Radical new take on *uni*verse questions by Smolin, could be important

[negativzero]

skydivephil,
i will stake my non-extant reputation on the fact that Smolin considers time as real.
.
He doesn't want to start with symmetries, he wants to start with stuff, real physical stuff that causes other stuff to happen, in time. Momentum is distributed from event to event, and a space time emerges in the model. Rules don't cause stuff.
.
For him, x=x is probably an obvious fiction. It's a rule not a fact. To understand that it's a rule, first you have to perceive that there are actually two "x's" in the postulate, one on the left, one on the right. In his universe no two things have the same characteristics, importantly to your question, he finds that they have separate histories. He manages to define the past, to my taste in a mathematically satisfying manner.
.
i could seriously get in the mood for Barbour, though! Like when I'm soaping my mirror so i don't have to look at my face. See? Time is an illusion; it's a soapy illusion!
-0

 

[Boy@n]

Science finally explains how and why time is an illusion, yet, one of the first ones saying that was Buddha...

 

[negativzero]

Ontology of events [after 17:50 in the power point chart]:
"The history of the universe consists of a series of events.
"The activity of time is a process by which new events are processed out of current events."
.
He almost discusses the future here but not quite. Far be it from me to spot circular logic, but for me at least i have a problem distinguishing "new" from "current." Not that i don't love the man...no, no, no.
.
Personally, my take is that if there is any illusion to the popular version of time, it's the future. All I've ever experienced is the present. Since we are talking about a universe of stuff instead of symmetries, i mention that everything i see that is a reference to the future is just a prediction of it.
-0

 

[Adrian07]

Time is real. Attempting to understand time is about as close to an alien concept as you will come across. Smolin appears to be on the first maybe second rung of a long ladder. Trying to go beyond where smolin is at the moment risks breaking the forum rules unless there is somewhere off the main forum where controversial can be discussed.

 

[negativzero]

http://inspirehep.net/record/1217854

i found this, in part:
...
Implications of the Reduction Principle for Cosmological Natural Selection
Lee Altenberg
Feb 6, 2013 - 6 pages
e-Print: arXiv:1302.1293 [gr-qc] | PDF

Abstract:

"Smolin (1992) proposed that the fine-tuning problem for parameters of the Standard Model might be accounted for by a Darwinian process of universe reproduction - Cosmological Natural Selection (CNS) - in which black holes give rise to offspring universes with slightly altered parameters. ...When mechanisms of variation themselves vary, they are subject to Feldman's (1972) evolutionary Reduction Principle that selection favors greater faithfulness of replication. A theorem of Karlin (1982) allows one to generalize this principle beyond biological genetics to the unknown inheritance laws that would operate in CNS. The reduction principle for CNS is illustrated with a general multitype branching process model of universe creation containing competing inheritance laws. The most faithful inheritance law dominates the ensemble of universes..."
."Darwinian Evolution" appears to be an entirely appropriate term in describing Smolin's approach, it's not the first context where he uses the idea.
-0

 

[marcus]

Smolin just recently gave another talk at Perimeter about this.
This time is a public lecture to a packed hall. More of his personal experience and how he came to these conclusions.

http://www.perimeterinstitute.ca/videos/time-reborn

Here is the PIRSA link to the same thing:
http://pirsa.org/13040103/

 

[marcus]

It's important to realize that given the basic principles he's working with the usual laws of physics are not eternal outside the universe acting on the universe without themselves being acted on.
And it must be possible to explain WHY THESE LAWS?

Smolin takes a page from Richard Feynman here. Look at the last 35 seconds of this YouTube:

The sequence is 9:35 long. So drag the button to minute 8 or 9 to catch this part. Sir Fred
Hoyle and Feynman are drinking beer at a Yorkshire pub. If you start around minute 8:00 you get some of the atmosphere.

For a text of the conversation go here
http://calteches.library.caltech.edu/35/2/PointofView.htm
and scroll 3/5 of the way down the page. It is from a Caltech archive:
==quote==
It is interesting that in many other sciences there is a historical question, like in geology – the question of how did the Earth evolve to the present condition. In biology – how did the various species evolve to get to be the way they are? But the one field which has not admitted any evolutionary question is physics. Here are the laws, we say. Here are the laws today. How did they get that way? – we don't even think of it that way. We think: It has always been like that, the same laws – and we try to explain the universe that way. So it might turn out that they are not the same all the time and that there is a historical, evolutionary question.
==endquote==

In Smolin's picture, a metalaw of causation, building up events layer by layer, allows regularities to emerge (somewhat as they do in legal systems respecting precedent, that so to speak poll legal precedents). In these emergent regularities we recognize laws of physics.

to explain why these laws, we must (as Feynman suggested) have an historical evolutionary process. Analogous to the way we explain why the various animal species.

