A scientific multiverse theory

In summary: This is testable.Maybe there is one of our standard model parameters which is not adjusted to promote holes. OK find it.The conclusion is that what we've got is apt to be very common.
  • #1
marcus
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A theory is scientific if it bets its life on at least one prediction that it makes about the outcome of a doable experiment

If a theory is part of science then there's a possibility it'll get shot down by an empirical observation---by some measurement----the theory makes predictions of so far unknown results that are that clear and unequivocal.

Smolin has come out with a Multiverse theory which can be shot down if anyone finds a neutron star of 1.6 solar mass or heavier.

Smolin Multiverse is not really part of LQG it just uses LQG-brand plumbing.
It happens to use LQG-brand fittings to connect the end of a black hole to the beginning of a universe.

But quantum gravity in general or LQG in particular does not need Smolin Multi to resolve some crisis. As far as QG goes it is fine if Smolin Multi gets shot down! We still have the good plumbing. And probably some other reason will turn up telling why 1/137 is 1/137 (which is for particle physicists to worry about anyway)

Smolin Multi is a falsifiable theory that offers a way to explain parameters in the standard model (particles) and the standard model(cosmology).
It should explain why 1/137 and why
planck/proton mass is 13E18
and why cosmo.constant is E-123
(Smolin says "the dimensionless parameters of the standard models of physics and cosmology", these are examples). And if Multi fails and dies on the launchpad, well there will be other explanations of those parameters.

Smolin Multi says that sets of basic constants become very common if they promote the formation of black holes. this is testable.
Maybe there is one of our standard model parameters which is not adjusted to promote holes. OK find it.

So according to Multi if there actually is an ensemble of universes then those with hole-promoting ("holific"?) parameters are very common---the overwhelmingly most common are universes presumably like ours, in that they promote holes. The inference is that our parameters are not especially rare!

Conscious life is accidental to the theory. I suppose it could play a role in some variant theory but it doesnt----Multi is simple and doesn't need to consider that angle. In Multi what drives evolution is holes and only holes.
The conclusion is that what we've got is apt to be very common.

there are other Multiverse stories floating around in which our type of universe is very rare. there is an ensemble of a huge number of universes which are unfriendly to life or otherwise inconvenient. these are not predictive AFAIK because the premise cannot be shot down by some future empirical observation. those stories do not predict anything (we live in a rare exceptional case and are excused from explaining why it is like this) so they are cop-outs.

At least one such non-scientific Multiverse story seems to have been invented in response to the string theory Kachru crisis of too many vacuums.
But this doesn't matter. the main thing is we now have a Multiverse theory which (whether its wrong or right) predicts something definite for checking where we don't yet know the outcome.

http://arxiv.org/hep-th/0407213 [Broken]
Smolin
Scientific alternatives to the anthropic principle
 
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  • #2
So, what Smolin is saying is that at a black holes singularity, it will tear the facric in spacetime? Then a flop transition or something occurs and a new universe is born, or what?

Paden Roder
 
  • #3
PRodQuanta said:
So, what Smolin is saying is that at a black holes singularity, it will tear the facric in spacetime? Then a flop transition or something occurs and a new universe is born, or what?

Paden Roder

about the plumbing that connects what used to be a singularity in BH to what used to be a singularity in BB there are some papers by other people.
it is essentially off the shelf connectors

getting rid of the BH singularity:
Leonardo Modesto
http://arxiv.org/gr-qc/0407097 [Broken]

getting rid of the BB singularity:
Martin Bojowald
http://arxiv.org/gr-qc/0102069 [Broken]

Bojo result has been extended and confirmed many times by many people in the years since 2001 and a recent paper is
Date and Hossain
http://arxiv.org/gr-qc/0407074 [Broken]

Bojo is the king of removing singularities
and the recent surprise is that although he was working
on eliminating the BH singularity and had not yet
posted, yet suddenly a new-comer Modesto (apparently a postdoc working
for Rovelli in Marseille) posted.

