Free will, undecidability, and the problem of time in quantum gravity by Rodolfo Gambini

Dear Prof. Gambini,

i enjoyed reading your paper. i find in it something of an intuitive resonance with my personal experience of reality in it.

i do, however, have one minor issue with what you have written here.

re:

"In the first case the system would keep its entanglement with the rest of the

universe (i.e. the environment), in the second it will lose its entanglement. The availability of this choice opens the possibility of the existence of free acts."

i've run into this curious perspective here in the presentations twice now, that a theory will determine wheather we have free will or not.

i have the distinct impression that this is taking theories a little too seriously. theories have absolutely no impact on what actually is. they cannot permit or deny anything actualizing.

to hinge a determination of free will, be it yeah or nay, upon a theory enslaves what little free will you may have had to start with to that theory, building a whole new conceptual prison, apparently voluntarily, for the will.

it's a jail break; i'm here to spring ya.

of course, you have the option to remain in that lovely prison you've built, if you so desire.

i must admit, it's not half bad as far as prisons go; looks pretty comfey - an open door policy honor system. you might even find people wanting to join you in there, get to looking more like a clubhouse. just be mindful that it's subject to having the door unexpectedly locked come the next scientific revolution.

re:

"In fact if quantum mechanics only implies a mere lack of causal determination in the occurrence of events, this is not sufficient to ensure that it makes sense to consider a free act for which responsibility is possible."

ah, glad you noticed that here; i was about to say something about this also. nice treatment. fun prison. :-)

re:

"It would be quite disappointing if a universe that naturally includes in the laws of physics the capability for free acts will end up disallowing them for human beings."

well, it does and it doesn't. my personal experience with 'free will' strongly suggests that it has some distinct limitations. i don't seem to be permitted to choose to both sit here at the computer typing away and take a walk around the block at the same time. in fact, i don't appear to be allowed any more than one discrete action set at any given moment. i don't seem to be able to walk to the moon. my experience is also that the exercise of what 'free will' one might have is somewhat negotiated - this feature comes into sharp focus under such circumstances as crossing busy streets.

it would be significantly more disappointing if bright minds continue to fail to notice the conceptual limitations they impose upon themselves.

be free.

be well.

stay out of jail ;-)

glad to meet you.

:-)

matthew kolasinski.

Hello Rodolfo,

Thanks for the paper!

Your abstract begins with:

"In quantum gravity there is no notion of absolute time."

Would it not be more proper to write, "In our universe there is no absolute notion of quantum gravity." By that I mean there is no experimental nor theoretical evidence for quantum gravity. Gravitons have never been seen, and gravity has never been quantized in any respected, accepted manner in any theory, nor in any finite manner, for that matter.

Might it not be dangerous to let something that does not exist--quantum gravity--inspire and/or dictate our contemplations on time? I mean theoretical physics is hard enough, even when it is built on reality. But to build theoretical physics upon the unreal--is this not the very "Trouble With Physics" Lee Smolin writes about, which is better suited to building sociological movements, even when begun with the best intentions?

Do we have to quantize gravity? Could it be that nature is as it is, and that God or the Prime Mover/Creator came up with both QM and GR, which seem to coexist perfectly well in their current forms? For instance, this laptop computer is powered by quantum phenonema, and too, it is held on my lap by gravity. Each one has a role, and each seems perfectly content to play it. Perhaps both mathematical predictions and the experimental search for gravitons has fallen short because gravitons do not exist. Now this is no reason to stop looking, but too, it is not exactly a reason to keep looking, and it is certainly not a reason to get rid of time, which does seem to exist, as my laptop's clock tells me I am running late, yet again. :)

A book you would enjoy is Freeman Dyson's THE SCIENTIST AS REBEL. On page 219 Freeman Dyson writes,

"(Brian) Greene takes it for granted, and here the great majority of physicists agree with him, that the division of physics into seperate theories for large and small objects is unacceptable. General relativity is based on the idea that space-time is a flexible structure pulled and pushed by material objects. Quantum mechanics is based on the idea that space-time is a rigid framework within which observations are made. Greene believes there is an urgent need to find a theory of quantum gravity that works for large and small objects alike. . . As a conservative, I do not agree that a division of physics into separate theories for large and small is unacceptable. I am happy with the situation in which we have lived for the last eighty years . . . The question I am asking is if there is conceivable way we could detect the existence of individual gravitons. I propose as an hypothesis that it is impossible in principle to observe the existence of individual gravitons." --Freeman Dyson, THE SCIENTIST AS REBEL, pp 219-220

Perhaps we should found our contemplations on time not upon the unreality of quantum gravity, but on the reality of *physical* theories represnting *physical* phenomenon.

