Hello Emmanouil Markoulakis,

Let me try to give you a possible answer.

The definition of the unit of time is the number of oscillations between to levels of caesium electrons. When you place the two clocks apart then you might get variations in these clocks. Then comes the question how you will measure their deviations. You need to tell at one position what is the clock value of the other position. That message needs to travel the distance of the clocks. The measurement of the gravity waves means that I have an oscillating signal. It deviates from the mean value but in the end it returns to that mean value. It is not enough to compare the clocks at the end. You need life comparison.

The transmission of light waves over a distance and the comparison of the travel time with interference measurements is also a kind of time measurement. I think that the solution taken by LIGO has a much easier way of implementation than the solution with clocks.

If the measurement results of the LIGO system are based on the expansion and contraction of space or that some other principle is involved is another chapter.

Regards,

Paul Gradenwitz

Dear Paul Gradenwitz ,

Thank you Sir for your expert input.

I was thinking to measure strictly and exclusively the time only with nothing else involved via direct observation of the atomic clocks on locations A and B. No any signal transmission lines or any other electronic link involved for the observation. Observer on B is totally electronically isolated (except its electromagnetic connection with light) no transmissions, no laser beams and measurement equipment is present in A where the event is taking place and vice versa.

I am suggesting a direct remote optical observation method on the clocks alone on each opposite location to measure with the aid of special apparatus any change in the rate they are "ticking" compared to the reference on each observer's site. The cross reference on A and B should detect the wave with most unwanted interference ruled out.

Let's say for example with two telescopes connected to special visual recognition S/W... sounds silly I know but so is the real-time measurement of variation in distance of one billionth of the nuclei measured inside the noise of our planet... I believe.

Kind Regards,

Emmanouil Markoulakis

There is a beam splitter at the crossing point of two LIGO arms which splits a laser beam into two perpendicular directions. Detector is kept at the dark point of interference fringes (minima). When GW passes through the area lengths of arms change then detector sees some light. It measures difference in length (not time). Your proposal perhaps aims at looking at time difference between two fixed points on the same reference frame (the frame is attached to earth).

" Your proposal perhaps aims at looking at time difference between two fixed points on the same reference frame (the frame is attached to earth). "

Yes this is correct although I make the assumption that when GW reaches location A, location B is still in the dark side and vice versa.

Dear Emmanouil Markoulakis,

You plan to observe the two clocks from a distance. That means that you observe with a light speed delay. Your observation is effected by the same gravity wave you want to observe with the clock. You are talking about deviations that are several orders of ten smaller than the size of an atom. That means that your telescope distance variation to the clock will give a larger signal than what you are looking for.

That is what I meant with that you need signal transmission, information transmission. You use a telescope. That means you read the clock information by light transmission. So better take the light itself as the measurement tool and forget the clocks.

Regards,

Paul Gradenwitz

There are two problems, the first being that gravitational waves would not necessarily affect the clocks at all, the waves primarily vary only the distance between them.

EM: I am suggesting a direct remote optical observation method on the clocks alone on each opposite location to measure with the aid of special apparatus any change in the rate they are "ticking" compared to the reference on each observer's site.

To measure a change of rate of on clock, you need to compare it against another clock, but if you have two clocks at the same location, any effect will apply to both so you would not measure a change, even assuming there was any effect to be seen.

Dear George Dishman,

You can position the atomic clocks in such an orientation that they get affected by the GW . That's not a problem I believe. Pardon my boldness but measuring the momentary time change by the GW is any different than measuring one billionth of a nuclei distance although with much less equipment involved and parasitic noise by the Earth's environment.

Time does not vibrate as matter does or space.

GD: "To measure a change of rate of on clock, you need to compare it against another clock, but if you have two clocks at the same location, any effect will apply to both so you would not measure a change, even assuming there was any effect to be seen. "

Although both locations are on Earth the phase velocity of the GW does not reach both locations at the same time. Correct me if I am wrong but I thought changes occur by the GW as it passes through space by its phase velocity and not group velocity.

Kind Regards,

Emmanouil Markoulakis

TEI of Crete

EM: You can position the atomic clocks in such an orientation that they get affected by the GW . That's not a problem I believe.

It is a problem because the clocks would just keep ticking at the same rate regardless of the passage of the waves so what do you propose to measure?

