Make out the position of Andromeda

[nightcleaner]

Very quiet around the board today. And yesterday. Where is everybody?

I spent a night in the deep woods, lying on my back on the ground, looking at the stars. There was very little silence in the woods. The peepers have been joined by chorus frogs and tree frogs, and they are raving in every direction. I suppose we are justified in thinking that our own rantings, here and elsewhere, are more important than that orgy down in the swamp.

There was a light haze in the sky, but I could still make out the position of Andromeda. The great bear was almost at zenith. I didn't see any meteorites, but there were curious little flashes of light, so swift that I doubt my sight. Maybe it was just too much coffee, or maybe sprites were leaping off the thunderstorms building to the west.

One of the troubles with being a theorist is that you have nothing to hold on to. I could wish for a telescope or a microscope, or even a big number crunching computer terminal, when the world begins to spin. Where is the calm clear center point? I have to remember, on days like today, that it is within.

Heirarchs have always tended toward absolutism, as it is difficult to maintain an elevated position in a society where no two people can agree which way is up. We seem to need a king or a pope or a shaman of some kind to give us a sense of stability, to be the single fixed point at the center of the whirlpool. I am not surprised that those who need to worship some thing have chosen as they have, to wall themselves in against ethical relitivaty.

So black holes are not so black after all, and may be more like tunnels than like holes. So it has become much harder to find G-d in a universe which just seems to go on and on and on. So the Big Bang may have been more of a back-fire, a pop, a baby blowing bubbles in drool. So the constants might just vary just a little bit. So the scout leader turns out to be gay and the war hero has murdered his own wife and children.

There are no weapons of mass destruction, we have invaded a country because we didn't like their leaders style in facial hair. Rape and pillage happen in war because they always happen in war, atrocities happen because they always happen, but the leader who led us into war is innocent. His smile is still confident. He is still the leader of the free world, center of the whirlpool.

I have heard that Andromeda sings and I would like to listen to that. I would like to understand covarient and contravarient differentiation. Well anyway I think I would. I would like to live in a world where leaders try to help their people find their own destinies, rather than in a world where leaders insist on defining and enforcing their own narrow vision of the future.

But hey, I'll go along with the crowd. It is not much fun singing to yourself in a swamp all alone. The croaking and chirruping and chorusing is lots more fun when everyone joins in. Let the orgy begin. We can worry about G-d later, when we wake up with dry mouth and a headache.

nc

 

[selfAdjoint]

I have heard that Andromeda sings and I would like to listen to that. I would like to understand covarient and contravarient differentiation.

Covariant differentiation is not hard. I don't believe there is any contravariant differentiation :).

First of all consider ordinary differentiation of vectors. You define quotients by taking the difference between THIS vector and some other one close by, and dividing by the gap between them. Then you take the limit of the quotients as the gap shrinks to zero. This is great if the vectors everywhere in your space line up nicely, but what if your geometry varies from point to point? How are you going to make sense of the difference between two vectors at different points?

Levi-Civita found the answer; you move your original vector parallel to itself, over to the other vector. When they are defined at the same point, you can take the difference. But when you do this, you find your original vector "turns in your hands" although you have done your best to keep it parallel to itself, because of the varying geometry. When you get it over to the other vector yes, you can take the difference, but now it is the difference between the other and the turned vector instead of the original. Mathematically the quotients will have a term involving the metric tensor of the geomety, to allow for the turning. And when you take the limits this term won't go away, and that's what makes the covariant derivative.

 

[marcus]

... It is not much fun singing to yourself in a swamp all alone. The croaking and chirruping and chorusing is lots more fun when everyone joins in. Let the orgy begin. We can worry about G-d later, when we wake up with dry mouth and a headache.
...

Let's agree that god is a very cool idea. Personally I like haydn's creation where there is a lot of chirruping and chorusing in praise of (personified) creation. I don't see the need to wait for later, if you want to discuss the Creator of the Universe. Let that discussion be our orgy, if we must have one.

god:

?o¿


orgy:

:!)
¿¿

 

[marcus]

how about that smiley? AFAIK I just now made it up! never saw that combination, with the inverted question-marks, before (but admittedly I don't get around on the internet much)

I like the idea of a Creator who boots up and starts the Works and then goes off and let's it run. but that happened way before the big bang and before the 26 parameters of the Standard Model.


he (of course he is a guy) let's things DESIGN THEMSELVES

and that goes for the laws of physics and the constants of nature, as well as the gazelle.

It is a demeaning insult to His Creatorness to assume that he applied his intelligence to designing, say, the anus of a housefly or an antelope. so as, you know, to get it just right.
And likewise demeaning to imagine (as the "Intelligent Design" philosophers apparently do) that he got down on his hands and knees and adjusted each one of the 26 constants of the Standard Model so that houseflies and antelopes would be able to exist.

the universe, as I picture it, is a Self-Designing Tree
worthy of whoever invented it, if someone did
and worthy in its own right, if no one did and it sprang of its own into existence.

what I cannot stand is these guys who think that an Intelligence had something to do with the Big Bang, and with selecting the constants that shape our version of nature. these are things which we may reasonably expect to explain, as we better understand the evolving world..

guys who tell us the constants either were chosen by some mind (or, just as bad, must be the way they are for us to exist) are saying in effect that they have no mechanistic explanation and it is hopeless to try to find a cause why they are this way. they just are this way and we should not try to understand how they came to be this way.