So that is why under the given assumptions, time must be real.

I seriously recommend people watch this video lecture
http://pirsa.org/13020146/
given in the Quantum Foundations seminar at Perimeter on 26 February of this year.
"The universe as a process of unique events"

 

[Paulibus]

In two posts here Marcus touches on matters that have to do with Evolution. He remarks first (in post 23) that

(Smolin)...is proposing something totally new here: he is challenging the Newtonian paradigm in which Laws stand above and outside the universe and just Are what they Are, eternally, and our job is to discover those laws, and the initial conditions that (under the operation of the laws) led to the present state of affairs.

and secondly (in post 42) that in 1973 Feynman said to Hoyle:

It is interesting that in many other sciences there is a historical question, like in geology – the question of how did the Earth evolve to the present condition. In biology – how did the various species evolve to get to be the way they are? But the one field which has not admitted any evolutionary question is physics. Here are the laws, we say. Here are the laws today. How did they get that way? – we don't even think of it that way. We think: It has always been like that, the same laws – and we try to explain the universe that way. So it might turn out that they are not the same all the time and that there is a historical, evolutionary question.

Marcus kindly gives the origin of the latter quote:

For a text of the conversation go here
http://calteches.library.caltech.edu...ointofView.htm and scroll 3/5 of the way down the page. It is from a Caltech archive

I'd like to point out that Yes, we are still following the Newtonian paradigm, and Yes, it is possible that this is a false paradigm. But we don't follow it blindly. It's the way the available evidence points; namely that physics works the same way everywhere in the observed universe, and everywhen over its multi-billion year history. Until evidence appears to the contrary we had perhaps best stick to our cobblers last.

Indeed Evolution seems to rule over just about everything other than the laws of physics. But we should not forget what physics does: it predictively DESCRIBES with the help of mathematics the way things work (the Baconian method), but only from the limited, prejudiced and anthro'centric perspective of the talkative kind of large African primate. So we shouldn't take it too seriously as the ultimate truth.
Good luck to Smolin in his attempt to evolve our perspective further!

 

[Boy@n]

physics works the same way everywhere in the observed universe, and everywhen over its multi-billion year history.

Not my intention to sound rude, but how do we (really) know anything else outside Earth perspective?

From what I saw on another forum, we even don't (really) know if light from Sun to Earth has same speed (and takes same amount of time) as light from Earth to Sun... (We just assume it does.)

 

[Mordred]

Not my intention to sound rude, but how do we (really) know anything else outside Earth perspective?

From what I saw on another forum, we even don't (really) know if light from Sun to Earth has same speed (and takes same amount of time) as light from Earth to Sun... (We just assume it does.)

/

Yes we do, and its no assumption. The tests done on GR is incredibly numerous. We tested time dilation as well.
With all the satelites we sent into exploration you didn't think we take advantage and test multiple application?

the length of time for light from the sun is a critical measurement, for cosmology. This sets our standard for the unit AU and its redshift properties. Without that we would not have any accuracy in any larger scale distance measurements. So you can bet its been tested and retested numerous times.

 

[Boy@n]

/

Yes we do, and its no assumption. The tests done on GR is incredibly numerous. We tested time dilation as well.
With all the satelites we sent into exploration you didn't think we take advantage and test multiple application?

the length of time for light from the sun is a critical measurement, for cosmology. This sets our standard for the unit AU and its redshift properties. Without that we would not have any accuracy in any larger scale distance measurements. So you can bet its been tested and retested numerous times.

I agree with the point you made, but also, since I am no expert here, while Samshorn seems to know this light speed question very well, how can I put both views together? (so they agree one with another?)

see: https://www.physicsforums.com/showthread.php?p=4361004

 

[Mordred]

What they are arguing about is the one way-two way speed of light tests.

http://arxiv.org/ftp/physics/papers/0609/0609202.pdf

http://arxiv.org/abs/1011.1318.

http://arxiv.org/abs/1103.6086

One of the main problems with most test methods is the illusion of a 1 way test, when it was in fact a two way test. In this area its more a case of preferred frame of reference. Not that the speed of light isn't constant in a vacuum.

