Breaking the Universe's Speed Limit

Will we get any testable predictions form these speculations?

SR is applicable for objects in space and not for the expansion of space itself.

The standard model of cosmology indicates that galaxies which have a red-shift of 1,5, their wavelength of light equals 150% of the one we measure in the laboratory, move away from us at the speed of light.

Right now we know of about 10.000 galaxies with a red-shift greater as 1,5. these objects are moving away from us at a recession speed faster as the speed of light.

The cosmic background radiation has covered a much longer road, its cosmological red shift is about 1100 !!!. So when the hot plasma that radiated the waves that we observe today, it is probable that it (relatively) moved away from us at a speed of 50 times the speed of light. The emitted photon has its local speed of light, so it looses distance compared with its origin (like someone trying to go up on a fast moving down staircase ) here we meet the Hubble Constant .

The Hubble constant right now is 70Km/sec/Mpc (one Mpc=3.262.000light years). In this view also the speed of light is variable and without its limit as indicated by Einstein. It would be interesting also to read the essay of Peter Jackson : 2020 Vision. A Model of Discretion in Space (Is reality digital or analog Contest)

When the above is applicable then the visible Universe should be much greater as the 13,6 milliard years that we are talking of now.

I think this article has excellent timing considering the previous FQXI article was about real-time physics. Does John Donoghue postulate that time emerges from the microcosm of the quantum world? If these particles in the early universe are interacting and converging to a constant value for the speed of light then does that mean time had not yet emerged? If we keep time do Donoghue's ideas no longer work? Why is that last row of the Rubik's cube take an hour to solve when the first two rows can be solved in a few minutes?

I apologize if these questions seem puerile but please remember I am outsider to this community. I think a conceptual precis comparing and contrasting the big ideas for real time and emergent time would help me.

Hi dear Robert,

How are you it was time, but where were you?

rationalization's revoltion.....

Steve

For this article

it's interesting.I admit that the light limit is a problem for future travel inside our universal.The gravitational waves are relevant.Now of course we could find others linear speeds more important above the gauge of light and even without the light.The light is for the perception and like a fuel.It exists probably others linearities, but of course it's for the future.Can we find now, is it important to invest now, is it rational....

The gravitational waves are rlevant in all case.If you take some binar system with stars ,as pulsars, their rotations are improtant.We take the orbital period ,the time of arrival of signals,and the phasis of the orbital of the pulsar and the position and the topology spherical.The waves are under the general relativity , insert the volumes of spheres and the evolution linked witht the speeds of rotations orbitals and spinals see maxwell for the distribution of velocities and the cooling since the hypothetical BB,the rule of spheres become so important and the volumes also considering the entropic evolution.The cinetic momments are purelly correlated and the orbitals momments also, in logic of spherization repecting the cooling,we see the effect of mass and light...now considering the volumes for BH we see the pure relativity if we understand the 4D space time and the distribution of velocities of these spheres, quantics and cosmologics.The gravitational waves are correlated but we see only the light gauge constant.In logic of distribution and with the evolutive volumes, we can find others linearities more important.perhaps the extrapolation of Taylor eissberg can help.The dr Corda and his very relevant works can find very relevant roads if we consider the spherical 3D waves and the pure ditribution of velocities of rotations.The volumes are a key and seem so essential as all thermodynamical links.

Regards

Steve

If the space expands with a speed faster than that of light then it will be torn apart into causally unconnected regions. However, gravity may have to travel faster than light in order to maintain the integrity of the universe.

Excuse the typo in my initial comment.

My question is a serious and sincere scientific question.

Is there any way to test Prof. Donoghue's ideas via predictions that are prior, feasible, quantitative, non-adjustable, and unique to those ideas?

Or not?

Speculation is fine and useful in the initial stages of theory development, but a scientific theory must eventually lead to definitive predictions, or it is not testable and therefore not science.

Robert L. Oldershaw

http://www3.amherst.edu/~rloldershaw

Discrete Scale Relativity; Fractal Cosmology

Hi Robert,

I see possible overlap between your ideas and John Donoghue's. Are you and John collegues at Amherst? Suppose that our Classical Scale is defined on the large-scale side by the Speed of Light Scale limit, on the small-scale side by Planck's Scale limit, and has complexergy of ~10^41 (Dirac's Large Number).

A greater Scale (say the Cosmic Scale?) may have complexergy of ~10^123 (and thus the origin of the "Cosmological Constant" of 10^(-123)). I haven't read your ideas closely, but don't you have a scale number of order this number's square root ~3 x 10^61?

The greatest scale may be an infinite Multiverse (and our Observable Universe is but a fragment of fractal dust). OK - this scale isn't testable, but 10^(-123) deserves questioning. Is 10^123 dependant on a Cosmic Scale number, or is it Dirac's Large Number cubed (3 spatial dimensions)? What if Dark Energy is "leakage" from a greater Cosmic Scale?

Now to connect your ideas with John's:

A greater (say Cosmic) Scale should have a greater speed limit. I suspect that these different scales interact with Spacetime in such a manner as to "pinch off" Spacetime in certain extremes. Near the Black Hole "singularity", Spacetime rearranges into a Buckyball or toroidal lattice geometry because "Infinity" cannot exist in a Finite Observable Universe (we are Scale-limited from "Infinity"). On the outer edges of our Observable Universe, we may have a graphene-like lattice of Spacetime separating our Classical Scale and the greater Cosmic Scale. If Quantum Gravity exists in this Cosmic Scale with a greater speed limit, then it could be transferred holographically across this "graphene-like boundary" as an effective "Spacetime Curvature".

