Is a Revolution in Physics Imminent?

[math_04]

I just finished reading Niels Bohr's times: In Physics, Philosophy and Polity by Abraham Pais. It is an amazing book on the life of an extraordinary genius. This book really got me thinking into the state of physics in the 21st century. The last great discovery, unless I am mistaken, was the Standard Model of particle physics way back in the 70s. Since then, physics has hardly progressed with more and more strange theories of extra dimensions, string particles etc. popping up.

I have read a lot on the history of physics and this reminds me of the year 1895 when physicists thought that almost all of physics had been explained and only a few small things remained. It seems that the time is ripe for another Einstein or Bohr to revolutionise physics as we know it. String theory, even though I am still a second year college physics student, seems to me to not be 'revolutionary' enough. It builds on previous ideas which of course is important BUT maybe that is not the path. The time may be ripe to seriously question the basic ideas of quantum physics (interpretations since the mathematics and physics are sound and backed up by tonnes of evidence) and maybe modify existing theories.

I keep wondering what would have happened if Einstein never thought of his 'crazy' ideas. The aether theory would have gone on and dominated science and we would have to make lots and lots of modifications to keep that theory alive. The same thing seems to be with string theory with the ideas of extra dimensions, branes and exotic particles.

Anyways I would like to know what you all think about the state of physics right now and whether there has to be a radical change in ideas.

 

[waht]

Hopefully we will know where we stand in a few years, when the data from the LHC starts coming out.

 

[math_04]

Well, I doubt that data from the LHC will provide conclusive proof that proves or disproves any current scientific theory regarding the unification of the four forces. As Lee Smolin mentioned in his book, The trouble with Physics, theories like string theory are extremely hard to falsify because apparently certain parameters can be set that would agree with the experimental evidence.

To add on what I said above, Einstein and Bohr's ideas did not spring out of thin air, they came from already existing principles. In Einstein's case, the photoelectric effect came as a result of Planck's work and Bohr's ideas were a combination of Rutherford's scattering experiments and the failure of classical mechanics to explain things like electron orbitals. In both cases, existing theories were interpreted differently but were not thrown out of the window.

The existing unification theories as far as I know do not aim to modify existing theories per se but attempt to get around it. Smolin summed it up best in his book when he said that radical theories were getting too marginalised. All I can say is that I await the next revolutionary physics thinker with open arms!

 

[Dmitry67]

String theory, even though I am still a second year college physics student, seems to me to not be 'revolutionary' enough. It builds on previous ideas which of course is important BUT maybe that is not the path. The time may be ripe to seriously question the basic ideas of quantum physics (interpretations since the mathematics and physics are sound and backed up by tonnes of evidence) and maybe modify existing theories.

I agree with you. This is what I wrote in another topic:

----------------

When we approach the truth we make sacrifices on every step: we give up eucledian space, we give up flat spacetime, we give up realism in QM. On every step science gains a lot, but there is always high price to pay, and each time this price is higher and higher and more and more contre-intuitive.

I doubt the superstring/TOE theory will be just new formulas in the 10,11 or 26 dimensional space. I think the reason why we still don't have a final theory is that all these M-theories do not suggest any sacrifices... Something which makes all people say "oh, no, this is really crazy, I can not believe, something is definitely wrong here... I can believe in non-realism or curved spaces, but not this!"

 

[math_04]

No one seems to be addressing the deeper issues of physics but instead, seem to be happy calculating equations and spending an awful lot of time on mathematics. What happened to the Physics community of 50 years back where debates about the interpretations of space,time and the nature of particles were argued?

It seems like we have reverted to the 'Shut up and calculate' mode that does not seem to be getting us anywhere. Obviously, we should not base our radical ideas that vehemently do not agree with any known physics principle or we should not argue for the sake of arguing but we need to take a break from calculating and make sense of it all.

 

[Chrisc]

I think most people will agree a revolutionary new model of a fundamental nature is necessary to move physics in the direction of a greater understanding of nature.
The revolution started by Einstein was two fold. It was Einstein that proposed quanta as well as the transformations of dimensions necessary to uphold the laws under the constancy of the speed of light.
Einstein took a very pragmatic approach in developing SR. He accepted the empirical evidence of the constancy of the speed of light and the evidence that electromotive force contradicted the notion of absolute rest. He put these two ideas together and showed us what must be happening in our observations (dilation) if the laws are to be upheld.
I think the next revolution will not begin until physics is willing to accept a fully relativistic theory of dimension. It will require the same kind of pragmatic approach Einstein adopted, extended to the most fundamental notions of physics - dimension.
The problem of reconciling QM and GR is a problem of Time - time in QM is the clock on the laboratory wall, time in GR is the evolution of the metric, an evolution that occurs because time occurs. Neither of these notions of time will suffice to resolve the conflict between QM and GR.
The problem stems from the notion of quantization first proposed by Einstein (from Planck's work). How does the universe present a continuous (and relative) nature of dimension on one scale and yet become finite and discrete dimension on another?
Is this a question of spatial scale and/or temporal scale? Are space and time the same thing at each scale but greater and lessor at each? Or is the scale of dimension the determining factor in what dimension is in the first place? If space and time are a continuum and each is a relativistic measure of the other, at what point does space become finite and what happens to time at that point? At what point does time become finite and what happens to space at that point?
I think the next revolution will begin when physics is prepared to consider space, time and mass are relative measures of each other, their continuous and discrete nature are simply a question of recognizing the quantities we measure are determined by what we measure and at definite and relative scales our measures of space and time are in fact a measure of mass. This is not very radical when you think about how we define mass.

