Zenos Universe

[Quoll]

How do we know that the speed of light is constant?


This may seem like a simple question. We measure the distance between a light source and a detector, then measure the time taken for a pulse of light to pass between them. Divide the distance by the time and we have the speed of light. Simple! Maybe not.


We all have a good idea what a distance is and physics doesn't have any great issues with it. But when it comes to time we all have a vague idea of what we think it is until we try to describe it. As for physics, the two dominant theories, Relativity and Quantum Mechanics, differ greatly. Relativity uses the Block theory and Quantum Mechanics isn't sure if it even exists or not (maybe both at the same time?).


What is the Block Universe?

The Block Universe assumes that time is a 4th dimension in which the past and future are real and the present is somehow played out. There are variants, The Growing Block Universe where the past is real and the future isn't, Presentism where only the present is real. All of which have serious problems and no evidence exists for any of them.


Don't get me wrong SR and GR have passed every test applied to them. Before the end of the 19th century physicists were starting to proclaim that they understood how the universe worked. That went well. Similar claims started to be made in the 1960s - 1970s.

Since then the following issues have arisen:-

The Big Bang

Inflation

Dark Matter

Dark Energy

Black Holes

All of these require entirely new physics to explain them.


To illustrate my concerns I would like to introduce you to Zenos universe. Do I think it is how our universe operates? Probably not, but it should at least raise some questions in your mind and food for thought. Enjoy!


Zenos universe*

Zenos universe is intended to be like our own with the same results to any experiment that can be performed.

It has

Flat Euclidean space

4 space dimensions*

No time dimension*

Particles have an Absolute Velocity (AV) property

Space has a 'fixed' reference frame which determines the AV.

A particle's energy is proportional to the AV squared. (Consider E=mc2)

Most Physics equations should be essentially the same, possibly requiring generalisations. Eg Maxwell's Equations will appear to be identical in any reference frame with the resulting value for c being the same as the AV of the experimenters reference frame.


Let us now consider how a particle would orbit a more massive particle in an inverse square field. If the orbit was perpendicular to the AV of the larger particle then the energy of the particle is essentially constant and stable. On the other hand if the orbit included the AV dimension then the particle would have to gain and then lose energy each orbit. So it would thus be unstable.

This would have significant consequences. Electric fields would be constrained to be perpendicular to the AV. Photons will only be emitted perpendicular to the AV.

This appears to give the direction of the AV all the generally perceived characteristics of our time dimension without the inconsistencies. It is a dimension that we cannot interact with, a vague perception of flowing from the past to the future. It provides a consistent reference for the measurement of speeds. The concept of time travel has no sensible meaning. Moving forward or backwards in time are equivalent not to mention up down left or right. Causality is assured.

Observability

Let's consider an observer (A) travelling at a velocity CA. The observer detects a photon (P) that has been emitted from a light source (B). The observer can't claim to have detected the source until further photons arrive from the same location or path. Let's consider just two photons the first when the source is coincident with the observer the second P is emitted some time later. The directions of the observer and source differ by an angle alpha and the relative velocity is in the X direction.




Assuming linear motion, any other configuration of the light source with respect to the observer will render it unobservable. Note that observability is not a two way possibility unless alpha is 0. Consequently Zeno will be able to observe his own planet and anything that is gravitationally bound with it. Most of the Baryonic matter will not be observable (Dark Matter). Particles whose path is slightly skewed may appear to pop in and out of existence.

The Michelson Morley Experiment*

If Zeno performs the Michelson Morley experiment a null result will be returned, the speed of light will always appear to be constant. The interferometers used in the experiment are always orientated perpendicular to the AV.

The de Sitter Double Star Experiment


The de Sitter Double Star experiment will also return a null result for two reasons.

As in the Michelson Morley experiment the orbit of the stars is always perpendicular to their AV.

For this experiment, the light sources and observer are a lot further apart than in the Michelson Morley experiment so a second effect comes into play. Any light source will be affected by the random motion of its constituent particles imparting a certain randomness to both the speed and direction of the photons. Only those photons that conform to the observability criteria above can be detected. This effectively filters out the effect that the experiment is looking for.

This second effect also results in the brightness of an object transitioning from the inverse square of the distance to the inverse cube of the distance as the distance increases.


There is a fundamental assumption in the Block Theory of time that a photon that travelled faster or slower than c would consequently be detected earlier or later as the case may be. We have no evidence that this is correct. You can't assume something that is undetectable doesn't exist because your detector didn't detect it.

