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Personal Proceedings after reading the stuff, as a virtual letter to the author.

Guido "Wugi" Wuyts @ Dilbeek, Belgium, Europe, World, Solar System, Milky Way, Local Cluster, ...

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Reader's Indigest
Consciousness requestioned
Reflections upon reading "Consciousness explained", the great book of Daniel Dennet.
Time and again
Reflections upon reading "About Time", the great book of Paul Davies.

Consciousness requestioned.

Reflections in the aftermath of reading "Consciousness explained", the great book of Daniel Dennet.


I read your magnum opus "Consciousness explained" with much delight. It is no easy stuff and I am sure I didn't, or couldn't, understand every argument of reasoning. But then, even mathematics got used to Gödel's interdiction that it could prove all of its theorems, that is, understand itself to the full extent (at least, that is one of the interpretations. As far as I remember, Gödel's proof makes use of paradoxes that arise when statements start referring to each other or to themselves. When it comes to self-reference, systems are trapped in the endless process of adding layers of description upon themselves). I write to you because of my own need for trying to formulate and understand some intuitions as they arose in response, whether confirmative or in doubt, to your propositions.

I put to a try the functioning of the blind spot. Your book comes in paragraphs separated by a blank line. If I hold the book with the text running vertically, a blank line entering the blind spot area virtually disappears, or rather, is "filled" with the general pattern so that I get a firm impression of a homogeneous page of vertical text. That this process takes only information on the pattern and not on the text, is shown as soon as I try to read the words, and the effect "pops away". The same goes for colour: the blind spot is "painted" with the prevailing colour from around.

As for the experience with the unreal ring with the rose glow, unfortunately my Dutch translation comes with the whole discussion and mentions the figure being on the front leaflet, but it just isn't there: a view of the fractal brain structure is actually shown. But from the other figures appearing in the text I understand that the effect concerns the emergence of a figure as a negative, out of the background of another figure. Figures, like messages, rise as an interpreted foreground structure out of a background, further discarded. Unless, by accident or clever device, this background contains itself the structure of a figure or message. A master in this technique was the Dutch graphist Escher, with his famous black and white Siamese twin-like tableaux amongst many other ideas. Again, the message itself might be hard to get out of its bearer. It might be concealed in a wealth of seemingly nonsensical information (to be filtered out by coded positioning). Or it might carry different meanings. Or be itself the bearer of other, sub-level messages, in a fractal way, the way nature itself carries different informations on different scales. Hofstadter had some nice examples of this type. Imagine for instance the word YES! whose letters are formed by bands of repeating NO!'s, and so on.

Regarding the tests of inner visual perception, for instance when trying to visualise a purple cow or a rotating figure, I have the impression that there may be such a perception but it would rather be short-lived. When I think of a cow and of purple, that is, when I formulate their words mentally, or when I look away from the illustration of a figure that I'm going to manipulate mentally, there seems to be a mental picture for a brief time. But as soon as I start rationalising this "picture", trying to detail or modify it, I am aware I'm dealing with abstract patterns and perceptions, and the more I try to visualise them the less it "works". I had a similar experience with dreams, in which I would, out of a standing position, start rising up, first slowly, overlooking a street, then passing the highest edges of a building, then getting into view panoramas growing vaster, until reaching planetary scales. But on some occasions I would worry about some detailing of the landscape, and as I would run out of fantasy, the dream would stop. The idea that inner seeing is brief (and then overtaken by reasoning about it) seems to correspond with rare occasions when you think you really saw, in a flash, somebody or something.

An inner perception that seems to work better than seeing, is listening, despite (or thanks to?) its being a serial, time-consuming process. I can, without difficulty, reproduce mentally (but is that listening?) a melody, a chord, a correct pitch, but also barking, mooing, words, a poem. Still, the melody goes by a non-identified timbre: it is possible, but harder and not easily sustained, to reproduce the timbre of a precise instrument. As for words, I have them spoken by an inner voice which is no better identified than the timbre; or perhaps it reproduces my own voice as I perceive it myself (which, as anybody knows who has heard his voice reproduced by audio-equipment, is quite different from what others hear of you). What I notice also is that, although my vocal machinery is not doing the actual production of inner words, it has to be "in line" with them. It is impossible to hold on formulating words mentally, if at the same time the mental monitoring of the vocal apparatus is geared towards pronouncing other words or phonemes. For sounds, as for vision, the nearest feelings of actually hearing them come in flashes, for instance the moment you really think you heard your name called.