Have Fun!

Dr. Cosmic Ray

At the risk of coming across as "old-fashioned" and/or of belaboring what should be obvious, it seems worthwhile at the outset of this (or any) discussion to ensure that all participants in the discussion share a common understanding of the terminology involved. Would it be safe to assume that the term "speed" as use in this article (and related discussion) is defined in the standard way, i.e., as being a ratio of some distance per some unit of time?

If the answer to the above question is yes, then is it also safe to assume that the definition of time being used is the so-called "operational definition of time," i.e., "time is that which is measured by clocks"? And then would it be safe to further assume that a clock is defined as being "a device which measures time"?

If so, let the discussion proceed. If not, please clarify how the terms being discussed here differ from the above. Thank you.

jcns

Dear JCNS,

The assumption of Scale Invariance and/or Scale Relativity set fundamental length scales upon which everything else could be based. The awkward fact is that multiple scales exist, and therefore, multiple definitions may be required.

We need to look at important dimensionless numbers for clues about Scale behavior. A couple of very relavant dimensionless numbers are the inverse fine-structure constant: 137, and Dirac's Large Number: 10^41.

Perhaps John and Robert could explain their definitions.

Have Fun!

Dr. Cosmic Ray

Hi Robert,

I doublechecked your ideas. OK - You expect Lambda = 1.7 x 10^58, which isn't exactly the inverse square root of the Cosmological Constant ~ 3 x 10^61, but in the grand scheme of scale building, it sounds related to me. It is mathematically improbable and philosophically illogical to expect fine-tuning on the order of 10^60 (or 10^120 or 10^40) - THIS MUST BE REAL PHYSICS! They "invented" Supersymmetry to solve the Weak-GUT Hierachy Problem and that is only 16 orders of magnitude of fine-tuning - How can they ignore such extreme fine-tuning?

What do you think of my 2011 FQXi essay?

Have Fun!

Dr. Cosmic Ray

The idea that time does not exist and the speed of light varies, might be complementary to a situation where space does not exist but time does. In a noncommutative coordinate geometric setting this might then recover the constancy of the speed of light.

Cheers LC

LC,

Wait, please; you're making my little head hurt. This is exactly why I asked (somewhere above) for clarification of the terminology being used here. As I understand the conventional use of the word "speed," it is defined to be a ratio of some distance per some unit of time. But if you then propose that ". . . time does not exist and the speed of light varies. . . ." (as you appear to have done) how do you determine speed without time? I fear that perhaps I'm too easily confused by what should be very simple concepts? Please explain. Thank you.

jcns

Not to rain on any parades, but yesterday morning I received my latest Phys Rev Lett in the mail. The following quote from Physical Review Letters 106, #131802 (1 April 2011) tend to agree with my C-field predictions on SUSY:

In the first LHC search for supersymmetry, "no excess above the Standard Model background expectation is observed"

and

"These ATLAS results exceed previous limits set by other experiments."

Edwin Eugene Klingman

Quantum gravity depends upon inertial and gravitational equivalency in keeping with space that is made equally larger and smaller in keeping therewith. This balances attraction and repulsion, as the space is BOTH flattened/contracted and stretched/expanded in a balanced fashion.

Look at the ground and your feet. Gravity is key to distance in/of space.

I already proved this in/as dream experience. The center of the body is the linked origination and generation of our experience.

You all are repeatedly going about the unification of physics in the wrong manner.

DREAMS COMBINE AND INCLUDE OPPOSITES.

Hi Edwin,

If we are going to talk about Atlas, have you heard the rumor on this diphoton bump with effective mass of 115 GeV?

Have Fun!

Ray,

Yes I have. What do you think it is?

Edwin Eugene Klingman

Hi Edwin,

It is where SUSY phenomenologists expect the Light SUSY Higgs. The strength of the diphoton signal is so strong that it doesn't look like a Standard Model Higgs. I suppose it could be a composite Techni-pion that provides a Goldstone origin of mass, but Technicolor has other problems that probably requires SUSY as a solution. The graph at the top of page 30 in this old paper with my colleagues and me shows how a relatively light-weight Light Higgs could exist, while m_1/2 (and most gaugino masses - most Neutralinos and Charginos) remain quite massive. This implies that we need to look closely for the Light Stop Squark.

The Tevatron has not confirmed this observation, although LEP had gotten to the edge of this region a decade ago, and thought they were on the edge of seeing something. The "leaking" of this paper did not follow protocol, and may or may not stand after the other couple of thousand LHC researchers "sign off".

I guess data and time will tell...

Have Fun!

The argument involves quantum uncertainty between different coordinates. Principally this is between time and position. Suppose there is a theory that time does not exist. All that exist with some geometric content is space. Suppose there is another theory where only time exists, but not space. It might then be that these two theories are complementary sets. They are complementary in the same way that position and momentum are complementary in standard quantum mechanics. If you read my article here on FQXI I indicate (though the calculations are not presented in detail as they are formidable) how light cones and Heisenberg groups emerge from a single structure. I will try to indicate how this works from more elementary considerations.