Back in the Seventies I used to think it was pretty neat that the constants seem fine-tuned to foster life, by allowing complex chemistry, longlived stars, etc. Now that idea has metastasized like a mind-cancer and threatens to obstruct empirical science' quest for understanding.

 

[wolram]

Dead end philososophy.

 

[marcus]

I think so too, wolram. Anthropic dead end philosophy, and dead end religion as well.
No respectable Creator would be caught messing with those 26 knobs on the Std.Mdl. If he's going to do it, then he's going to do it right---and create the whole Shebang to self-design, back to the umpteenth level.

I expect that some places the constants are not so nice as they are here----not so conducive to prolific reproduction, branching, whatever. Probably some tracts of spacetime are more fertile than others because infused with better constants

have to think about how the constants can be immanent in a patch of spacetime, how a region can have a signature that tells what particles can live in it and how they interact----so if it collapses it can pass on its physics to the next branch of universe stemming from it.

La gloria di colui che tutto move
per l'universo penetra, e risplende
in una parte più e meno altrove.

Nel ciel che più de la sua luce prende
fu' io, e vidi cose che ridire
né sa né può chi di là sù discende;

perché appressando sé al suo disire,
nostro intelletto si profonda tanto,
che dietro la memoria non può ire.

it is natural for a person to have their own cherished image of the universe. The german word, IIRC, is das Weltall (Welt-all: the "world-all"). We don't have to be bashful about this. Dante visualized the universe. We are just as good as Dante, so we can too.

"the glory of him (or It) that moves all
penetrates thoughout the universe, and shines
more in some parts than in others.

I was in the branch that gets the most of his light
and I saw things which nobody can retell
who has come down from there

because our eagerness to know
gets us into such depths
that memory can't follow along behind"

Hey, I translated that without looking it is the first lines of the first canto of Paradiso.

 

[nightcleaner]

What, no contravarient differentiation? The frogs have been lying to me again. But if it doesn't exist, that should make it easy to understand.

Wolram, forgive me for guessing but you seem young. That is a safe bet for me because it is right more than half the time at my age, but in this case it is inspired by your contempt for philosophy. I should like to find out if your armor piercing realizm gets you any further than it has the rest of us in the attempt to escape philosophy. Personally, having looked a long time for a floor that will not give way and a roof that does not leak, I have come to the conclusion that philosophy is all we are ever going to get, so we might as well be satisfied with the draught.

I am going to go have a talk with the frogs about that contravariant thing. Doesn't exist? Preposterous.

Thanks

nc

 

[marcus]

Wolram, forgive me for guessing but you seem young. That is a safe bet for me because it is right more than half the time at my age, but in this case it is inspired by your contempt for philosophy.

that is a strange guess, nc. Of the three of us (myself, wolram, you) I would guess you to have the good fortune, if it may be called that, of being the youngest.

I'm inclined to consider us all natural philosophers
(in Newton's day science was called Natural Philosophy) and although perhaps somewhat cantankerous and idiosyncratic at times, all of an intensely philosophical bent.

It just takes different forms.

 

[nightcleaner]

Hi Marcus

Could be I am younger than I think. Wouldn't be the first time. But it is probably just that I am the most ignorant and easily confused that makes me seem young. Wolram seems young to me because of the seeming belief in something that doesn't shift when you aren't looking. But then, again, I may be projecting my own errors on others.

Marcus, could there be a consciousness principle to match the anthropic principle? Well it seems rude of us humans to deny that say, bonobo's, do not have a form of consciousness. Or computers. I am not sure about lug nuts. (Yes, Marcus, there are bonobos that do have computers, but you know I am not talking about that.)

Consciousness exists so the universe has to exist, because consciousness, after all, needs some place to be in. Con-sci-ousness, is that the ability to discriminate? In the sense of telling things apart. Registering one response for one condition and another response for another condition. Heck, even electrons do that. How else do they know not to jump into someone else's quantum swimming pool?

Smolin's CNS prediction, per your sig line, has a curious structure. There does not exist, that is a negation. No problem with that. But can we gain anything by examining tenses? Has there ever existed or might there ever exist, under this definition, a slightly differing set of parameters which would increase the prevalence of black holes?

I ask because the idea of an evolution seems to imply some "experimentation" to find the right balance. A few more branes here, a little thicker in the girth there, just barely touch this knob. Something changes. The parameters were different but then they adjusted somehow to regain the balance point of maximizing the quantity of black holes.

Well it is a minor point perhaps. I don't like the image of the hairy old guy twiddling his knobs either. Is it the hairy old guy part or the twiddling knobs part that is more obnoxious? Either way, if there is a creator who deserves to be worshipped, I agree it isn't that one.

Maybe it is LGM who are the knob twiddlers. They twink the knobs with tentacles instead of thumbs. Multidimensional, they play with us as they like. I don't like that image either. Wouldn't it be terrible if it turned out the universe was really proven to be one of them?