I think it is a safe bet Bojowald will present his removal of the BH
singularity and then (for me) that will be somewhat more trustworthy
than the work of Modesto, whom I never heard of till now.
----------------------------

Smolin's paper is more than just connecting the pit of a hole to the beginning of a universe.
(that part is the plumbing connectors bit)

what Smolin presents is a theory of how fundamental physical constants evolve
A. if every black hole terminates in a bounce from which buds a new universe
B. and if the constants of the laws of physics only change slightly as they go thru the hole

then it will lead to an overwhelming predominance of sets of constants which are good for making holes---a typical U will be one that makes a lot of holes.

so first of all it has to have enough gravity to pull stars together, and enough chemistry to radiate heat of condensation away, and enough lifetime to let stars and galaxies form, before the universe itself collapses, and when neutron stars form (as in a supernova) there has to be some limit to how big they can be before they too collapse and make a BH, and so on-----physical constants that influence these things (like a stable carbon atom is a Good Thing for radiating away heat when stars condense) will be affected by evolution and move towards high-fitness configurations.

So you can see ProdQ that Smolin is talking more about what makes the fundamental physical constants what they are. It is not just the LQG joint between a hole and a universe. he is making a theory with explanatory power which he neither believes nor disbelieves but challenges us to test.
Can you prove this wrong? Can you show the constants do not evolve so as to favor black hole formation?

the aim, I think, is to exhibit a testable Multiverse theory. One that predicts something instead of just being a nice daydream
 
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  • #4
(edit: never mind, I've already said all this in the other thread)
 
  • #5
Interesting. Since the electron degeneracy limit is thought to be ~1.44 solar masses and the neutron degeneracy limit is thought to be ~ 3 solar masses. So the obvious question is what happens between 1.6 and 3 solar masses? [Maybe I just need to read Smolin's paper :)].
 
  • #6
marcus said:
A theory is scientific if it bets its life on at least one prediction that it makes about the outcome of a doable experiment

And scientific research programs have the goal of producing scientific theories.
 
  • #7
jeff said:
And scientific research programs have the goal of producing scientific theories.

I agree with jeff about this.
I imagine that what those who fund and direct research programs would
like to see, in some instances, is steady progress towards the goal of
a testable predictive theory----it wouldn't be reasonable to demand of a young theory still under construction that it be already at that point. (But I mustn't pretend to guess how NAS committee-wizards think, there could be a lot of politics to it.)
 
  • #8
Chronos said:
Interesting. Since the electron degeneracy limit is thought to be ~1.44 solar masses and the neutron degeneracy limit is thought to be ~ 3 solar masses. So the obvious question is what happens between 1.6 and 3 solar masses? [Maybe I just need to read Smolin's paper :)].

chronos, I expect you have looked at pages 33-34 of smolin's paper
section 6.3 "why a single heavy pulsar would refute [the theory]"

It is a short passage (much of which i can't follow) that relies on work by Hans Bethe and George Brown. Bethe and Brown calculated a dependency between the strange quark mass mu and the upper limit on neutron star mass. If the real mu is below a critical value which they called mu-crit then there is a low upper bound on neutron star mass----Bethe and Brown estimated it to be 1.5 solar.

there is nothing special about the number 1.6, it is just something clearly bigger than the bethe and brown 1.5. Instead of 1.6 let us be generous and say 2.

If one would find a neutron star of 2 solar mass, then one would reason that the strange quark mass mu is greater than the mu-crit that Bethe-Brown calculated.

then one would say "if nature had made mu smaller then some of these more massive neutron stars would have collapsed to form holes! So nature is a slacker! She is not making as many black holes as she could be!"
And this would shoot down Smolin's conjecture that we live in a Multiverse which has evolved to produce lots of holes. It would make it very improbable that this is the case.

Now so far my grasp of this is only partial and I have to look at the Bethe Brown papers---since Smolin is building on their work---and make sure I have it right.

these papers are:
"Kaon condensation in dense matter"
"Observational constraints on the maximum neutron star mass"

plus 2 papers from 1994 in Astro. J.
and 1 paper from 1994 in Nucl. Phys. series A.