Language and consciousness. Does the latter need the former, does an idea enter consciousness only when formulated? I don't think so. I think language is just part of a chain of reflection, be it a powerful tool to improve, extend, and communicate the fields of attention of our consciousness. As it is a temporal process, it will not give me an "instantaneous" experience of consciousness whilst it is produced. Instead, as you put it colourfully, a whole pandemonium is needed for its production, dealing with divers levels ranging from classes of perception, their associations and relationships, via words, their phonemes and syllables, via paragraphs, their sentences and grammar, to a complete statement. But the same, in reverse order, goes for understanding and interpreting language. How many different kinds (in level and duration) of memory are not needed for understanding language: to distinguish sounds, separate the words, consult their associations, consult grammar, pick out sentences, anticipate or correct figures of speech, retain the relationships within and between the sentences, figure out the coherence of the story. The more you try to detail the processes the less you can point to linguistic activity, or to initiation of consciousness.

Turing-tests and heterophenomenology. Does a machine that succeeds the Turing-test have consciousness of the same kind as we do? As you've pointed out, it is dangerous to deny this conjecture, because it opens the way to racial discrimination. Still, to me it remains a doubtful matter. Of course we could, as you suggest, declare ourselves all to be zombies in some way or another, if only not to overestimate our consciousness. But the question remains whether a Turing-machine would be the same kind of zombie as I am, provided it can sustain all kinds of dialogue that are satisfactory to me. I will never be sure if it has the same kind of heterophenomenology as I do, or if it produces any heterophenomenology at all.

Centres of narrative gravity. A Turing-machine looks like a "centre of narrative gravity" all right, but is that enough for it to be conscious? In fact, given the way it sustains dialogue, one may also attribute some "responsive" or "communicative" gravity to the machine. Still, this doesn't convince me. I am doubtful if this suffices to generate a real "mind", who is interpreting what is being said and answered, thereby weaving and witnessing the changes in its own heterophenomenological world. This contingency, one may call a centre of "interpretative" gravity. The Turing-test will not give me a decisive proof of the presence of interpretative gravity. But then, neither will a conversation with my best friends. All I can do is not to stop wondering and respecting the achievements of a thinking machine, for similar reasons why I respect life.

Selves and uniqueness. I agree with the relativity of the self. As it remains with us during a lifetime, it is already a thing evolving with time, and the only way to see it as an accomplished uniqueness is by invoking Einstein's trick of spacetime description. Anyway, where is my self while I'm asleep, or unconscious, in coma, under hypnosis? But it does exist all right, generally confined to a bodily life. It looks naive to me to try and salvage this self by providing it with any of the outlets religions have conjectured: a place in the hereafter, conscious nothingness, reincarnation. How could these possibly preserve the essence of my here and now life's self, without adding other features that have nothing to do with it? Still, reincarnation works in a way: matter that only recently participated in a cow's self now starts a venture with mine as I'm eating my steak. Later on, worms' selves might take advantage of some of the rejects, birds' of the worms, grass's of the guano, and so on. It's like an ocean where selves are born, mingle and disappear like waves. The selves of identical twins (and clones !) remain an intriguing case. For all I know, they might represent almost undistinguishable centres of narrative gravity, but very different centres of interpretative gravity. But then, the opposite might apply for two very different minds, say, a man and a computer.