 

[SW VandeCarr]

Will someone please tell me where Lee Smolin got the number 10^500 string theories? I read his book "The Trouble With Physics" but, unless I missed it, the source of this number was never identified. I think Leonard Susskind used it in terms of the number of possible universes (each with their own distinct physics) that would be consistent with current versions of string theory. It's an unimaginably huge number. I was thinking, a number like this would actually be a sensible estimate of the number parallel universes in Hugh Everett's "Many Worlds" interpretation of QM. But, these parallel universes would need to have the same physics, so that can't work. Clearly, this number has to be pared down if string theory is to have any future...like say 10^50?

 

[math_04]

VandeCarr, I am not sure where Smolin got that number from, but I am guessing that it is accurate since he himself has done extensive research in the field of string theory. The fatal flaw with theories like Hugh Everetts many world interpretations and indeed string theory is that it seems an 'easy way out' of describing nature. The problem is it seems likely that string theory is going to have a possible future since many physicists, while brilliant in their own right, have trouble understanding the concept of scientific principles.

It is unfortunate to hear many leading physicists like Michio Kaku or Edward Witten stating that string theory is our best chance to a quantum gravity theory. If it really was our best chance, you would think after 20 years working on it, there would be some progress. Instead, the theory has become more confusing with no underlying principle to connect it with quantum gravity as far as I know.

And yes Chrisc, someone out there has to stop his calculations and think, just think about the meaning of space,time, the quantum nature of particles and keep asking why. In my first quantum physics course last year, in the syllabus, it stated that the important thing to note is that interpretations and thinking about the nature of quantum physics is not important but rather, its the calculations that sit in the front row. That to me stinked of conservativeness.

You may say to me, hey why don't you do something important and then talk! All I am saying is read about the philosophy and history of physics because that is an important aspect of study as well. Discoveries in physics were not made purely by calculations, they were made by first thinking about what the problem is with existing principles, making new and brave insights based on the shortcomings of those principles and then the calculations and proofs began. Theories like string theory may have started out that way but unfortunately, somewhere down the line, something went wrong.

 

[SW VandeCarr]

VandeCarr, I am not sure where Smolin got that number from, but I am guessing that it is accurate since he himself has done extensive research in the field of string theory. The fatal flaw with theories like Hugh Everetts many world interpretations and indeed string theory is that it seems an 'easy way out' of describing nature. The problem is it seems likely that string theory is going to have a possible future since many physicists, while brilliant in their own right, have trouble understanding the concept of scientific principles.

Math 04: If string theory is the 'easy way out', I shudder to contemplate the hard way. Can you imagine rotating the highly complex topology of the Calabi-Yau shape in six dimensions (or 7 depending on which string theorist you talk to)? Compare the math of string theory to the (relatively)simple beauty of Einstein's tensors. It's inadequate to say the math of string theory is to Einstein's tensors as Einstein's tensors are to simple arithmetic. The gap is wider than that. This is no complement to string theory. Just the opposite. All this hyper-math and ultra-computation is beyond any testable hypothesis.

Yes, complex models can perhaps explain the world we observe, such as Ptolemy of Alexandria's (200 CE) complex system of cycles and epicycles which correctly predicted the motions of the planets. But is was wrong. Putting the sun at the center of the solar system was far simpler and actually correct.

 

[math_04]

Exactly, the laws of nature have always had a simple, underlying principle which holds for any branch of science. Darwinian evolution had natural selection, chemicals were organised according to the Periodic Table and physics has classical mechanics, electromagnetism and modern physics. Some of the quantum gravity theories out today seem to lack a fundamental principle that governs the theory. The mathematics may be beautiful but does the physics add up?

 

[Chrisc]

Exactly, the laws of nature have always had a simple, underlying principle which holds for any branch of science. Darwinian evolution had natural selection, chemicals were organised according to the Periodic Table and physics has classical mechanics, electromagnetism and modern physics. Some of the quantum gravity theories out today seem to lack a fundamental principle that governs the theory. The mathematics may be beautiful but does the physics add up?

Theoretical physicists are looking for a way to put the Sun at the center of their solar system (the Standard Model).
Until a successful model is found, there will be many ugly and overly complex attempts.
I think you will find few (even string theorists) disagree with the tone of your objections.
The complex maths of ST are not necessarily the final construct of the model. It is often the case that
an overly complex mathematical modeling is developed on the road to what will eventually be a much simpler,
more elegant model.
We used to build airplane wings from hundreds of sticks of wood, cloth, glue, nails and twine. It was only after proving the sound principles of flight with these complex constructs that we could then replace all of these materials with a single sheet of metal.

 

[math_04]

What you bring up is intriguing, sort of the brute force tactics that shaped the physics scene from the early 50s. That was the transition from the classical way of thinking into the more modern method of research in physics. Reading into what the great physicists thought processes, every great discovery was made was shaped by simple thought experiments and phenomena that could not be explained.

Actually fluid mechanics was well known in the early 20th century thanks mainly to the work of Bernoulli and company. Undoubtedly, very little was known about wings BUT the underlying principles were known way before the Wright brothers and Kitty Hawk. I am not saying that all quantum gravity theories are false and should be abandoned but what should be understood is that they are unproven and till then, should not be taken at face value. Many of my fellow students think that string theory is true and even some of its distinguished proponents believe that it is the BEST solution. For me, that just undermines others who work on different theories.

 

[Chrisc]

Actually fluid mechanics was well known in the early 20th century thanks mainly to the work of Bernoulli and company. Undoubtedly, very little was known about wings BUT the underlying principles were known way before the Wright brothers and Kitty Hawk.

You're right, it was a poor analogy. I should have stuck to the principles of engineering the wing.