The self-evolving universe is most appealing, for avoiding those images if nothing else. But again the question is, what if lug nuts have a sort of consciousness? Fermi sea on a boson shore, reflecting the universe on a quantum foam surface more complex, potentially, than the neural folding of our crude chemical brain. Maybe the universe was originally set up to reproduce lug nuts!

We monkeys think we are so dang smart with our vending machines and computers. But who wrote the rules for the quantum universe?

Who is not the right answer. Who implies a differentiated being, and the universe by definition cannot be differentiated. As you say, there is only one universe. We are only little threads in the whole story, but our arrogance makes us believe we are the very pattern of the cloth. We are not. The whole thing has an intelligent design, but that is not the same thing as saying it has an intelligent designer, by the hundred monkey's theorum. Sooner or later an infinite universe, or a multiverse of universes, as which you like, will produce Shakespeare, and the dreams of the nightcleaner.

We are, collectively, G-d, while individually of course we are just a bunch of knob twiddlers.

Happy knobs, glad twiddling,

Richard

 

[marcus]

Smolin's CNS prediction, per your sig line, has a curious structure. There does not exist, that is a negation. No problem with that. But can we gain anything by examining tenses? Has there ever existed or might there ever exist, under this definition, a slightly differing set of parameters which would increase the prevalence of black holes?

...

The self-evolving universe is most appealing, for avoiding those images if nothing else.

I agree! If for no other reason is right.

I am still fumbling with the wording of that CNS prediction. As Smolin stated it in a 1995 paper, it is put in a positive way:

(remember he wants to say that we have a parameters which are as good as they can get for prolific black hole production, so any change should make black holes less prevalent if it changes things at all, so he says)

"Any small change you could make in the parameters of the standard physics and cosmology models would cause black holes to be fewer, or leave their number unchanged."

 

[nightcleaner]

There are some twentysix parameters, IIRC? Can they be stated in terms of mass, charge, spin, time, space, what? Or are they all independent?

 

[marcus]

I checked that article and got the exact wording, and also discovered that it was dated 1994
---quote from http://arxiv.org/gr-qc/9404011 ----

...contemplated by particle physicists and relativists for many years. As I will describe, it leads to a definite and testable prediction, which is that, Almost every small change in the parameters of the standard models of particle physics and cosmology will either result in a universe that has less black holes than our present universe, or leaves that number unchanged. After I motivate it, the bulk of this paper will be devoted to presenting evidence in favor of this prediction.

2 Cosmological natural selection

A natural solution to the problem of the fate of black hole singularities, that has been discussed for many years*, is that quantum effects cause a bounce when densities become extreme (presumably of order of the Planck density) so that the worldlines of the stars atom that have been converging begin to diverge. As there is nothing that can remove the horizon, before, at least, the evaporation time of the black hole, which is at least 10^54 Hubble times for an astrophysical black hole and therefor, plausibly, beyond the scope of this paper, whatever new region of spacetime is traced by these diverging geodesics remains hidden behind the original horizon. Moreover, any observers in this new region see themselves to be in a region of spacetime which is locally indistinguishable from an expanding cosmological solution with an apparent singularity in the past of every geodesic. Thus, it would make sense to call this process the creation of a new universe that is (at least on scales shorter than 10^54 Hubble times) causally disconnected from our universe.

*I learned of it from Bryce DeWitt in 1980, but I do not know who was the first to discuss it.

----end quote----

 

[nightcleaner]

Almost every small change in the parameters of the standard models of particle physics and cosmology will either result in a universe that has less black holes than our present universe, or leaves that number unchanged.

Yeah, I think you made some reasonable adjustments to the language. Can we change the parameters physically in some location? Not really the issue. He is talking generally about any change, possible now or ever or not? Why small change I wonder? Large changes too hard to predict?

Anyway can you vary one parameter up and the other down so that they cancel? Or is there some order or dependence of one parameter on one or more of the others? How are the parameters connected? Are they all just tied up in a sack together or are they stacked in some heirarchy? Tied up in orderly bundles?

nc

 

[nightcleaner]

Anyway I am comfortable with how many black holes we have in this universe. It doesn't seem to me to be too many or too few. I don't see any locally unless they are very small, and I am not even sure that is possible.

With bounce or no bounce, it seems acceptable to assay that the black holes are not exactly the nothing we once thought they might be and which was so abhorant to the flock. They are something, altho what might ever be beyond the scope of this paper. I suppose they might be the cables that we ants are permitted to dream that we might walk upon in some kind of practical joker's cosmic string theory. Going around and around. Give it enough time and it isn't the same space anymore. How deep is a hole? Can we measure the horizon? How much is light bent anyway?

Garth says that light gets twice as bent as matter in freefall. Have you discussed this already with him? I see that there are lots of posts on SCC between you but I havn't read them all.

What has this got to do with frame dragging?

nc

 

[marcus]

Why small change I wonder? Large changes too hard to predict?