Dualism. Your general goal, banning dualism in science, I am afraid will not convince easily in the long run. Your approach of the mind is, well, just mechanic, isn't it? One way of putting it, if I understood well, is the statement that heterophenomenology might be entirely explained by a full understanding of the brain's physical processes, in response to the world. Would full knowledge of these indeed explain, yes predict, the way I perceive blue? And the way it feels different from red? Or sour? Or a chord? Admittedly, every perception is influenced, as is my whole personality, by my brain's processes. Any changes or damages to my brain have repercussions on my mind. My perception of blue is using brain processes involving neuronal and chemical transfers. These may conform to my perception a posteriori, top-down. But would they explain it a priori, bottom-up? I doubt it, I feel perception rather as an emergent, that is unpredictable, (hetero)phenomenon. But then, even unpredictability has gained recognition in chaos theory, and so my mind shouldn't "mind" using unpredictable processes as a physical seat for its functioning.

Emergent features. Let us reconsider the limits of understanding. Besides self-reference already mentioned, there is the aspect of non-superposability in non-linear phenomena. Such systems are said to be "greater" than the sum of their constituents. We may include here the emergence of orderly (or intelligible, describable, predictable, computable) behaviour out of chaotic (or non-intelligible etcetera) sub-behaviour. And, why not, the emergence of heterophenomenology out of brain activity. Emergent features may be explained top-down, after their being noticed. But predicting them, or describing other possibilities than the ones realised, would seem much harder, and at times impossible, remembering Gödel. People who like to think of the universe as the stuff of which God's dreams are made, or in any other way as utterly ununderstandable, needn't worry too much about the spectacular achievements of materialistic investigation. This will always be dealing with confined parts, with sub-system description.

Message and messanger. What if the universe, or the brain, were just a bearer of information, not the information itself? Would its scrutiny and understanding bring us any closer to its information, or its heterophenomenology? It's like when getting a message in coded text: you don't engage in analysing the physics of the medium on which it is brought in order to decipher it! My favourite example is a game of chess:

Suppose Martians get hold of a game set of chess and try to understand what purpose it serves. They start a thorough analysis of the game's pieces and board, down to the mineral, molecular, atomic and subatomic level. Will they ever "explain" chess this way? Suppose they are able to see the game being played (without being aware of the players). They would investigate the "laws" of movement of the pieces. They would state that all pieces move one by one, each in its own way, and if a piece bumps into another of opposite colour the latter annihilates, and seldom pieces may reach the board's limit and transform. Will they explain chess?

To us humans it is obvious that the medium on which the game "comes" is not determinative for its description. You could put down a game through filling out a codex of identical grids on paper, or completing a table of coded positions and actions. Or it could be transferred, as has been done, to a computer screen. Suppose our Martians are looking at a computer game. They could watch the graceful change of patterns on the screen, the dazzling dance of bitmaps that goes with it, the spaghetti of text code that makes up the program, the parade of machine code that puts its active components in RAM, the messy army of ones and zeros that make up this code, the entangled web of electronic signals that carry them. Will all this lead our alien witnesses into formulating a comprehensive description of chess?

It is "easily" felt that such an approach is not what they would need for a full understanding of chess. Instead of looking into the mechanics of the game, they would need to look into its functionalities: a set of rules, an understanding of the strategies it involves, an appreciation of the satisfaction offered by a well played game (or of the nervousness as induced in myself by the sole idea of chess), say, a heterophenomenology of the game. This makes use of, but is not explained by, a medium to be played on, not to forget the players. Even when I play against the computer, I might find it a satisfactory game. As far as chess is concerned, the computer player is a very Turing-machine, making the right responses for me to carry happily (well...) on with the game's "conversation". Its narrative gravity is all right; if the game were to be played at distance, I couldn't tell a man from a computer. I might even feel the (heterophetcera) "thrill" of the game. But the computer might not, and you won't find it in its RAM. When I let the computer play against itself, I may engage in reflections upon the wonders of chess, say, I play meta-chess. But when I leave the room, the only activity left in the computer is a dull screen saver (or filler): there remains no centre of interpretative gravity.

Time and again.

Reflections in the aftermath of reading "About Time", the great book of Paul Davies.