Many of my fellow students think that string theory is true and even some of its distinguished proponents believe that it is the BEST solution. For me, that just undermines others who work on different theories.

It can be frustrating, but give them credit for having a passion for their work and providing a lot of new insight. Only time will tell.

 

[SW VandeCarr]

You're right, it was a poor analogy. I should have stuck to the principles of engineering the wing.



It can be frustrating, but give them credit for having a passion for their work and providing a lot of new insight. Only time will tell.

The problem is there is no such thing as "string theory". Lee Smolin claims there are 10^500 string THEORIES! Real theories come in the singular, although there might be minor variations.

String theorists cannot agree on the topological genus of the Calabi-Yau shape, which is basic to any string theory. Since topological transformations are the most general of all geometric transformations, there is no more general a frame for differing topological genae to inhabit.

String theories can model many aspects of the Standard Model, but, as far as I know,there is no fleshed-out string theory that can offer a simplification of the Standard Model or a new testable hypothesis. Moreover, with so many to choose from, I don't see how progress can be made. A collider the size of the Galaxy wouldn't be sufficient to test any given string theory.

 

[math_04]

yes, hopefully there are buddying scientists like us out there who would think of alternative theories to what is currently being pursued.

 

[nickyrtr]

I am only a grad student in Physics, but what I observe is a general unwillingness to entertain fundamental questions, among established researchers in the field. Let me qualify that ... as long as fundamental questions are discussed in a "pedagogical" setting, they may be very superficially discussed and then sort of brushed off as just a curiosity. However, if one raises fundamental issues in the context of a serious, ongoing research topic, it is met with great hostility.

A past advisor put it very honestly. "Only the most famous researchers are allowed to think about big ideas". If anyone lower on the totem pole tries to explore fundamental questions as a serious research topic, they can expect to be dismissed as a crackpot.

 

[humanino]

Will someone please tell me where Lee Smolin got the number 10^500 string theories? I read his book "The Trouble With Physics" but, unless I missed it, the source of this number was never identified.

You must not have searched very hard, because sources are quite easy to find. Even here :
String theory landscape
you will find
"The statistics of string / M theory vacua", JHEP 0305, 46 (2003)
"Counting flux vacua", JHEP 0401, 060 (2004)
from which you will find plenty. Reviews :
"Flux Compactification", Rev.Mod.Phys.79:733-796,2007
"Basic results in Vacuum Statistics", Comptes Rendus Physique 5 (2004) 965-977
Lectures :
"Status of Superstring and M-Theory", @ Erice 2008 CALT-68-2714
"Les Houches Lectures on Constructing String Vacua"
"Lectures on Nongeometric Flux Compactifications", Class.Quant.Grav.24:S773-S794,2007
up to recent PhD thesis (for instance), where you probably can find even more that you want to know
Phenomenology from the Landscape of String Vacua

 

[Fra]

A past advisor put it very honestly. "Only the most famous researchers are allowed to think about big ideas". If anyone lower on the totem pole tries to explore fundamental questions as a serious research topic, they can expect to be dismissed as a crackpot.

I recognize this too, but my experience is that some researchers lack the confidence necessary to have faith in their own questions, not matter how formally well educated, which is somewhat weird. My experience is that most people do acknowledge the deep questions, but they seem to somehow lack faith in their own ability to tackle them. They seems to somehow have "surrendered to reality" thinking that these questions are simply too difficult. But then why not step aside and let someone with some guts try, or at minimum encourage young students to go for it with all they've got instead of telling them they are fools to think they can solve the big issues :)

I think most people with sanity realize that many people are likely to fail before one succeds, but without courage no one will even try hard enough to ever succeed. So I think encouragement is more in place than is leader trying to prevent the individuals with som guts to make mistakes.

/Fredrik

 

[sirchasm]

My opinion is that we have a 'problem' with QM, because we can't think in quantum terms, we are constrained to a classical frame.
Which is why we can have a general kind, or a specific kind, of understanding, but we can't have a 'global' one.

We can only ever understand it 'momentarily', as soon as we think "I understand QM", we don't any more. We have to develop a group 'infomation velocity'; the individual contributions to it can only be a small interval.

I've noticed that thinking about quantum processes, when you try to look "beyond the math" and grasp it ontologically, it vanishes immediately; understanding is like a wave that you see the top of now and then, and then it moves away.
It's like you have to forget any preconceptions, based on 'what you know', every time you do encounter a QM phenomenon up close.

 

[Fra]

My opinion is that we have a 'problem' with QM, because we can't think in quantum terms, we are constrained to a classical frame.
Which is why we can have a general kind, or a specific kind, of understanding, but we can't have a 'global' one.

We can only ever understand it 'momentarily', as soon as we think "I understand QM", we don't any more. We have to develop a group 'infomation velocity'; the individual contributions to it can only be a small interval.

I've noticed that thinking about quantum processes, when you try to look "beyond the math" and grasp it ontologically, it vanishes immediately; understanding is like a wave that you see the top of now and then, and then it moves away.
It's like you have to forget any preconceptions, based on 'what you know', every time you do encounter a QM phenomenon up close.

I used to have issues with quantum weirdness, but don't anymore. The old realism ideals are dead to me since many years.

However if we just talk about quantum mechanics as in the formalism currently formulated, it's IMO not yet finished. Quantum mechanics is still a semiclassical construct. It still contains old style thinking in many ways.

At the birth of the theory, the step from determinism to probabilistic thinking was probably a large step, but when you analyse the physical basis of probability, it is still very clear that there are still strong elements of old logic in there, that I think is very malplaced. Most people, with some exceptions that know QM, get uncertain when you probe these questions. Some acknowledge the problem but don't see how to resolve it, some educated people mysteriously manage to convince them selves that these questions are philosophical pottery that have no bearing to the future of physics.

