Smolin's 1995 Landscape of Physical Law idea

In summary: Susskind was one of the first people to speculate about the vast array of potential universes that could exist based on the constants of string theory. He suggests that the landscape is so diverse that it gives credence to the anthropic principle, the idea that the universe is fine-tuned for the existence of humans. He goes on to discuss some theoretical and conceptual issues that arise in developing a cosmology based on the diversity of environments implicit in string theory.
  • #36
Woit has a dismissive post about Susskind's paper on his blog. He and his commenters see it as more a symptom of intellectual bankruptcy than as real physics.
 
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  • #37
selfAdjoint said:
Woit has a dismissive post about Susskind's paper on his blog. He and his commenters see it as more a symptom of intellectual bankruptcy than as real physics.

somehow I expect Smolin to reply, maybe not to Susskind solely.
I suppose he might wait untll several of his points have been challenged by several people and then reply to several challenges. But I expect something more.
I haven't read the comments at Not Even Wrong yet, only the brief
mention by Woit of Susskind's posting.

hey selfAdjoint, as a man of general culture you are supposed to know that the doxology or "Gloria" of the standard latin mass is not the same as the "Sanctus"------it goes Kyrie, Gloria, Credo, Sanctus, Benedictus, Agnus.
I had to find this all out in middle age and you got some instruction as a child so you should be up on it :smile:
 
  • #38
Must be a "latin" religious thing :smile:

All I heard is reverberating echos, of yesteryears. A language taught, long since forgotten.

From a science point of view, was this how a lot of it was taught? :confused:

If this is the case then, the alchemists must have been a roque branch of a logical world in those mddle ages? :smile:
 
  • #39
sol2 said:
Thanks...lots to learn :smile:

But if eden is atop the mountain of purgatory(hell?)

no dammit sol, purgatory does not equal hell
Dante wrote a trilogy: hell,purgatory,heaven
they are all quite different

personally, you know, I am an atheist with no childhood intro to religion
(my parents were considerate and left me alone)

but humans, and particularly Westerners, have a thing about cosmology
---we get it from our best ancestors, the Jews and Greeks. And Dante is an example of a cosmology poem----it visualizes intensely and vividly the whole Shebang, the whole Cosmos.

this intense interest in the System of the world is bred into us and it is worth understanding it. It is not just in our Science it was there before.

In our blood almost, in greek thought, in the Latin Mass, in Dante, in the Ptolemaic minds of those who set fire to Giordano Bruno, in the passionate and obsessed Kepler who dreamed of the Platonic solids and the musical scale embodied in the planets, and a lot of these people calculated. Even Dante has very meticulous calculations---and describes a physics experiment with a candle and 3 mirrors in the paradiso, he is empirical in 1305.
Anyway these are our people and they didnt just fantasize, they ocassionally got out the old abacus or the pencil and paper.

so when I notice that some contemporary, Smolin, has envisioned a way to explain why 1/137 is what it is, and not 1/136, and he has envisioned this happening because of a budding multiverse and made empirical predictions he wants us to check----then I have to laugh because this is so traditionally Western. It is the old obsession with the cosmos, with the old Keplerian stubbornness that insists on calculating and insists that the numbers work out and match the observations. Oi veh Mama, they are at it again!

Sol, do you know how important 1/137 is? Do you realize what it means to have a credible explanation for why it is what it is? One says immediately, no this is crazy, Smolin must be wrong. he has some nerve! there must be some mistake. And the cosmological constant too----the 1.3E-123 number.
can he have an explantion of that too? And the ratio of Planck and proton mass 13E18? This is very Kepler. It is what we have civilizations for, that and for colonizing the galaxy too of course. hee hee
 
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  • #40
Marcus said:
Sol, do you know how important 1/137 is? Do you realize what it means to have a credible explanation for why it is what it is? One says immediately, no this is crazy, Smolin must be wrong. he has some nerve! there must be some mistake. And the cosmological constant too----the 1.3E-123 number.
can he have an explantion of that too? And the ratio of Planck and proton mass 13E18? This is very Kepler. This is what we have civilizations for, and for colonizing the galaxy too of course. hee hee

Jeff spoke to this point, and so did Susskind.

Marcus I did read one of Dante's book and it was about a thousand pages(after thinking about it today the book was called Urantia and had nothing to do with Dante), but its obvious I didn't retain anything, but the ideas of dimensional significance. I am having trouble even remembering which book. Will have to take a trip back to the library and look.

