Naked Science Forum

On the Lighter Side => New Theories => Topic started by: RTCPhysics on 25/05/2017 11:10:30

Title: On Einstein’s ‘Light Clock' thought experiment.
Post by: RTCPhysics on 25/05/2017 11:10:30
Einstein’s ‘special theory of relativity’ led to the statement that the ‘laws of physics’ are always the same, whatever their frame of reference. The only restriction upon this statement that is incorporated within his ‘special theory of relativity’, is that it applies to movement within a frame of reference that has a constant velocity.

Einstein’s ‘Light Clock’ thought experiment is used to explain the slowing down of the passage of time with movement. It is classed as a ‘thought experiment’, because it is technically difficult to count the number of times a ‘visible’ photon bounces up and down between two parallel mirrors within an ‘evacuated’ glass enclosure, without impinging upon the photon’s movement.
 
However, by assuming that the reflections of the visible photon within the 'light box’ can be counted and displayed above the light box for all to see, then the light clock thought experiment can be analysed.

It starts with the first owner of the lightbox clock standing ‘still’ within their frame of reference, who is able to observe that the lightbox clock consistently counts the same number of reflections, during a specified interval of time.

The occupant of another frame of reference, which is moving in a parallel direction at a constant velocity relative to the first frame of reference, also has an 'identical' lightbox clock with the photon being reflected vertically up and down between the central points of the two parallel mirrors.

It is here that an assumption is made in the lightclock ‘thought experiment’, which leads to the concept of time slowing down. The assumption is that ‘the photon will continue to be reflected between the central points of two parallel mirrors of the light box, regardless of the movement of the glass box.’ But this is not how the laws of ‘photon physics’ work.

Within the moving box, the photon spends most of its time travelling between the two mirrors and as such is unaffected by the movement of the evacuated glass box. In addition, when the photon is reflected perpendicularly off the moving mirrored surface, its speed is unchanged. If it gained or lost kinetic energy during its reflection off the mirrored surface, then this would result in an increase or decrease in its kinetic energy leading to a change in the magnitude of the photon’s speed, which we know is not the case. It is not possible to accelerate or decelerate a photon.

In effect, therefore, the photon travels between the two parallel mirrored surfaces completely ‘independently’ of the movement of the lightbox enclosure.

As a consequence, during the time it takes the photon to be reflected and counted, the ‘lightbox’ has moved forwards by a minute amount and the photon finds itself displaced by the same minute amount away from the centre of the mirror against the direction of travel and towards the rear side of the glass box. But the photon being unaffected by the movement of the glass lightbox, still continues to bounce vertically between the top and bottom mirrors.

Over a finite number of reflections, the photon displacement will reach the side of the glass box and be refracted outside and the lightbox clock will cease to work. If the photon enters the eye of its holder, then the holder will be given a glimpse of the inside of the empty glass box.
     
Light does not obey the ‘addition of velocities’ law that is experienced by two bodies of matter interacting with each other, such as someone jumping off a moving bus, where the kinetic energy of the jump interacts with the kinetic energy of the moving bus.
 
At the moment of the cessation of the light box counter in the ‘moving’ frame of reference, both owners will observe that their lightbox clocks have ticked up exactly the same count. All that has happened is that the 'moving' lightbox clock, ceased to work after the passage of a finite period of time.

However, the universe has no ‘fixed point’ of reference by which an object can quantitatively determine its velocity and direction of movement. All objects moving at a constant velocity, can view themselves as being stationary, with everything else moving relative to them.
 
Hence, from the perspective of the ‘moving' lightclock frame of reference, the ‘stationary’ lightclock is travelling in the opposite direction away from it. As a consequence, the photon in the ‘stationary’ lightbox, moves across the lightbox against the direction of travel and towards the front side of the lightbox, such that both light boxes simultaneously cease to work.

But In physics, nothing is still and you cannot say without a datum point, that one body of matter is moving faster or slower than another.

The reality of this simultaneous cessation of the two lightbox clocks is not that one clock is moving relative to the other 'stationary' clock, but that they are moving apart with a relative velocity, which affects both of them equally.

The independence of the photon’s speed within the lightbox, is true for all ‘lightbox clocks’ that are moving at a constant velocity, whatever their frame of reference, as the laws of ‘photon physics’ are the same in all frames of reference.