Given such attitude I think what we need to make progress is a solid fool.

/Fredirk

 

[Gear300]

I keep wondering what would have happened if Einstein never thought of his 'crazy' ideas. The aether theory would have gone on and dominated science and we would have to make lots and lots of modifications to keep that theory alive. The same thing seems to be with string theory with the ideas of extra dimensions, branes and exotic particles.

Interesting question...almost the same as: if humans did not evolve to perceive light and instead relied primarily on mechanical waves, then how long would it take us to perceive the phenomenon of electromagnetic waves?...in which this would apply to a lot of instances of the concepts of modern physics: just because we do not experience it, does not mean it does not exist. This would apply to dark matter, quantum strangeness, strings, etc...

 

[math_04]

Well with regards to quantum mechanics, there are still a great many people, lecturers, students who claim to understand quantum mechanics or impose their interpretations on others. The problem is that quantum mechanics works wonderfully well, it is the most precise, fundamental theory of nature. The classical theories, relativity are all special cases where you could neglect quantum effects.

There are some who still fail to grasp the surprising reality of the main parts of quantum mechanics like the Heisenberg uncertainty principle or wave particle duality. To my understanding, it is meaningless to picture an electron without doing an experiment to determine its nature but yet, there are some who still try and picture an electron. Some may say ' what the heck, who cares'. Of course, if you wish to use quantum theory like a cookbook, it is your wish but if you want to make sense of it and further your understanding, you might want to dispense with the pictorials. That is just one example.

Nickyrtr, you do bring up an interesting debate. Like Niels Bohr, Schrodinger and Einstein did a long time ago, we have got to get back to the drawing table, try and ask the deeper questions of why and how. I just hope it will be now and not later.

 

[Dmitry67]

I believe that the 'deeper questions' might be misleading
Questions like 'what is time?', 'what is space', 'what is a quantum particle?' - to answer these questions you have to explain literally everything. And it creates just tons of blah blah blah.

Max Tegmark's idea is great: on the deepest level there are just formulas, no place for that blah blah stuff.

 

[math_04]

Dmitry67, by asking what is space and time made physicists question its absolute nature? When Newton's laws professed an absolute time and space, Leibniz, Mach and a few others questioned them and set up thought experiments. Later on, Einstein based his theory of general relativity on those questions.

Time is another question. Entropy seems to be related to the arrow of time, I am not familiar with Thermal Physics yet so hopefully someone will help out but apparently, there is a relation.

So all those questions should be asked if we are really going to have a fundamental theory that can reconcile quantum mechanics and gravity. Maybe there are formulas but how are those formulas thought? It is by questioning, developing a satisfactory theory in words and then using the mathematics.

 

[Dmitry67]

When we ask 'what is water'? we get an answer that water is H2O, 2 hydrogen atoms and one O. We define more complex thing as a combination of more fundamental things. So you examine 'inner' properties of water.

However, that approach is not applicable for something which is fundamental. You can not say for example "space consists of spacions". Well, you can, but in that can you ask what is a spacion :)

Fundamental things can be defined only based on their relationships with the other fundamental things, based on their 'outer' properties.

But this is exactly what we have in the mathematics. Check the peano axiomatic and formal arithmetics. imagine someone asking silly questions "what is more fundamental, next operator or 0? what numbers are made of? is '+' real?" It sounds silly for arithmetics, but people continue asking such questions in physics over and over again, intuitively hoping to hear an explanation based on the "inner" properties.

Make an experiment, answer "space is made of spacions" and you will see that a person is relieved for at least few seconds, until he/she starts wondering what the hell spacions are :)

 

[Fra]

Max Tegmark's idea is great: on the deepest level there are just formulas, no place for that blah blah stuff.

But this misses the physical basis of representation and ecoding of information. Where are these formulas encoded? I think even the physical representation of mathematics is quite relevant in this context.

That said, I liked reading some of Tegemarks papers but I'm not a total fan :)

/Fredrik

 

[Fra]

But this misses the physical basis of representation and ecoding of information. Where are these formulas encoded?

As I see it, this is where the observer must come in, to encode information about it's own enviroment. I think Tegemarks is unlikely to find his extreme "bird view" anywhere from the inside. Therefor I think the very question must be revised.

I consider myself the frog, and I need to develop a frog-compatible logic, tegemarks idea seems mor suitable to be implemented in Gods brain ;)

/Fredrik

 

[Dmitry67]

But this misses the physical basis of representation and ecoding of information. Where are these formulas encoded? I think even the physical representation of mathematics is quite relevant in this context.

That said, I liked reading some of Tegemarks papers but I'm not a total fan :)

/Fredrik

He answers this question in his article.
Another versions of this question:

Stephen Hawking famously asked “what is it that breathes fire into the equations and makes a universe for them to describe?” [93].

...

If the TOE at the top of Figure 1 exists and is one day discovered, then an embarrassing question remains, as emphasized by John Archibald Wheeler: Why these particular equations, not others?

And the answer

In the context of the MUH, there is thus no breathing required, since the point is not that a mathematical structure describes a universe, but that it is a universe.

Could there really be a fundamental, unexplained ontological asymmetry built into
the very heart of reality, splitting mathematical structures into two classes, those with and without physical existence? After all, a mathematical structure is not “created” and doesn’t exist “somewhere”. It just exists.

As a way out of this philosophical conundrum, I have suggested [12]) that complete mathematical democracy holds: that mathematical existence and physical existence
are equivalent, so that all mathematical structures have the same ontological status.