Red shift

The energy of a photon detected needs a factor of at least cos2(alpha) applied. Alpha has the range 0 to pi/4. In other words everything observable is red shifted.

The brightness will also decrease with increased values of alpha in addition to that resulting from the increased distance giving something resembling Hubbles Law. This will become more pronounced at extreme red shifts where distant objects will not be bright enough to be detected.

The end of the universe.

The current view of the evolution of the universe is:-

A big bang

Rapid expansion (Inflation) required to account for the homogeneity seen in the CMB.

Slow steady expansion. (Red shift)

Steady increase in the rate of expansion. (Dark Energy)


For Zeno's Universe there is a very different possibility.


To demonstrate this possibility let's imagine that there is only one type of particle. Under appropriate circumstances two of these particles can collide resulting in eight of the same particles with an AV half that of the original two. Energy is conserved because the energy of a particle is proportional to the AV squared. The reverse process whilst it might be possible would not be probable.

For the new particles the universe has suddenly changed because the magnitude of every measure has changed by a factor of two. Their universe suddenly appears to be twice as big because their ruler is half the size.

Each time a pair of the particles collide they will drop down into a smaller/bigger universe. The rate of collisions will be determined by the density of particles. Thus at each level the average density would be constant.

There is something of a paradox in that at each level the four dimensions means that there is 16 times the space requiring 4 times as many particles. But if space is infinite and there are an infinite number of levels? (Turtles all the way down!)


Whilst the particle interaction described above is not a reasonable proposition, it provides an insight into the possibilities of a more subtle interaction.

If a two particle interaction occurs that results in more than two products and a small reduction in the AVs whilst still leaving the products still able to interact with what was previously surrounding the particles. Then the change in AV could be dispersed either through gravity or electromagnetic forces, ultimately affecting the whole universe. This may result in an isotropic universe which from Zenos perspective is continually expanding. All of which is driven by local processes at the smallest scales not by universe wide processes.


‐-----------------


So how do we know that the speed of light is constant if we don't know what time is?

[profloater]

I have some questions
If Zeno has no time, how is causality retained.?
As you know, we now define the speed of light, to fit the standard model, so does that answer one of your questions.?
Recent news puts MoND back in the frame, where gravity effects might explain dark entities. Are you including that?
MoND would also then, IMO, affect light, because gravity affects light. Is that so in the Zeno model?

[Noclevername]

No time dimension means the universe comes and goes all at once. Light has no speed, particles have no velocity because speed and motion are functions of time's arrow. You cannot perform experiments or observations. There is no entropy or thermodynamics.

[profloater]

No time dimension means the universe comes and goes all at once. Light has no speed, particles have no velocity because speed and motion are functions of time's arrow. You cannot perform experiments or observations. There is no entropy or thermodynamics.

But that is not what is described in the OP. That is a snapshot. It is not clear though, in the OP, whether the “clue” is to allow light to change in speed and colour shift. In order to avoid all that new physics.

[Noclevername]

OK, then what does "no time dimension " mean?

[Quoll]

Hi Profloater and Nocleavername

Lets get rid of MoND to start with. It is of no relevance at all. This thread is about time and the consequences of not having a theory of time which is consistent and well defined.
To paraphrase what has been said by many before me, we all think we know what it is until we are asked to explain what it is.
SR and GR use the block theory which is not consistent with QM which isn't even sure that it exists.
So to understand this thread you need to look at the functions that use time and how we achieve that.
When we measure something we usually compare like with like ie mass with mass, charge with charge the exception is time. We compare time with the motion of something over a given distance. This suggests that time is not fundamental but a composite. In Zenos universe it is split into a dimension and a property of particles, a velocity, with magnitude and direction. This ensures causality is guaranteed because a particle cannot return to somewhere that it previously occupied and interact with itself.
If you view this thread through the lens of the block theory of time it will not make sense

[profloater]

But Zeno and his paradoxes of time are countered by differential calculus. In human terms we use memory to establish time as a measure of change. If we get stuck in the deduction that time is an illusion, that is just solipsism, a good base but it makes no predictions. Staying agnostic about our model, we can model time like Newton for every day experience. Our evolution is ever better predictions for survival and prediction implies change and hence time. Then we get clever and look to the stars and wonder about why heat makes light and so on. We have a model as you say, with many unobservables to explain what we can observe. If we escape those problems by questioning time we must still have a model for our illusions from memory, consistency of experience and change. In that way time is a place holder for change. The sun rises and sets. We get better predictive models for that. Paradoxes are excellent challenges for our models, but do not force us to abandon experience. Individual reality seeks consensus. So I ask you to clarify your alternatives to time as a dimension, as understood now as spacetime.