I don't believe an agreement has been reached yet on it but I could be wrong

edt: if you want to discuss this further I recommend a separate thread in GR forum

 

[Paulibus]

I commented in post #43 about the apparent immunity (for us, for near-Eternity --- about the last 13 billion years or so) of the laws of physics to Evolution. Evolution seems to have happened to just about everything else one can think of, excepting perhaps Heaven and Hell. Before speculating about the possibility that this immunity might somehow vanish "beyond the big bang", as it were, and that the laws "emerged" from something, is there not a simpler question to be asked, namely:

Why don't the known laws of physics evolve?

Their evidence-based apparent immunity to this pervasive process of change seems to be their uniquely distinctive signature.

 

[Adrian07]

Watched the lectures. He seems to have missed the obvious i.e Time dilation is a proven fact, how do you dilate something that is not real? If time is real then what is it? The answers may lie in linking the expansion of the universe with the strange behaviour of the quantum world. I still think he is unsure of what he is looking for but knows there is something to be found, nothing I have heard tells me he is looking in the right place, I do not consider the question Why these Laws to be particularly relevant.

 

[marcus]

Watched the lectures. He seems to have missed the obvious i.e Time dilation is a proven fact, how do you dilate something that is not real? ...

I'm told that time dilation discussed in chapter 14 of book, I've seen a sketch of how it turns out to be consistent. I was intrigued by the argument but have to withhold judgment for the time being. Smolin's thesis (or one of the core ideas) is that time is real. "The reality of time" is a phrase that occurs in titles of articles, lectures, or gets referred to as a major theme here. I'm glad you watched the lectures! I just watched the video of the seminar talk---didn't get to the public lecture yet.
Seminar talk:
http://pirsa.org/13020146
I can't say I understand your comments, but let's keep trying to understand.

 

[marcus]

...
Why don't the known laws of physics evolve?
...

I'm puzzled by this, Paulibus. Could you give me an example of what you mean by a "known law"?

It seems to me just thinking back over the past 400 years that all the KNOWN laws have been evolving very rapidly, and that is not what Smolin is talking about.

Nowadays I think a reality-based physicist's attitude is that the laws we humans have are not in any absolute sense TRUE but are simply the best, most reliable ones we have at the moment. And the community is constantly trying to probe their weakness wrongness limitations of applicability and is constantly yearning to be able to improve or replace them.

What Smolin seems to be talking about is the Platonic fantasy some people have of there being some UNKNOWN laws of physics, veiled from our mortal eyes but eternal ineffable and operating constantly and unerringly on every atom of our affairs...

 

[Adrian07]

Dont worry about understanding my comments, they are based on ideas based on things like everything we see is in the past, wheres the edge of the universe, quantum weirdness etc and go beyond anything Smolin has said so far but are not up for discussion on this forum which is a pity as this forum seems to be the best I have found.

 

[Paulibus]

Marcus: here's an example of "known laws" (almost certainly) not evolving, as I see it.

Quite recently, with the Herschel observatory and other telescopes, astronomers have been observing the faint galaxy HFLS3. All their observations, of happenings 12.8 billion years in our past, are interpreted with conventional physics, working just as we describe it to work here and now. The conclusion they came to is that new stars were being formed in HFLS3 at an unprecedented rate of about 3000 per year. This conclusion is preferred (by Occam's razor or common sense) to fanciful (until they become evidence-based!) guesses about how the laws of physics themselves might have evolved to account for this surprising result.

This is quite different from the way physics, as our evolving description of the way nature works, changes to accommodate new facts we discover, such as the fact that photographic emulsions left in a Wurtzberg drawer with certain elements are changed by such exposure. We are careful to accept new physics only after much experimental checking and re-checking. Physics is quite a sceptical science and is fallible when it strays too far from its narrow path.

But thankfully there are exceptions. Be nice if Smolin stumbled on such a path!

 

[j1mcross]

I've been jumping around in the book.

Smolin's main driver for evolving natural laws seems to be cosmological natural selection. Universes with more black holes give birth to universes with more black holes. Life and intelligence evolve more as side effects of natural constants and structures that tend to give rise to universes with more black holes. It seems like he mostly thinks the particular laws of any given universe get set during its creation but don't change much after that.