I read your book "About time" (appreciating the puns of some titles) and, some time ago, "The edge of infinity", with much enthusiasm. I am writing you, not with a view to rebuking relativity (which you properly discourage in your interlude), as I am an enthusiastic of science in general, and the physics of space and time in particular. Though bearing a 1977 university degree of civil construction engineer, I think I obtained a fairly good understanding of special relativity through extensive reading afterwards, not in college itself: as a matter of fact I am pretty sure the prof didn't master all of even special relativity himself. In my experience an essential ingredient for comprehension is the systematic use of Minkowsky diagrams, which I discovered in my latter readings. Indeed, a theory on space and time, and its explanation, ought to be essentially geometric to remain sensible.

As you mention somewhere, the algebraic description of special relativity is rather basic, and many a discourse has been given confining itself to that. Einstein himself stayed content with it for some time, before reluctantly admitting the merits of geometric representation. In my view the algebraic axioms of special relativity imply some hidden or neglected assumptions with reference to the isotropic nature of time: a priori, time could be a function depending not solely on location and motion, but on orientation as well. Also, before coming to the rule of constancy of light velocity, one would like an extensive definition of length and time intervals, and their calibration in moving systems. All this is more or less taken for granted in the algebraic approach, whereas starting from geometric axioms they have to be developed exhaustively, yielding the constancy of c as an obvious consequence, not as an axiom!

The main motive for my writing you is to seek clarification on some points which, not surprisingly, remain obscure to me. Also, to seek your comment on some ideas of mine I would like to mention on the occasion. I am referring to the 1995 Penguin edition of your book "About Time".

Poincaré theorem, p 37

I don't know how strong the proof of time cycling systems is held to be. It may be true in some restricted phase space of the system, but in my view certainly not in the, down to earth, space-time description of it. Take the case of a volume of gas, and look at the career of a single molecule. It may be described as a succession of collisions linked by straight stretches of path. Stating that the gas will cycle, comes to stating that this molecule will ever return in its present collision point and start the same career again (and this for all molecules). This would mount to stating that a continuous space (the volume of gas, plus the velocities obtained at each collision) could be entirely covered by a countable set (the succession of collision points separated by finite time intervals). This seems nonsense to me.

The only way I can approach this view is considering the case when the gas has reached its thermal equilibrium, after which all the subsequent states will represent this same phase and time, though flowing, will not so much be cycling, but rather be flowing to nowhere, so in a way have come to an end.

Minkowsky diagrams, p 74

As I argued in my introduction: a pity that they are not used more extensively in explaining some phenomena, tachyons for example, and when developing numeric cases!

Cherenkow radiation, p 79

I don't understand how matter in a medium could travel faster than light in the same medium (it voids my view of matter as light clocks as I explain in appendix 1), unless light itself would behave matter-like in such media.

Tachyons, p 80

If they exist, how would they interact for energy and information exchange with sub-luminal matter? I used to view them as a possibility, being space-like instead of time-like light clocks; but considering your argument on phase correlation versus scrambling it appears that only time-like light clocks conserve phase correlation, so from this standpoint tachyons become highly improbable. See also appendix 3.

Cosmic time, p 83, p 193...

Only if some cosmic time-scale exists can space-time be described globally, as successive slices along this scale, don't you think? If it does not, or not uniquely so, then space-time could not be regarded as a coherent thing, but at best as an amalgam of loosely linked local space-times containing matter subject to their local inertial framework, isn't it?

Moreover, even as a coherent thing, I perceive that it would be pointless to regard space-time, considering the case of a closed geometry as, say, a ball, or rather an egg, or a cube. It would seem to possess only topological, not geometrical meaning. Is that correct?

Clocks and light frequency clocks, p 89

The distinction between "proper" time and time from elsewhere compared with it is perhaps not always clear. The gravitational time shift, in contrast to inertial time dilatation, appears to be asymmetric, in that two locations agree on the difference. In that respect it would be the gravitational equivalent of the twin paradox, this being the accelerational case: is that correct?

Event horizon and observing it, p 119

One of my usual "observations" on the space-time discourse is the frequent confusion between two different processes of observation: watching and measuring. Whereas length contraction and time dilatation are measuring results, the case of watching a moving length pass by is more complicated, see my example in appendix 4: a simple case I never met in literature, whereas more fancy speculations on watching are to be found, but less telling.