In 1930 there was a famous Solvay conference where Einstein and Bohr sparred over the reality of quantum mechanics. Einstein was convinced of reality and locality and argued staunchly for an incompleteness of quantum mechanics. Quantum theory could only be made complete if there are some hidden variables that underlay the probabilistic, nonlocal quirky aspects of quantum mechanics. At the 1930 Solvay conference Einstein proposed an interesting thought experiment. Einstein considered a device which consisted of a box with a door in one of its walls controlled by a clock. The box contains radiation, similar to a high-Q cavity in laser optics. The door opens for some brief period of time $t$, which is known to the experimenter. The loss of one photon with energy $E~=~\hbar\omega$ reduces the mass of the box-clock system by m = E/c^2, which is weighed. Einstein argued that knowledge of $t$ and the change in weight provides an arbitrarily accurate measurement of both energy and time which may violate the Heisenberg uncertainty principle ΔEΔt ~ ħ.

Bohr realized that the weight of the device is made by the displacement of a scale in spacetime. The clock's new position in the gravity field of the Earth, or any other mass, will change the clock rate by gravitational time dilation as measured from some distant point the experimenter is located. The temporal metric term for a spherical gravity field is 1 - 2GM/rc^2, where a displacement by some δr means the change in the metric term is ~ (GM/c^2r^2)δr. Hence the clock's time intervals T is measured to change by a factor

T --> T sqrt{(1 - 2GM/c^2)δr/r^2} ~ T(1 - GMδr/r^2c^2),

so the clock appears to tick slower. This changes the time span the clock keeps the door on the box open to release a photon. Assume that the uncertainty in the momentum is given by the Δp ~ ħΔr < TgΔm, where g = GM/r^2. Similarly the uncertainty in time is found as Δ T = (Tg/c^2)δr. From this ΔT > ħ/Δmc^2 is obtained and the Heisenberg uncertainty relation ΔTΔE > ħ. This demands a Fourier transformation between position and momentum, as well as time and energy.

Consider an example with the Schwarzschild metric terms. The metric change is then ~ 1x10^{-12}m^{-1}δr, which for δr = 10^{-3}m is around 10^{-15}. Thus for a open door time interval of 10^{-2}sec, the time uncertainty is around Δ t ~ 10^{-17}sec. The uncertainty in the energy is further ħΔω, where by Fourier reasoning Δω ~ 10^{17}. Hence the Heisenberg uncertainty is ΔEΔt ~ ħ.

This argument by Bohr is one of those things which I find myself re-reading. This argument by Bohr is in my opinion on of these spectacular brilliant events in physics.

This holds in some part to the quantum level with gravity, even if we do not fully understand quantum gravity. Consider the clock in Einstein's box as a black hole with mass m. The quantum periodicity of this black hole is given by some multiple of Planck masses. For a black hole of integer number n of Planck masses the time it takes a photon to travel across the event horizon is t ~ Gm/c^3 = nT_p, which are considered as the time intervals of the clock. The uncertainty in time the door to the box remains open is

ΔT ~ Tg/c(δr - GM/c^2),

as measured by a distant observer. Similarly the change in the energy is given by E_2/E_1 = sqrt{(1 - 2M/r_1)/(1 - 2M/r_2)}, which gives an energy uncertainty of

ΔE ~ (ħ/T_1)g/c^2(δr - GM/c^2)^{-1}.

Consequently the Heisenberg uncertainty principle still holds ΔEΔT ~ ħ. Thus general relativity beyond the Newtonian limit preserves the Heisenberg uncertainty principle. It is interesting to note in the Newtonian limit this leads to a spread of frequencies Δω ~ sqrt{c^5/Għ}, which is the Planck frequency.

The uncertainty in the ΔE ~ ħ/Δ t does have a funny situation, where if the energy is Δ E is larger than the Planck mass there is the occurrence of an event horizon. The horizon has a radius R ~ 2GΔE/c^4, which is the uncertainty in the radial position R = Δr associated with the energy fluctuation. Putting this together with the Planckian uncertainty in the Einstein box we then have

ΔrΔt ~ (2Għ)/c^4 = L^2_{Planck}/c.

So this argument can be pushed to understand the nature of noncommutative coordinates in quantum gravity.

So these arguments concerned with the existence of time are interesting in some sense. I have not been a particular partisan in either say, where Fotoni argues time exists, but not space. Of course space and time are really just holographic manifestations from strings and Dp-branes, which means space and time have no degrees of freedom of their own. However, it does seem that it is possible that space and time are complements in a quantum mechanical sense within quantum gravity. The speed of light is something which emerges from this parabolic group structure I work with which derives Heisenberg groups and light cones.

Cheers LC

LC,

Thank you very much for your excellent reply to my question. You have explained this as clearly as I could have asked or hoped, and your answer is very logical, indeed. Moreover, I'm certainly not in any position to pick an argument with anything you've spelled out here.

That said, however, I'd like to clarify what I see as being probably the primary reason why some of us who are part of what I've come to think of as "the FQXi Time Mafia" seem to be talking past one another when it comes to discussing these things. That reason is, in my opinion, that we are coming at the topic of time from two rather dramatically different paradigms regarding the fundamental nature of time. These different paradigms naturally lead to different ways of interpreting the same empirical observations.

I'm not trying to say that either of these paradigms is necessarily more "correct" than the other, only that they are different and lead to different ways of thinking about the same things, just as there are different ways of interpreting what we're seeing when we look at a Necker cube, for example.