I will try to post a link to the "Observational Constraints" paper since that will have references to the others.
 
  • #9
marcus said:
I imagine that what those who fund and direct research programs would
like to see, in some instances, is steady progress towards the goal of
a testable predictive theory----it wouldn't be reasonable to demand of a young theory still under construction that it be already at that point.

Precisely my friend.
 
  • #10
Thanks marcus.

Paden Roder
 
  • #11
Bad news for Smolin?

Apparently, that neutron star mass limit thing has been stuck in the back of my mind ever since you pointed it out in this thread. This jolted it loose and it floated back to the surface.
http://www.edpsciences.org/articles/aa/abs/2003/13/aah4013/aah4013.html [Broken]
 
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  • #12
bad news for Smolin's CNS (cosmic natural selection) theory

maybe not conclusive yet, their lower limit 1.88 solar might not shoot it down but their upper limit 2.27 +/- 0.17 solar masses looks like it would refute the theory if it were confirmed that the neutron star was in fact that massive.

thanks for finding this! Now I must re-read Smolin's artilce to make sure that I have not made an error.

here is the online preprint of that article
http://arxiv.org/abs/astro-ph/0301243
 
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  • #13
marcus said:
bad news for Smolin's CNS (cosmic natural selection) theory

maybe not conclusive yet, their lower limit 1.88 solar might not shoot it down but their upper limit 2.27 +/- 0.17 solar masses looks like it would refute the theory if it were confirmed that the neutron star was in fact that massive.

thanks for finding this! Now I must re-read Smolin's artilce to make sure that I have not made an error.

here is the online preprint of that article
http://arxiv.org/abs/astro-ph/0301243
My bad, I am such a maverick. That prediction really bothered me and I could not help commenting about it. I admit to being a die hard skeptic. I wasn't even looking for that information, just stumbled upon it.
 
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  • #14
I looked at the paper and saw it was dated back to January 2003 but in the Edge discussion (posted after Jan. 2003) Smolin still defends his CNS scenario, so I don't believe it has been falsified.
 
  • #15
Chronos said:
My bad,...

On the contrary, your good

scientific theories are meant to be shot down.

Maybe this observation does not absolutely conclusively shoot down CNS.
But it seriously crowds it IMHO.

My guess is that Smolin did not know about this observation, or he would have mentioned it (challenged it, or pointed out that it was not conclusive because 1.88 solar masses is still a possible interpretation.)

It is interesting to notice what Smolin gives as his reason for presenting CNS theory in this paper. He uses it to show that one can have a multiverse theory which makes testable predictions and does not appeal to the Anthropic Principle.

Smolin's quantum gravity ideas do not depend on CNS. It is an intriguing idea but disproving CNS does not disprove LQG.

Maybe one of us should write Smolin email about this 2003 observation.
 
  • #16
Curious6 said:
I looked at the paper and saw it was dated back to January 2003 but in the Edge discussion (posted after Jan. 2003) Smolin still defends his CNS scenario, so I don't believe it has been falsified.

I can only assume no one told him about this observation of a rather massive neutron star. Or does he require TWO observations of a neutron star that is too massive for his theory before he cries "uncle"?
I don't know what we should do about it, if anything. Write Smolin? He should at least insert a footnote in his essay to be published ("this theory has subsequently been shot down, see, I told you it was falsifiable!")

I look on this with some degree of equanimity. CNS is a nifty theory but there will be other explanations offered for why the constants have the values we see and at least some of the theories will be testable, like CNS,
by making predictions.

maybe Smolin himself will come up with another candidate.

I suspect the values of some of the basic physical constants really are explainable by a predictive theory---and applaud the ambition of anyone audacious enough to propose one.
 