I am still trying different rewordings. I want it to be concise if it's to be used as a sig.

small is actually important to the idea

think about the natural selection of animals
it proceeds by gradual small changes and only finds "local" optimums
the system will go up whatever hill it finds itself but it cannot 'see' a distant mountain.

there might be some extreme change that would make a better bonobo-----say with eyes in the back of his head, or wings, or a talent for trading in junk bonds, something really radical---
well nature is not very likely to find it.

an extreme change is one where on the way towards it the species has to LOSE fitness, like crossing a valley, to get to a distant mountain. evolution normally won't do that. if it is on the mountain already, it will climb it. but if is not it will just climb whatever hill it is on, for local advantage.

mostly a species will find it self on some slope and natural selection will drive it up that slope towards higher reproductive success or fitness, but only what is achievable by small changes

the words "small change" is intentionally left vague, it will depend on context and people studying evolution of some species will know what kinds of changes to expect, and what kinds of discontinuous jumps not to expect.

I know it's vague. but Smolin said "small changes" on purpose

 

[Chronos]

I still can't shake the feeling Smolin proposed CNS as a challenge directed at Susskind to produce a falsifiable version of the anthropic landscapes. I saw it as a suggested course correction.

 

[Garth]

Garth says that light gets twice as bent as matter in freefall. nc

Actually 1.5 times as much. If the light path is 2km long the extra deflection under terrestrial gravitation is only about 1 Angstrom.

N.B. The SCC light deflection by the Sun is the same as GR - as this deflection is a combination of two effects, the free fall attraction towards the Sun plus the effect of space curvature. In SCC the first is 1.5, and the second 0.5 the GR effect.

"The first day of creation, who can act rationally on such a day?" Aleksandr Solzhenitsyn

Garth

 

[Garth]

I still can't shake the feeling Smolin proposed CNS as a challenge directed at Susskind to produce a falsifiable version of the anthropic landscapes. I saw it as a suggested course correction.

The problem with the Anthropic Principle is not that it is not verifiable but that it is not falsifiable - its predictive power is too good - the universe has to be propitious for life because we are here!

"The first day of creation, who can act rationally on such a day?" Aleksandr Solzhenitsyn

Garth

 

[wolram]

Thoughts of a youngster.

It has been said that we live in a "preposterous universe", well as our understanding of the universe is only embryonic it may seem that way,
in trying to understand the universe we the humans contrive ways
to define it, but how can the least part of the least part define the whole.
I think if the human race is to endure, then at some time in our evolution
we must travel to and inhabit other worlds, if we attempt to do this
without a deep understanding of our surroundings we will fail and perish.
So us human micro states have a monumental task unraveling the
every thing fur ball that is our universe, today we seem to be entangled
unable to make real progress, unable to undo some of the knots, lost
in the fur ball weave, we are awaiting mother to come along with her
scissors to snip us some new beginning.

 

[marcus]

I still can't shake the feeling Smolin proposed CNS as a challenge directed at Susskind to produce a falsifiable version of the anthropic landscapes. I saw it as a suggested course correction.

there are two aspects to this, one is that AFAIK the most thorough exposition of CNS is this 1994 paper

http://arxiv.org/gr-qc/9404011

It is a great paper, we should discuss it. BTW turns out that the essential elements in CNS go back to John Wheeler! Smolin gives some history.
He first heard the "bounce" idea in 1980 from Bryce DeWitt (of the Wheeler-DeWitt equation). It was Wheeler's idea that the parameters of the Standard Model might change slightly when the bounce at the pit of a black hole formed a new universe.

It looks like in 1994 Smolin just connected the dots. the paper is interesting partly because he gives his reason for considering the main constants optimal for black hole production.

The 1994 paper is called "The Fate of Black Hole Singularities and the Parameters of Particle Physics and Cosmology"

the other aspect, in line with what you said, is WHY THE 2004 PAPER?

the 2004 paper is motivated, IMO, by a desire to defend empirical science (which deals in falsifiable theories) from pseudo-science (which deals in untestable belief). It explicitly targets the string landscape use of the Anthropic Principle. The 2004 paper ("Scientific Alternatives to the Anthropic Principle") argues that appeals to Anthropic Principle are not science and that we don't HAVE to appeal to the AP because there are alternatives.

Smolin uses CNS, in the 2004 paper, as an "existence proof" as in mathematics where you show that a set is non-empty by constructing one example of something that belongs to it. There are falsifiable alternatives to AP because look, here is CNS.

In the 2004 paper Smolin makes a detailed argument for the immorality of appealing to the Anthropic Principle. Appealing to untestable, non-predictive principles damages the community's ability to resolve issues empirically. Because scientific enterprise and communication relies on empirically resolving differences, a scientist has a moral obligation not to appeal to non-predictive beliefs (such as AP) because doing so degrades scientific discourse and blurs the distinction between science and non-science.

So this is obviously a serious concern of Smolin (and quite a few other people these days!) and it is different from what he was doing in 1994 when he was mainly just giving a clear exposition of CNS and putting it up for testing.

 

[marcus]

The problem with the Anthropic Principle is not that it is not verifiable but that it is not falsifiable - its predictive power is too good ...

a theory which is not falsifiable has no predictive value

Not being falsifiable means that it is mushy, in the sense that it can accommodate any conceivable outcome of any future experiment.

Something as mushy as that does not predict anything because it does not unpredict anything.

 

[marcus]

I still can't shake the feeling Smolin proposed CNS as a challenge directed at Susskind to produce a falsifiable version of the anthropic landscapes. I saw it as a suggested course correction.