One paradigm for the nature of time, the mainstream, prevailing paradigm, which is a key component in the foundation of modern physics, including especially special and general relativity, is most succinctly summarized, in my opinion, by what has been called the operational definition of time, i.e., time is that which is measured by clocks. Taking this view as a starting point, everything else which is taken as orthodox thinking about physics follows logically and consistently (certainly for the most part, at least).

The other paradigm is the one which I've attempted to spell out in purely qualitative terms in several essays such as those here and here. I don't even know what to call this paradigm. Perhaps it could be called a relational paradigm for time? In a nutshell, it holds that particular times correspond with, and are identically equivalent to, particular configurations of the universe. This view takes clocks to be specific subsets of an evolving universe; in this view, the special role given to clocks in the mainstream paradigm is viewed with skepticism. Far from being a magic bullet for resolving all of the outstanding conundrums of modern physics (see Lee Smolin's 'The Trouble With Physics,' for example), this paradigm raises a host of knotty problems and questions of its own, and I have answers to none of them.

I do not know how to describe this "relational paradigm" in a more rigorous fashion, but it is possible that another, far more clever, person, Joy Christian, has made a stab at this in an essay here. I would not presume to speak for Mr. Christian on this point; it is possible that he would totally and vehemently disagree with me.

Regardless, thank you for engaging seriously on this topic, LC.

Regards,

jcns

J.C.N. Smith,

The nature of time is an interesting subject. I don't get very partisan over the issue of time existing, for physics seems not to welcome ontological or existential ideas from the outset, but only suggests these within some theoretical construct. We have some issues with reality in a quantum mechanical content, in particular with nonlocality and a local definition of reality. Time and space though are not impacted by this. However, it is likely that quantum gravity will have implications along these lines. Julian Barbour is pretty much into the notion that time does not exist. This is based largely on the Wheeler DeWitt equation HΨ[g] = 0, which is a quantum version of the Hamiltonian constraint in ADM relativity.

I could well enough imagine presenting how time exists, but space does not. We could presume there is some one dimensional space, a line or curve, and there is a fibration on that space by a three dimensional space. This internal space is a symmetry of the dynamics of this one dimensional parameterized space we label as time. This then connects to relativity when we consider the metric line element

ds^2 = -c^2dt^2 g_{ij}dx^idx^j,

where mixed time-space metric components are not included. We have here two notions of time. The first is the proper time τ = s/c, which is the invariant of relativity. The other time is a coordinate time t, which is not an invariant.

The obvious question to ask is whether ds is real. We can multiply it by mc^2 and define an action according to the extremal principle of the proper interval

S = mc∫ds,

which appears real in some sense. It has units of action, or angular momentum, which is a measurable quantity. Yet there is something a bit troublesome about all of this. How does the observer on this world line actually measure this interval? A clock is employed which must have some system of oscillations, such as a spring. Yet this is measuring the invariant interval according to something carried on that world line that deviates from the world line. Hence some sort of nongeodesic motion is being used to define or measure an interval along a geodesic path. Of course I am thinking primarily of a mechanical clock, but an atomic one still appears to hold for an EM field must be applied to knock electrons in the Ce atoms.

This Lagrangian is measured according to something which is not invariant. So we might then consider that action as dS = pdq - Hdt. Now we have some Hamiltonian, which might include a part for the dynamics of the clock. Hamiltonians must be specified on some Cauchy surface of data with a coordinate time direction. Yet this has gotten us into some funny issue, for to define an invariant interval it appears that we need a coordinate defined clock.

So far we have some identification of Hdt, or the square of this, with the c^2dt^2 in the interval above. We then have that the bare action term ∫pdq is identified with

∫pdq = mc sqrt{g_{ij}dx^idx^j}.

So we have a bare action given by our fibration, but we also have some constraint, where H acts as a Lagrange multiplier. So we then have our one dimensional curve defined in a spacetime, where the space is the space of fibration and the Lagrange multiplier determines the symmetry of that fibration which is the Lorentz group.

Now to make things curious, we could imagine this picture as dual in some ways to the picture where time does not exist, but space does. The duality might then have a noncommutative coordinate geometric content in quantum gravity.

The acceleration can be found by a number of means. F = ma with the Newtonian law of gravity and the centripetal acceleration a = v^2/r,

mv^2/r = -GMm/r^2.

This gives v = sqrt{GM/r}, which is v = 29.5km/s or v = 2.95x10^4m/s, for the mass of the sun and r = 1.5x10^8km. The acceleration is then 5.8m/s^2.

As I indicated I think there is some noncommutative geometric issue with the nature of space and time in quantum gravity. This will be a noncommutative geometry that is more general than the Kahler geometry of geometric quantization. That extends the pseudo-complex symplectic structure of classical mechanics into a complex structure with a Hermitian complentarity between conjugate variables. A simplectic group with z_i = (q_i, p_i} (index notation implied) obeys dz_i/dt = Ω_{ij}z_j. In quantum mechanics this is generalized to a commutation system, and the symplectic 2-form implies an operator valued Hamiltonian. However, this is not the most general system possible. This may be extended to in noncommutative geometry with more general Usp(n) groups. A unitary Lie structure can give rise to commutators [q_i, q_j] = ħω_{ij}, which are necessary in string theory with uncertainty principles involving transverse and longitudinal string modes ΔX^ΔX^- ~ L_s = 4πsqrt{α'}, α' = string parameter and L_s the string length. Noncommutative geometry is then a setting for complementarity principles.