  • #17
I have always suspected that Smolin WANTS to have the CNS through BH theory shot down- just to proove his point that falsifiable multiverse theories are possible and that it isn't necessary to rest on the Anthropic principle-
 
  • #18
setAI said:
I have always suspected that Smolin WANTS to have the CNS through BH theory shot down- just to proove his point that falsifiable multiverse theories are possible and that it isn't necessary to rest on the Anthropic principle-

:smile:
that thought has crossed my mind too
(maybe in 1995 he proposed it seriously and hopefully but
now in 2004 is using it in just the way you indicate)
 
  • #19
Well... so who's going to email him?! Let's get this goin! :smile:
 
  • #20
Tsunami said:
Well... so who's going to email him?! Let's get this goin! :smile:

commendable impatience Tsunami, he has been notified
(someone I know just emailed him)

If there is any credit for Chronos noticing this he should write Smolin
himself. my friend did not mention PF or the source of the information, just sent the link to the paper.
 
  • #21
Well, that is unfair. PF should get all the credit for bringing the skeptics and their microscopes to the table.
 
  • #22
Chronos said:
Well, that is unfair. PF should get all the credit for bringing the skeptics and their microscopes to the table.

then why don't you write smolin yourself
and refer to the board in what terms you think appropriate!
Please correct me if I am mistaken, I believe smolin's email is

lsmolin@perimeterinstitute.ca

Bravo chronos, by the way. You are the only skeptic who
showed up with a microscope, so if I knew your name i would
be glad to credit you in my private narrative of the
Cosmic natural selection saga.

but I don't know whether, at this point, the information is
new to Smolin or not. we may not even get a reply.
 
  • #23
Flattery will get you everywhere. I suspect Dr. Smolin has better things to do than flush my naive observations down the email toilet. I am fairly certain his collegues have already told him about the overweight neutron star by now... in fact, I wouldn't be surprised if the authors of that paper gave him the news before they went to print. Scientiscts tend to be pretty well read and understand the implications of their discoveries.
 
  • #24
Chronos, the omission has been rectified.
Smolin has been informed that the information came to light at PF
where it was posted by one Chronos.

sorry about the earlier omission
 
  • #25
Chronos said:
Flattery will get you everywhere. I suspect Dr. Smolin has better things to do...

Focus on the main thing. Nothing is a fools errand if Tsunami asks you to do it. Tsunami said "write Smolin about the star" and it was promptly done.
Now we can get back to thinking about guy stuff.

have you ever seen Tsunami use smilies?

no, that isn't guy stuff.
you think of something
 
  • #26
No omission, I just made an off-hand observation. I doubt Smolin was not already aware of that paper. He is a bright guy. Perhaps the observation and interpretation is wrong. It would not be the first time. I am somewhat comfortable talking to people about this stuff on PF. I am very uncomfortable about making a fool of myself in front of Dr. Smolin.
 
  • #27
marcus said:
Focus on the main thing. Nothing is a fools errand if Tsunami asks you to do it. Tsunami said "write Smolin about the star" and it was promptly done.
Now we can get back to thinking about guy stuff.

have you ever seen Tsunami use smilies?

no, that isn't guy stuff.
you think of something
:rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:
Marcus, you are cracking me UP, here! :biggrin: :rofl: :biggrin:

Yes, Gentlemen. I rarely post in this forum - mostly I just read and try to absorb what little I can, but I think this is important! So many of you are so AWESOME and I'm so proud to 'know' you! You need to be getting into the 'big game', too! :approve: You have MUCH to contribute! (Actually, I often wonder who of you are already in the 'big game' and we just don't know it! :wink: :biggrin:)
 
  • #28
Tsunami used 16 smilies in her last post. I theorize she is of summarian descent.
 
  • #29
Chronos said:
Tsunami used 16 smilies in her last post. I theorize she is of summarian descent.

Yes it does seem as if Tsunami comes from the ancient city of Ur, in Sumeria, where everybody did hexadecimal arithmetic (or else counted by Sixties, i forget)

(actually I am a bit confused about the reference to Sumerian ancestry)

In any case she brought us luck! The person who wrote to Smolin about the overweight neutron star reports that Smolin replied, as follows:

---quote---
Thanks, a quick read of this paper leads to the conclusion that a mass
of less than 1.6 solar masses is within one sigma of the central value,
assuming that the measurement is reliable. So this is not very worrying,
so far as CNS is concerned, but thanks, and I will keep it in mind.