Instead of being built on the unreal, my simple theory--Moving Dimensions Theory--is built upon the rock-solid empirical evidence supporting widely-accepted theories of relativity, quantum mechanics, and statistical mechanics.

And MDT tells us a lot about time and its arrows across all realms, showing that they are phenomena that emerge from a common, deeper principle--a fundamental universal invariant--dx4/dt=ic.

MDT views time as a phenomenon that naturally emerges because the fourth dimension is expanding relative to the three spatial dimenions at the rate of c. Change is fundamentally woven into the fabric of spacetime via dx4/dt = ic, which makes sense, because change is fundamentally woven into our everyday existence, empirical observations, and all branches of physics! Indeed--it would not be possible to make a measurement without change! A great thing about MDT is that it allows us to keep all of relativity while unfreezing time and liberating us from the block universe, which is yet a meaningful artefact that arises from certain interpretations of relativity. And who knows, perhaps MDT will tell us something about quantum time, which will tell us something about quantum gravity. For MDT also provides a *physical* framework for quantum entanglement and nonlocality, and thus it provides a *physical* model underlying qm's inherent nonlocal, probabilistic nature.

Think about MDT as a simple *physical* unification of relativity and QM--both entanglement and nonlocality can be accounted for via the same principle--the same hitherto unsung univeral invariant of dx4/dt=ic--that ensures a photon does not age, no matter how far it travels. A photon's timelessness, implied by relativity, represents a nonlocality in time. Both quantum entanglement and the agelessness of a photon descend from a common principle--a fundamenatl, universal invarinat: dx4/dt = ic. A photon is matter that "surfs" the fourth expanding dimension, and thus it remains in one place in the fourth dimension, while traveling through the three spatial dimensions at c. Ergo the fourth dimension is expanding relative to the three spatial dimensions. Perhaps this is MDT's simplest proof: The only way to remain stationary in the fourth dimension is to move at c through the three spatial dimensions: egro, the fourth dimension is expanding relative to the three spatial dimensions.

And a great thing about MDT is that it also presents a *physical* model for entropy, as briefly elaborated on in my paper:

http://fqxi.org/community/forum/topic/238

MDT represents the kind of theory we have not seen for awhile--a simple postulate and a simple equation that present a novel, hitherto unsung aspect of the universe--the fourth dimension is expanding relative to the three spatial dimension: dx4/dt=ic. This fundamental invariance underlies the invariance of the speed of light--both the constant velocity of c meausred by all inertial observers and, the constancy of c that is independent of the source. MDT also underlies relativity's two postulates, and all of relativity may be derived from MDT's simple principle of a fourth expanding dimension.

When we look at Einstein's 1912 Manuscript, we see that time plays a different role from position. x1, x2, x3 represent the three spatial dimensions, which we generally use to demarcate position. And then along comes x4, which Einstein equates with ict. So as t progresses on our watches, x4 must progress. Time is very, very different from the three spatial dimensions! Perhaps it is not a dimension after all, but a parameter that emerges because the fourth dimension is expanding relative to the three spatial dimensions, as suggested by x4=ict.

MDT and dx4/dt=ic also underly time's thermodynamic arrow, and in my paper I account for and unify all of time's arrows and assymetries with MDT's simple postulate and equation. And in addition to this, all of relativity may be derived from MDT, while qm's entanglement and nonlocality are explained with a *physical* model, along with entropy.