More so than for Hell and Heaven, Dante has significant leeway in imagining and representing this realm of the Christian afterlife. While there is no specific reference to a place called "Purgatory" in the Bible, the concept took shape over the course of early Christianity and the Middle Ages on the basis of biblical support for what would later become Purgatory. (This concept has been a major point of doctrinal disagreement since the Protestant Reformation and Catholic Counter-Reformation.) Thus Judas Machabeus, honoring the custom of offering prayers for those who died in God's grace, proclaims that it is "a holy and wholesome thought to pray for the dead, that they may be loosed from sins" (2 Mach. 12:46). The idea of trial by fire, another important conceptual component of Purgatory, figures prominently in the Bible: "Thou hast proved my heart," sings the psalmist, "and visited it by night, thou hast tried me by fire: and iniquity had not been found in me" (Psalm 16:3). John the Baptist, who baptizes in water, prophesies the greater power of Jesus, saying "[h]e shall baptize you in the Holy Ghost and fire" (Matt. 3:11). Based on these and other passages, medieval theologians introduced the idea of 'purging fires' as a way to imagine the purification of souls who died in God's grace but bore the stains and habits of sin. From the adjective purgatorius arose the noun Purgatorium as the concept of Purgatory received full theological legitimation in the mid- to late twelfth century (e.g., at the Second Council of Lyons in 1274).

http://danteworlds.laits.utexas.edu/purgatory/01antepurgatory.html

Marcus indeed I do realize how important it is. Let me give you a example.

The acceptance of Gr and moving it beyond the current dimensions is a case in point. A lot of people do not like this, so we see some similarities of being burned at the state, for radicalism :smile:

Smolin's support of http://superstringtheory.com/forum/relboard/messages20/50.html and VSL, and you spoke to that already.

Selfadjoint said:
His patron is/was Lee Smolin, which is why anyone took him seriously in the first place. Advice to folks with crank theories: don't waste your time posting here, go suck up to Witten or somebody. For additional evidence look at Lynds. His theory is one of those screwy philosophical redefine spacetime ones that would just be an average days catch on M-theory/Duality. But he got endorsements from John Wheeler, so he's famous.
http://superstringtheory.com/forum/relboard/messages20/54.html

Lubos talked about Granfathers in regards to Penrose, but here is another Grandfather, John Wheeler. Kip Thorne is very proud I am sure, to have such guidance.

LQG asks us to look at the interaction of photons from the early universe (Glast)while String asks us what interaction is possible through the field of gravitons?

This Marcus, goes to the heart of the logic. What existed in the beginning? Nothing?
 
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  • #41
marcus said:
somehow I expect Smolin to reply, maybe not to Susskind solely.
I suppose he might wait untll several of his points have been challenged by several people and then reply to several challenges. But I expect something more.
I haven't read the comments at Not Even Wrong yet, only the brief
mention by Woit of Susskind's posting.

hey selfAdjoint, as a man of general culture you are supposed to know that the doxology or "Gloria" of the standard latin mass is not the same as the "Sanctus"------it goes Kyrie, Gloria, Credo, Sanctus, Benedictus, Agnus.
I had to find this all out in middle age and you got some instruction as a child so you should be up on it :smile:

As a child I attended a Protestant church, and we sang what they called the Doxology. It was almost identical to the Sanctus of the Mass. "Holy, holy, holy, Lord God Almighty.."
 
  • #42
It's enough with the arts and humanities already. Checking out new posts which repeatedly turn out to have nothing to do with the topic of the thread - or with science even - is annoying and a waste of my time. Knock it off.
 
  • #43
well maybe we should indulge jeff's desire to get back on topic

what I've been meaning to discuss is at the bottom of page 31 of the
Smolin paper:

"Thus, the hypothesis of cosmological natural selection explains the values of all the parameters that determine low energy physics and chemistry: the masses of the proton, neutron, electron and neutrino and the strengths of the strong, weak, and electromagnetic interactions..."

I would propose that we NOT argue about whether this is correct but try to assemble among ourselves a list of the dimensionless numbers that he is talking about.

Because he says electromagnetic interaction I gather he means 1/137.

Since he says mass of the proton I gather he means 13E18 or rather the reciprocal.

And the famous number 1836.

there are a handful of numbers he is talking about, that determine all of low energy physics and chemistry---maybe we should try to make these numbers common knowledge. these numbers are what Smolin imagines to be the "genes" of a world----and think may have been optimized for black hole making.