Despite its potential to be the most accurate clock ever built, the concept of a ‘light box clock' is not a practical proposition to manufacture, but whilst it is working, it never 'runs slow'.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: David Cooper on 25/05/2017 17:23:24
Within the moving box, the photon spends most of its time travelling between the two mirrors and as such is unaffected by the movement of the evacuated glass box. In addition, when the photon is reflected perpendicularly off the moving mirrored surface, its velocity is unchanged. If it gained or lost kinetic energy during its reflection off the mirrored surface, then this would result in an increase or decrease in its kinetic energy leading to a change in the photon’s velocity, which we know is not the case. It is not possible to accelerate or decelerate a photon.

It's only if you accelerate (or decelerate) your box that the photon will stop hitting the middle of the mirrors and move towards one end of the box. If you move the box at a constant speed, the photon will hit the middle of the mirrors every time because it doesn't move through space perpendicular to the direction of travel of the box, but at an angle which is specific to the speed at which the box is moving. When the photon is emitted in the first place, assuming that it is emitted from something that is moving along with the box and which is aimed at the middle of one mirror from the middle of the other, it will already be moving in the right direction to hit the middle of the opposite mirror even though that mirror is moving. If you point a gun sideways out of a moving car, the bullet doesn't travel perpendicular to the direction the car is moving in, but at an angle which enables it to stay level with the car as it moves away (meaning that car and bullet remain aligned on the perpendicular to the direction of travel of the car). The same happens if you use a laser pointing directly sideways - the light doesn't leave the laser on a path perpendicular to the car, but at an angle that again keeps the pulses of light level with the car as they move away from it.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: Alex Dullius Siqueira on 26/05/2017 18:25:34
The experiment was/is correct, the only miss interpretation is the use of the term "photon moving trough space-time"...
  The photons can't move, although they are "produced" at C from one frame of C to the next....
  The photon outside -in, the photon during, the photon inside-out, are not the same traveling photon, although they are corrected because space-time is interconnected....

 The photon only seems to move at C because of the past frame on space, a mere reference, although space has no past without the photon(reference)...
  Space is there everywhere on this universe, photon is not there(present), photon was there on the past and photon will be there on the future, happening not existing....

  There is no moving photon from the photon own perspective...
Photon exists on the distance in between frames of C(a to b), it only exists "trapped in between time"/"xyz".
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: guest4091 on 26/05/2017 18:49:04
Velocity vectors of objects with mass add in the standard way. A vector has two components, magnitude (length), and direction (angle), with angle measured relative to an arbitrarily chosen reference direction. One end of vector B is connected to the free end of vector A and the angle of B is added to the angle of A. The result is a vector connecting tail of A to the head of B.
Light propagation in a vacuum is independent of its source regarding speed. A photon does not acquire the speed of the source. With no acquired speed the photon should move perpendicular to the direction of motion, toward the mirror. In reality the light clock works, and a pair of moving particles communicate. Why doesn't it fail?
Just as a bird hunter leads his target by aiming ahead of its current position, the photon needs to be directed at the correct angle to intercept the mirror. The only property the photon has that could do this is momentum p=h/w, plank constant/wavelength. Thus the vertical component of the photon vector is <c and requires more time to intercept the mirror. If the photon vector added in the standard way, there would be no time dilation, and outside observers would measure photon speeds >c.
refer to 'photon' at wiki
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: PmbPhy on 28/05/2017 02:20:28
Einstein’s ‘Light Box’ thought experiment is used to explain the slowing down of the passage of time with movement.
Its not called a light box, Its called a light clock. And to be precise the light clock is one way to arrive at the expression for time dilation. The light box is used to derive something totally different. See
http://www.newenglandphysics.org/physics_world/sr/einsteins_box.htm

For those not familiar with the light clock see
http://www.newenglandphysics.org/physics_world/sr/time_dilation.htm



It is classed as a ‘thought experiment’, because it is technically difficult to count the number of times a ‘visible’ photon bounces up and down between two parallel mirrors within an ‘evacuated’ glass enclosure, without impinging upon the photon’s movement.
Not at all. It was originally conceived of by using a pulse of radiation, e.g. a beam of light. As such its readily accessible to actual construction rather than a thought experiment. Following the derivation shows that the use of a single photon is not inherent in the experiment.

It is here that an assumption is made in the lightbox ‘thought experiment’, which leads to the concept of time slowing down. The assumption is that ‘the photon will continue to be reflected between the central points of two parallel mirrors of the light box, regardless of the movement of the glass box.’ But this is not how the laws of ‘photon physics’ work.
That is quite incorrect.