But I would ask why can't the evolution of laws being occurring in our own universe?

The laws of our universe might not be constant but particles, forces, and matter evolve in response to expansion and might be significantly different in the future. The reason this is not apparent is that we are living at a time when we are unable to see into the earliest beginnings of this universe and, of course, cannot see into the future. We may be living at a point of relative stability. However, there are some indications from Planck and, I believe, measurements of electroweak forces that even now we might suspect some of these forces are not constant.

 

[marcus]

Hi Paulibus, I mentioned that known laws of physics have evolved rapidly over past 400 years so I guess I should illustrate. I don't think there are any KNOWN laws that are not in people's heads and written in their languages (math and other).

So the known law of geometry used to be rigid Euclid, and then around 1820-1850 with Gauss Lobachevsky Riemann it evolved so that triangles might not add up to 180 and you could define shape from the INSIDE rather than needing a geometry to be embedded in a surrounding Euclidean space. And then around 1915 the known law of geometry became DYNAMIC so that it could be affected by the flow of of matter, and the change in geometry could have a kind of persistence analogous to momentum. If it started expanding it would tend to continue and only gradually be slowed down if at all.

And the known law of GRAVITY also evolved in a fairly radical way from say Newton to say 1915.

But I don't think any physicist believes that these are really true laws that are precisely built into Nature. They are just approximate and provisional.

I think that is the way with all our KNOWN laws of physics. Everybody realizes they are evolving and are constantly subject to revision and are in fact constantly being probed for error by those whose job it is to help them evolve.

You know the Plato Cave business where Platonists believe in the actual eternal existence of ideal absolute Forms, Laws if you wish.

The question here (when discussing Smolin's proposal) is about the status of UNKNOWN laws. Do ideal eternal Laws somehow exist? How do they do that? How do they manage to govern the whole humble secularly changing universe if they themselves are outside of it? Why are they not reciprocally reacted on by what they affect the way everything else is? and so.

And if there are ideal unchanging efficiently acting Laws, how did they get that way, why did THOSE particular ones turn out to be the ones? Of course we don't KNOW them, we only have provisional approximate evolving ones that we so far managed to figure out. but what about the Platonic Ideal Laws?

So I'm saying that what we are discussing here is the existence/non-existence and other details about some conjectured UNKNOWN laws.

 

[Chalnoth]

Hi Paulibus, I mentioned that known laws of physics have evolved rapidly over past 400 years so I guess I should illustrate. I don't think there are any KNOWN laws that are not in people's heads and written in their languages (math and other).

So the known law of geometry used to be rigid Euclid, and then around 1820-1850 with Gauss Lobachevsky Riemann it evolved so that triangles might not add up to 180 and you could define shape from the INSIDE rather than needing a geometry to be embedded in a surrounding Euclidean space. And then around 1915 the known law of geometry became DYNAMIC so that it could be affected by the flow of of matter, and the change in geometry could have a kind of persistence analogous to momentum. If it started expanding it would tend to continue and only gradually be slowed down if at all.

And the known law of GRAVITY also evolved in a fairly radical way from say Newton to say 1915.

But I don't think any physicist believes that these are really true laws that are precisely built into Nature. They are just approximate and provisional.

I think that is the way with all our KNOWN laws of physics. Everybody realizes they are evolving and are constantly subject to revision and are in fact constantly being probed for error by those whose job it is to help them evolve.

There's a useful distinction to be made between our evolving knowledge of the laws of physics, and having laws which, by their nature, change in time.

I'd just point out that it is always possible to come up with a set of laws which do not change in time. This is a pretty trivial observation: if you have a set of laws which change over time (or space), then there is some way to write down the mechanism by which those laws change. Once you have written down the full mechanism for how those laws change, you now have a theory which doesn't change in time. By way of example, consider the following law of gravity:

$$F_g(r,t) = {Gm_1m_2 \over r^2} - {f(t) \over r^3}$$

Here we have a law of gravity which is the normal, Newtonian gravity, plus an extra cubic term that changes over time. This means that for masses that are far away from one another, this law of gravity is just Newtonian gravity. But when the masses get close together, there is a correction to the law of gravity that is different at different times.