What is your short list of numbers?

I'm interested in the actual numbers, but only with limited accuracy.
For example let's just say 137, and not 137.036...
Let's maybe merge lists and winnow it down to get a collective list
and actually see what the genes of a world look like.
 
  • #44
As for Jeff, we should not indulge him at all as it might feed his appetite :smile:

Okay Okay,

Back to work marcus and those numbers.

Smolin said:
The result is that the standard model of elementary particle physics has more than 20 adjustable parameters. These include the masses of all the basic stable elementary particles: proton, neutron, electron, muon, neutrinos etc, as well as the basic coupling constants and mixing angles of the various interactions. These are not determined by any principle or mechanism we know; they must be specified by hand to bring the theory into agreement with experiment. The standard model of cosmology has similarly about fifteen parameters.

Two of the biggest mysteries of modern science are then how these 35 or so parameters are determined.

There are two especially puzzling aspects to these problems.

The first is the naturality problem. Many of these parameters, when expressed in terms of dimensionless ratios, are extremely tiny or extremely large numbers. In Planck units, the proton and neutron masses are around 10−19, the cosmological constant is 10−120, 7 the coupling constant for self-interactions of the field responsible for inflation cannot be
larger than 10−11 and so on.

http://arxiv.org/PS_cache/hep-th/pdf/0407/0407213.pdf
 
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  • #45
the reason I'm specifically asking for numbers (not dimensioned physical quantities like masses and energies) is because of what Smolin says on page 29:

------quote page 29-----
The methodology of natural selection, applied to multiverse theories, is described by three hypotheses:

1. A physical process produces a multiverse with long chains of descendents.

2. Let P be the space of dimensionless parameters of the standard models of physics and cosmology, and let the parameters be denoted by p. There is a fitness function F(p) on P which is equal to the average number of descendents of a universe with parameters p.

3. The dimensionless parameters pnew of each new universe differ, on average by a small random change from those of its immediate ancestor. Small here means with small with respect to the change that would be required to significantly change F(p).

Their conjunction leads to a predictive theory, because, using standard arguments from population biology, after many iterations from a large set of random starts, the population of universes, given by a distribution RHO(p), is peaked around local extrema of F(p).
----------end quote-------

Now some people (selfAdjoint, jeff, ...) know very well already that
by "dimensionless parameters" Smolin means out and out numbers that are the same whatver system of conventional units

but other people at PF may not have had that sink in. the parameters that really matter in the standard models of cosmology and physics are the ratios and these do not change whether you think feet or meters or pounds or Newtons or farads or coulombs or parsecs or lightyears. they have nothing to do with conventional human units they are nature's pure numbers. they are built in proportions in nature that are sort of intrinsic.

Like 1836 is the ratio of proton to electron mass. someone in andromeda galaxy could find the same number hidden in nature---he might write it in a different number notation---like binary or hexadecimal or whatever----but he would see that number 1836 if he looked at atoms.

And 13E18 is the ratio of Planck mass to proton mass. Same thing.

And what is 1/137?

anyone want to say, or shall I do that one?

we could get into these numbers---why do they determine the energy levels of the hydrogenatom and why do they determine what are the stable elements of the periodic table and what chemical reactions go and don't go. these numbers really are the world genes. its good to get familiar
 
  • #46
sol2 said:
As for Jeff, we should not indulge him at all as it might feed his appetite :smile:
...

sol2 you are in a high good humor this evening, I have never
known you so jovial :smile:
 
  • #47
http://www.cerncourier.com/objects/2003/cerndesy1_4-03.jpg

The host of quarks, antiquarks and gluons inside a proton all have intrinsic spin, but their constant movement also creates orbital angular momentum. Understanding how these individual angular momenta together yield the total spin of the proton is still proving to be a challenge. (DESY Hamburg.)"

Marcus as I was reading something came to mind about the Mendeleev table of elements. What would seem amazing to me is that if any of these models, Smolin's or anyone elses for that matter, http://wc0.worldcrossing.com/WebX?14@59.WFutcbOosid.0@.1dde61c6/18 using these other means? This would be natural would it not?

I added to previous post

Stop me if I went off track here?
 