 

[Fra]

Make an experiment, answer "space is made of spacions" and you will see that a person is relieved for at least few seconds, until he/she starts wondering what the hell spacions are :)

This is a good point, and it's exactly why I think we need an evolutionary dynamical model. In theory there may be a point where then questioners brain is full of information and incapable (complexity-wise) to encode and post further questions. This is how I see it.

This does not necessarily lead to the usual objection of "infinite regress", but I think the thing is that the smallest parts are relativt to the observer. A complex(massive) observer should have the potential to distinguish details that a simple observer are incapable of.

I see no reason why asking and probing these things should not lead to significant progress. But understanding our own understanding, we can reach yet one level beyond the simpler "information mechancs" we have right now, and understand how nature organizes itself, on the level of structure of matter and the level of structure of law.

/Fredrik

 

[jambaugh]

I think one of the problems is that the philosophy of science is not taught sufficiently in the early physics program only the mathematical mechanics of calculating physical predictions from classical ontological models. Then when students get to quantum theory they stumble over the ontological interpretation of QM because they've no sufficient basis for understanding the philosophical foundations.

The problem I see with string theory is that it is trying to construct an ontological model (quantized) from scratch and then get predictions. The domain of imagination is infinite so this is a rather inefficient approach. Add to this that it replicates the same general problem (though not in the same way) which cause QFT to fail with gravity. The divergences stem from overcounting degrees of physical freedom. The fixes e.g. BRST methods and renormalization are not up to the task because there is an underlying prejudice toward "quantizing" a classical ontological model rather than examining in more detail the "classicalization" process. If one assumes "all is quantum" then this second is the key point. The whole emphasis on Lagrangian methods is I think keeping the poisoned seed of depending on an fundamental classical model (be it strings branes or point sized harmonic oscillators).

I'm sure we will again see some maverick physicist or group ignite a revolution which will take years to be appreciated and accepted. Who knows but that there's an obscure paper out there in the publication universe with the seeds of the next revolution spelled out... or maybe not. It may be a century before someone smart enough and with the right perspective comes along.

 

[jambaugh]

I think one of the problems is that the philosophy of science is not taught sufficiently in the early physics program only the mathematical mechanics of calculating physical predictions from classical ontological models. Then when students get to quantum theory they stumble over the ontological interpretation of QM because they've no sufficient basis for understanding the philosophical foundations.

The problem I see with string theory is that it is trying to construct an ontological model (quantized) from scratch and then get predictions. The domain of imagination is infinite so this is a rather inefficient approach. Add to this that it replicates the same general problem (though not in the same way) which cause QFT to fail with gravity. The divergences stem from overcounting degrees of physical freedom. The fixes e.g. BRST methods and renormalization are not up to the task because there is an underlying prejudice toward "quantizing" a classical ontological model rather than examining in more detail the "classicalization" process. If one assumes "all is quantum" then this second is the key point. The whole emphasis on Lagrangian methods is I think keeping the poisoned seed of depending on an fundamental classical model (be it strings branes or point sized harmonic oscillators).

I'm sure we will again see some maverick physicist or group ignite a revolution which will take years to be appreciated and accepted. Who knows but that there's an obscure paper out there in the publication universe with the seeds of the next revolution spelled out... or maybe not. It may be a century before someone smart enough and with the right perspective comes along.

 

[nickyrtr]

I believe that the 'deeper questions' might be misleading
Questions like 'what is time?', 'what is space', 'what is a quantum particle?' - to answer these questions you have to explain literally everything. And it creates just tons of blah blah blah.

Max Tegmark's idea is great: on the deepest level there are just formulas, no place for that blah blah stuff.

Of course, each answer to a question raises more questions. As in your example, "what is water" is answered "it is one oxygen atom bound to two hydrogen atoms". But now we have new questions, "what is an atom and what are oxygen and hydrogen", which leads us to understand electrons, protons and neutrons. Exploring the nature of these particles leads us to quarks and the standard model. But still we are not finished ... understanding the nature of quarks and the limits of the standard model keeps many scientists busy to this day.

Yes, the answer to "what is space" could lead to a theory of "spacions" or something, which only opens more fundamental questions, but that is still progress! On the original question, "what is space?" we have progressed from having no answer to having at least a theoretical answer, which can be expressed precisely with mathematical formulas. On the new question about "spacions" we have progressed from not even knowing the question exists, to being able to ask the question at all.

This is my view of the progression:
stage 1: total ignorance (we don't even think about it)
stage 2: intuitive speculation ("blah blah")
stage 3: consistent, precise models (mathematical formulas)
stage 4: models tested by experiment

You seem to suggest we should leap directly from stage 1 to stage 3, but how can we create a new mathematical model when we have not yet figured out what we should be modeling?

 

[Dmitry67]

No, an in this subforum we are doing #2 :)
I wanted to say that this

Of course, each answer to a question raises more questions. As in your example, "what is water" is answered "it is one oxygen atom bound to two hydrogen atoms". But now we have new questions, "what is an atom and what are oxygen and hydrogen", which leads us to understand electrons, protons and neutrons. Exploring the nature of these particles leads us to quarks and the standard model. But still we are not finished ... understanding the nature of quarks and the limits of the standard model keeps many scientists busy to this day.

can be done only limited number of times.

 

[nickyrtr]

No, an in this subforum we are doing #2 :)
I wanted to say that [reduction of Physics models to more fundamental principles] can be done only limited number of times.

On what basis do you conclude this? It seems to me unprovable, since we do not know the future of science.

I would at least suggest that now, in 2009, we have not reached the end of scientific revolutions, since our most basic theories (general relativity and quantum field theory) are inconsistent with one another.