The case of Betty's approaching the event horizon, causing Ann to observe her twin sister "freezing and dwindling" in that position till the end of (Ann's) time, and the graph that goes with it, seems to me a description of Ann's watching process. I suppose that even after measuring she will conclude of a time barrier at the event horizon, but I would have been happier with a neat distinction between both descriptions.

Time scales and clock paces, p 143, p 193...

My view that light clocks lie at the basis of all matter's organisation (appendix 1) may alleviate somehow the prospect of multiple time-scales. Although even then the question remains of how to compare and calibrate light clocks, and hence distances and time intervals, in distant systems. Also, how to conserve calibration should light velocity itself change, in cosmic time... (appendix 2).

Quantum erasers and limbos, p 169...

The argument that photons and particles may follow a number of different paths, and find themselves in a confused state of superposition, until someone decides to observe them, is relatively easily understood when considering matter as a system of light clocks: these may disperse themselves somehow for bending past obstacles that otherwise would interfere with their wavelength(s), and may do so until the system is obliged to interact in an irreversible way with some macroscopic system. One could say that at such moment phase scrambling begins, whereas in the particle's previous paths phase correlation was preserved.

All the fuss in quantum mechanics about the process of observation influencing the observed process, seems to me merely a particular case of the general phenomenon of interaction between (partly) reversible micro-, and irreversible macroscopic processes.

The mystery of Schrödinger's cat living a limbo life until someone comes to look at it, would then prove an anthropocentric mystification: well before indeed, the radioactive decay, if it occurs, will have interacted with the macroscopic system of the bottle containing poison so as to trigger its scattering to pieces, and the cat -itself an observer!- will be dead.

Imaginary time, Hawking theory, p 183...

Is time an illusion? Is space-time the real thing? Is imaginary time the same thing as space, and a basic tissue at some epoch? Is the Big Bang an illusion? (through proper co-ordinate changes you could transform it "away", as with South or North poles which then become just ordinary points..., unless it would indeed be a real singularity...).

Whenever I read Hawking, I get this feeling of "not to let your theory run away with your sense of reality". Let us be careful not to put our models in place of the things they describe.

The arrow of time, and phase conservation, p 196...

Still, why does phase conservation point to the future, and phase scrambling reach us from the past? In the Wheeler-Feynman argument, what impedes the reverse description t ® -t, "explaining" how the retarded secondary radiation could double the strength of the advanced primary wave to full power, and cancel out the retarded primary wave? Unless, perhaps, because of the Big Bang the reverse scenario does not provide for sufficient time and space with a view to producing the full range of echoes required for the reverse process. See also appendix 2.

Particle time reversal, p 204

In contrast to tachyons -Minkowsky would have been useful!- particles with reversed time, when I view them as light clocks, would preserve phase correlation, so their existence is compatible with my light clock description. Why should their lifetimes be so much shorter however, than the ones of their "normal" counterparts? An argument by the way against the vision in fig. 9.2. of the "single" electron...

Cosmic time reversal, p 221

To me it seems that the epoch of the time arrow's reversal acts as a barrier between the forward and backward universe. No influence can flow from one into the other, as it has ever to flow where the arrows point... This seems to be overlooked, or denied, in descriptions of communications between both parts as in p 222..., 228, 230.

If time points away from the big bang, there is no such thing as a big crunch (see also appendix 2). Only half of the picture is representative for our universe: this would certainly comply with thermodynamics. The other half may or may not be there, the only link with ours being its final state. It may even be viewed as folded somehow with ours along this final state. This leads me even further to a picture of a manifold of universes, held together in a bread shape, each universe starting at the edge with some big bang, and evolving toward (somewhere in) the middle where the expansion stops and time reverses... This model would account for a multiple universes theory, allowing "slices" of universes running next to, separating from, or crossing each other...

Moreover, if my view that light velocity may reflect directly space expansion (appendix 2) is correct, then, at the final epoch when expansion stops, time would, after having slowed down, literally stand still at the very moment it comes to stop. Time, that is, local time as compared to cosmic time used for representing the expansion. This would mean our world stops at a given moment without having given notice! Unless the time retardation would be noticeable in light reaching us from earlier epochs, or could indeed be felt directly through lagging light speed.