EM: Correct me if I am wrong but I thought changes occur by the GW as it passes through space by its phase velocity and not group velocity.

There is no dispersion of GW so the phase and group velocities are identical, they are both c. The speed of the GW is not too important as they are generally of very long wavelength compared to the apparatus used to measure them (excluding proposed space versions) but there is a phase difference in the GW between the sites. That is used to localise the source.

However, perhaps I misread your previous suggestion, I thought you were saying you could measure each clock locally in which case what happens at one site is of no relevance at the other. The part I don't understand is how you propose to make any measurement of a wave at all using a clock.

GD: " The part I don't understand is how you propose to make any measurement of a wave at all using a clock. "

I meant atomic clocks. I believe these will be affected by GW.

EM: I meant atomic clocks. I believe these will be affected by GW.

The theory says they are not.

However, even if they were, what would you compare them against locally, if local time is affected, every form of clock would change by the same amount so there would be no indication of any difference. This goes back to what you said some time ago:

EM: with the aid of special apparatus any change in the rate they are "ticking" compared to the reference on each observer's site

What kind of "reference" were you considering? If you want to compare one local clock against the other remote clock, then you have to consider the effect of the gravitational waves on your communication channel. that is what LIGO measures, the variation of the length of that signal path.

George Dishman

No communication channel or data transmission needed. Please read my previous posts. When A gets hit first by GW, B is not. No need to wait for B to get hit. Direct remote visual observation data are recorded and analyzed after. If B location gets hit first instead if A location the same above process is repeated. In any case the data of the hit zone are compared with the reference data of the non-hit zone.

Volodymyr Krasnoholovets

I can see your logic. First they have to give us some hard data that black holes really exist.

EM: No communication channel or data transmission needed

Then you are comparing two clocks at one location so no detection is possible.

EM: No communication channel or data transmission needed. ... Direct remote visual observation ..

You cannot do "remote observation" without a communication channel. If you use a telescope for example, the light that travels from the clock to the telescope is your "communication channel".

EM: When A gets hit first by GW, B is not

Perhaps you should look at the actual data. The time difference between waves arriving at the Livingston and Hanford sites is less than 0.01 seconds. The waves of GW170817 seen above the noise lasted for 50 seconds.

Further, when the waves pass a clock, it's time is not affected in any way.

VK: I think the LIGO project should be closed because gravitational waves of general relativity do not exist, which is obvious.

What is obvious is that they have been seen and therefore they do exist. That means it is also obvious that any theory that says they cannot exist must be wrong.

HvL: They were not interested in what kind of gravitational vibrations passed the location.

The detailed analysis is starting to give a great deal of information but with just a handful of events captured, it is still early days.

HvL: The passage of the front occurred in a fraction of a second.

GW170817 was audible for over 50 seconds when you remove the noise. What LIGO detects is just the last portion of a waveform that has existed continuously for thousands or perhaps millions of years as it rises above about 30 Hz.

Dear Volodymyr,

VK: 1) the solution of nonlinear field equations of general relativity corrects only in the presence of the metric in which they were obtained;

There is only one metric throughout space and that has no analytic form, we can however approximate it in many ways, The Robertson-Walker metric at cosmological scales, Kerr (or Kerr-Newman) for dense bodies and Minkowski where curvature is negligible.

VK: 2) in the framework of the other metric (in particular, flat metric) the solution cannot exist and hence the appropriate "wave" cannot travel through flat metric;

If the surface of a pond is precisely flat, by definition it has no ripples on it, but drop in a pebble and ripples can travel as perturbations over the "flat" surface, the same is true of gravitational waves. In deep space far from the source, they are essentially plane waves but as they pass a compact body like a star or galaxy, they are bent and lensed just like light.

VK: 3) thus, no physical criterions for the existence of gravitational waves of general relativity.

The solutions are well known, your statement is incorrect. The fact is that LIGO has recorded waves with exactly the level and shape those solutions predict so any theory or interpretation that says otherwise is wrong.

Dear Readers,

I like to thank you all about your well defined expert answers.

However, I fail to see why in my proposal sites A and B as suggested by many of you to be in the same frame of reference and therefore impossible to measure GW whereas LIGO and Virgo were not?

