show all replies (4 not shown)

hide replies

show all replies (1 not shown)

hide replies

Hi Giovanni

I read your interesting and thought-provoking essay. I have some comments and doubts about some issues that I would be grateful if you could make some comments. You mention that:

But in some sense we never actually "see" spacetime, we never "detect spacetime", and over the last century we gradually came to appreciate that there would be no spacetime without...

view entire post

Hi Giovanni

I read your interesting and thought-provoking essay. I have some comments and doubts about some issues that I would be grateful if you could make some comments. You mention that:

But in some sense we never actually "see" spacetime, we never "detect spacetime", and over the last century we gradually came to appreciate that there would be no spacetime without particles.

You argue against space-time, but it was not clear to me what new conceptual framework or formulation you propose to replace space-time. For instance, in thermodynamics time is not an indispensable item for the calculation of the physical quantities, by only knowing the pressure, the temperature and the volume one can predict the outcome of a system no matter how much time elapses. To be honest, I did not get well why you see space-time redundant, the arguments you lay down appear to me somewhat messy, in what sense you think they are redundant?

On the other hand, I have been studying the problems of the measurement of the one-way speed of light and of clock synchronization and one of your statements call my attention particularly this: "Alice and Bob establish that they are in relative rest at a distance L with synchronized clocks."

According to my research the one-way speed of light has been never measured and clock synchronization a la Einstein assumes that the one-speed of light is isotropic which turns out to be redundant and thus a dead end. I have realized that clock synchronization has become a non-trivial task as at first sight it may seem.

Moreover, you mentioned in relation to the aether that:

I shall leave these questions to the appetites of philosophers... And then quote Poincaré:...Whether the ether exists or not matters little - let us leave that to the metaphysicians... Later you argue that the concept was rule out from physics because it turned out to be useless.

However, in my essay I hold the opposite opinion that reviving the aether it is more useful to solve most of the present problems of physics. Bell, Dirac and others contented that the situation of the aether in 1905-1915 was quite different from the situation of the aether in the middle of the XX century. This seems to me very plausible and I discuss in my essay some of the misconceptions around this concept. I claim that certain assumptions should be revived in physics because of their usefulness. One case of this was the notion of light as a particle brought back to life by Einstein. I would like to quote what Newton thought about the aether and its connection with gravity (Vesselin Petkov also holds that gravity is not a force and thus quantization of gravity is chimera), which I think it could be of great relevance to physics:

"Gravity is the result of a condensation causing a flow of ether with a corresponding thinning of the ether density associated with the increased velocity of flow..."

To make even clearer that Newton was actually Cartesian in the philosophical matters of gravity, in a letter to Bentley in 1692 Newton wrote:

"It is inconceivable that inanimate brute matter should, without the mediation of something else which is not material, operate upon and affect other matter, without mutual contact, as it must do if gravitation in the sense of Epicurus be essential and inherent in it. And this is one reason why I desired you would not ascribe 'innate gravity' to me. That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance, through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an ABSURDITY, that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it."

Making the assumption that the quantum vacuum is some sort of fluid (as the CERN experiments have revealed) it has been shown that the bending of light due to the presence of a massive object can be equivalently explained by a gradient in the refractive index of the vacuum.

Finally you mention that:

But how should one describe the position of the particle when it is formally "inside" the barrier? And especially how much time does it take a particle to quantum-tunnel through a barrier?

Besides reconsidering the aether in physics one should get rid of the notion of particle. Instead, I propose to use solitons which, as it is well known in several field of mathematics and physics, behave as particles in all aspects. The essay of Jarek Duda explains all the similitudes and at the same time the advantages of dealing with solitions in physics instead of particles. If one incorporates these two ingredients into physics the wave-particle duality disappears and experiments such as the double-slit experiment become quite intuitive and easy to handle.

I wish you good luck in the contest and I would be grateful if you could leave me some comments about my essay.

Israel

view post as summary

Dear Giovanni

What an essay! Congratulations! It is extremely clear and simple, while the questions you address are certainly very deep and complex. My essay and yours have a lot in common, as I will explain, and there are some points you might find interesting to discuss.

Like you and many other physicists, I feel the space-time abstraction is not fundamental. I find your arguments...

view entire post

Dear Giovanni

What an essay! Congratulations! It is extremely clear and simple, while the questions you address are certainly very deep and complex. My essay and yours have a lot in common, as I will explain, and there are some points you might find interesting to discuss.

Like you and many other physicists, I feel the space-time abstraction is not fundamental. I find your arguments for the ''cumbersomeness'' of it whitin the context of QM very interesting. Your proposal of ''detectors'' first is compelling, and resembles a lot the Machian arguments against Newton´s classical mehanics, which I assume you´re aware of.