Looping time, p 237.

Maybe. But only so if time starts and stops really at some position, implying a fissure in the cylinder and reducing it to a flat sheet. Truly looping time seems to contradict the law of thermodynamics and my objections to Poincaré's cycling time.

Arrow and flow of time, p 257.

I adhere to the view that both must correspond, either of them pointing to events with increasing entropy. I cannot conceive of growing older while travelling towards ever earlier epochs, less still of growing younger while doing so. The latter case corresponds entirely to our world anyway, but depicted in the wrong direction of time.

Flow of time, p 275

I cannot but adhere to the reality of time's flow, calling the theory that it is an illusion, itself an illusion. Given that reflection, all the riddles remain: "my" time and now exist only locally, so how can they be compared with a far-away place's time and now? Via cosmic time? So, is there a cosmic Now (if, perhaps, inertially relative as in special relativity...)? Why does time not flow slower, or faster? Why does it flow now? Why is it now Now? ...

Quantum collapse, p 278

(See my remarks on Quantum erasers and limbos, p 169...)


(Note on appendices.)

To my regret I am not yet able to include the figures that go with them. On request I could forward them by mail.

Appendix 1: matter and light clocks.

When it comes to the question of how matter holds together, and maintains its proportions of dimensions, distances and cycles, the answer points to the presence of some internal clocks and rods. The ultimate process governing these would be what is generally called light clocks, involving at once a clock and a rod, and entailing a light ray shooting to and fro between two supposedly fixed points.

In my geometric approach, they become the cornerstone for defining and calibrating space and time intervals within, and between, inertial systems. These are determined as systems allowing light clocks to run while maintaining their mutual proportions (conservation of homothecy), which are then used for calibration. Light clocks sharing a common return point and giving the same return time define equal "rods" in different directions (definition of isotropy). This holds within moving systems as well. Light clocks along a y-axis moving along an x-axis define equal rods if at some moment they share both return points (calibration between moving systems). All these criteria result in length contraction, time dilatation, relativity of simultaneity, and constancy of light velocity.

The next step is to explain "away" the material character of the "rods" and "return points" of light clocks. I haven't explained matter, have I, as a fabric of material rods and points supporting light clocks. So I came to view matter itself as constituted solely of electromagnetic rays obeying light clock rules. The only elementary movement, then, is luminal speed movement, matter being a "trick" of electromagnetism to move, and carry energy, at infraluminal speeds composed of "to and fro" luminal speed.

All this should be fine, if at least the energy involved obeys Einstein's energy and mass relations:

E = M c2, and M = M0 g (v); thus E = E0 g (v).

In order to determine the energy carried by a light clock, we must specify to which electromagnetic wave a given light clock may be assigned. Realising that a photon covers events sharing the same phase, when a photon leaves a return point and comes back after having gone through a cycle we can say that this point has traversed at least one cycle. But we will also require that the event of the photon's reaching the opposite return point should correspond with the same phase, so that both return points should be separated by at least one wave length. Let us consider this case, firstly in a system "at rest".

Let the light clock's "rod" distance be l 0, being at the same time the photon's wave length, and giving return times t 0 = 2 l 0 / c, and wave frequencies n 0 = 2 / t 0 = c / l 0. The photon's energy is then e0 = h n 0. As a light clock cycle is formed by a photon "to" and another "fro", and assuming that each photon's chance to transfer its energy is proportional to the number of wave cycles it passes, which is one for either photon, we may take it that both photons contribute with equal chance to the light clock's energy per clock cycle, which then becomes

E0 = 1/2 (h n 0 + h n 0) = h n 0.

Let us now compare this with the energy contained in the clock cycle of a moving light clock, having speed v, so that b = v/c and g = g (v) = 1 / Ö (1 - b 2). Let also

h = Ö ((1- b ) / (1+ b )).