Thanks for the paper! I just think it would be prudent to wait for a consistent theory of quantum gravity, or some experimental evidence, before using quantum gravity as a tool to probe time's great and vast mystery. It would be like hanging something on a sky hook, or shifting smoke with a left-handed smoke shifter.

http://www.urbandictionary.com/define.php?term=left%20handed%20smoke%20shifter

As a new boy scout on my first campout back in sixth grade, I was sent forth to other campsites to go find a left-handed smoke shifter (to shift the smoke from the breakfast campfire) and a sky hook. Of course, this is a big inside joke to everyone but the youngest scouts, so people at the next campsite always smile and nod and say, "We just lent our sky hooks and left-handed smoke shifters to that troop down yonder." And so it would go, as we ran from campsite, to campsite, to campsite, looking for that which did not exist.

This pretty much sums up postmodern academia, where a postdoc might be sent from campus, to campus, to campus, looking for things that do not exist, as the elders get a good laugh. All the postdoc can really hope is that someday they'll be allowed to fund others to seek out their left-handed smoke shifters, to keep the cash flowing.

The big difference is that the joke only lasted a couple hours in boy scouts. When you returned to the campsite after running a few miles, scouting all the neighboring campsites for the left-handed smokeshifter, you were let in on it, and then taken on a snipe hunt that same night:

http://en.wikipedia.org/wiki/Snipe_hunt

It was all good fun, but in academia we are talking about entire careers and hundreds of millions of taxpayer dollars, so all this snipe hunting kindof loses its humor after a day or two.

Best,

Dr. E (The Real McCoy)

Wow. This is a tremendous essay Rodolfo. It will be a course of study for me for some time to come, because I think I can see a way to use the physical principle of undecidability in my own work, as a description of something I have been struggling to articulate.

You are true when you explain that 'the evolution is trivial'; better is to say that Probability Theory is trivial (and proved its inefficacy in Economics recently): symmetry points the extrapolation and the (absolute) 'fake' Time between 'a priori' and 'a posteriori'.

But the Relativity Theory is a symmety too and it is based on extrapolation that is to say (absolute) fake time.

(I must add that I do not agree when you write that can happen something physical on a point. Points are ony measurements.)

Dear Rodolpho,

Sorry that i missed going through your essay till this day. i admire the way you have introduced freshness through some holistic considerations and have expanded the Paradigms in Physics. I also feel strongly that new Physics has become static for over a decade and most studies are mere minor modifications of major studies done in the past. It is clear that there is something non-physical behind the physical world. The question of what existed before Big Bang dominates still. What do you feel about the 'consciousness' playing a role and we have not developed linkage with it in a scientific manner? As time left is short, i ccclose here

Dear Prof. Gambini,

Your solution to the time problem in Quantum Gravity, as well as the surprising result of evolving with or without collapse, is of real interest. And indeed, it seems to have implications on the free-will problem. I cannot help comparing your results, with the direction I am exploring. My version of Quantum Mechanics replaces the discontinuous collapse with delayed initial conditions, combined with entanglement, without violating the unitary time evolution (at least at the larger level). It is deterministic, but allows free-will exactly like the indeterministic QM, via the delayed initial conditions (and not by "compatibilism"). I refrain here discussing my ideas on your thread.

Congratulations for your work,

Cristi Stoica

"Flowing with a Frozen River",

http://fqxi.org/community/forum/topic/322

-My 'Libertarian' objection against this D. Hume 'revival' is more general than the one that R. Gambini is pointing at the end of his essay.

Major objection against Gambini is that there is no Freedom at all in randomisation which is a binary algebraic system entirely based on Symmetry. Standard Model of this symmetric system is a Mirror and the deductions are just the hypothesis Reflex to which a factor is sometimes applied.

Some Scientists will take the Sunset (or Particle and Wave), some others will only take the Set, although the sole Sun is part of Nature.

Closer you are to the Nature, narrow the Mirage (and the LHC is so far away from Natural things!). Fragmenting Energy as M. Planck is doing with Boltzmann Quanta Arithmetic is only possible at the algebraic theoretical level.

'The abrupt change in the wave function' as Gambini says, this 'broken wave' is just a 'coming back to Nature': Inflexion of the Reflex!

-Wether it is made on purpose or not, the Question of the Nature of Time is cleverly skipped in Gambini's theory. How? Just because Time presumption is still there in his Epistemology.