Amrit,

Congratulations on the article in Physorg:

http://www.physorg.com/news/2011-04-scientists-spacetime-dimension.html

Is c scalable? That's a worthy pursuit. I would like more details about the program for which you were awarded the grant.

A harder question might be what is not scalable. Is pi scalable? I would say no, but the ratio components are scalable. We think we know what is extensible and scalable by looking at networks. So, in this context, is a node scalable and thus emergent? A black hole is definitely scalable and we measure it in terms of star masses. Conserved quantities and invariant forms, constants of nature seem to go in lock step. Scaling an object seems to be the only way to normalize it. The size and shape of. say, a network matters at every node and stage of development. Are there certain nodes that are not scalable? Even when a node desires to limit its scalability could not halt the extensibility around it. The discreteness of the problem becomes elusive: at the very small, the kernel becomes degenerate, vanishing; at the opposite end, accountings must be made for stuff we can only observe indirectly (dark matter and energy). Must one conclude that energy is not scalable but a totality? If c is not a self dual of some ultimate form, is there some other normed space that can be constructed from dark matter and dark energy to give a sort of quantum Hall effect for c being scaleable? What kind of object will this "light" be? It will not be guage invariant if a rank two tensor, so it must be a tensor of higher rank. Where can I learn more details?

LC,

Again, thank you for engaging on this. I fear, however, that because we have not explicitly addressed the paradigm issue which I raised in a previous post we continue, in essence, to talk past one another. This can be corrected, but it will take some effort. I'm willing if you are; I firmly believe it's well worth the candle.

You wrote, "The nature of time is an interesting subject. I don't get very partisan over the issue of time existing, for physics seems not to welcome ontological or existential ideas from the outset, but only suggests these within some theoretical construct."

Let me ask, do you get partisan over the issue of paradigms such as the pre-Copernican vs. the post-Copernican cosmological paradigms? This is the sort of thing I'm talking about here, and I do get partisan over such issues. In this regard, I strongly believe that when you use the word "time" you mean something by it which is very different than what I mean when I use the word "time."

As an example to help clarify this point, please consider the word "day." The word "day" had a very different meaning in the pre-Copernican era than it has now. We no longer think of a day as being the time required for the sun to revolve once around the Earth, but rather as the approximate time it takes for the Earth to rotate once on its axis.

Would it not, therefore, be fruitless to engage in a debate over whether a "day" exists or not? In my opinion, debates about whether "time" exists or not fall into much this same category. Before we can have a fruitful debate about whether something exists or not we need to have a clear and mutual understanding regarding the meaning of the term the existence of which is being debated.

I saw nothing in your previous reply which leads me to believe that you have given serious thought to the different paradigms which I suggested we are using when we think about and talk about the nature of time.

Along these same lines, I also must retract a statement which I made in my post of April 24th (above). In that post I wrote, "I'm not trying to say that either of these paradigms is necessarily more 'correct' than the other, only that they are different and lead to different ways of thinking about the same things, just as there are different ways of interpreting what we're seeing when we look at a Necker cube, for example." That was spoken in error; I do believe that one paradigm for the nature of time is more correct than the other, just as I believe that the post-Copernican paradigm is more correct than the pre-Copernican paradigm. We are not talking about Necker cubes here.

Moreover, I believe that the paradigm which I've spelled out in my various essays (referenced elsewhere) moves forward the longstanding Heraclitean-Parmenidean (essentially "presentism" vs. "eternalism") debate. This debate is not purely academic or metaphysical, by a long shot, any more than are debates about the virtues of pre-Copernican vs. post-Copernican cosmology.

jcns

JCN

Yes, we are the "time mafia" and I am probably the worst of the bunch.`

I was tired of playing with shadows and ghosts. I devised a logical path for the reification of time directly from the requirement of a universe based on (or abiding by) the rule of non-contradiction. The passage of time is now a dynamic and substantial process that follows simple rules of logic which define both existence and causality. The passage of time makes everything and matter can be seen as a form of time replacing time passing by simple logical substitution.

Logic itself requires the ultimate reductionism, that, for the universe to be operational i.e. to work by itself, it has to be made of only one substance.

The "nature of time" is the most wrongly uttered words. The word "nature" calls for a specific aspect of time; what it is by itself, its ontology.

Looks simple and yet, I am the only one in the whole world who seem to be able to fathom this distinction. Everybody else is running around, wanting it all, but not willing let go anything...

Marcel,

Logic says we can't add apples and oranges. This means that logic only allows operations on elements of the same nature. So, an equation like E=mc2 can only be viewed as being logical if/if we realize and accept the fact that every variable and constant on both sides of the equation represent, at the most fundamental level, elements of the same nature and logically computable.

The reductionism in physics has followed our knowledge and has seen a reduction in the number of independent variables: electricity and magnetism, electro-magnetism, mass and energy, space and time etc. but, always gaining in the process the relation that tied them together. But physics limits the amount of reduction we can achieve because we must keep those dimensions around that allow us to do physics... We have to move right into metaphysics in order to effect the final reduction and gain, not one more relation, but the actual logical understanding of the universe. But for this, we have to let go of our reality, just for a moment.

The type of shotgun reductionism that Amrit proposes is about shooting down one important variable without gaining its proper relation to the rest of physics i.e. where it really fits into the big puzzle.