For instance, time is an abstraction we have built upon the notion of motion of obejcts. If everything in the universe speeded up, including clocks, the flow of an invisible paramater t seems meaningless; it becomes more easy to see that time may be just a practical abstraction and not a fundamental theoretical building block for physics.

So look at your example: ''x = vt (1)

Of the infinitely many ''otential truth'' codified in this equation only two facts are established experimentally: the particle is emitted at Alice at time t = 0 of Alice's clock and the particle is detected at Bob at time t = L=v of Bob's clock''

You see the space/time abstraction renders more information than a ''minimalist physical description'' would require. But also, we can ask: what is a clock? Shouldn´t we also remember that time is derived concept from motion in order ro provide a ''minimalist description''?

Since your proposal is a ''detectors first'' type, we should be well aware about what we mean by an instant of time and a position in space. This leads directly to Julian Barbour´s relational physics. In my essay Absolute or Relative Motion...or Something Else? I have also serached, just like you, for a minimalist description of the universe and speculated about a possible substitute for space-time. I think we can have an awesome discussion.

Best regards,

Daniel

view post as summary

Dear Giovanni,

I read your essay with great interest. A few remarks/questions.

1. I agree wholeheartedly that modeling classical spacetime as a manifold over the continuum is at the very best redundant. Some would argue that it "does no harm" and that it "makes no difference" what the structure is at arbitrarily small scales, but something that bothers me about this view, in...

view entire post

Dear Giovanni,

I read your essay with great interest. A few remarks/questions.

1. I agree wholeheartedly that modeling classical spacetime as a manifold over the continuum is at the very best redundant. Some would argue that it "does no harm" and that it "makes no difference" what the structure is at arbitrarily small scales, but something that bothers me about this view, in addition to the issues you raise (tunneling, etc.), is the fundamental role the representation theory of the Poincare symmetry group of Minkowski space plays in constraining the properties of particles in quantum field theory. I do not think it is at all obvious that altering this symmetry at small scales would have no practical effects.

2. What is your favorite interpretation of quantum theory? I ask this because it seems to me that the conceptual role of spacetime depends on this to a large degree. For instance, if you prefer a sum-over-histories view, you can separate the properties of classical spacetime from quantum effects arising through superposition of universes. If you prefer to think about a single universe and view classical physics as a limit via the correspondence principle, then it seems clear that such a universe is very unmanifold-like.

3. On a related note, one possible way of thinking about nonlocality is to provisionally banish the spacetime metric and simply regard direct influence between events as defining locality. The idea is that spacetime is a way of talking about relations among events, that it closely resembles a Lorentzian 4-manifold at large scales, but that "nonlocal interactions" with respect to the metric of this "nonphysical manifold idealization" are simply indications that the manifold is really fictional. Personally, I tend to think that the most prominent nonlocal phenomena such as entanglement have more to do with superposition than nonmanifold structure, but I do think that the large-scale properties of spacetime arise from more primitive microstructure, or, more conservatively, that models based on primitive microstructure will eventually outperform manifold models experimentally. See my essay here for more on this: On the Foundational Assumptions of Modern Physics.

3. I will have to have a look at your papers about observer-dependent association of processes to points in noncommutative spacetime. That is an idea I have not heard of before.

Thanks for the enjoyable read. Take care,

Ben Dribus

view post as summary

Hello Giovanni,

I found your essay one of the best I've read, and you argue very well for weaknesses in the spacetime interpretation at a small scale in some areas. But you talk as if all is well with spacetime elsewhere and generally, as intuition says it should be. Of course SR is right, but a close look and you'll see that all is not well generally with the spacetime interpretation. You...

view entire post

Hello Giovanni,

I found your essay one of the best I've read, and you argue very well for weaknesses in the spacetime interpretation at a small scale in some areas. But you talk as if all is well with spacetime elsewhere and generally, as intuition says it should be. Of course SR is right, but a close look and you'll see that all is not well generally with the spacetime interpretation. You say:

"The redundant abstraction of a macroscopic spacetime organizing all our particle detections is unproblematic and extremely useful in the classical-mechanics regime."

In fact it is not 'unproblematic', as spacetime leads unavoidably via a rigourous proof to block time, which requires motion through time not to exist, which in turn removes cause and effect. This loss of cause and effect is somewhat problematic in the classical mechanics regime.

You also say:

"Of course, the spacetime abstraction is unrenounceably convenient for organizing and streamlining our description of observations done in the classical-mechanics regime."

That is all true, except for the word 'unrenounceably'. It is convenient, and it seems harmless. But we don't understand time, and Minkowski spacetime contains a set of assumptions about time. Because we don't understand time, we have to look at the clues about time, as I've argued in my essay. If we don't look at the clues in front of us, however unexpected, I'm not sure how we're going to reach a point where we understand time. There are also missing pieces of the puzzle, and we need to allow for their existence.

