Just another clock but this time not using distance of travel as a determiner.
Instead only the intensity or strength of the light is measured which will give a measurement that can be computed to velocity.

I'll use the same diagram I used in another thread "light clock revisited":

<img src=http://www.paygency.com/lightclock1.jpg>

But instead of mirrors we have sensors that measure light intensity.
The clock was calibrated on earth and is traveling at 0.8'c'

Now I would like to ask how time and length transforms would effect the invariant intensity of a common light source? :)

keeping in mind that time has no relevance to the measuring of intensity, so time dilations are no longer a factor. [unless some one woudl like to suggest otherwise?]

Why would intensity liberate you from time dilation/length contraction? Intensity is simply the amount of light, per second, the receiver detects. Intensity is not invariant under SR.

Intensity is the amount of light "hitting" our sensor at any given moment. Time is not required to determine intensity. Maybe I need another word for it. Strength, brightness, etc.....

As time is not needed in the equation to determine distance we are able to use light as an absolute time reference.

Thed, would what you are saying be like comparing voltage with ampheres; pressure with current flow?

If I am not mistaken if we look at our leading arm [A] then as the clocks velocity increases the length contracts under transform and of course the time dilation factor accomodates the velocity aspect to retain invariants.
However the intestity of the light would remain coinstant regardless of the contraction I would propose becasue intesity is not directly related to velocity.

Thus as length contracted the light would become brighter. And if this was the case then the discrepancy would indicate the contracted state of the clocks arm therefore give an absolute time reference.

Thed it is not surprising that SR does not place the "cross" of invariance on light intensity because if it did I would suggest that SR fails.

Another simple way of gettng past this light velocity issue is to use optical geometry.

If an object is say 10 meters in diameter at zero distamce then it's reflected diameter could be only 5 meters in diameter depending on distance.....as the distance contracts the reflected objects image will increase in diameter.THus again our light clock can be use to achieve absolute time [universal Earth time]

I have tried to delete this post due to it's obvious mistake

Intensity is the amount of light "hitting" our sensor at any given moment. Time is not required to determine intensity

At any given instant, there is zero light energy received on the sensor.
Intensity is a measure of light power - energy received per unit time.

Pete,by measuring intensity over time aren't you just measuring the change in intensity. If you take a snap shot in a frame no longer than 1 milli second you still get an intensity reading..... yes? or if you reduce the time even further etc wouldn't you still get the same, intensity reading?

The other interesting question popped up today and that was if we took our light clock with a common light source would the light source maintain it's brightness at relativistic velocity or become dimmer due to dilations etc...

If dilation is atomic slowing then I would think that the light would get dimmer.
So whilst the velocity issue is dealt with by the transforms what happens to the brightness of our light?

QQ,

Thought you might find this interesting.

http://www.edpsciences.org/articles/epl/pdf/2001/03/6393.pdf

************************************************** *
ABSTRACT:

G. Sardin

Applied Physics Department, University of Barcelona - Barcelona, Spain

Gsardin@fao.ub.es

(Received 7 April 2000; accepted in final form 20 November 2000)

Abstract
An electromagnetic speed-meter made of a three-dimensional frame is proposed, which allows measuring speeds independently of any external reference. The device is constituted by three orthogonal light beams and uses the motion-induced aberration of light or Bradley aberration. The frame is formed by three orthogonal beams which stand for the three axes. On the top of each axis arm of the frame a diode laser is fixed whose divergent beam impinges on a convergent lens which focalizes the light on an optoelectronic position detector of high resolution, placed on the base of each arm. The shift of each beam spot due to aberration of light is recorded, from which the motion of the frame is derived. Furthermore, if it is settled on a spacecraft its motion can be controlled in a way to record no aberration shift on any axis, indicating that the spacecraft is then at rest in the cosmic space. Since the referential frame does not use any external reference, it can be taken as a universal frame from which absolute speeds can be defined.

PACS
06.30.Gv - Velocity, acceleration, and rotation.
07.87.+v - Spaceborne and space research instruments, apparatus, and components (satellites, space vehicles, etc.).
95.55.-n - Astronomical and space-research instrumentation.

********************************************

Others have argued that this will not work however. My point is your thoughts are not totally unique.