A few explanations about this: D. Hume is quoted but E. Kant after or saint Augustine before could be too who are deducing a model of Scientific 'Understanding' FROM Time Reference, i.e.: Memory (Past), Intelligence/Contemplation (Present) and Free Willing (Future). Put a dot on a circle for Present or Observer and you have a sketch of this 'trigonometric' epistemology -with the Infinity idea above of course.

-The Question of the Nature of Time is vanishing in the Epistemology but Time does resuscitate everywhere in the Probability Theory, the Quanta Physics and, last but not least, in Einstein's Theory as arrows, vectors, cells, blocks, entirely conventional scales or variables.

-Two examples: 1. How can Gambini says that 'In general relativity there is no notion of Absolute Time'?? Relative Time is splitting of 'Absolute Time' -that is to say an analogy with Infinity in distance or addition...

Or does 'Absolute Time' means 'Objective Time' for Gambini? And in this case if 'Objective Time' is not in Einstein's Reference it is not in Gambini's Theory either except as an implicit Postulate.

2. 'A classical non-fluctuating Time is an idealization': what the hell does that mean? Poincaré or Einstein elastic or fluctuating Time is the same 'idealization'. It is classical algebraic geometry of Newton against variable algebraic geometry of Einstein or Poincaré. There is no real elasticity or flow. H. Poincaré admitted it in one of his last books, underlining the contradiction between the conclusion of General Theory and its absolutely necessary postulate.

-I want to say as a conclusion that bad news is that LHC-Experience is just a gigantic video-game for rich Scientists. But good news is that I demonstrate also that Science is cheap Sports, not Golf (I do not even have high speed web-connection!)

Dear Rodolfo,

I believe that your contribution contains an implicit and wrong assumption. When you state "Acknowledging that the real clocks and rods that one may use to measure space-time are not arbitrarily accurate requires reformulating the theory in terms of such clocks and rods." it becomes clear that you consider clock as a tool for measuring something a-priori given. You can say that something is fluctuating only if you consider that there is some real value with respect to which you fluctuate. Later you also talk about unitary evolution of QM as somthing given. I believe that, on the contrary, the point consists of understanding what is a clock, and how it observable quantities are related to other quantities. When talking about the nautre of time, evolution is a word with no meaning.

John

I love it -- a way around the decoherence problem without invoking a many worlds interpretation. But what rules (if any!) would control whether a state "chooses" to decohere?

Dear Rodolfo Gambini,

In the future quantum theory of gravitation in addition to a problem of time the solution of a problem of gravitational energy is necessary. This question still remains open in the general theory of relativity. In the essay The Theory of Time, Space and Gravitation the problem of localization of gravitational energy is solved.

Yours faithfully

Robert Sadykov

Dear Professors Gambini and Pullin,

I enjoyed your essay. You miht take a look at mine, which has some elements in common (it focusses on reduction.)

Dear Prof. Gambini

Time exists only when we measure it.

Universe is atemporal.

From that point gravity force is carried by the atemporal space where time is a "coordinate of motion".

yours amritAttachment #1: In_The_Theory_of_Relativity__Time_is_a_Coordinate_of_Motion__Sorli__FOUNDATIONS_OF_PHYSICS_2009.doc

Dear Dr. Gambini,

When nature put the squeeze on the degrees of freedom of some particle, this particle exhibits a quantized behavior. And when we make a measurement on that particle,we too are putting the squeeze on the particle`s freedom and change its quantization state.

Measurement necessarily introduce a new constraint on the system which is by that fact totally redefined. Adding constraint on a quantum system creates a new temporary quantization of the system. Any constraint on a system creates a new quantum number and quantization. Here is, I believe, a not so recognized example.

A photon can travel in any direction. If one squeezes the direction of the photon along its path, like with a slit, "direction" becomes a "quantum number" and past the slit, this "direction is now quantized i.e. a fringe pattern emerges.

This is the essence of quantum mechanics: constraints define the states of the quantum system. Measurement adds constraint which in turn redefines the system.

After this measurement, the new temporary quantization is gone and the system reverts to what it was before.

This make sense to you?

Thanks

Marcel-Marie LeBel

fqxi_limits of physics contestant