If heavy neutron stars do exist sooner or later one will be observed in a
binary pulsar, which affords a much more precise measurement of its mass.
There are many caveats and uncertainties in this kind of indirect
measurement that these results are not definitive, whereas a measurement
of a 2 solar mass neutron star in a binary pulsar would be compelling.

Thanks,

Lee
---end quote---
 
  • #30
marcus said:
Yes it does seem as if Tsunami comes from the ancient city of Ur, in Sumeria, where everybody did hexadecimal arithmetic (or else counted by Sixties, i forget)
I've counted my AGE in hex for quite a few years now! :biggrin:

(actually I am a bit confused about the reference to Sumerian ancestry)
(me, too.)

In any case she brought us luck! The person who wrote to Smolin about the overweight neutron star reports that Smolin replied, as follows:

---quote---
Thanks, a quick read of this paper leads to the conclusion that a mass
of less than 1.6 solar masses is within one sigma of the central value,
assuming that the measurement is reliable. So this is not very worrying,
so far as CNS is concerned, but thanks, and I will keep it in mind.

If heavy neutron stars do exist sooner or later one will be observed in a
binary pulsar, which affords a much more precise measurement of its mass.
There are many caveats and uncertainties in this kind of indirect
measurement that these results are not definitive, whereas a measurement
of a 2 solar mass neutron star in a binary pulsar would be compelling.

Thanks,

Lee
---end quote---
WOOHOO! COOL! :biggrin: :cool: :biggrin: :cool:
I'm very happy to have helped! :biggrin: Almost makes me feel like I'M playing with the BIG DOGS, too! :rofl: :rofl: (Mom keeps telling me I'll be a big dog when I grow up, but I don't know... I've been this size for an awfully long time now... :wink: )
 
  • #31
hello Tsu not-caring-which-big-or-small dog,
I am thinking of possibly making a thread about
Smolin's Six-ring circus because it seems to me that
he has a halfdozen things in progress right now---
the complexity is getting to be both exciting and
hard to follow.

1. Race to testability
2. DSR Soccerball
3. Dynamical triangulations
4. Immirzi parameter
5. Kodama state
6. Extended diffeo(chunky)morphisms

so much is happening that one must list what is playing in each theater
or one quickly forgets parts of the action. I will try to give a recent paper in each of the six
 
  • #32
Sounds fun, marcus! I'm always up for a circus! :wink:
 
  • #33
It seems simpler to connect the black hole by a "dark string" to the continuing creation of OUR universe at a leading edge of an expanding bubble...

...rather than BH's leading to creation of new universes

I wonder if occam would agree ?
 
  • #34
RingoKid said:
It seems simpler to connect the black hole by a "dark string" to the continuing creation of OUR universe at a leading edge of an expanding bubble...

...rather than BH's leading to creation of new universes

I wonder if occam would agree ?

RingoKid it looks to me as if you have made up an original theory. I don't see right away what it is about, or what the aim is, but if it is a theory you invented then some usual questions to ask about a new theory are
what does it assume?
what does it predict (that could make it testable)?
what does it explain?

Just to illustrate what I mean: Smolin Multiverse (which he calles CNS) is a testable theory that offers a way to explain parameters in the standard models of particle physics and cosmology.
It offers an explanation (which may be useful or not depending on whether the theory survives testing) why alpha is right around 1/137.036... instead of some other number and why
proton wavelength is 13E18 Planck lengths instead of some other number
and why the cosmological constant is E-123 instead of something different.

Smolin's CNS offers an explanation of "the dimensionless parameters of the standard models of physics and cosmology", these numbers are just a few examples chosen to illustrate the kind of thing it explains.