Thanks MacM,

In a way it all stems for the question : "if you were in a fast traveling spacecraft between stars, how would you know how fast you were going?"
And if an absolute time reference is achieved even if one is constructed such as an absolute universal Earth frame the issues of absolute time becomes clearer.

Pete, thi squestion about intesity/time....if I apply 100 kgs of force to a brick wall. Can I say:
I apply a force of 100kgs or
I am applying a force of 100 kgms.

I understand that in all instances it involves time but I wonder whether time is relevant to the measurement except to qualify changes in intensity.

100 kgs applied for 10 seconds then 120 kg applied for another 10 seconds etc etc....

Pete,by measuring intensity over time aren't you just measuring the change in intensity.
You misunderstand - to measure intensity, you need to measure energy over time - intensity is a measure of the rate of change in energy collected.

If you take a snap shot in a frame no longer than 1 milli second you still get an intensity reading..... yes? or if you reduce the time even further etc wouldn't you still get the same, intensity reading?
Yes.
If I collect 1 millijoule in 1 millisecond, that's the same intensity as 1 joule in 1 second, or 1 nanojoule in 1 nanosecond, etc.

However, 0 joules in 0 seconds tells me nothing.

Pete, thi squestion about intesity/time....if I apply 100 kgs of force to a brick wall. Can I say:
I apply a force of 100kgs or
I am applying a force of 100 kgms.
I'm not sure about force.
It's units are mass x distance / time², (ie neither kg nor kg.s are units of force) but I haven't followed through all the variations to determine if it is a true instantaneous measure (I think it is, but that's just my intuition speaking).

ok ...you have drawn a distinction between intensity and force.....hmmm..terminology issue again.....

"is the intensity of gravity or magnetic attraction/repulsion determined over time?"
Intuitively the answer would be time is irrelevant or no.....
Brightness or intensity of light would always be a measure made in the 'now' and compared with measurements made over time...I would think.

The measure of velocity inherantly requires the passage of time but the strength of that light or object would be a "now" based measurement.


A car collided with mine with a force of 1000kg impacting at the front.
A photon hit my eyes that was so intense I was momentarilly blinded....

the brightness of my desk light dimmed as my room on board my ship accelerated to 0.9c

Brightness or intensity of light would always be a measure made in the 'now' and compared with measurements made over time...I would think.
Can you suggest how you could measure light intensity at an instant?
I can't think of a way... I've tried, and I think it's impossible. I think you always need measurements at different times and or places to get a meaningful measure of intensity


Think of light as waves, then think of water waves as an analogy.
Can you examine a single point at a single time in a body of water and tell whether there are any waves passing that point, and whether those waves are ripples or 10m swells?


Now think of light as particles, then think of a stream of bullets from one or more machine guns striking a target as an analogy.
Can you examine the target at one instant only and tell the intensity of the machine gun fire? (assume the bullets are very very short)

Pete say we attach an osciliscope to a high pressure balloon in a wind storm and take a reading over 1 minute. The read out would show a wave form over the one minute. We print it all out on a sheet of paper that is about 2 meters long.

At any given point along the wave we can tell the pressure of the balloon. Be as detailed as you like or as general as you like.

the read out is a center of time document as it was created showing how the "now' was changing.

You use the example of photonic bullets.
If we had equipment sensitive eneough we could measure the impact intensity of a single photon [if one believes in photons in the first place...which I don't as you know]

An instantaneous pressure doesn't tell you anything about the wave itself. The wave power depends on how the pressure changes.
For example, continuous unchanging high pressure means a wave of zero intensity.


A single photon tells you the frequency of the signal - but that's all.
Don't you think that a signal with 10 billion photons per second is more intense than a signal with 1 photon per second?

Pete, do you remember that diagram where I showed a "Now" axis and time peeling away.

here it is:
<img src=http://www.paygency.com/dilatedtimeaxis.jpg>

Now If we disregard the dilation issue raized and just for a minnie focus on what is happening when light hits our reflector.

As soon as the light has touched the reflector it becomes a memory or exists in the past.

The strength of that impact also exists in the past.