[profloater]

And just to note, I avoid the question of what is real. It is a mind trap because my reality is n my mind and I cannot test anything else. So I prefer to stick to consensual observations, good predictive models, and known problems with models.

[Quoll]

Profloater, I'm not sure where to start with your post.
The reference to Zeno is not resolved with differential calculus. Its quite the opposite. Zeon's universe is vastly bigger than ours, firstly it has four spacial dimensions with particles that can freely move in any direction with any velocity. The catch is that their mass is proportional to their velocity squared. It is this velocity vector that becomes a particles time dimension, think E= mc2. It is this value of c that becomes the reference for everything to do with the particle. Because of the geometry of things only a very, very, very small part of Zeno's universe will be observable from the particle.
You suggest that we should be agnostic about the models we use but the point being made is that the model might be giving the wrong answer. In the case of measuring the speed of light the block theory assumes that if light did travel at some other velocity then we could detect it. As we havn't detected it then it must be constant! This is a circular argument. The primary evidence for the block theory is a constant speed of light, but the model assumes that the speed of light is constant.

[Noclevername]

Hi Profloater and Nocleavername

Lets get rid of MoND to start with. It is of no relevance at all. This thread is about time and the consequences of not having a theory of time which is consistent and well defined.
To paraphrase what has been said by many before me, we all think we know what it is until we are asked to explain what it is.
SR and GR use the block theory which is not consistent with QM which isn't even sure that it exists.
So to understand this thread you need to look at the functions that use time and how we achieve that.
When we measure something we usually compare like with like ie mass with mass, charge with charge the exception is time. We compare time with the motion of something over a given distance. This suggests that time is not fundamental but a composite. In Zenos universe it is split into a dimension and a property of particles, a velocity, with magnitude and direction. This ensures causality is guaranteed because a particle cannot return to somewhere that it previously occupied and interact with itself.
If you view this thread through the lens of the block theory of time it will not make sense

I must admit I'm having trouble understanding your definition of time, then. Could you clarify it?

[Quoll]

Hi Noclevername

The problem is that modern physics doesn't know what it is. As I have mentioned already the block theory is flawed and QM isn't even sure that it exists. So if you use that as your starting point then you are behind the 8 ball to start with.
The best way of getting your head around it is to consider what you are actually doing when you measure time. You need something that is moving at a calibrated speed across a calibrated distance. Something that is moving along a ruler, the hands of a clock around a dial, a photon and its wavelength.
No dimension is required. BUT. A stable reference is very handy. In Zeno's universe the direction of motion is that reference though its stability is only an illusion.

[Noclevername]

Hi Noclevername

The problem is that modern physics doesn't know what it is. As I have mentioned already the block theory is flawed and QM isn't even sure that it exists. So if you use that as your starting point then you are behind the 8 ball to start with.
The best way of getting your head around it is to consider what you are actually doing when you measure time. You need something that is moving at a calibrated speed across a calibrated distance. Something that is moving along a ruler, the hands of a clock around a dial, a photon and its wavelength.
No dimension is required. BUT. A stable reference is very handy. In Zeno's universe the direction of motion is that reference though its stability is only an illusion.

Let's say that it's true, that "modern physics doesn't know what [time] is." So what do you propose as a replacement for current mainstream theories?

[Quoll]

Let's say that it's true, that "modern physics doesn't know what [time] is." So what do you propose as a replacement for current mainstream theories?

Here is a quote that appears quite regularly, extracted from Wikipedia "Time in physics*is operationally defined as "what a*clock*reads"."
There are many books on the subject and Physicist whose expertise is in this area can't even agree that time exists. So its not just my opinion.
As for a mainstream theory I doubt that one exists. As I have noted SR and GR use the Block Universe MODEL. QM uses what a clock measures.

To clarify what is in the initial post Zeno's universe has 4 space dimensions where particles have an energy proportional to their velocity squared. The consequence of this is that an orbit/orbital cannot include the direction of this velocity and photons cannot be emitted in that direction. No observation using EM will occur in that direction. It becomes a time dimension without the causality issues of the block theory. The concept of going back in time no longer makes sense. Physics will work in any direction with entropy always increasing.