 

[Dmitry67]

Well, I don't have any proof but if would be very sad.

If the number of reductions is infinite then physics is infinitely complex. In that case TOE contains infinite amount of information -> infinite enegry/mass to store it. Any system which is trying to reach some level of knowledge will inevitably become too massive and becomes a black hole. So anyone who is trying to understand everything will be veiled by the event horizon from the rest of the world... I don't believe that God is so evil. It would be a really bad joke...

 

[nickyrtr]

...If the number of reductions is infinite then physics is infinitely complex. In that case TOE contains infinite amount of information -> infinite enegry/mass to store it. Any system which is trying to reach some level of knowledge will inevitably become too massive and becomes a black hole. So anyone who is trying to understand everything will be veiled by the event horizon from the rest of the world... I don't believe that God is so evil. It would be a really bad joke...

We are already in this predicament, even with simple Newtonian physics. To numerically represent the masses and distances between Newtonian bodies, with exact precision, would require an infinite number of digits, i.e. an infinitely large computer memory. Furthermore, an infinitely fast computer processor is required to exactly calculate the motions of these bodies, according to Newton's equations of motion.

On the other hand, this does not mean we need to give up physics. A first generation TOE, for example, could still be very useful and explain much that is today a mystery, even though some day it may be explained by an even more fundamental 2nd generation TOE, 3rd generation TOE, and so on. We do not need to understand everything, to understand more than we do now.

 

[Dmitry67]

We are already in this predicament, even with simple Newtonian physics. To numerically represent the masses and distances between Newtonian bodies, with exact precision, would require an infinite number of digits, i.e. an infinitely large computer memory

This is correct: the size of sets different states even of 2 Newtonian bodies is continium.

However, in QM matter in a finite volume can be only in the countable set of states, and even more, if energy inside that volume is limited (which is always true, otherwise it would be a black hole) matter can be in finite number of states.

 

[nickyrtr]

However, in QM matter in a finite volume can be only in the countable set of states, and even more, if energy inside that volume is limited (which is always true, otherwise it would be a black hole) matter can be in finite number of states.

A single measurement will always find one of the countable states, but the volume's actual quantum state (before measurement) is some linear combination of them. Those linear coefficients are any complex numbers, so we are back to the continuum problem to completely describe the system.

 

[Dmitry67]

Agreed. However, let's take peano axiomatcs (formal arithmetics). Set of axioms is very short, but the number of numbers :) and number of their properties is infinite. So finite set of equations of TOE can govern infinite physical entities.

I can not prove that your idea with an intinite sets of TOE models is wrong, but I just don't like it. BTW Max Tegmark discusses it too.

 

[math_04]

We cannot know EVERYTHING about the universe but hopefully we can learn enough to progress our technology. My knowledge of quantum physics is still pretty limited but I think quantum mechanics is as fundamental you get and maybe, with some modifications here and there, the solutions may be interesting. But of course, that is just an ignorant student talking.

Abraham Pais once said that Einstein himself predicted that a unified field theory would churn out all the details without us having to worry about the extra particles etc.

 

[nickyrtr]

Agreed. However, let's take peano axiomatcs (formal arithmetics). Set of axioms is very short, but the number of numbers :) and number of their properties is infinite. So finite set of equations of TOE can govern infinite physical entities.

I can not prove that your idea with an intinite sets of TOE models is wrong, but I just don't like it. BTW Max Tegmark discusses it too.

That is part of human diversity perhaps, one person is excited by an infinite field of knowledge to explore, another hopes to find a single ultimate solution. On a philosophical note, if conscious thought can go in both directions of preference, perhaps the reality is somehow a synthesis of both ways of viewing truths. In other words, perhaps the question "is there a final, ultimate theory of physics" is not an ontological question at all, but a question of how one chooses to view and discuss reality, in which case either point of view can find satisfaction :)

 

[Fra]

His response have some good points but misses some points in my objection.

the point is not that a mathematical structure describes a universe, but that it is a universe.

I see this is what he has in mind, but it makes no sense to me. If you stick to observable ideals, then the description/image/expectation of whatever is out there is all we have.

The question is not what is, but what I can KNOW. It's the frog vs bird view again. Tegemark sees no problem with the birds view, as it seems. I do.

After all, a mathematical structure is not “created” and doesn’t exist “somewhere”. It just exists.

This defense is what you might expect from him. I disagree. The physical basis on the structures, at least exists in Tegemarks brain.

Set aside humans, the information about the environment exists somewhere, and it's in the microstructure of hte observer. Where else? It's the one obvious place for it.

As a way out of this philosophical conundrum, I have suggested [12]) that complete mathematical democracy holds: that mathematical existence and physical existence
are equivalent, so that all mathematical structures have the same ontological status.

In a sense this si a good point, but he still wants to ignore that all structures has a basis. I would like to tweak this to say thta, ok there is a kind of equivalence but my conclusion is that rather than it making everything crazy possible, physical constraits, constrains the possible mathematics! In particular when you consider elementary particles and the small. There is a limit as to what can be encoded in a small strucutre. Without this, what means to be have to constirna possible mathematical models? We would get crazy landscaps of possible models and get lost.

/Fredrik

 

[Dmitry67]

Fra, I see your main objection is that a 'pure' matematical structure can not exist without a 'basis'. It reminds me a story of either: it was so obvious for everyone that lightwaves needed some basis, some substance to propagate in, right? :)

You call it 'crazy' - yes, I agree. And, based on the history of physics, is a best sign that it could be true!

And then again, you say 'encoded'. You always assume that there is some substance needed to give life for the mathematical structures. Why?