Seems that explanation of Hans van Leunen ( @Hans van Leunen ) of GW longitudinal dispersion of spherical wavefronts (really more like acoustic compression waves) over the enormous distance of 1.3 Bilion light years is the most realistic resulting to subsecond periodic space rippling passing through our solar system and frame of reference of Earth. A and B locations in my proposal are inside this frame but are receiving the gravitational ripple at different moments in time.

Also unless atoms are spaceless I can not understand how atomic clocks are not affected by GW? If the notion is that this is not currently practically measurable for GW then I submit that yes.

However, I imply in my future proposal abstractly a method and special apparatus to be invented in order to achieve using only as a information communication exchange channel the visible light spectrum (direct remote optical observation) and then analyze the data recorded using a computational (probably quantum computer) optical pattern recognition method. No long rarge interferometers involved or any other equipment for for a link.

You would just measure the momentary inaccuracy of the atomic clock at the hit zone and compare it against the non hit-zone. Most parasitic parameters and noise messing up the LIGO experiment are not present here and really the only parameter which can affect momentarily the operation of the atomic clocks apart their intrinsic time drift ( JILA strontium-87 of 2014 optical lattice optical clock is expected to neither gain nor lose a second in more than 15 billion years ) is a GW.

Also I never mentioned in my proposal the caesium atomic clock. Not accurate enough for GW. For black hole mergers we need 10^(-21), zeptosecond accuracy. Currently the most accurate we have is the JILA strontium-87 of 2014 optical lattice optical clock rated at normalized with caesium second at 2.1 × 10^(−18), attosecond accuracy [ https://tinyurl.com/ychyyxvp An optical lattice clock with accuracy and stability at the 10^(-18) level ].

Kind Regards,

Emmanouil Markoulakis

Technological Educational Institute of Crete

Dear Emmanouil Markoulakis,

You propose

'a information communication exchange channel the visible light spectrum (direct remote optical observation)'.

I think that in this tread we several times have pointed you at the situation that the time delay from observing the clocks with a communication channel, that transfers the phase of the clocks with the speed of light, is in the same way sensitive to the gravity waves as the clocks. You need to compare the phase relation between the clocks at different location. That is only possible with observation. Imagine when there is hot air in your path of light. The you see vibration in you image. Now your observation is in vacuum, but the gravity waves, that affect the clocks, in the same time traverse through your vacuum tube and modify the arrival time of your clock phase information. The LIGO setup is an ultra stable clock that compares the phase relation of an ultra synchronous clock configuration. The time between the paths of the light in the orthogonal light paths. Only here they made a smart setup where the clocks are distributed over a long distance so that they become more sensitive to the signal. A second is defined as the time that light travels in vacuum over a defined distance. In the LIGO setup they use that time definition and compare the phase relation of their two clocks.

Regards,

Paul Gradenwitz

HvL: In my opinion a wave is a periodic phenomenon.

I agree Hans.

HvL: I do not apply the term wave for non-periodic phenomena.

Nor do I.

HvL: A moving wave package will disperse.

A single wave does not disperse, it travels at a speed that depends on the refractive index. Dispersion is apparent only where the package contains waves covering a range of frequencies.

Until the last few cycles, a gravitational wave is monochromatic, it has a single frequency. That frequency drifts very slowly. In addition, unlike light, gravitational waves are not affected by matter so the speed is independent of the frequency and a wave package will maintain its shape.

HvL: In contrast to waves, spherical shock fronts keep their shape.

Shock fronts tend to be unique events, they not periodic phenomenon nad a train of shock waves would have a large harmonic content. Gravitational waves are pure sine waves with a slowly rising frequency and no harmonic content until the last few cycles.

Emmanouil,

That’s a very good question and great idea!

You may be interested in my design of a ‘Time Variance – GWD’ described in detail on my website: http://pcmhahn.wixsite.com/foamyether/detector-design.

It shows how an array of three distant lasers (synced by atomic clocks), connected through a fiber optic network, can be used as a GW detector.