CNS theory also can be checked and proven wrong (assuming it is wrong) because it makes some definite predictions like about the masses of certain type stars.

In line with your mention of Occam, the CNS picture does not assume much new---black hole and bigbang are not new ideas: They have been studied using Loop Gravity methods and found to be (as far as anyone can tell by the mathematics) the same thing---a quantum bounce that can be modeled and calculated with reasonable detail, though as yet without certainty. The bounce, an instantaneous fuzzy blur when contraction reverts to expansion, although calculable by LQG rules, is admittedly difficult to imagine.

Since these two former singularities are impossible to tell apart, it is not a great leap for Smolin to connect them, and assume that BH leads into BB. The major new thing Smolin assumes is (simply, I would say) that the parameters of physics change only very slightly in going thru a quantum bounce.

What you might think about, as regards your theory, is do the things it talks about really exist (black string, expanding bubble, leading edge)? Has anyone detected signals from them like they have from bigbang and black holes? More seriously, does your theory (or any other known multiverse theory besides CNS) predict numbers that would allow it to be tested? Does it predict the mass of some type of star that could be observed---so we could throw the theory out if it was wrong.

And finally, does it explain any of the parameters of the real world
like the number 1/137 which is basic to the periodic table of elements and to chemistry etc.? For me that is crucial---there are phyics constants basic to how and why things work (gravity, chemistry, fusion in stars, etc) and a multiverse theory should explain why those numbers are the sizes they are.

It could be that your theory is testable, predictive, explains something about how the world works---it is up to you to elaborate. I can't say whether it is or isnt, does or doesnt
 
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  • #35
Thanx Marcus

Can you think about this ?

If everything in a black hole gets deconstructed and reduced to Planck unit sized strings that could join end on end to become infinitely long but still have large mass yet not be visible...

...then I reckon it's simpler to have that dark string which could also account for dark matter to then stay within our universe but gets drawn to the leading edge/frontier of our big bang bubble that is still bangin away ?

it eliminates the need for multiverse scenarios in regards to black holes.

Just curious as well but...

Does his theory suggest why black holes form in exactly the place that they do or why there are big ones in the middle of most galaxies and what purpose they serve ?

Believe me, if i could afford the time and the cost to study astrophysics i would but to prove what and gain what ?... a research grant and a footnote in history, sorry I got more pressing concerns

I don't feel i need to justify my speculations just put em out there and hope it leads to questions or even better answers that others can verify. As far as predictions for my speculations, how about a bubble braned universe fixed around a central expansion point.

I'd appreciate it if you would check out my "dark strings", "wave of thought" and "string and brane shapes" threads and see if you can get what I'm on about if not then just ignore me but i probably won't go away.

peace and cheers
 

1. What is a scientific multiverse theory?

A scientific multiverse theory is a theory that proposes the existence of multiple universes beyond our own observable universe. It suggests that there could be an infinite number of universes with different physical laws, constants, and even different versions of ourselves.

2. What evidence supports the idea of a multiverse?

There is currently no direct evidence for a multiverse, but there are several theories and observations in physics that suggest its possibility. For example, the inflationary theory of the universe and the concept of quantum mechanics both suggest the existence of multiple universes.

3. How does a multiverse theory impact our understanding of the universe?

A multiverse theory challenges our traditional understanding of the universe and raises questions about the nature of reality. It also has implications for the concept of the anthropic principle, which suggests that the universe is uniquely suited for life. A multiverse would suggest that our universe is just one of many possible universes, making the anthropic principle less significant.

4. Can a multiverse theory be tested or proven?

Currently, there is no way to directly test or prove the existence of a multiverse. However, scientists are working on developing new theories and experiments that could potentially provide evidence for its existence. It is also possible that advancements in technology and physics could one day allow us to observe or interact with other universes.

5. Are there different types of multiverse theories?

Yes, there are several different types of multiverse theories, including the bubble universe theory, the parallel universe theory, and the many-worlds interpretation of quantum mechanics. Each of these theories proposes a different way in which multiple universes could exist and interact with each other.

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