What if we were to discover that this was our law of gravity, and then later discover that $f(t)$ was driven by some particular physical process. I don't know enough to know what sort of physical process might cause this to occur, but let's just imagine, say, that it's some sort of scalar field that changes over time. We'll call this scalar field S. Then the law of gravity might become:

$$F_g(r,S) = {Gm_1m_2 \over r^2} - {S \over r^3}$$

Now we have a law that is independent of time, though S changes over time, and it might do so through some sort of gravitational interaction or other.

My contention is that you will always be able to do something similar to this: if something is changing over time, there is always a mechanism we can write down to describe how this changes to produce a time-invariant law.

 

[Paulibus]

Marcus: the word “Evolution” has caused much misunderstanding over the years, and should
be used with caution! As biologists use it, it is a process of evidence-based and gradual natural change that created out of relatively simple materials the complex fabric of life that now exists on this planet. The time it took to do this was of the order of a billionyears. Or perhaps more.

Physics is a "just!" a human description of how some parts of real Nature work. The whole cloth of language and mathematics from which this description is cut is quite new, compared even with
the known history of its tailors, who have discovered that Nature rides on rails of reality
that physics describes and codifies as laws. It’s true that in perfecting our description to more closely approximate Nature we change these laws, sometimes gradually, sometimes with periods of equilibrium punctuated by revolutions, like those of the 20th Century. But it turns out that it’s not Nature that changes, but our descriptions of Nature that do. Chalnoth has clearly shown how changes of Nature could be incorporated in our descriptions, but astronomical evidence suggests that our present codified take on the way Nature works ,over this domain of knowledge, is adequate to describe stuff that happened nearly 13 billion years ago.

For me, this is the astonishing and noteworthy conclusion: no evidence of change, certainly no evolution for the way Nature operates. This is what needs explaining! It’s like Conan Doyle’s story of Silver Blaze and that dog that didn’t bark in the night!

 

[Adrian07]

Have been following this thread with some interest. Can I take it that what we are looking for is why the laws take the form that they do rather than the way our perception of the laws has changed as with gravity from Newton to einstein. So if there were no laws in place before the universe began then what caused the laws to become laws as the universe began, or what lies behind the laws as we know them. Of course the laws can only describe how and not why. Criminal laws evolve as civilization becomes more complex but all laws exist because of a common factor i.e crime, so are we looking for a common factor from which the natural laws evolved?

 

[marcus]

Have been following this thread with some interest. Can I take it that what we are looking for is why the laws take the form that they do rather than the way our perception of the laws has changed as with gravity from Newton to einstein. So if there were no laws in place before the universe began then what caused the laws to become laws as the universe began, or what lies behind the laws as we know them. Of course the laws can only describe how and not why. Criminal laws evolve as civilization becomes more complex but all laws exist because of a common factor i.e crime, so are we looking for a common factor from which the natural laws evolved?

Hi Adrian, I think you have it more or less RIGHT. Or at least your perception agrees with mine. It's really important that everyone in this discussion watch the first 30 minutes or so of
http://pirsa.org/13020146
and download the slides
or I guess get the book.

You see there that Smolin is not talking about the KNOWN laws of physics.
but rather about the EVOLVING regularities in the process called the universe WHICH except in an approximate sense WE DO NOT KNOW.

the concept of evolution is all-important here as he makes clear and underscores with quotes from richard feynman and charles sanders peirce

We only approximate these evolving regularities using our human languages, at any given moment we only have the provisionally best available, but this is not the issue.

What he is proposing is quite radical (though in line with the quotes from feynman and pierce) namely that these regularities are part of the temporal universe
they can be explained by past history like everything else
they are not eternal outside or above the ongoing process of the universe
everything that acts on events is acted upon, we know of no action that is not reciprocal in that sense, and so it is with these regularities.

Slides #4 and #5 are very important. I would urge you to go to 13020146 and click on the slides PDF and check it out. #4 makes the point that this analysis only applies to studying the universe as a whole. the traditional Newtonian scheme works fine for isolated subsystems where there is an outside observer. Then you analyze it as usual according to fixed external laws and initial conditions. He calls this the "Newtonian paradigm" and it is perfectly appropriate and works fine for studying isolated subsystems.
It is, however, fallacious to apply it to understanding the cosmos as a whole, he argues. And the main purpose of this book and the other one now at publishers is to develop some ideas for treating the universe as a whole (including its laws or evolving regularities)

Slide #5 makes explicit a specific form of the Leibnizian "principle of sufficient reason".
and another logical postulate that he is taking as basic rules of the game in this line of investigation.