Marcel,

The Parmenidean view is similar in a way to the block universe view of time. The Heraclitean perspective is more in line with the ADM relativity view of time.

Cheers LC

LC,

Thank you for that clarification. I've tended to think of all versions of general relativity as being closely associated with the Parmenidean or block universe view of time, which is the antithesis of the paradigm for time which I've attempted to spell out in my various essays.

The disparity between the Heraclitean and Parmenidean views clearly is *not* an example of a distinction without a difference. The difference between these views (and what this difference means in terms which are meaningful to us as flesh and blood humans) could hardly be more dramatic, just as the difference between pre- and post-Copernican cosmology could hardly be more dramatic. And it is exactly for this reason that I'm puzzled (an immense understatement) that this question of which view is more "correct" has not been settled long before now. Using the more correct paradigm for the nature of time should, at least in principle, allow advances in science not unlike those which were made possible once the post-Copernican cosmology was accepted as being more correct than its predecessor.

I agree with David Deutsch that ". . . one of the most valuable, significant and also useful attributes of human thought generally is its ability to reveal and explain the fabric of reality." (D. Deutsch, 'The Fabric of Reality,' p. 3) Thus far, however, human thought apparently has not succeeded in finally resolving the Heraclitean-Parmenidean debate. This is astounding, in my opinion! And I place much of the blame for this failure directly on the faulty paradigm for the nature of time which has dominated western thinking since prior the advent of physics as a science.

The mainstream, prevailing paradigm for the nature of time has led to many brilliant successes, and this fact has tended to blind us to its less obvious shortcomings, in my opinion. I attempted to spell this out explicitly and as clearly as possible in my essay 'Time: Illusion and Reality.' Going back to the drawing board with a clean sheet of paper and reinventing physics using a different paradigm for the fundamental nature of time understandably is not something which would appeal to many of today's working physicists. And I certainly can't blame anyone for that. If I were more clever I'd give it a go myself, but I fear that the task far exceeds my abilities.

Regards,

jcns

Marcel,

Since Tom insists on questioning every term I use, I keep have to respond by further focusing my argument. I'll post this latest itineration and see if you think it makes sense, as a description of time:

There is only that thermal medium/particle cloud/quantum state.

As the energy/mass/plasma/waves/particles moves around, it changes configuration.

Since it is in a constant state of flux, these configurations are constantly being replaced.

Some areas in which there is greater activity naturally change shape faster than those with slower levels of activity.

Now since we are mobile points of reference, we are also one of those particles moving about. We are moving forward from our individual perspective and the larger situation is changing, so it is quite easy to conflate our sense of motion with this larger change, thus we seem to move from one configuration to the next, in much the same way we move along a path.

The larger reality though, is that our actions are balanced in this larger context, so there is that non-linear reaction to our motion, which compensates for our motion, to maintain the larger equilibrium.

Because there is just this sea of energy and energy is conserved, it is impossible to have sequential configurations co-existing, because they are constituted from the same energy.

So the old configuration fades into what we colloquially refer to as the "past." As all this energy bounces around, the new configurations emerge from this action. Those ranges of probabilities of what might happen as this energy interacts, are what we colloquially refer to as the "future."

So this current configuration emerges out of this action and is replaced by it.

What we colloquially refer to as the "present" doesn't move along some fourth dimension, because it is all that energy/mass particles/waves/thermal medium/cloud of motion that is all that exists.

Thus these moments of configuration emerge from that "future" and recede into that "past."

It is only because we can only exist in that present state, that we sense it as going from past configurations to future ones, but it is not the present which moves, only that it changes shape.

So while we have this subjective sense of "moving" from "past" to "future," the objective reality is that potential becomes actual and is replaced, ie. the future becomes past.

John,

I have great difficulty with the structure, format and content of the text.

What is well understood can be expressed clearly. I am not sure you understand well the idea you are trying to convey.

This appears to be the typical struggle when we mix elements of our reality and element of a real universe as can be deduced from various accepted theories.

1- future, present and past are true in our reality because we have no choice about it, this is the way we think and work. Period. There is no sense in screaming and kicking about it.

2- The real universe is different from our reality and can be inferred/deduced from literal understanding of SR & GR. and applying it to something that exists

in substance.

Again, contradiction and paradox appears when we mix and compare elements from our reality and elements from the real universe.

I am always interested in a theory of time that addresses a specific component of time. I always do it; try to re-formulate it in simple terms ..

The Perception of time I leave to psychologist and neurobiologists and maybe some philosophers etc.

Marcel,

To JCN Smith,

Einstein probably made the biggest push forwards in our understanding of time. He demonstrated with the invariance of light speed that time was interchangeable with space. This is the Lorentz transformation. This extends to general relativity, where now spacetime is in a sense the "field" of gravity. However, something is odd here, for gravitational degrees of freedom are contained in the Weyl tensor. So the field of gravity has physical degrees of freedom in the case of gravity waves where C_{abcd} =/= 0. In the case of a black hole, a stationary observer may watch clocks on objects falling into the black hole slow down to a stop as they asymptote to the horizon. However, this is not a system which interacts with the exterior world by gravitational degrees of freedom in this stationary configuration. An object fall towards a black hole is observed so the frequency of radiation from the body decreases as it red shifts "to infinity," which is the same as watching time slow near the black hole. What does change, or is not entirely static, is the fact that a body approaching a black hole adjusts the mass of a black hole. As a result the stationary (noninteracting) degrees of freedom associated with a black hole changes. This is a sort of gravitational form of the measurement problem.