Within the moving box, the photon spends most of its time travelling between the two mirrors and as such is unaffected by the movement of the evacuated glass box. In addition, when the photon is reflected perpendicularly off the moving mirrored surface, its velocity is unchanged. If it gained or lost kinetic energy during its reflection off the mirrored surface, then this would result in an increase or decrease in its kinetic energy leading to a change in the photon’s velocity, which we know is not the case. It is not possible to accelerate or decelerate a photon.
It appears that you have a poor understanding of photons since that assertion is incorrect on two points. It confuses the notions of velocity and speed. It also makes the mistake that if the photons energy changes its because its speed changes, which is wrong. When a photon bounces off of a mirror its velocity changes, since its direction changes, but its speed remains the same since speed is the magnitude of velocity. There are very easy ways to change the kinetic energy of a photon such as bouncing it off a mirror which is moving in such a way that the photon is moving along the direction parallel to the normal of the mirror. This change in kinetic energy manifests itself in the change in wavelength of the photon, not its speed.

This is really a well known fact which is used on a daily basis by the police. The operating principle of a "speed gun" which utilizes radar is the observed fact that EM radiation will change frequency when bounced off a moving target which is either moving towards the source of radiation or away from it.

I'm ignoring the rest since there are too many errors in it to cover.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: Bored chemist on 28/05/2017 11:36:19
"In addition, when the photon is reflected perpendicularly off the moving mirrored surface, its velocity is unchanged. If it gained or lost kinetic energy during its reflection off the mirrored surface, then this would result in an increase or decrease in its kinetic energy leading to a change in the photon’s velocity, "
The energy of a photon isn't classical kinetic energy.

You can measure photon pressure.
If I point a laser beam at a mirror I can measure the force from the reflected photons.
If the mirror isn't held down rigidly then it will accelerate as a result of that force.
The moving mirror gains kinetic energy.
The mirror is, therefore, collecting energy from the photons.
So the photons must bounce off the mirror with lower energy than they hit it.

But what changes isn't their velocity, but their wavelength.
They are effectively "Doppler shifted"
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 29/05/2017 08:41:08
http://www.newenglandphysics.org/physics_world/sr/time_dilation.htm (http://www.newenglandphysics.org/physics_world/sr/time_dilation.htm)

Pmbphy,

Very well, this figure and explanation are persuasive almost for everybody.

However, naked science or authentic reality requires advanced questioning instead of low gear.

If we send the light by the angle φ (tangentφ = c/v); at this position the path of light will be perpendicular line according to mirrors and time tempo will be faster. When these two options are considered simultaneously (that is possible) time tempo will have to be faster and lower on a clock (that is impossible).

Please examine the figures and their explanations in attachment.

Light may be kidding with our mind. ;) 8) ::)
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: PmbPhy on 29/05/2017 13:56:10
If we send the light by the angle φ (tangentφ = c/v); ...
It's unclear what angle you're referring to since c/v is not the tangent of any angle in that diagram.

Are you referring to the angle tan φ = L/(vt/2)?

at this position the path of light will be perpendicular line according to mirrors //
What does "perpendicular line according to mirrors" refer to?

Sorry but your response makes no sense. Please restate it.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: PmbPhy on 29/05/2017 14:13:30
Very well, this figure and explanation are persuasive almost for everybody.
Its persuasive for everyone well educated in physicist.

However, naked science or authentic reality requires advanced questioning instead of low gear.
This is actually high gear as is all relativity and the correct understanding of it.

Please examine the figures and their explanations in attachment.
What figures and attachment?

Light may be kidding with our mind. ;) 8) ::)
In your dreams.

What is it with all you folks? Do you actually believe that over 100 years of relativity and countless relativists all made the exact same mistake when in fact the predictions of it all correspond to what's observed in nature? Let me clue you in - Every single poster in this forum who has ever claimed that there was something wrong with relativity used flawed arguments and as such were all 100% wrong.

Why don't one of you actually think like a real physicist and point to some observation made in the lab or in nature which contradicts what's predicted by relativity? Now that would be something that I'd be impressed by.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 30/05/2017 08:10:42

Are you referring to the angle? tan φ = L/(vt/2)

Yes,     tan φ = L/(vt/2)  according to your figure  ( http://www.newenglandphysics.org/physics_world/sr/time_dilation.htm (http://www.newenglandphysics.org/physics_world/sr/time_dilation.htm) )

 
What does "perpendicular line according to mirrors" refer to?