 

[marcus]

Since we have turned a page, I will bring forward some links to what I think is most essential to the discussion.
==quote post #42==
It's important to realize that given the basic principles he's working with the usual laws of physics are not eternal outside the universe acting on the universe without themselves being acted on.
And it must be possible to explain WHY THESE LAWS?

Smolin takes a page from Richard Feynman here. Look at the last 35 seconds of this YouTube:

The sequence is 9:35 long. So drag the button to minute 8 or 9 to catch this part. Sir Fred
Hoyle and Feynman are drinking beer at a Yorkshire pub. If you start around minute 8:00 you get some of the atmosphere.

For a text of the conversation go here
http://calteches.library.caltech.edu/35/2/PointofView.htm
and scroll 3/5 of the way down the page. It is from a Caltech archive:
==quote==
It is interesting that in many other sciences there is a historical question, like in geology – the question of how did the Earth evolve to the present condition. In biology – how did the various species evolve to get to be the way they are? But the one field which has not admitted any evolutionary question is physics. Here are the laws, we say. Here are the laws today. How did they get that way? – we don't even think of it that way. We think: It has always been like that, the same laws – and we try to explain the universe that way. So it might turn out that they are not the same all the time and that there is a historical, evolutionary question.
==endquote==

In Smolin's picture, a metalaw of causation, building up events layer by layer, allows regularities to emerge (somewhat as they do in legal systems respecting precedent, that so to speak poll legal precedents). In these emergent regularities we recognize laws of physics.

to explain why these laws, we must (as Feynman suggested) have an historical evolutionary process. Analogous to the way we explain why the various animal species.

So that is why under the given assumptions, time must be real.

I seriously recommend people watch this video lecture
http://pirsa.org/13020146/
given in the Quantum Foundations seminar at Perimeter on 26 February of this year.
"The universe as a process of unique events"
==endquote==

I could be wrong but I think that PIRSA 13020146 video lecture and the accompanying slides PDF has the core argument of the book. I will be getting the book, to check that this is so.

 

[Chalnoth]

For a text of the conversation go here
http://calteches.library.caltech.edu/35/2/PointofView.htm
and scroll 3/5 of the way down the page. It is from a Caltech archive:
==quote==
It is interesting that in many other sciences there is a historical question, like in geology – the question of how did the Earth evolve to the present condition. In biology – how did the various species evolve to get to be the way they are? But the one field which has not admitted any evolutionary question is physics. Here are the laws, we say. Here are the laws today. How did they get that way? – we don't even think of it that way. We think: It has always been like that, the same laws – and we try to explain the universe that way. So it might turn out that they are not the same all the time and that there is a historical, evolutionary question.
==endquote==

In Smolin's picture, a metalaw of causation, building up events layer by layer, allows regularities to emerge (somewhat as they do in legal systems respecting precedent, that so to speak poll legal precedents). In these emergent regularities we recognize laws of physics.

I'm very skeptical of this sort of view. Ultimately, I think a combination of a mathiverse a la Max Tegmark combined with a prolific universe similar to the string theory landscape are more likely solutions.

 

[marcus]

I'm very skeptical of this sort of view. Ultimately, I think a combination of a mathiverse a la Max Tegmark combined with a prolific universe similar to the string theory landscape are more likely solutions.

Right,

I was aware of your taste in the matter, and opinion as to what is "more likely".
De gustibus non disputandum est.

BTW I am not laying odds as to what is "more likely" or trying to pick winners. The two things that seem to me to matter here, that I care about, is what is interesting and what is testable.

I find it intensely interesting that someone constructs a world system in which certain laws of physics are not eternal and inexplicable but instead may have some reasonable explanation.
In which they are not givens, in other words.

 

[Adrian07]

Laws depend on the circumstances underlying them. Why these laws could also read why these circumstances.
Take gravity for example 3 choices
1 The value of G was predetermined before the universe began
2 Did it start at 0 and settle at its current value for some unknown reason
3 It was decided by a third party (God)

Only with option 2 could the laws evolve, for 1 and 3 G is predetermined and so must be the law it is set by circumstances.
All systems require rules/laws to work but does an evolving system require the governing laws to evolve with it, is the universe such a system.