I think David Gross vision (keynote address at String 2003 conference) is instructive. I can probably find a link if you want. that was the strongest condemnation of Susskind "landscape" thinking and resorting to Anthropery. He said it was giving up. and he quoted a Churchill WW2 speech (something like: "never, never, never give in except to the convictions of decency and good sense"). String theorists should not give up trying to explain nature in the manner of empirical science, that is with predictive, therefore falsifiable, theory.

David Gross (head of KAVLI Santa Barbara) is of course a major string figure, so his condemnation of AP stands out. I do not see any possible "course correction" besides the line taken by a few gutsy people who refuse to give up.
The alternative, I guess, is to shift out of superstring/M and move in the "form theories of gravity" direction, which I gather is being talked up by Cumrun Vafa. The codename there is "topological M-theory" and you can do it in 4D or 5D. It shares a family resemblance with some developments in Loop Quantum Gravity

that would, I suppose, correspond to the Churchillean idea of giving into the convictions of "honour and good sense" (the one allowable case)

so I see Smolin's 2004 as aiding in the fight to preserve scientific integrity in theoretical physics, but not as an isolated effort. He is hardly the only one to "challenge" Susskind and his followers.

 

[Garth]

a theory which is not falsifiable has no predictive value

Not being falsifiable means that it is mushy, in the sense that it can accommodate any conceivable outcome of any future experiment.

Something as mushy as that does not predict anything because it does not unpredict anything.

Given our existence the AP is tautological.

"Any conceivable outcome of any future experiment" will be consistent with the existence of complex life forms somewhere within the universe, and the AP is able to predict those outcomes in advance, it does not have to accommodate itself, it can be a hard prediction such as Hoyle's prediction of the berylium-carbon resonance.

It does have predictive power, however what it is not capable of doing, if applied correctly, is making a false prediction, because we do exist (at least I think we do!)

Perhaps an example of a 'mushy' theory, in your sense, which is taken seriously is the theory of evolution. For a case example I reflect on the possibility that there was a 'gay' gene, (although the existence such a gene/gene complex is seriously questionned now). On the surface the existence of such a gene would seem to be countra-indicated by the need for fitness to reproduce until it was suggested that the 'gay' uncle/aunt's genes would be passed down through nephews/nieces that they could help to bring up.

Garth

 

[nightcleaner]

Hi Garth.

You show no fear. I can respect that.

Lets say G-d wanted to create intelligent free-willed co-creationists. He could just snap His fingers and So Be It into existence, but that might not be much fun. Maybe He would want to stretch the process out a bit, so that He could be amused by the various antics of the free-willed co-creationists in training. So He created Evolution. And other bed-time stories. Why doesn't that satisfy the fundamentalists?

But fundamentalists are generally not satisfied by reason. They not only want to ignore the question, they want everyone else to ignore it too. That is where we come into difficulties.

In grade school we had to put our heads down on the desk top to take a "secret ballot" type of vote. You were not supposed to try to find out how anyone else was voting by taking a peek.

"Miss Williams Miss Williams!"

"What is it Sally?"

"Tommy is peeking!"

I knew better than to burst out laughing. If I had laughed, Tommy and Sally would both go unscathed, and I would be the one whapped on the back of the head by the ruler. I never trusted Miss Williams' count either, but it didn't matter. The things we voted on were all trivial.

I suspect today that she only had us put our heads down so that she could steal a quick puff or two off a cigarette. That's what democracy will get you.

But Garth, I have been holding this idea of gravitation affecting light differently than matter for some time now, and it has been sinking into my gravelly sea like a polished stone. Frankly I don't know where it fits in, or if it does. It makes me uncomfortable. I could throw it back up on shore and hope some nice tourist comes by and takes it away, but then, in some ways it is good, or at least useful, to be uncomfortable.

I gather that this effect is actually measured and calculated somehow and that SCC differs from GR not in the presense of the effect but only in the magnitude? I have not been able to think of a mechanical meaning for this odd factoid, which comes to me as a new bit, which I don't recall from my antiquated University physics courses, nor from subsequent happenstance readings of the popular media over the interveneing years. In fact, since light has no rest mass, I am not quite sure what to make of free-fall light compared to free-fall matter. Light does not have inertial mass. And how is inertial mass different from rest mass? Does GR not argue that they are equivalent?

Maybe this is something for me to think about while working over the grease. Thanks,
nightcleaner

 

[marcus]

Lets say God wanted to create intelligent free-willed co-creationists. He could just snap His fingers and So Be It into existence, but that might not be much fun. Maybe He would want to stretch the process out a bit, so that He could be amused by the various antics of the free-willed co-creationists in training. So He created Evolution. And other bed-time stories. Why doesn't that satisfy the fundamentalists?
...

Yes, why can't they be satisfied with what we arent ready to try to explain yet! then we could all live in peace.

Just let them keep their mitts off of the constants of nature and the big bang. that is our turf, and all the stuff that comes after the big bang, with the amoebas and warthogs and poison ivy and brussel sprouts and stuff.
Just let them keep their theological snoots out of what looks like it might be fun and possible to explain, and then everybody can be happy.

they can have God make a really propitious-to-life, terrifically providential and comfy General Setup, within which the universe as we begin dimly to understand it can have arisen, perhaps by an evolutionary process like we've been discussing. That should satisfy God and we will all be grateful for the admirable propitious Setup.