Lets say TOE equations are published tomorrow. What do you expect to see? Do you expect to have there some purely physical axioms, which can ot be expressed in a mathematical form?

 

[Fra]

Fra, I see your main objection is that a 'pure' matematical structure can not exist without a 'basis'. It reminds me a story of either: it was so obvious for everyone that lightwaves needed some basis, some substance to propagate in, right? :)

I see quite a difference from the quest for a material classical ether filling space, to a informational basis. This base I'm looking for need not "sit in space", it rather makes up space. So in a certain sene, even space requires partially a representation. But it's not a material ether ot me, it can very well sit in the matter in space, and the relation between them defining space are encoded in the microstructure of the matter concenrtrations.

I am NOT looking for a "realistic basis" like the old ether advocates wanted. It's more subtle, but a basis nevertheless.

And then again, you say 'encoded'. You always assume that there is some substance needed to give life for the mathematical structures. Why?

"Life" wasn't my choice of word in this case, it sound strange.

But mathematical models are only representations, it "lables" something else as a kind of abstraction.

If I describe an atom with equations, then the state space and the action encoded in this, are just an abstract representation of what the atom itself is a manifestation of.

Therefor there is in some sense IMHO at least (I guess it's also part of my personal reasoning and intutition, so there is nothing I can "prove") a one-2-one correspondence between a minimal representation of observed reality and mathematics.

This is also why I have objections to the use of continuum as a fundamental starting point. In this representation mapping, the information capacity is important. I can not stretch myself to picture infinite information content, in a small region of space. It makes no sense to my brain. THAT choice of abstraction is IMHO redundant, and is only obscuring things. IT is not one bit surprising that you get infinites coming up all over the place. I have yet to see nature produce a representation of an infinity.

Lets say TOE equations are published tomorrow. What do you expect to see? Do you expect to have there some purely physical axioms, which can ot be expressed in a mathematical form?

Ok. Good question. If we by TOE mean unification of all forces including gravity, then I think first of all that theory would still not be closed and leave no further questions. I'd expect the theory to take the form of an evolutionary relation between observations. The best possible understanding would in my imagination be implemented in a specific observer, by designing the observer along these principles.

So I expect to see a kind of learning model, where physical interactions, and emergent structure of matter are a result of intrinsic logic between interacting parts. This "logic" is what I consider to be the CORE of a new model. Particle masses etc, would be outputs following from processing experimental data in line with this principle.

To me the mathematics is just a representation. If I am going to write down a model
in a paper, it will be in the form of mathematics and algorithms. Probably some information processing algorithms along with normal dynamics equations with initial conditions. But no equation on a sheet of paper can answer everything. I think what we can write down, are the core of the logic of our understanding, the further encodes howto process the information at hand in the best way.

I see physical interactions, as communication between system. Each and every one part can consider themselves an observer, observing the rest. Each choice of observer will give a different picture, and I think the tension between these pictures is the origin of forces. Internal forces are after all a manifestation of a sort of disagreement or inconsistencies.

It's a description at this level, I am looking for, and the core I expect to be: the logic of how nature processes, acts and encodes this. IF you sense a chicken/egg case here, I like Zureks statement that "what the observer IS, and what the observer KNOWS" is inseparable.

Meaning that your knowledge does not SIT on external hardware (memory device), reather the hardwre is inseparable from the information encoded into it.

But I haven't yet seen a full implementation of these ideas, but it's what I expect to see tomorrow when You publish the TOE equations

/Fredrik

 

[Fra]

IThis base I'm looking for need not "sit in space", it rather makes up space.

It's difficult to not notice the similary to this, and Tegemarks statement regarding mathematics :)

Indeed, I can partially see sense in what he says. But I think the main difference is that I require that all of this, is constrained into a frogs perspective.

Tegemark seems to have some strange idea that he will find a master bird view, from which he can "compute" any given frogs view. That's exactly what I think is impossible. His birds view, even if it did exists, would not fit into tegemerks own brain! :)

That may seem both silly and obvious, but I think it does change the strategy a bit.

/Fredrik

 

[Fra]

Tegemark seems to have some strange idea that he will find a master bird view, from which he can "compute" any given frogs view.

I think the more realistic "problem", is howto GUESS the behaviour of one frog, beeing one of the other frogs. Ie. reasoning and acting based on incomplete information. In this quest, it is a desirable trait to develop an "image" of the environment, on which your decisions are made. And moreoever this image, is continously update depending on the feedback. As I see it, space is encoded in this image. And when all observers agree upon space, they agree upong the relations between them. But as I see it, this connection that restores the symmetry is emergent by an indeterministic process.

Similary, I think there are emergent bird views, between local groups of observers, that can even be seen by some "larger frogs", but the ultimate birds view is I think just an illusion. OTOH, the action of a frog, will be as if his image is a birds view. But when a third largers frog analysis this, he will (personal conjecture here) see an inconsistency in the two birds view. Therefore, calling them bird views make little sense. The actual BIRD never enters the equation, because it's an abstraction. There are only frogs, to interact, observer and compare each other. The only difference is that some frogs are smaller, and some frogs are bigger. The big frogs may feel like gods, giggling at the small frogs interacting, without realising that they are themsleves also just frogs.

/Fredrik

 

[Dmitry67]

1
But mathematical models are only representations, it "lables" something else as a kind of abstraction. If I describe an atom with equations, then the state space and the action encoded in this, are just an abstract representation of what the atom itself is a manifestation of.

2
This is also why I have objections to the use of continuum as a fundamental starting point. In this representation mapping, the information capacity is important. I can not stretch myself to picture infinite information content, in a small region of space.