It represents the smallest distance (L) between mirrors.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 30/05/2017 08:53:10
Very well, this figure and explanation are persuasive almost for everybody.
Its persuasive for everyone well educated in physicist.

Why don't these well educated physicist analyze other options (for example, the light travels to the direction + x ;  while the source travels toward the direction - x) Please try to analyze this option by the same method in accordance with SR or Lorentz mentality and confirm the inferences of SR for this option. 

However, naked science or authentic reality requires advanced questioning instead of low gear.
This is actually high gear as is all relativity and the correct understanding of it.

 Please examine the types of relativity and then repeat this phrase ( http://gsjournal.net/Science-Journals/Research%20Papers-Relativity%20Theory/Download/6600 (http://gsjournal.net/Science-Journals/Research%20Papers-Relativity%20Theory/Download/6600)   section III)

Please examine the figures and their explanations in attachment.
What figures and attachment?

Figure 15 (my answer 6)  You may see at (b) alternative option for light's way (that total length becames the value L)

Light may be kidding with our mind. ;) 8) ::)
In your dreams.

I don't like it. Please. We must/may talk by scientific contents.

What is it with all you folks? Do you actually believe that over 100 years of relativity and countless relativists all made the exact same mistake when in fact the predictions of it all correspond to what's observed in nature? Let me clue you in - Every single poster in this forum who has ever claimed that there was something wrong with relativity used flawed arguments and as such were all 100% wrong.

Why don't one of you actually think like a real physicist and point to some observation made in the lab or in nature which contradicts what's predicted by relativity? Now that would be something that I'd be impressed by.


Humans had got dogmatic opinion about the Sun turns around the Earth for very much years than 100. The visual proof was apparent.

Well. SR is first approach about light kinematics and it never be revised for 112 years. The theory SR considers the fixity of light's velocity; because the target of SR was to prepare the scientific base for Fitzgerald contraction (If you examine the texts of Einstein, he begins by affirmation about Maxwell's definition and then he results by confirmation about the aether concept) . Whereas the target of light kinematics is to analyze space-time. And the most evident reason of the illusion space-time is the limited/finite value of light's velocity. If its velocity would be infinity value we could perceive everything simultaneously.

What is the observations in lab or nature (muons?)
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 01/06/2017 12:10:44
 
OK. Let’s analyze opposite option.

Lorentz transformations (Coordinates of a photon according to new position of its source):

x’ = (c – v) t / (1 – v˛/c˛)˝

t’ = (1 – v/c) / (1 – v˛/c˛)˝

Confirmation :     x’/ t’ = c 


If we consider reverse option : The photon travels toward + x while the source goes to - x  (use the parameter v by negative mark); or  the photon at the direction - x, source at + x (use the parameter c by negative mark).

x’’ = (- c  -  v) t / (1 – v˛/c˛)˝

t’’ = (1 + v/c) / (1 – v˛/c˛)˝

Confirmation:         x’’/t’’ =  - c
 


 
 
 
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 02/06/2017 08:45:18
Quote
pmbphy

Why don't we? Well, actually we do. This is a trivial exercise and its a question posed in almost all textbooks on relativity.

Now I have a question for you: Why do you make accusations such as the one you just did (i.e. you made an assumption) rather than merely ask whether its done or not?

Note: A mistake has been happened. My calculation has been deleted and your answer has located instead of my message. I try to set aright; I did copy+paste your message.

Please examine Lorentz application; there is a serious clue.



I don't agree your comment; everything is for "NAKED SCIENCE".  Absolute reality is always predominant.

I can understand the reflecting of emotional connection about a paradigm. However, in my opinion the result/interpretation (one of all options that causes minimum excitement) is probably correct. The science don't like excitement, mysticism, emotional attitudes etc.

Of course, to improve an alternative/effective solution is more reputable / positive  attitude instead of dissidence. I had realised an alternative method to analyze space time (LCS concept:
 http://adsabs.harvard.edu/abs/2013PhyEs..26...49E (http://adsabs.harvard.edu/abs/2013PhyEs..26...49E) )

My main study is the analyzing of space-time or light kinematics. The flaws of SR are by-product of this study.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 03/06/2017 14:40:09
Well. We find the coordinates of the photons (that travel toward +x and –x directions) while their source (that has uniform motion) goes toward +x.  And we provided confirmations of these calculations:

x / t = x’ / t’ = Ι x’’ / t’’ I =  c   

Already the aim of theory SR and Lorentz was this result: The relative velocities of light are same and fixed value according to any moving body that has uniform motion.