The "rod" length of this clock as measured in the system at rest will be l = l 0 / g , and its return time t = t 0 g . These quantities are consisting of two components "+" and "-", determined by the light's reaching the opposite return point, so that we have

l = l + + l -, and t = t + + t - . This implies the system at rest observing two wave-lengths l + and l - to describe the moving light clock's photons. Supposing that the "+" length is the longer one, and observing that e.g. in time interval t + light speed covers the distance l +, but speed v covers only l + - l , the following relations may be deduced:

l + = l 0 / h , l - = l 0 h ;

t + = t 0 / 2h , t - = t 0 h / 2 ;

n + = n 0 h , n - = n 0 / h .

Along the same lines of thought as for the system at rest, we may describe the energy of the moving light clock as:

E = 1/2 (h n + + h n -) = 1/2 h n 0 (h + 1/h ) ... = E0 g .

So it appears that light clocks comply with the transformation law of energy (and mass)! If we admit that a light clock can release this energy at a rate determined by its clock cycle, we can define the light clock's power rate as

P0 = E0 / t 0, and P = E / t = E0 g / t 0 g = E0 / t 0 = P0.

This would mean that, regardless of its state of motion, a light clock (and mass) can always release, or absorb, the same amount of energy per unit of time.

If we consider the ways this energy can be communicated we can distinguish the following cases:

- kinetic energy (mass impact) deliverable "along" the world path of the light clock;

- continuous radiation which would be proportional to the clock cycle's frequency 2/t , and comply with the Doppler effect according to the receiving system being approaching (1/t -) or receding (1/t +);

- incidental emission of a photon which should then have the energy h n - toward a receding system, or h n + toward an approaching one, i.e. the opposite of the previous case!

Is there any evidence for this observation in matter's energy exchanges?

Of course this argument for matter being composed of light clocks is only qualitative, in that the patterns of light clock needed to describe and distinguish the various particles and sub-particles, and arrive at their de Broglie wavelengths, would be another story yet. And what makes light clock photons reverse their routes anyway, if it is not a material obstacle, or neighbouring light clocks, which would lead us to an infinite regression?

Still, some phenomena are rather nicely pictured by this qualitative approach:

Virtual particles may be seen as the continuous process of loosening and restrengthening bonds between co-operating light clocks.

Time-reversed particles are compatible with, at least partly, time-reversible light clocks.

Spin effect may be pictured as "rotating" light clocks, carrying thus rotative energy.

Mutual attraction or repulsion may be seen as nearby light clocks interfering with each other's coherence-preserving neighbourhood.

Multi-path behaviour of particles in a "quantum" environment, until observation, is understood as splitting and reconnecting paths of light clocks and photons, remaining phase coherent, until some non-reversible process absorbs their energy, scattering phase correlation.

Appendix 2: cosmic expansion and light speed.

A problem rarely, though sometimes, touched upon concerning cosmic expansion is why it is not felt on the galactic scale. If space expands, then why doesn't matter enter its step, why don't we, or solar systems, or our Milky Way expand? Another speculation I don't "feel" is the possibility of light rays lagging behind cosmic expansion, such as in the De Sitter model: if nothing is allowed to exceed light speed, why should distant receding galaxies be?

Asking myself why light speed is what it is, I came to wonder if it may reflect, on some cosmic time scale, the "velocity" of cosmic expansion. This would mean that an observer, could he "instantaneously", in cosmic epoch terms, and taking the case of closed space, look into his own back, he would see himself receding at exactly light speed: the maximum observable recession speed of far away objects, in whichever direction one would be looking (this property would follow from requirements of isotropy, see appendix 1).

At every point in space and time then, light would be "surfing" on the edge of spatial expansion, as if all of new space was created at that point and stacked between itself and the receding light wave. And matter, in the form of light clocks, would be "surfing somewhere within" this wave, retaining its phase coherence through the light clock's photons with the "initial" point. Phase correlation would reflect events having shared literally "the same space" at a given place and time. This would only apply in the direction of space expansion, thus pointing to the future; the opposite direction sees converging light not sharing any common spatial origin, thus pointing to the past.

If such view were correct, it would imply that light velocity, as described in cosmic time, would evolve according to the rate of expansion! This leaves the problem how such evolution could be perceived, if at all, by the internal (light) clocks of matter, and how these would be able to maintain calibration criteria for unit cycles, distances and time intervals. If there would be no such perception of change, then any talk about the evolution of the cosmic expansion rate would bear only meaning on a cosmic epoch scale, not on everyday's material time scale!