Because it leads to block time, spacetime is in contradiction with the standard view of quantum theory about whether the future currently exists. That is a deep contradiction. And there are some places where the implications of spacetime jar with our picture that deeply, and conflict directly with what we observe. So although it is convenient to use, it looks like it might be flawed.

This means it is not like your analogy with the aether, which was portrayed in your quote as a useful concept, whether or not it actually exists. You sound almost like it makes little difference whether spacetime exists - and yet if it does exist, motion through time doesn't, and if it doesn't, motion through time can. That's a big difference.

So to me, you've not gone far enough in criticising spacetime, and could have strengthened your argument by pointing out other weaknesses. Of course SR is right, that has been extremely well confirmed by experiment. But the spacetime interpretation has not been confirmed, and if one gets conceptual problems with an interpretation, then one probably needs a new interpretation.

I'd appreciate any thoughts you might have on my essay. Yours and mine together show the problems with spacetime very well, though they deal with different areas.

Good luck. Best wishes,

Jonathan

view post as summary

show all replies (1 not shown)

hide replies

Hi Giovanni,

In my theory everything is emergent all from a mathematical structure that describes random numbers and imperative relations between them. Interpreting the random numbers as line lengths, the relations between these lines generate all of the laws of physics. You get a beautiful unified picture of space (its points are the crossing of the lines-dynamic-),...

view entire post

Hi Giovanni,

In my theory everything is emergent all from a mathematical structure that describes random numbers and imperative relations between them. Interpreting the random numbers as line lengths, the relations between these lines generate all of the laws of physics. You get a beautiful unified picture of space (its points are the crossing of the lines-dynamic-), time(change of state-does not actually exist-), mass, charge, and energy.The theory is called “Quantum Statistical Automata”.

It is a kind of an automata conjectured by Wolfram and Conway, but mine derived from a more fundamental idea of why reality had to come about. Of course Dr Tegmark is also a believer in the mathematical universe. I did not know any of these great people back then, but I came to believe that reality is nothing but a mathematical structure and went directly to the simplest system to implement such program. I hit on the right system in no time due to a combination of a flash of brilliance (which we all experience), my engineering/problem solving background and extraordinary luck.

From the following results it can be seen that the system shows how ordinary physics results arise plus some results that standard physics can only dream of. But the most important conclusion is that the system points to the REAL final theory. All is needed is some smart people to take it seriously, or wait for me to finish it up in due time. Of course the former will be much quicker than the later.

Fundamental Theory of Reality,"Reality is nothing but a mathematical structure, literally".

1. How I arrived at the idea.

2. Basic results that shows how QM arises, written in BASIC program.

3. Description of two particles interacting and explaining the program in C++.

4. Showing the results for Bohr atom hydrogen 1s simulation.

5. 1/r law and the running phase

6. The amazing formulas deduced from the system.

7. How spin arises from 2D simulation.

8. The appearance of the mass of the electron through simulation.

9. How gravity arises.(basic simulations not shown yet)

There are many other results not shown.

view post as summary

hallo there, I came across this paper during these Christmas holydays, through FB.

I've got a point or two about the issue, which I'd like to discuss - at best, perhaps, with the author himself, Giovanni.

( BTW: I'm italian, so if he should come across this comment he may, of course, reply in italian )

Not knowing if a comment, written 2 months from the last one published,...

view entire post

hallo there, I came across this paper during these Christmas holydays, through FB.

I've got a point or two about the issue, which I'd like to discuss - at best, perhaps, with the author himself, Giovanni.

( BTW: I'm italian, so if he should come across this comment he may, of course, reply in italian )

Not knowing if a comment, written 2 months from the last one published, will even be read, I'm a little reluctant to write extensively my point of view, but I'll take myself some time to present some keywords and basic ideas. I hope I'm not doing this for nothing… for once that I encounter a VERY interesting article, it HAD to be on a page that no-one probably ever visits any more! ;-))

======================

COMMENT to the paper:

======================

Firstly, I find the space-time inference absurd: to postulate an universe giving itself the hard work of building en entire 4D (or more!!) continuum with highly complex mathematical properties, is insane to the least; that's why I completely agree with the historical/operational explanation of our "space-time-way-of-thinking" given in the paper. Also, a scheme of the type "emitter-detector" can be helpful to investigate some aspects of the entire problem, reducing it down to its essentials. Thus: reductionism, approved ;-)

(THE BEEF): My understanding is that 'space-time' is a complex construct, most probably EMERGING as an average reference frame for classical objects with no underlying reality of its own. A continuous, local (as opposed to "non local" in Bell's sense) classical-relativistic reality, though, holds for EVENTS in space-time, and cannot be eluded.

