transfer

I am just busting the popular myth that 'any event splits the whole Universe'
DevilsAvocado
#104
Nov27-09, 06:40 AM
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Okay I buy that, if we are PEFFECTLY simulated.

Though it could involve a risk for Max, since he base his argument on something that maybe looks a little like Catch-22:

1) There is NO way to find out if we are PEFFECTLY simulated.
2) Then it is IRRELEVANT if we are simulated or not.
3) For the same reason there is NO difference between physical and mathematical systems.
4) Hence there is NO way to prove physically if statement 3 is true or false.

This could be one level above my understanding. But I always thought that science required; first a theory, and then a physical experiment, approving or disapproving the theory? This seems impossible with MUH/CUH...?
DevilsAvocado
#105
Nov27-09, 06:46 AM
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Quote Quote by Dmitry67 View Post
You are split.
In order to split an observer in Andromeda Galaxy, that observer must look in the telesope and receive enough photons so there will be difference (even if he is not aware of it) for him between 2 outcomes - dead can and alive. So it is a physical process which requires information transfer

I am just busting the popular myth that 'any event splits the whole Universe'
This must be true, because I feel split.
Dmitry67
#106
Nov27-09, 06:55 AM
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Quote Quote by DevilsAvocado View Post
This could be one level above my understanding. But I always thought that science required; first a theory, and then a physical experiment, approving or disapproving the theory? This seems impossible with MUH/CUH...?
Then, as you can not tell the difference between REAL or BEING EMULATED, or PHYSICAL and MATHEMATICAL there is no use to say that 'we are emulated'

The Ocamms razor is used then: if we can't prove that we are emulated, then we are NOT emulated. If we can prove that some magical substance makes mathematical formulas 'real', then there is no difference between physical and mathematical.
DevilsAvocado
#107
Nov27-09, 07:01 AM
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Dmitry67, doesn't a PEFFECTLY simulated physical world looks disturbingly like God...?

(I no like, I no 'believer'...)

Edit: Forget this. Since we cannot prove we are simulated, we cannot prove God = same as 'yesterday'.
DevilsAvocado
#108
Nov27-09, 07:51 AM
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Quote Quote by Dmitry67 View Post
Then, as you can not tell the difference between REAL or BEING EMULATED, or PHYSICAL and MATHEMATICAL there is no use to say that 'we are emulated'

The Ocamms razor is used then: if we can't prove that we are emulated, then we are NOT emulated. If we can prove that some magical substance makes mathematical formulas 'real', then there is no difference between physical and mathematical.

AHA! SOME MAGICAL SUBSTANCE MAKES MATHEMATICAL FORMULAS 'REAL'!!

This is what I have been waiting for! Now it's even more interesting! This substance must be THE REALITY COMPUTER!! Wow!! This is even hotter than TOE! You could, with the help of mathematics and programming, build NEW WORLD'S!!!!!

Weird, spacey and (today) unscientific, but EXTREMELY COOL!


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