On the other hand through this view it becomes somewhat clear how matter, although surfing on the waves of cosmic expansion, does not itself partake in the expansion, being confined from moment to moment to the world paths of its constituent light clocks.

It would also somehow explain why photons, though themselves not experiencing time and space -their time stands still!- would be "aware" of the arrow of time, pointing away from the origin of expansion. It is indeed the arrow along which phase correlation, token of a common spatial heritage, is carried.

For all these reasons I would think it worthwhile to investigate a bit on these speculations, unless they are to be refuted by observational or theoretical arguments I am not aware of.

Appendix 3: the case of tachyons.

As I mentioned earlier, I used to look upon tachyons as a space-like equivalent of (time-like) ordinary matter. As a matter of fact, it is possible to draw a light-clock along a space-like axis in much the same way as it is along a time axis. This first impression is, however, complicated by two more observations.

First, in the case of a space-like light clock the return points successively consist of two departing, and next, of two arriving photons. There is no a priori reason why the arriving photons should be phase correlated, so the "arriving type" return points would not be able to conserve phase correlation. Recollect that in the case of ordinary light clocks the arriving photons have departed from correlated return points. (It is possible though to inverse the line of thought completely, by thinking of space-like light clocks as "surfing on waves of time-expansion"! Time could indeed be depicted along a space axis in much the same way as space along a time axis and, why not, give evidence of some kind of expansion. Space-like light clocks would then bear witness of this temporal expansion rate, and carry with them temporal, in contrast to spatial, phase correlation. This contingency seems, I admit, a bit far-fetched. It is further rebuked by the second observation.)

Secondly, when leaving the uni-dimensional case for space, one realises that space-like light clocks look very different from ordinary light clocks. Indeed, whereas a normal light clock describes a course, through a given point in space, along the -single- time axis, a space-like equivalent should describe a route, through a given moment in time, along all of three space dimensions. For a given inertial system, a tachyon would look like a standing wave in a substantial part, if not all, of space, at a single moment. (Recollecting the first observation and the speculation of temporal expansion, we see now that any spatial arrow would have to be allowed to evolve along all spatial directions, and doing so by rotation to arrive at its own opposite, cancelling out any well-defined space arrows for temporal expansion.)

According to these reflections it seems rather naive to look upon tachyons, should they exist, as mere space-like dummies of ordinary matter running faster than light.

Appendix 4: measuring and watching.

The most obvious case for examining the difference between these two observation processes is a uniformly moving rod passing by the observer. As I didn't come across a clear description of it in literature, I take the liberty of producing one here, completing the picture a bit by considering a train coach instead of a rod.

From what appears at the figure one can deduce the following relations:

Let the (contracted) length of the coach be L (proper length would be L0 = L g ), and its velocity v. These are measuring results. The quantities seen instantaneously depend upon the light path through the moving coach, and are perceived at the very moment the light reaches the observer. Therefore they behave differently during the approaching and receding phases.

During approach, length and velocity as seen amount to

L- = L / (1 - b ) ; v- = v / (1 - b ) .

During recession, these quantities become

L+ = L / (1 + b ) ; v+ = v / (1 + b ) .

From the above relations it may be deduced that

L- > L and even > L0, and v- > v, whereas

L+ < L , and v+ < v.

So during approach there is no length contraction being perceived, but on the contrary a length dilatation, whereas during recession an extra length contraction appears. Speeds are respectively higher and lower than measured speed. It should also be noted that there is no symmetric position while passing the observer, as symmetry cannot appear simultaneously at both extremities of the coach on the one hand, and around the coach's centre as it passes the point of observation on the other.

In the limit case v ® c, the previous relations tend to

L- ® 0 / 0 ... = L0 / h = µ ; v- ® µ , and

L+ ® 0 ; v+ ® c / 2 .

So all of the approach becomes condensed in one single moment of perception, the coach appearing to be elongated infinitely, after which the recession is perceived at zero length and half the light speed.