[profloater]

It seems to me you are setting up straw men arguments. It is true that time has become complicated by Einstein showing how space and time look different to different observers, and introduced the model that nothing moves faster than light speed. Observers will measure light speed to a value. Of course that model does not require a constant light speed, light interacts with mass. The observers must sit in the same frame to agree. I do not see how a velocity per particle does not use time exactly as Newton did. It also seems mystical to just call up four space dimensions. But then we do use the word dimension loosely in physics. Velocity does imply time’s arrow but can have a negative value when measured in three orthogonal directions.

So I am still unclear what you mean or what predictive value you are going to claim for Zeto. I suggest you are using “understand” in a non defined way. We use models for their predictive and reassuring status. When our model becomes self contradictory, we try to use a better one, often using languages like maths or multiple dimension that we cannot directly observe. So we do not understand time in the absence of a model but we do understand time in a model of our choosing. Making the mental step to “reality” is where the paradoxes arise.

[profloater]

Profloater, I'm not sure where to start....
You suggest that we should be agnostic about the models we use ....

No, this is important, I suggest we should be agnostic about the reality of the models we use.. I do want to understand your proposed model. But my grandfather clock ticks away using a time model good enough to fly to the moon.

[Noclevername]

Here is a quote that appears quite regularly, extracted from Wikipedia "Time in physics*is operationally defined as "what a*clock*reads"."
There are many books on the subject and Physicist whose expertise is in this area can't even agree that time exists. So its not just my opinion.
As for a mainstream theory I doubt that one exists. As I have noted SR and GR use the Block Universe MODEL. QM uses what a clock measures.

To clarify what is in the initial post Zeno's universe has 4 space dimensions where particles have an energy proportional to their velocity squared. The consequence of this is that an orbit/orbital cannot include the direction of this velocity and photons cannot be emitted in that direction. No observation using EM will occur in that direction. It becomes a time dimension without the causality issues of the block theory. The concept of going back in time no longer makes sense. Physics will work in any direction with entropy always increasing.

All science relies on models. But the current model is consistent with all the experimental evidence done for over a century. All our technology and scientific accomplishment is consistent with the current models.

[profloater]

All science relies on models. But the current model is consistent with all the experimental evidence done for over a century. All our technology and scientific accomplishment is consistent with the current models.

Well, up to a point, we have probability models that explain particle experiments but they remain hard to understand when compared to macro behaviour. But as yet I cannot see how Zeno helps!

[stutefish]

I'm sorry, but I'm still stuck on:

Don't get me wrong SR and GR have passed every test applied to them. Before the end of the 19th century physicists were starting to proclaim that they understood how the universe worked. That went well. Similar claims started to be made in the 1960s - 1970s.

Since then the following issues have arisen:-

The Big Bang

Inflation

Dark Matter

Dark Energy

Black Holes

All of these require entirely new physics to explain them.

I'm pretty sure black holes were predicted (or predictable) from SR and GR long before they were first observed, and are completely explained by the mainstream physics that preceded their observation.

And I'm pretty sure the Big Bang theory is also a direct result of SR and GR predictions plus cosmological observations.

Not sure about the others, but "require entirely new physics" seems to be hyperbole and gets the whole thing off to a bad start.

[Noclevername]

Quoll, a direct question:

What is your theory of time? Please state it as clearly as possible and why it fits observations, on its own merits.

[Quoll]

I'm sorry, but I'm still stuck on:



I'm pretty sure black holes were predicted (or predictable) from SR and GR long before they were first observed, and are completely explained by the mainstream physics that preceded their observation.

And I'm pretty sure the Big Bang theory is also a direct result of SR and GR predictions plus cosmological observations.

Not sure about the others, but "require entirely new physics" seems to be hyperbole and gets the whole thing off to a bad start.

Actually black holes were first predicted in 1784! But modern physics understanding of BHs ends at the event horizon. As for the Big Bang there are many questions that current theories can't begin to answer like where and how did it come about. I'm not sure that we even have the language and concepts to ask the questions that need to be asked.

[Quoll]

Quoll, a direct question:

What is your theory of time? Please state it as clearly as possible and why it fits observations, on its own merits.

Currently Time is considered to be fundamental, which one might cynically consider to be a cop out because we don't know what it is.