It just gets better and better the more we understand it.

now I am visualizing it as a kind of evolutionary tree, where maybe branches can fall of and start their own trees

 

[marcus]

Speaking of co-creationists in training you know Alan Guth who first invented an Inflation Scenario in cosmology. Or else he and some russians got the idea about the same time. Well there is an article by Guth and somebody named Farhi that was published in "Physical Review Letters Series B" in 1987, which is a quite respectable journal, and the article is called

An obstacle to creating a universe in the laboratory

Another article published in Phys. Rev. Lett. Series B at around the same time was by Frolov, Markov, and Mukhanov, and it was called

Through a black hole into a new universe?

this just shows what happens if you allow pond scum to form in your universe, eventually you get creatures like Alan Guth who spend their time thinking about contriving a Big Bang in their laboratory

 

[Garth]

If I make a comment.

The AP does not necessarily imply belief in God. That the propitious nature of the universe might be due to a Creator is only one of a range of possibilities. Another of these possibilities is that these propitious constants are the 'fortuitous' by-product of Smolin's Cosmological Natural Selection, not only in our universe but in every other 'co-evolved' universe.

Others also define the AP too narrowly, Professor Mary Migley, a moral philosopher formerly Senior Lecturer in Philosophy at the University of Newcastle, (a secular academic British university), in her book "Science as Salvation" argues that the AP has been used by atheists to replace God in a sort of "Man-of-the-gaps" theory.

Some argue that too great a prominence is given by the AP to God, others to Humanity'.

Fundamentalists also cannot stomach the AP - because it allows different possibilities of interpretation and therefore jars with their 'black and white' method of argument and impossible, so called 'litertal', interpretation of Genesis.

I sit in the middle as far as the AP is concerned and am amused and bemused by the shots fired from both sides!

Garth

 

[marcus]

... "Science as Salvation" argues that the AP has been used by atheists to replace God in a sort of "Man-of-the-gaps" theory.
...

sounds confusing. can't imagine why an atheist would want to replace "God" with anything at all! What is "Man-of-the-gaps"? It sounds like the Missing Link

I will also make a comment, Garth.

AFAIK Darwin's biological evolution theory does not favor either belief or disbelief in a Creator. It just shovels the God-talk out of the way of understanding biology.

AFAIK the various lab and theory chemical analyses of how living organisms with DNA could have accidentally formed in primordial conditions do not favor belief or disbelief in a Creator. Again, it just pushes back the boundary and enlarges the area of scientific investigation.

AFAIK Smolin's physical evolution theory does not favor either belief or disbelief in a Creator. If it passes some tests it will simply help to clear some more God-talk out of the way and enlarge the area of scientific investigation. One will have at least one way of testing how physical law might be adaptive or self-organizing.

I notice that some people like to be in a church and sing sacred music and appreciate religious art and watch rituals being performed and some people dont. I suppose one can be a deeply spiritual person with a profound enjoyment of pretending God exists and also consider that God-talk is a kind of rubbish when it gets in the way of doing science. In my humble judgment, there are some areas like cosmology and physical law where it needs to be shoveled out of the way of regular scientific discourse.

What you mean by "AP" I take to be a Good Feeling that all's right with the world, that the universe is "propitious" or somehow friendly. I often have those feelings myself and I even suspect that lots of well-adapted organisms may take satisfaction in the fact that they are well suited to their environoment and (conversely) their environment is well suited to them.

maybe by "AP" you also mean a Good Feeling that is analogous to a gambler's belief in Luck. It has been favorable so far and that is a "propitious" sign that it will continue to be friendly. A "big rip" won't suddenly occur. A violent "bubble domain wall" moving at the speed of light will not suddenly pass through our galaxy.

If you have those Good Feelings (basically of trust and satisfaction with how basically good things are and admiration for the beauty of it) well I certainly share those feelings with you. And it is all right with me if you want to call them "AP".

 

[marcus]

what I mean by AP

But I don't call these good feelings "AP". For me, the Anthropic Principle has nothing to do with a Good Feeling of all's right with the world or anything remotely like that.

for me it is the claim by some people ( a self-serving claim in some cases IMO) that there is a huge plethora of distinct and disjoint universes, mostly hostile to the formation of galaxies, hostile to the formation of long-lived stars, mostly with very few stable chemical elements, mostly unable to form rocky planets. This vast multitude of unfriendly universes exists---these universes exist in the same sense as our tables and chairs exist (to quote Smolin's characterization of the version of the AP he is countering).

AND WE ARE ABSOLVED FROM HAVING TO EXPLAIN why the universe around us has parameters friendly to the formation of galaxies, long-lived stars, rocky planets, a large periodic table with rich chemical possibilities and stable elements SIMPLY BECAUSE WE COULDNT EXIST IN ONE OF THE OTHERS.

In other words the AP, in the definite and restricted sense that it is used as a defense by scientific theories that cannot predict or select between a welter of possible versions of physics, in the definite and restricted sense that Smolin tells us he is dealing with IS A HUGE COP OUT.