An ongoing ociliscope pattern is describing the changes in intensity over time.
At any point in the graph one can determine what the intensity WAS....not what the intensity is.....if the graph is flat and has been for a while then we can only PREDICT that the intensity will stay the same and the signal will be recorded as flat.

If I hit a nail with a hammer with a force of or intensity of 10 tons persqinch then at what point in time am I recording?

If we went into the macro world you would see a graph over time and that graph would show how the intensity on the top of the nail increased suddenly to 10 tons starting from zero relative to it's ambience.

The intensity of a light signal over time is extrapolated into a form of graphic history of the impact in the NOW.

So therefore intensity can be measured at any given moment from this history.

I should have said that intensity in the past can only be measured at any given moment as even the osiliscope takes time to function.
But here is another little diag that shows my point:

<img src=http://www.paygency.com/trillionth.jpg>

The intensity read from the NOW axis is not passage of time related.

QQ, you've shown that intensity can't be determined from a single reading - you need to know some of the wave's history.

why?

If on the Now axis it says 1111units whhy do I need to compare it with anything otherthat the value of 1 unit......

When I used to use osciloscopes at work we would be measuring kilovolts by taking a value from the top of the spike.....How do I need to take the past in to account for this reading? 20 Kv is just 20 kv....but if I wanted to compare spikes then of course we would take a history observation.....which is what gerally happens but only to ensure that the spikes are even.....etc

QQ,

Thought you might find this interesting.

http://www.edpsciences.org/articles/epl/pdf/2001/03/6393.pdf

************************************************** *
ABSTRACT:

G. Sardin

Applied Physics Department, University of Barcelona - Barcelona, Spain

Gsardin@fao.ub.es

(Received 7 April 2000; accepted in final form 20 November 2000)

Abstract
An electromagnetic speed-meter made of a three-dimensional frame is proposed, which allows measuring speeds independently of any external reference. The device is constituted by three orthogonal light beams and uses the motion-induced aberration of light or Bradley aberration. The frame is formed by three orthogonal beams which stand for the three axes. On the top of each axis arm of the frame a diode laser is fixed whose divergent beam impinges on a convergent lens which focalizes the light on an optoelectronic position detector of high resolution, placed on the base of each arm. The shift of each beam spot due to aberration of light is recorded, from which the motion of the frame is derived. Furthermore, if it is settled on a spacecraft its motion can be controlled in a way to record no aberration shift on any axis, indicating that the spacecraft is then at rest in the cosmic space. Since the referential frame does not use any external reference, it can be taken as a universal frame from which absolute speeds can be defined.

PACS
06.30.Gv - Velocity, acceleration, and rotation.
07.87.+v - Spaceborne and space research instruments, apparatus, and components (satellites, space vehicles, etc.).
95.55.-n - Astronomical and space-research instrumentation.

********************************************

Others have argued that this will not work however. My point is your thoughts are not totally unique.

Here is another 3D absolute velocity measuring system.The dynamics are dfferent from the QQ model, but more similar in some respects to your reference to the G. Sardin model above.

geistkiesel

When I used to use osciloscopes at work we would be measuring kilovolts by taking a value from the top of the spike.....How do I need to take the past in to account for this reading? 20 Kv is just 20 kv....
20kV relative to the bottom of the spike, yes?
Or is it relative to ground?
Either way, 20kV is only 20kV relative to some local reference.
You're not suggesting that all ground voltages are equal, are you?

Try this:
I measure the top of a water wave as 1.5m high.
What is the height of the wave? 1.5m, right?

Wrong... the bottom of the wave is 1.499m high - the wave is a 1mm ripple in a 1.5m deep pool.

Here is another 3D absolute velocity measuring system.The dynamics are dfferent from the QQ model, but more similar in some respects to your reference to the G. Sardin model above.

geistkiesel

As I mentioned in my post, others have claimed that doesn't work. I think because of the forward momentum believed to be associated with the light beam where it retains the motion of the source.

However, you may want to add this to your quiver: Failure of SRT

I measure the top of a water wave as 1.5m high.
What is the height of the wave? 1.5m, right?

Wrong... the bottom of the wave is 1.499m high - the wave is a 1mm ripple in a 1.5m deep pool.
Pete, the height of teh wave is a vertical measurement agreed?

so how does other waves have anything to do with the height of this particular wave?.........