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  • #48
marcus said:
sol2 you are in a high good humor this evening, I have never
known you so jovial :smile:

Originally Posted by sol2
As for Jeff, we should not indulge him at all as it might feed his appetite

"+"

I do not want to contribute to the psychological corruption(my behavior) for such hunger(his grokking) is calling for :smile:
 
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  • #51
Arivero gave this link in another forum

I think I've made a rather interesting discovery here: It's well known that electron has two bigger brothers, the muon and the tau lepton. each of the three has its own anti particle. (The electron's anti-particle is the positron)



There are 3 generations of particles in nature. Three generations of leptons, three generations of neutrinos and three generations of quarks. The first generations form almost all of the matter in the universe. The 2nd and 3rd generation particles have limited lifetimes and seem to play a much less important role.

http://www.chip-architect.com/news/2004_07_27_The_Electron.html
 
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  • #52
There are 3 generations of particles in nature. Three generations of leptons, three generations of neutrinos and three generations of quarks. The first generations form almost all of the matter in the universe. The 2nd and 3rd generation particles have limited lifetimes and seem to play a much less important role.

Yes this is a known property of the standard model. There is also strong evidence that there are ONLY three generations, or flavors, as they are called.
 
  • #53
selfAdjoint said:
Yes this is a known property of the standard model. There is also strong evidence that there are ONLY three generations, or flavors, as they are called.
In fact De Vries' formula (that I quoted) can be see as an additional clue for having only 3 generations, because it gives a very strong relationship between second and third, namely
ln(mass of muon / mass of tau) = 2 sinh(ln(pi))

I can not see why this surfaces in this thread, but perhaps Sol2 aim was to point out the possibility of mathematical, not anthropic, constrainsts. In this sense, a more popular one is the sum of Cabbibo angle and solar neutrino mixing angle, which add to pi/4.

Yours,

Alejandro
 
  • #54
Hello Alejandro it's good to see you
I didnt see you around yesterday so I was afraid
I might have offended by my notice of your exchange with Lubos
the title was meant to be analogous to
Peter and the Wolf
Androcles and the Lion
also we have the story in English called
Goldilocks and the Three Bears and this
is perhaps even more germane to the generations of particles
than one might have expected
 
  • #55
Hi marcus. I was browsing very casually while I download some maps for my holidays (walking around spain, mostly).

Goldilocks could have offended me :-) Fortunately you choosed another title!
 
  • #56
Enjoy the Flower Children:)

arivero said:
In fact De Vries' formula (that I quoted) can be see as an additional clue for having only 3 generations, because it gives a very strong relationship between second and third, namely
ln(mass of muon / mass of tau) = 2 sinh(ln(pi))

I can not see why this surfaces in this thread, but perhaps Sol2 aim was to point out the possibility of mathematical, not anthropic, constrainsts. In this sense, a more popular one is the sum of Cabbibo angle and solar neutrino mixing angle, which add to pi/4.

Yours,

Alejandro

Yes thanks arivero. We were discussing natural numbers(marcus pointed these out in article by Smolin) and your link presented a interesting opportunity.

Why Baez quote is very important. Marcus might see this now.

G -> H -> ... -> SU(3) x SU(2) x U(1) -> SU(3) x U(1).
Here, each arrow represents a symmetry breaking phase transition where matter changes form and the groups - G, H, SU(3), etc. - represent the different types of matter, specifically the symmetries that the matter exhibits and they are associated with the different fundamental forces of nature

One has to follow the Model here?

Some might fail to realize that the continued geometrical effrts to describe this process, from then to now, has other psosibilties within the vast amount of "time" that such processes could have other things happening in the universe that live and die, and are reborn again? It is all very smooth transition from a "bubble perspective."

At the gravitataional collapse it can become very matter of fact? :smile:
 
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  • #57
sounds like a good way to spend the holiday
especially if in the mountains
I do not travel much for various reasons but if I were to
walk in Iberia I would first think of exploring the kingdom of
Alfonso the Wise
----added later----
By a strange coincidence a couple of hours after thinking of
Alfonso X, and posting this, I happened to visit Peter Woit's
blog Not Even Wrong and found a new blog which mentioned
Alfonso---the topic was the overcomplicated kludginess in
string theory's way of connecting to the Standard Model
and Zwiebach's comparing it to the Ptolemaic system with its
epicycles upon epicycles----intersecting branes in extra dimensions.

So commenting on the ugliness Zwiebach quoted Alfonso the Wise (1221-1284) who said, regarding the Ptolemaic system:

"If I had been present at the Creation I would have offered some helpful
advice as to the ordering of the universe."

a nice king with a quiet droll sense of humor.
strange he came up in two web-postings almost at once
 
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