"God" is not involved here. Your happy feeling that the world is favorable to life (which I too often get, with a full belly under a blue sky watching the butterflies in the garden) or that it is "propitious" as you say-----your happy feeling is irrelevant to this particular version of the Anthropic Principle.

We each, I think, should be free to choose what version of the AP interests us. The version that interest me is the version that large numbers of string theorists began appealing to in 2003. It is the cop out I described, which has no Good Feeling attached to it, but is the the one with a myriad (10¹⁰⁰) of separate, inhospitable, often very short-lived, or radioactive, but nevertheless physically real, universes. It is not much fun for the pond scum that tries to get started in some of those other places, but the scenario has the one big advantage of getting String Theorists off the hook.

The subtext or basic message of the version of the AP which I am talking about (not your happy sense of "propitiousness") is that physics theory no longer demands of itself that it explain the values of the constants---the rules are to be changed so theory no longer aspires to, or is expected to, offer a mechanism for why things are this way. the message is, they can be and indeed are "any which way" according to the 10¹⁰⁰ distinct string vacuua, in those other places we imagine to exist, but we just couldn't live there.

 

[Garth]

I agree with your criticism of using the AP as a cop out.

You are defining the AP as the Weak Anthropic Principle, Smolin's CNS is an example of the Strong AP.

My use of the word 'propitious' is not a personal use but that used in the published literature.

The cop out you and Smolin mention is similar to those of a religious persuasion who do not seek a mechanism for natural phenomena but say, "God did it", that god is the god-of-the-gaps, the god who is constantly squeezed out by the advance of scientific knowledge. Migley was referring precisely to your above example of a cop-out by saying that some, perhaps Martin Rees with his multiverse, were simply replacing a 'god-of-the-gaps' with a 'man-of-the-gaps'.

Incidently, the God I believe in is the author and guarantor of the laws of science, not the gaps in it. As I have quoted elsewhere, I follow Uncle Albert, "I want to know how God created this world. I am not interested in this or that phenomenon, in the spectrum of this or that element. I want to know His thoughts; the rest are details." (A.E.)
Garth

 

[marcus]

Incidently, the God I believe in is the author and guarantor of the laws of science, not the gaps in it.

Garth

that is a noble concept of the Deity

 

[marcus]

I don't take a stance either way and don't want to give any indication of a position pro or con. but I am impressed

 

[nightcleaner]

On re-reading this thread it occurs to me that there is a curious parallel between the AP and CNS. AP says the universe was made so as to benefit Man, and CNS says the universe was made to benefit black holes. It seems clear to me that the black holes win. They last a lot longer in this universe than do humans.

But I still want better information on this bent light idea. GR, I think, says light always travels in straight lines, but that gravity bends spacetime, so that light passing near a star will appear bent to an observer further up the gravity slope. Am I correct that SCC says spacetime is bent, which makes light look bent, but that light also experiences additonal bending due to gravitational attraction?

Bent spacetime is invoked in GR to explain gravitational attraction between masses. It doesn't make any difference if the attraction is due to rest mass or to kinetic energy. Light has lots of kinetic energy but no rest mass.

SCC says there is an additonal effect of gravitation on light...not only is it bent by bent spacetime, but it also experiences an additional attraction? Light is doubly bent?

And I still don't see where the evidence for this idea is, nor do I understand how gravity probe B is going to tell us the difference between the two theories.

nc

 

[Garth]

Hi nightcleaner!

But I still want better information on this bent light idea. GR, I think, says light always travels in straight lines, but that gravity bends spacetime, so that light passing near a star will appear bent to an observer further up the gravity slope. Am I correct that SCC says spacetime is bent, which makes light look bent, but that light also experiences additonal bending due to gravitational attraction?
Bent spacetime is invoked in GR to explain gravitational attraction between masses. It doesn't make any difference if the attraction is due to rest mass or to kinetic energy. Light has lots of kinetic energy but no rest mass.
SCC says there is an additonal effect of gravitation on light...not only is it bent by bent spacetime, but it also experiences an additional attraction? Light is doubly bent?
And I still don't see where the evidence for this idea is, nor do I understand how gravity probe B is going to tell us the difference between the two theories.

OK! Where do we start?

Think of the standard GR situation of a path of light being ‘bent’ by the Sun. You are probably familiar with the analogy of the gravitational field of a spherical object like the Sun represented by a round rubber sheet curving down to its centre by the presence of a large ball in the middle. ‘Straight’ lines (i.e. paths of the shortest distance) drawn on this surface will seem ‘curved’ because of the curvature of the surface on which they are drawn. Two adjacent initially ‘parallel’ lines will diverge or converge because of this curvature. The curvature of the surface of the rubber sheet can therefore be described intrinsically by such di/convergence without having to leave that surface.

Take the point of view of an observer co-moving with the centre of mass of the Sun and take a slice through space-time of simultaneous events in that frame of reference. That surface will be bent in towards the centre as in the analogy above.

Now consider the passage of a ray of light traveling in a straight line across that sheet and just grazing the central body. It will be deflected towards the body by the curvature of the surface on which it is travelling. This is the curvature of space.
However a photon in that ray of light will have energy and that energy has a mass equivalent so it will be gravitationally attracted towards the mass. It will fall towards the Sun, this is an effect of the equivalence principle.