 

[Adrian07]

Just to clarify option 1 in the last post.
This means the universe can start with any value of G but will only succeed if G has a certain value. So the universe can start and fail any number of times until the right mix allows it to succeed so is essentially a random process.

 

[Paulibus]

I find it intensely interesting that someone constructs a world system in which certain laws of physics are not eternal and inexplicable but instead may have some reasonable explanation.
In which they are not givens, in other words.

(My bolding) Someone like Smolin, or just whom? Certain laws, like GR geometry/gravity, the second law of thermodynamics or the values of say 1/137,c,h,e and G ? Eternal, or just good for lasting at least 13 billion years? Inexplicable --- by those like myself, certainly; by the Einstein/Witten class of folk? Reasonable, like the complete bootstrap scenario?

An interesting remark worth amplifying, Marcus.

 

[j1mcross]

Laws depend on the circumstances underlying them. Why these laws could also read why these circumstances.
Take gravity for example 3 choices
1 The value of G was predetermined before the universe began
2 Did it start at 0 and settle at its current value for some unknown reason
3 It was decided by a third party (God)

Only with option 2 could the laws evolve, for 1 and 3 G is predetermined and so must be the law it is set by circumstances.
All systems require rules/laws to work but does an evolving system require the governing laws to evolve with it, is the universe such a system.

Let me add a 4. The universe did not start with gravity (gravity = 0) and its value is changing as the universe goes through various phase transitions. All of the visible universe at this time is in the same phase so its value appears constant to us.

 

[Chalnoth]

Right,

I was aware of your taste in the matter, and opinion as to what is "more likely".
De gustibus non disputandum est.

BTW I am not laying odds as to what is "more likely" or trying to pick winners. The two things that seem to me to matter here, that I care about, is what is interesting and what is testable.

I find it intensely interesting that someone constructs a world system in which certain laws of physics are not eternal and inexplicable but instead may have some reasonable explanation.
In which they are not givens, in other words.

I guess I'm just more interested in what's likely to be correct, rather than just playing in a sandbox to make something that looks neat. To be fair, I think it is ultimately extremely useful for physics for there to be lots of people who just like playing with models and taking, "What if?" questions to the extreme.

And ultimately, I just don't think it's likely that the laws of physics are the way they are because they had to be that way due to some fundamental behavior of the universe. I think this is a human conceit that probably has little to no application to reality, not when we're talking about how our low-energy laws of physics came to be.

 

[marcus]

Thanks for explaining your position on the matter, Chalnoth.

I'm very skeptical of this sort of view. Ultimately, I think a combination of a mathiverse a la Max Tegmark combined with a prolific universe similar to the string theory landscape are more likely solutions.

 

[Hernik]

I have a question about the OP Perimeter lecture of Smolin http://pirsa.org/13020146/ from approx 44.00: Here Smolin concludes that Spacetime emerges from the equations.

This part is strange to me. Maybe just because I can't read the equations. :-) But also because It seems to me that space logically was there from the start when the concept of an event is introduced. I fail to understand how an event can take place if not in a space of some kind.

The way I see it: Any ”event” must contain some kind of change otherwise nothing has happened.

Either the change can happen internally in an entity: A change in a level of energy for example. For that to happen you need the excess energy to go somewhere else/the missing energy to come somewhere else from. So you've automaticly introduced another place outside the entity. You need at least two places for energy to go away or arrive.

Or a change can involve two or more entities. Like two entities hitting each other, one entity splitting up, two or more entities absorbing each other. Again this kind of change requires more than one place.

So it seems to me any change would require that at least two separate entities are involved. Separated not only in time but spacially – am I wrong here?

So doesn't that indicate that space is already present in any model where events can happen?

Also Smolin's introduces ”momentum” as being a primitive in the model – just a number from a colorimeter, but indicating direction and energy, he says.

But here it seems to me that he adds ”direction” to the model. And by then it looks to me as if spacetime has been put in the model in the form of Distance, Direction and Time.

So I don't understand how spacetime can be emerging, Wasn't it there already – introduced when ”time” ”events” and ”momentum” were put in the diagrams and formulaes?

Hope someon can help me understand this better.

Henrik

 

[John86]

Nice read from Edge

http://www.edge.org/conversation/think-about-nature