Lets take the equation v = d/t
when v is a velocity d is a distance and t the time taken to cover the distance.
both distance and time are considered fundamental.
Lets now change that around t = d/v
with the distance and velocity are fundamental and time the derived property.

The current definition of a second has the distance at 9,192,631,770 periods of a cesium atom (with a bit more detail) and the velocity is the speed of light.
This is a problem if our speed of light isn't constant.

In Zeno's Universe there are no constants the best you can do is use to your own reference frame which an Absolute Velocity with respect to the four space dimensions which you define as c.

[Noclevername]

In Zeno's Universe there are no constants the best you can do is use to your own reference frame which an Absolute Velocity with respect to the four space dimensions which you define as c.

I don't really understand this statement. Can you show your work so I can see how you arrived at this conclusion?

[Quoll]

In Zeno's Universe there are no constants the best you can do is use to your own reference frame which an Absolute Velocity with respect to the four space dimensions which you define as c.

I don't really understand this statement. Can you show your work so I can see how you arrived at this conclusion?

Let me be clear I'm not referring to constants like pi and e.
I'm referring to c the speed of light which in Zeno's universe is variable, in fact for any particle it is the same as its Absolute Velocity with respect to the 4 spacial dimensions.
If you haven't re-read the original post since the start then it might be a good time to do so and reference any questions to it.

[Noclevername]

In Zeno's Universe there are no constants the best you can do is use to your own reference frame which an Absolute Velocity with respect to the four space dimensions which you define as c.



Let me be clear I'm not referring to constants like pi and e.
I'm referring to c the speed of light which in Zeno's universe is variable, in fact for any particle it is the same as its Absolute Velocity with respect to the 4 spacial dimensions.
If you haven't re-read the original post since the start then it might be a good time to do so and reference any questions to it.

You just keep repeating the same vague and unclear assertions without explaining them. That's not an answer.

What data or calculation supports your claims? Do you have any evidence, details or specifics to present?

[Quoll]

You just keep repeating the same vague and unclear assertions without explaining them. That's not an answer.

What data or calculation supports your claims? Do you have any evidence, details or specifics to present?

I'm sorry but I don't know what you want. What do you not understand?

[Noclevername]

I'm sorry but I don't know what you want. What do you not understand?

Your theory. It makes no sense to me as presented.

I'm asking you to please lay out all the details of how the passage of time would work in Zeno's Universe. Give whatever equations and data support this model. Does it make predictions consistent with observations?

[Quoll]

Your theory. It makes no sense to me as presented.

I'm asking you to please lay out all the details of how the passage of time would work in Zeno's Universe. Give whatever equations and data support this model. Does it make predictions consistent with observations?

There is no such thing as time. You can compare the position of some object of interest with respect to a reference and call that time but there is no time.

Have you re-read the original post? You might note the post is a longer than most. To give a full and detailed explanation of everything as you request would be more than this forum would permit.
Try pinpointing something that you don't understand and we can go from there.

[profloater]

The standard model does start with v, the definition c. But while c is defined the actual speed of light in say , glass, is a different v.
Spacetime is a distribution of mass, where mass forms spacetime and spacetime forms gravity which controls individual mass freefall. V for a mass is thus relative to an observer’s frame. Surely you are saying the same, except objecting to dark matter etc.?
So for me, your rejection of MoND which might be called modified spacetime, is not consistent with your (absolute) v. Surely v is a relative quantity?

[Quoll]

The standard model does start with v, the definition c. But while c is defined the actual speed of light in say , glass, is a different v.
Spacetime is a distribution of mass, where mass forms spacetime and spacetime forms gravity which controls individual mass freefall. V for a mass is thus relative to an observer’s frame. Surely you are saying the same, except objecting to dark matter etc.?
So for me, your rejection of MoND which might be called modified spacetime, is not consistent with your (absolute) v. Surely v is a relative quantity?

This looks like word salad to me. Can clarify what you are saying.

[profloater]

There is no such thing as time....

Ah, is this about existence? Change in existence? That is where I am agnostic. I model time, it makes sense of being. If I can measure a local speed of light, (which is impossible without instruments) then non locality follows as night follows day, so to speak. So my model has distance and time. This is convenient since my mind tries to keep the world still while the stars revolve around me. Time is not a thing for me, it is change. However I am stuck in three space dimensions, with mass making itself very evident.!