I am also working on the development of a TV-GWD that can detect ‘local’ changes in the rate-of-flow-of-time:

https://www.researchgate.net/project/Version-3-4-Build-of-a-Time-Variance-Gravitational-Wave-Detector

and

https://www.researchgate.net/publication/303803700_Design_for_a_Time_Variance_-_Gravitational_Wave_Detector_V2

The design is based on the premise that an incoming GW will cause time to fluctuate, thereby causing the frequency/wavelength of the laser to fluctuate. A diffraction grating and high-speed digital cameras record these changes.

Peter Hahn,

I looked into your TV-GWD. Impressive!!

Research Design for a Time Variance - Gravitational Wave Detector V2

Now that is what I call novel and out of the box thinking... but of course it must be big and expensive as LIGO so we get the founding of billions of dollars.. I forgot.

Congratulations Peter! this is a complete and novel research. I don't believe in Km long science. Nature and all its phenomena can be scaled down in size I believe and emulated.

Kind Regards,

Emmanouil Markoulakis.

HvL: For me, a monochromatic wave of just one or only a few cycles is a strange object.

Indeed, but a sine wave with a period of 7.75 hours that will run continuously for the next 300 million years can pragmatically be described as monochromatic. That is the case for the system studied by Hulse and Taylor, the eventually merger will take place that far into the future.

https://en.wikipedia.org/wiki/Hulse%E2%80%93Taylor_binary#Star_system

Of course the frequency of those waves at 35.8333 μHz is much too low for current detectors but the example serves to illustrate the nature of the waves.

For mergers like GW170817 we see a few thousand cycles of a sine wave with smoothly rising frequency and roughly the last dozen having some waveform distortion due to local tidal and coupling effects. Overall, this bears no resemblance to a train of shock waves.

Sorry but I believe it is not hard to see in my little remote direct observation thought experiment I started here in this thread, that a GW passing through the hit location A will cause a space ripple in that location and consequently ripple momentarily the overall time its takes for the light information of the clock reading to reach the non-hit zone effectively causing a time ripple in hit location A which will be observable momentarily at the non affected by the time ripple location B.

All the other systematic and communication time delays for a known each time parameters set can be calculated, measured and ruled out leaving only the GW ripple effect.

However I submit did not consider the enormous wave front size of the GW and therefore locations A and B must be at best at the opposites sites of the planet as @Peter Hahn (Peter Hahn) pointed out. Therefore remote direct observation on locations A and B clocks without the aid of a communication channel might not be possible. This will introduce too many variables and noise in the system and mess up the whole experiment I am suggesting.

Nevertheless, there is an alternative. since the two clocks in locations A and B are synchronized their recorded data can be analyzed and cross referenced after. No direct observation of locations A and B is needed.

Closing, the only factor inhibiting the much more stable noise immune, broadband and more reliable suggested Direct Time Measurement Gravitational Waves Detection (DTGO) experiment than LIGO, is that we don't have invented yet atomic clocks with the 10^(-21) zeptoseconds accuracy needed for the detection of the GW...

...not yet.

Emmanouil.

Sometimes I get very depressed, and think that some things are out of the intellectual capacity of humans and awareness and scope and meant never to be truly discovered.

Maybe because when we finally find out where we living in and what we really are... we get kukooo!

Do the microbes maybe are aware where they live and what they really are looking from our plane of existence down?

EM: However I submit did not consider the enormous wave front size of the GW and therefore locations A and B must be at best at the opposites sites of the planet as @Peter Hahn (Peter Hahn) pointed out.

The size of the "hit zone" for GW170817 is 1100 times larger than the diameter of the Earth in the detector band (above 30Hz).

You would need to place your reference clock on another planet. This is similar to the way some astronomers are trying to use pulsars as remote clocks to detect the waves.

[Apologies for the earlier duplication, some sort of network problem meant my first attempt vanished but reappeared after I had retyped and posted.]

Volodymyr, there is a great deal of information available. This paper is probably of interest as it gives an overview of the interferometer structure:

This paper might be of specific interest:

https://arxiv.org/pdf/1411.4547

This is a good list of publications but you need to work through them to find the specifics of what you need:

https://www.ligo.org/science/outreach.php

These are more general entry points and 'outreach' level sources:

https://www.ligo.caltech.edu/page/learn-more

https://www.ligo.caltech.edu/page/look-deeper

https://www.ligo.caltech.edu/page/ligo-data

https://www.ligo.caltech.edu/page/ligo-technology