Time may then be a one dimensional aspect of reality that reflects how gravitational degrees of freedom transform. In that setting time is something akin to a one dimensional communication channel, or a form of transmission line. It is then possible that time is a parameterization of a quantum error correction code for the universe, where the most general form might be the Jordan matrix algebra.

Jacob Bekenstein and Avraham May demonstrated how black holes are one dimensional channels of quantum information back in 2001. Ashoke Sen demonstrated something similar to this. An anti-de Sitter (AdS) spacetime of dimension n is equivalent to a conformal field theory of dimension n-1. The isometries of the AdS spacetime are equivalent to the conformal symmetries of a conformal field theory (CFT) on the boundary. The near horizon condition for a black hole in an AdS spacetime is AdS_2xS^{n-2}, where S^{n-2} is a sphere or dimension n - 2. The AdS_2 is a hyperbolic spacetime with a structure similar to the Escher prints of tessellated disks called circle limits. The boundary of this spacetime is CFT_1, in one dimension, where the isometries of this space are the group of conformal quantum mechanics. The group is the set of diffeomorphisms of the circle (which bounds the AdS_2 disk) and this defines the set of bosonic string states. The AdS_2 is then equivalent to a circle group on CFT_1 ~ S^1xS^0 (where this is a generalization of CFT_n ~ S^1xR^{n-1}) and the S^0 defines two points. These two points turn out to be dual states for the Hartle-Hawking vacuum (HHV). The HHV comes from their seminal paper in 1984 on the wave function of the universe.

The next interesting direction is that Borsten, Duff, Marrani, and Rubens published a paper which illustrates a mathematical correspondence between entanglements in 3 and 4 qubit quantum systems with BPS and extremal black holes respectively. To illustrate this it requires one work in the STU system with radial symmetry. In that case all the Killing isometries of the theory are timelike, and they are defined in one dimension of a moduli space. I have submitted for review a paper which connects this with the AdS theory above with AdS_2 ~ CFT_1, and a coset structure on the AdS constructs the counting of possible microstates on a black hole event horizon. This is a physical partition function, but it is equivalent to a partition function of the integers. This has been one of those unsolved problems in mathematics, which Brunier, Folsom, Kent, and Ono proved in January. This is the mathematics for counting up quantum states on a black hole, or equivalently on the boundary of an AdS spacetime. I have been working up a variant of the proof by Brunier, Folsom, Kent, and Ono, but where the partition function is derived by compactification condition with respect to the correspondence between multi-partite entanglements BPS/extremal black holes.

In the end time is a slippery topic, and how it is interpreted might reflect something of the appropriate field theoretic form of quantum gravity. As a result one has to keep an open mind on the topic, without making prior assumptions about the ontology of time.

Cheers LC

Lawrence,

"Einstein probably made the biggest push forwards in our understanding of time. He demonstrated with the invariance of light speed that time was interchangeable with space. This is the Lorentz transformation"

I think that a finite maximum speed of light gives us the time - space interchangeable relation, not its invariance. The speed of light may change from place to place ... But in any place, the speed of light is the local maximum speed.

For example, the light beam going to the moon and back changes speed a few times but in any point of this travel, it moves at the local maximum speed.

This is because the rate of passage of time varies locally between the Earth and the moon and c=m/s and those seconds don't run the same everywhere. This explains the local invariance; c is always adjusted to the local rate of time and the ratio is invariant. The measured value of c is invariant.

So, my point is that a local maximum speed is not the same thing as the invariance of that maximum speed relative to other various places. This said, it is locally measured as invariant, a constant, because we measure two aspects of the same thing; the local ratio of space-time to the rate of time.

This make sense to you?

Marcel,

Light cones one Earth, the moon and between the two are shifted a very tiny amount. However, given that time differences are ~ 2GM/rc^2 ~ 10^{-10} and that the light travels back and forth in about 2.5 seconds this is a very small effect. It would be on the order of a fundamental time unit of an atomic clock. Differences of this sort which involve the difference between ruler and clock distances are measurable for light or EM radiation passing by the sun have been measured.

LC

Lawrence,

Thank you for the equation. Yes! It is small! But it is there.

Small is relative to something and often to what we want to do.

For the engineer, it could be insignificant. For the scientist, it is small. For the ontologist, it is very significant because it is there, and if it is there, it is part of the understanding of the whole picture.

There are currently billions spent on finding very very small numbers... Gravity probe, gravitational waves detectors etc. In a first instance, we try to demonstrate the presence of something and then we try to measure the magnitude of parameter, more and more precisely.

I take it as a puzzle; every piece has equal importance.

Thanks,

Marcel,

I buttered my bread for a while working out how to synchronize Ce atomic clocks on satellites and the Earth's surface for GPS applications. Those small deviations in the g_{tt} elements δg_{tt} = 10^{-11} as meaning that for every second measured on the Earth surface there is 10^{-10}sec de-synchronization with a clock at 1/2-geosynch where the GPS sats orbit. If I multiply by c = 3x10^{10}cm/sec this implies an error drift of 3mm per second. As a result there are practical ways in which this does materialize.

LC

While the Parmenidean block universe persists within theoretical physics and religions, engineers like me are forced to prefer realism without following jcns who wrote "Heraclitean-Parmenidean (essentially "presentism" vs. "eternalism") debate". I see Einstein's presentism as faulty as the more obviously anticipatory eternalism attributed to Parmenides. Accordingly LC wrote: "The Heraclitean perspective is more in line with the ADM relativity view of time."