If light intensity is maintained as constant at the sourse then as length contracts teh light will be measured as getting brighter...... even if there is a light speed delay because the brightness is constant at source the difference in brightness will indicate the degree of dilation and contraction.

Pete, the height of teh wave is a vertical measurement agreed?
It's a vertical difference between the height of the water surface taken at two different points or times.

so how does other waves have anything to do with the height of this particular wave?.........
Who said it does? All I said was that to determine the height of the wave, you need to determine both the vertical position of the wave's top and the vertical position of the wave's bottom. You can't do that unless you make measurements at more than one place or more than one time.

so Pete how does this effect the light clock I am suggesting in:
If light intensity is maintained as constant at the sourse then as length contracts teh light will be measured as getting brighter...... even if there is a light speed delay because the brightness is constant at source the difference in brightness will indicate the degree of dilation and contraction.

1) received intensity depends on:
2) the intensity at the source
3) the distance from the source
4) the velocity relative to the source

If you know three of these items, you can determine the fourth.

What is your light clock supposed to be doing?

provide an absolute earth time reference when traveling at relativistic velocity.

By receiving some signal from Earth?

Relativity has no problem with that.

say our ship is 1000ly from Earth?
No I am referring to an onboard method......and of course relativity has a problem with that.

But I am suggesting that if a device is contructed that does not require a time interval to record a measurement then we have a way of determining length contraction. And once we have determnined length contraction we can dertermine time dilation. [on board our relativistic ship]
And then we can prove SR.

Light intensity is a any time measurement and requires no time duration to take a reading [unless rapid accelleration is involved]

so therefore the time dilation issue is no longer relevant to that reading. BUt Length contraction is. Therefore the transfroms ratio can be employed to calculate our other aspects.

If it's an onboard source, then item 4) is the kicker:

4) velocity relative to the source

If the detector and the source are both onboard, then the received intensity will never change.

but Pete velocity is a distance/time measurement...why would velocity effect the measurement of intensity?

Intensity is a relationship between energy and time.
Energy and time are both frame dependent.

ok...so the word intensity is the wrong word.
Lets use strength instead.

If I hit a naiol with a hammer with 1 ton of strength no matter how long it takes me to calculate the measurement it is still 1 ton of strength. at the time I hit the nail....can we agree on this?
It might take time for the strength to have an effect but that doesn't alter the measurement of strength....

Yes, that's correct.
In the same way, you can calculate the "strength" (energy, momentum, frequency, wavelength - your choice) of a single photon.

Note that all these photon properties are frame dependent, and you know nothing about how many photons received per second...


Note that the strength of your hammer blow is frame dependent as well. Your hammer head (the photon) hits harder if the nail (the light detector) is moving toward you, and weaker for a nail that is moving away.

Note also that I would describe a hail of (say) three hammer blows per second as more intense than a steady beat of one blow per second (assuming all blows are of the same strength).

Note that the strength of your hammer blow is frame dependent as well. Your hammer head (the photon) hits harder if the nail (the light detector) is moving toward you, and weaker for a nail that is moving away.
An interesting point....

if a reflector is 10 meters away is compared to a reflector that is 20 meters away [from our light source] you are saying the strength of the photon is different or is this only applying to frames that accellerating towards each other or vicer versa.....

I was under the impression that a single photon retains the same strength no matter how far it is from the source....becaus if it didn't it would slow down thus lose it's invariant nature

if a reflector is 10 meters away is compared to a reflector that is 20 meters away [from our light source] you are saying the strength of the photon is different

No. It's not the distance from you to the nail that counts. It's not the acceleration of the nail or yourself that counts. The only thigns that count are 1) how hard you swing the hammer (the source energy) and 2) the velocity of the nail relative to you at the moment of impact (the velocity of the receiver relative to the source).


A photon's (energy, momentum, frequency, wavelength) are unchanged with distance from the source (assuming no gravitational shift).

The (energy, momentum, frequency, wavelength) are affected by gravity and by the frame of the receiver. If two receivers are moving relative to each other, they would record different value for the photon.

However, the number of photons received per unit time does change with distance, because light beams spread out.