However this calculation indicates that;

t’’ >  t’   

The source’s or moving body’s clock/chronometer has to work by two tempos (faster tempo for the direction –x; lower tempo for the +x) simultaneously for providing the fixed value of light’s velocity.

But this result is impossible.
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 05/06/2017 11:13:04
Any objection?
Title: Re: On Einstein’s ‘Light Box’ thought experiment.
Post by: xersanozgen on 05/06/2017 12:00:27
Any objection?


Some objections would be possible to improve evidences of the SR’s flaws.

Earlier example was on the Earth; the source was in a train and its speed (v) is relative value according to rails. The times t, t’, t’’ indicate a single/same moment in accordance with entity of photon. In this experiment train’s clock had to show two or three different numbers of time, simultaneously.

If we prefer an outer and sequential reference frame (solar system or the Sun). The orbital motion of the Earth can be supposed a uniform motion for small distances. And resultant speed of train will be the value V(earth) +/- v. On this experiment, train’s clock is obliged to show 5 or 6 different numbers of time, simultaneously.

We can go on by other sequential reference frames. All relative values of light’s velocity are fixed value  c (according to each one of all sequential reference frames). But, the source’s relative speed will get different values.

At last, we will arrive / consider the most external reference frame (space) *.

Why did NOT we consider this major reference frame at the beginning? Is it anthropocentric attitude or captivity of locality?


*  Here is alternative/new theory for light kinematics: the concept of LCS (Light coordinate system)
Title: Re: On Einstein’s ‘Light Clock' thought experiment.
Post by: trevorjohnson32 on 05/06/2017 16:54:25
It is here that an assumption is made in the lightclock ‘thought experiment’, which leads to the concept of time slowing down. The assumption is that ‘the photon will continue to be reflected between the central points of two parallel mirrors of the light box, regardless of the movement of the glass box.’ But this is not how the laws of ‘photon physics’ work.

Within the moving box, the photon spends most of its time travelling between the two mirrors and as such is unaffected by the movement of the evacuated glass box. In addition, when the photon is reflected perpendicularly off the moving mirrored surface, its speed is unchanged. If it gained or lost kinetic energy during its reflection off the mirrored surface, then this would result in an increase or decrease in its kinetic energy leading to a change in the magnitude of the photon’s speed, which we know is not the case. It is not possible to accelerate or decelerate a photon.



A photon between two parallel mirrors will disappear once the source of the light is gone. Photons are silly. light is a squeezing on the same energy grid of space time that magnetism acts on. once the squeezing effect of the flashlight or whatever the light source is is taken away it no longer exists in the mirror.
Title: Re: On Einstein’s ‘Light Clock' thought experiment.
Post by: RTCPhysics on 06/06/2017 10:21:20
As you must realise, my job is to post articles in this Alternative Theories section, which aim to challenge current textbook concepts. No apologies needed there, I hope.

Having read with interest all the replies up to 29/05/2017, I reached the conclusion that there was no ‘show stopping’ argument made, which derailed this alternative explanation of Einstein’s ‘lightclock’ thought experiment.

There was some incorrect terminology used, which I have corrected in the text, but the main thrust of the arguments against this interpretation, seemed to fall into two separate areas.

The first one concentrated upon the physical force that photons can exert. Aim a laser at a mirror and there is a measurable applied force that could physically move the mirror, so the mirror needs to be held in place to prevent this.

Certainly true, but Einstein’s light box has ‘fixed’ dimensions, so no movement of either mirror is deemed possible. Action and reaction being equal and opposite, the photon will reverse course in a vertical direction at the same speed and without any transferred energy loss to the lightbox.

This applied force argument was followed up by an explanation of the Doppler effect, but as the ‘lightclock’ photon never has to reverse course off a mirror that is moving towards or away from it, the frequency change that photons undergo, is no more than an interesting diversion.
 
The second area concentrated upon the mechanics of such a light clock, in particular, the starting conditions that released the photon into the light box to make it into a working clock. The movement of the light source was viewed as causing the photon to be released at an angle into the light box, just like someone jumping horizontally off a moving bus finds their path follows an angled trajectory that incorporates the forward movement of the bus.

However, Einstein’s ‘lightclock’ thought experiment does not deal with the mechanism that generates the photon.
 
The arguments put forward have not led to a change in the author's conclusion in this post, which, if correct, undermines Einstein’s concept of ‘time dilation’ that arises from his ‘lightclock’ thought experiment.