But EVENTS are classical phenomena, they are described by 'macro-states'. A macro-states consists of an incredibly numerous collection of micro(or quantum) states; it is a portion in the configurations' space, that ends up coherently describing a shared overall picture.

This "shared overall picture", we call 'classical world' and it obeys relativity, causality, and locality (in the sense of Bell).



In my picture, however, the shared overall is only a kind of "average", consisting of a huge number of micro-states, all of them describing alternate "little" stories about the numerous constituents of the macro-system, à la "sum over stories" (Feynman).

The expansion of one portion of the configurations' space, necessary to produce a "new" (or, better: "different") macro-state generally happens in a measuring device; the coherent description of a defined macrostate with its classical properties (position, time, momentum, energy, etc..) we call the "outcome", is classical, and could be highly non-linear

As a matter of fact, a micro-state (describing a single quantum object, or phenomenon) isn't observable, and if this is to become observable, the microstate must necessarily undergo an amplification through a measuring device, of the type "avalanche expansion" (snowball amplification).

The measure process will then eventually produce an outcome, which is a classical one.

No quantum microstates can ever be observed, only their amplifications.

More than that: my idea is that only certain amplifications can be observed, and so can be christened "real": in those observable configurations a large enough number of microstates coherently describes a classical, physically self-consistent picture (*), that most other microstates in the universe will share form that very point onwards.

On one side, the measuring device is clearly entangled with the totality of all of the microstates involved in the measure process in the laboratory, but, on the other side, it also communicates the classical results with the rest of the classical world.

Once we rename the term "communicate the classical result" with the periphrasis "is a coherent description via a very large number of microstates, which differ only by a tiny quantity, but give the same overall picture, all entangled with observers across the rest of the universe" we get that the measuring system is quantum mechanically entangled with everything else, also on the other side, but mainly via macro-states.

==========================

[1] Some curiosities tend to enforce this sight, in my opinion: in certain carefully prepared experiments, e.g., a particle is observed in two locations at the same time, or other "oddities" can be produced (super-conductivity, super-fluidity, Bose-Einstein condensates, etc…).

But these "oddities" are achievable only in conditions special enough that they only can happen through special arrangements of detectors in which particular attention is given to the segregation of the experiment from the rest of the universe.

In this case, it seems that oddities can be sustained as long as little or virtually no communication happens with the world outside the laboratory, thus via segregation from the rest of the universe.

Outside of a laboratory environment, "oddities" generally do not survive for an enough long time to be observed by passers-by, before degenerating to dull defined 'classical' states.

==========================

During the measure process, a number of "stories" can theoretically be connected with the microstate examined, that will eventually produce alternate outcomes. Rarely (see [1]) these outcomes can both exist at the same time.

But why is so ? in my picture, it is conceivable, that different outcomes are related to different portions of the configurations' space of the system (microstate to analyze + "antenna" microstates in the measuring device) and perhaps the amplification process favours one groups of stories more than another, and the entire universe is then entangled with the option (group of micro-stories) that has more "offspring" outnumbering other possible outcomes.

This - and only this group of stories, or macrostate

[[ apart from exceptions in which an equilibrium can be maintained (with significant effort) between more possible outcomes, in the sense of [1] ]]

becomes "real" in the sense that we can observe it, and every physical system relying upon the measuring result will be entangled with all the microstates produced by the amplification, via an incredibly large number of quantum interactions.

We are talking astronomic numbers, here, as a single detection generally involves a number, N, of the order or 10^20 particles, with a configurations' space portion that can expand of a number in the order of magnitude of N, but factorial !!

The collection of micro-states that is comprised in a group of stories that only differ by a tiny little bit (ħ, fro example ?!?!) from one another describe the very same picture, but slightly different. It is a fundamental property of microstates' statistics in a snowball expansion, that the outcomes will concentrate around a bell-shaped curve, of the Gaussian type

These outcomes relate to one another creating, in my picture, a network of ever-growing degrees of freedom, where some properties can be interpreted as localizations in space, and in time.

Lastly: I have indirect proof that this approach could be the right one for a better model of QM, and some of these concern the nature of space-.time on large scale. This line of thinking goes so far, as to account for galaxy stability without dark matter, or even to change significantly our understanding of the universe's dynamics at very large scale (structure of the order of magnitude of the "great wall", filaments, or even the cosmic expansion rate, the dark energy problem and the like).

For the next times, however, my goal would be to show that in a so constructed space.-time, a limit would emerge: an insuperable velocity only for macro-states transporting information, whereas everything else could be thought of as non local in space and timeless (or: "non local" in time sense).

My aim is to make a specially relativistic space-time of EVENTS just out of nothing thought of as being local. Is it crazy enough? Any comments?

Kind regards, just in case... ;-)

view post as summary