3
Ok. Good question. If we by TOE mean unification of all forces including gravity, then I think first of all that theory would still not be closed and leave no further questions. I'd expect the theory to take the form of an evolutionary relation between observations. The best possible understanding would in my imagination be implemented in a specific observer, by designing the observer along these principles.

1
Remember, non-eucledian geometry was developed for purely mathematical reasons before GR needed it. We could say: curved space is an abstraction. And oops, there we live.

We used to say "complex numbers are just a way to solve some problems in physics mathematically. All physical variables MUST be real. And oops, vawefunction is complex!

Do you see a trend here?

You say "But mathematical models are only representations - I would add, "so far".
So may be it is time to actually make this step?
mathematical models WERE only representations...

1A
You see, if we accept Max Tegmerk's point of view, we don't need to answer "what the reality is". If TOE equations are just a model of reality, what is reality? Why it does not collapse and dissapear? Why the core nature of reality can no9t dissaper, like a virtual world in my computer, when I shut it down?

2
It looks like you are worrying about the Matrix, about being asked to emulate our world. So, you see the problem of having infinite amoutn of information is a finite region of space. But wait, space is infinite. Why don't you have a problem with an infinite information for the whole universe? No matter if information in some region is finite or infinite, it does not "help" your computer...

3
Thank you for riminding me about the mass spectrum. How many "free" parameters do you expect to see in TOE?

 

[Dmitry67]

Tegemark seems to have some strange idea that he will find a master bird view, from which he can "compute" any given frogs view. That's exactly what I think is impossible. His birds view, even if it did exists, would not fit into tegemerks own brain! :)

Again, it depends on if we talk about the EQUATIONS of the bird's view or all the details of all the worlds which obey these equations.

I believe that the equations of the bird's view are simpler then the ones for the frog's view. QM is a perfect example. In MWT, bird's view is QM without collapse. Frog's view is created by the Quantum Decoherence. And it is here, in the frog's view, where all the weirdness comes in place: randomness, non-locality, collapse.

If you read his article you problbly remember that "the whole ight be simpler then each part of it"

 

[Fra]

> 1A
> You see, if we accept Max Tegmerk's point of view, we don't need to answer "what the reality is". If TOE equations are just a model of reality,
> what is reality?

The TOE equations would ideally be the _best answer_ to What's reality. That's good enough for me.

> Why it does not collapse and dissapear? Why the core nature of reality can no9t dissaper, like a virtual world in my computer,
> when I shut it down?

There is still a state of the PC when it's shut down. You just removes the forced state from PC programs and circtuis. You can't make a direct analogy. In reality one can't pull the plug between the microstate and microstructure.

The reason for the "stabiliy of the image" is IMO related to inertia of the hardware. The hardware has evolved along with the state, and NO observed event can instantaneously change this, because I think the notion of time is entangled with this. It's impossible for me to try to convince you in this thread, but I see many ways in how the origin of inertia, in the context of information processing is why a "virtual" image actually does acquire inertia and stability.

This is because the construction of the "hardware" that SUPPORTs the image has a certain inertia, and deformation of the hardware is a slowly evolving process, compared to changing the STATE of the hardware. It's analogous to the dynamics IN spacetime, and the dynamics of spacetime geoemtry itself. There is a feedback, but the inertia of spacetime is large enough to give a certain stability.

> 2
> It looks like you are worrying about the Matrix, about being asked to emulate our world. So, you see the problem of having infinite amoutn
> of information is a finite region of space. But wait, space is infinite.
> Why don't you have a problem with an infinite information for the whole universe?

Why would there be a problem with that? As long as I don't see it all at once, which I don't I'm fine :) The point is that I can not even construct a measuring device to measure this infinite size.

> No matter if information in some region is finite or infinite, it does not "help" your computer...

First I should att the "computer hardware" in this case, is the matter itself. Computations are simply physical interactions. The memory is the STATE of the hardware - the microstate of matter. But even when solving the equations of a human theory, a normal Pc may be used, and it can not handle infinite information. You can't perform a computation in finite time on infinite information. That's one very practical part.

A local computer does not NEED all information in the universe for his daily business, because I think any local observer, responds only to his local information. Therefore, information unavailable has no impact, and can be disregarded with no ill effects.

It will never be possible to deterministically predict the future. The problem at hand, is to guess the future sufficiently good to survive in your given environment. This provides a selection for algorithms. Stupid algorithms doesn't get preserved, but neither do they need to be banned. They punish themselves out of business.

> 3
> Thank you for riminding me about the mass spectrum. How many "free" parameters do you expect to see in TOE?

I think this questions reveals that you may have a different idea of what the theory is like than me. I think the answer depends on it's evolutionary state. Ideally each parameters is a result of an evolutionary history, and if you loose the information of the history, then you end up with a "free parameter", but it really isn't "free", it's just that you might have lost track of it.

If we take a more practical question, as to how many of the current parameters in the standard model I execpt to see go away, then for sure all the particle masses should be explained. I think the spectrum of particles will correspond to different evolutionary stages as you scale up the mass. And I expect that the logic here should explain the hierarchies
we see. If you start the observation at a late stage, the more free parameters do you need to "fit" to experimental data. I think this is natural, and isn't a flaw by any means.

/Fredrik

 

[Fra]

different evolutionary stages as you scale up the mass. And I expect that the logic here should explain the hierarchies we see.

The scaling of mass is also the same as origin of inertia. The particles acquires large and larger inertia by evolving their information processing algortihms. Not all algortihms can be successful, therefore, a prediction of the algorithm spectrum that survices is expected.

If I'm right this will be the particle spectrum we see. And masses as well as the participation in the forces should hopefully come out.

/Fredrik