Thus we can split the deflection of the path of light into two component effects, one is due to the ‘gravitational’ attraction (in the Newtonian sense) of the photon, the other is due to the curvature of space. In GR these two effects are both equal and individually give rise to half the total solar deflection of ½ + ½ = 1 x 1.75”, which is due to the curvature of space-time.

Now in Self Creation Cosmology there is a ‘Machian’ scalar field, which endows particles with inertial mass, and which both perturbs the curvature of space-time and causes a ‘upwards gravitational-type’ force that acts on particles (rest masses) but not photons. The true gravitational force (curvature) is 3/2 the GR value, but the total force felt by particles is the GR – Newtonian gravitational force. Photons therefore ‘fall’ at 3/2 the acceleration of particles – even so in a 2km light path the deflection is only about 1 Angstrom.

The amount of space curvature caused by the Sun in SCC is ½ that of GR, whereas the amount of ‘gravitational attraction is 3/2, so the total deflection is ½ x ½ + ½ x 3/2 = 1 x the GR deflection = 1.75” as observed. This is one case of many tests in which the presence of the scalar field force has the effect of exactly balancing the effect of the presence of the scalar field.

There are three tests, however, where this exact compensation does not hold, the GPB geodetic precession measurement being one of them; the other two are a direct comparison of the ‘rates of falling’ of light compared with a physical apparatus, these are described in Self Creation Cosmology - An Alternative Gravitational Theory .
As the GPB measurement is being carried out at this moment we shall see! (Apparently in about a year)

I hope this helps.

Garth

 

[nightcleaner]

Hi Garth

I have been less than happy with the rubber sheet model of gravity since I first read of it. It undertakes to describe the attractive force between masses in terms of deformation of a two dimensional plane. Gravity, however, acts in our three dimensions of space, and the two dimensional plane invoked in GR is not physically apparent.

The rubber sheet model uses an impenetrable membrane. Where is this membrane? I don't see it spreading out between real objects in real space. Why is it visible in two dimensions (the model) but not visible in real three dimensional space? What causes it to resist penetration so mightily? And there are two forces in counterbalance in the sheet model, that pushing down on the masses, causing the deformation, and that pushing up on the masses, preventing them from passing through the membrane, and incidentally causing them to attract each other. What is this second force in GR?

The questions are rhetorical and intended to highlight the problems with the model. It is a good model in so far as it reproduces the behavior of masses in which we are interested, but it is a bad model in so far as it consists of physical elements which mechanically act to mimic the real behavior we are interested in, and may or may not represent the real operations resulting in the behavior.

The sheet itself is one physical construct which is not present in the real three dimensional system. Because it is not present, it cannot be the source of the second, resisting force. There is no sheet, and there is nothing analogous to the sheet in the real system.

The masses are also artificial. We do see real masses at macroscopic scales and they do look more or less like bowling balls and so on. But the whole question is to do with why masses attract in the first place. Plunking a mass down in the middle of it is like defining a word as the opposite of its opposite. The answer may be true but it is trivial. We want to know why mass behaves as it does. Saying that mass behaves as mass behaves because it is mass is no use at all.

And then there is the force and the counter-force, which I have already discussed, as well as the resultant third force in the equation, which the one thing in the model we are actually interested in, the attractive force.

If we are to make any progress understanding the physical process that is going on in Gravity, we have to begin by abandoning this toy model of rubber sheets and bowling balls, and begin to work directly in three and higher dimensions.

In our usual three dimensions of space there is a component of change, in which time is irrevokably involved. There is no possibility of change in the absense of time. This leads us into the frozen instant, the image of timespace as a landscape, a physical place in which frozen instant after frozen instant may be displayed in sequence like the frames in a movie film, produceing motion as a sort of illusion. In this view the only kind of motion, or change, that is possible is the motion of the observer, who, disembodied, may float or race across the landscape, thus experiencing the "illusion" of local three dimensional time.

Notice however that the observor is not limited to the three dimensions of space and one of time, but can presumably turn and circle and choose to move into whatever part of the landscape that is of interest, past present and future all frozen into one eternal surface. This means that the observor has to have additional degrees of freedom beyond the three space and one time system that we commonly inhabit. We need more dimensions of spacetime to accommodate the freedom of the observer. We talk of the observer as being able to change from past to future or future to past at will, so it is clear that the one time line, past and future, is not enough. The observer has to be higher dimensional than the observed spacetime landscape.

We need to have a better understanding of these higher dimensional relationships before we can have an understanding of the gravitational mechanism.

Garth, I am still trying to make the double gravitation idea fit into my head. At this point I am still inclined to think that the idea is an artifact of the model and does not describe reality.

I need to understand the GPB experiment better. I think it has something to do with the precession of the axis of a gyroscope in free fall, but I have not gotten a clear idea of the question. My guess is that the spin axis of the gyroscope is taken to be a referential absolute, and any changes in the axis when it is in free fall must be attributable to curvature in timespace.

I appreciate any discussion or guidance on this.

I also want to take a moment to thank the moderators and participants on Physics Forums for giving me so many interesting things to think about.

Be well,

Richard T. Harbaugh,
Nightcleaner