The obvious impossibility to analyze genuinely future data led me to the utterly simple but perhaps foundational thesis that while past time is primary an order of realized causalities, time in the sense of something that includes past and future is only a mental construct. Einstein argued: "time is what clocks read". Such (elapsed) time does definitely not include the future Minkowski cone. So future spacetime must not be considered reality.

Eckard

Consider what I wrote earlier about the complementarity between space and time on Apr. 24, 2011 @ 01:21 GMT. This suggests that ΔxΔt = constant between time and coordinates of space. The connection to philosophical or metaphysical issues is that the Parmenidean and Heraclitean perspectives may be related to each other by a noncommutative relationship between coordinates of spacetime, or between time and a spatial coordinate, in an uncertainty principle. The two perspectives may then be related to each other in a similar way that momentum and position are related to each other in the Heisenberg uncertainty principle.

This would work our in an interesting way, for time becomes a one dimensional communication channel for qubits, where this 1-dimensional channel has the geometry given by the AdS_2 ~ CFT_1. The AdS_2 (anti-de Sitter spacetime in 2 dimensions) has a system of isometries which are equivalent to the conformal symmetries of a one dimensional QFT. Further the AdS_2 decomposes from AdS_n for a black hole in that AdS_n and at the region near the BH horizon. The Euclideanized form of the AdS_2 has a tiling representation as seen in the Escher prints called "Circle limit" 1 through 4.

This might then mean the nature of time is far more curious than we have previously thought. I could mean that block time and non-block time (non-time) are quantum complements of each other.

Cheers LC

LC,

I am perhaps the first one who sees argues that both x and t are not as physically real in the sense of measurable as are r and elapsed time t_e. Only The latter have natural zeros. You are perhaps quite right in that both the Parmesidean and what is not quite correctly labeled Heraclitean perspectives are related to each other by a non-commutative relationship. My essay 833 tries to explain why both views are redundant: Obedience of the natural restriction to exclusively positive distance and exclusively realized temporal distance is the key to the commutativity of half-matrices instead of Hermitean symmetry, i.e., instead of Heaviside's split into real and fictitious imaginary part. In order to get most easily understood I remind of distance matrices between cities. If distance between NY and SF is the same as between SF and NY then one merely needs a half-matrix.

Look at Fig. 1 in my 833 essay. Both measurable time t_e and frequency f are always positive. See hyperbolas of the quanta delta t_e times delta f = const.

Don't worry: Frequency corresponds to energy or momentum with respect to the object of concern while elapsed time corresponds to distance from object of concern.

Given I guessed correctly when you wrote: "This would work our in an interesting way" and "I could mean" you meant out instead of our and It instead of I. Nonetheless, I cannot understand you. Doesn't block time contradict human experience? Why is non-block time no time? Didn't I clearly enough explain why the basic notion of time is the only measurable (unilateral and perhaps potentially infinite) elapsed time?

Regards,

Eckard

This is a sort of noncommutative geometry. It is the quantization of geometry, or the field theoretic content that underlies geometry. A for block time being contrary to human experience or intution, those do not really count for much. The non-block time is just a system of spatial geometries which are related to each other by a diffeomorphism group. The notion of time is actually somewhat lost in this picture.

Cheers LC

LC,

"A[s] for block time being contrary to human experience or intution, those do not really count for much. The non-block time is just a system of spatial geometries which are related to each other by a diffeomorphism group. The notion of time is actually somewhat lost in this picture."

Now we're getting into some interesting turf indeed! Regarding whether human experience and intuition count for much, I simultaneously agree with you and disagree with you. Certainly, everyone must agree that human experience and intuition have proven to be extremely fallible. This fact is perfectly illustrated by the pre-Copernican belief that the sun revolves around the Earth.

On the other hand, however, human experience and intuition must count for something, because our empirical observations comprise the very bedrock foundation of science! If we dismiss empirical observations as unimportant (not really counting for much), then what are we left with as the basis for doing science?

I believe most would agree that science is about discovering the "best" explanation (which I take to mean the most useful explanation) for our empirical observations, i.e., for our human experience. The post-Copernican cosmology has proven itself to be more useful than the pre-Copernican cosmology. In the meantime, however, absolutely *nothing* in the universe changed, aside from the way we humans think about and interpret our empirical observations.

I continue to suspect that a similar disconnect is manifesting itself here at FQXi in our discussions about time. Perhaps it is not unlike debates which must have taken place in earlier days between those firmly entrenched in the pre- and post-Copernican views of cosmology, with both sides failing to comprehend what the other was trying to say.

Back to what you were saying above, however, I agree that non-block time is indeed a system of spatial geometries. Whether they are related to each other by a diffeomorphism group or not I can't say off hand, but I agree with you that the notion of time (certainly the conventional notion of time) is indeed actually somewhat lost in this picture.

When paradigms come into conflict, the outcome typically has been decided on the basis of which paradigm is more successful in explaining empirical observations in the least complicated way. Thomas Kuhn's book 'The Structure of Scientific Revolutions' offers a fascinating look at this phenomenon. I suspect that we're witnessing (and participating in) the early stages of just such a conflict of paradigms regarding the fundamental nature of time. As the saying goes, time will tell!

jcns