Q&A with David Rideout: Testing Reality in Space

In a little introductory book I have which I highly recommend for beginners, 'Relativity for the layman' by J.A. Coleman, here is a response...

The third possible explanation for the inability of the Michelson-Morley experiment to detect the ether assumed that the velocity of light was always constant with respect to the source which emitted it. This would mean that light always traveled at 186,000 miles a second with respect to the interferometer, regardless of how fast or slow it was moving with the earth through the ether. As a result, the velocity of light would vary with respect to the ether...

The main objection to this explanation was that it required velocity of light to vary with respect to the ether. This was contrary to the generally accepted notion of wave motion that the velocity of the wave must be constant in the material which carried the wave.... It was thus difficult for anyone really to believe that the velocity of light through ether was influenced by the velocity of the source...

There were also various astronomical observations which indicated that the velocity of light was independent of the velocity of the source. One of these was in connection with double stars. Double stars are two stars which are approximately the same size and are relatively close together. They rotate about each other with a fairly high velocity in somewhat the same way as would the ends of a dumb-bell... Now, some of these double stars rotate so that we are looking edgewise at the plane of rotation, i.e. we see one star coming towards us while the other is going away, and vice versa. If we assume that the velocity of the light leaving the star is increased or decreased by the velocity which the star is approaching or receding from us, then the star approaching us would appear to be rotating much faster than the receding one... The overall effect would be as if the stars were alternately speeding up and slowing down in their rotation about each other. Actual observation shows that this is not the case, however, and that the stars actually rotate about each other with uniform velocities. We conclude that it is entirely unlikely that the velocity of light is influenced by the velocity of the source, or that it is constant with respect to the source.

University of Texas Refutes Einstein's Relativity

University of Texas: "Thus, the moving observer sees a wave possessing the same wavelength (...) but a different frequency (...) to that seen by the stationary observer. This phenomenon is known as the Doppler effect."

That is, in accordance with the formula

(frequency) = (speed of light)/(wavelength),

the speed of light waves (relative to the observer) varies with the speed of the observer, in violation of special relativity:

"Doppler effect - when an observer moves towards a stationary source. ...the velocity of the wave relative to the observer is faster than that when it is still."

"Doppler effect - when an observer moves away from a stationary source. ...the velocity of the wave relative to the observer is slower than that when it is still."

Pentcho Valev

Pentcho,

While relative speed is c+v light can't 'propagate' in the observers rest frame until it finds what that is! i.e. until it arrives (and Doppler shifts).

It is then logically wavelength that changes on arrival. The light going PAST (missing) the observer of course remains at relative c+v.

I suggest that until we distinguish between relative and propagation speeds physics will remain nonsense and your posts will be ignored.

Peter

Any reasonable interpretation of the Doppler frequency shift leads to the conclusion that the speed of light relative to the observer (receiver) varies with the speed of the observer (receiver), in violation of special relativity:

Albert Einstein Institute: "Here is an animation of the receiver moving towards the source: (...) By observing the two indicator lights, you can see for yourself that, once more, there is a blue-shift - the pulse frequency measured at the receiver is somewhat higher than the frequency with which the pulses are sent out. This time, the distances between subsequent pulses are not affected, but still there is a frequency shift: As the receiver moves towards each pulse, the time until pulse and receiver meet up is shortened. In this particular animation, which has the receiver moving towards the source at one third the speed of the pulses themselves, four pulses are received in the time it takes the source to emit three pulses."

The speed of the light pulses relative to the stationary receiver is:

c = d/t

where d is the distance between subsequent pulses and t is the time until pulse and (stationary) receiver meet up. For the moving receiver, "the time until pulse and receiver meet up is shortened". This means that the speed of the pulses relative to the moving receiver is:

c' = d/t' = c v

where t' is the time until pulse and moving receiver meet up (t>t') and v is the speed of the receiver relative to the source.

Pentcho Valev

Pentcho, Peter,

Doppler blue or red shift does not change the speed c of propagation. This holds for propagation wrt a medium like air as well as for light without a medium. In the latter case the only reasonable reference is the distance between the position of emitter at the moment of emission and the position of receiver at the moment of arrival. In other words, the speed of the relative motion between emitter and receiver is the speed of propagation. Because there is no natural point of reference in space, there is no point at rest to refer to.

Any moving frame seen in the rest frame of an observer is affected; the "seen" speed relative to the observer is just a seeming one.

Newton's idea of light as particles does not contradict to the wave model if one does not ascribe conveyed potential energy to a quantum of propagating energy.

Incidentally, Newton made an obviously wrong prediction; iirc he imagined the speed of light increasing with more dense media. I read this by chance in the Millennium tower in Magdeburg.

Eckard

Pentcho, (Eckard).

"Any reasonable interpretation of the Doppler frequency shift leads to the conclusion that the speed of light relative to the observer (receiver) varies with the speed of the observer (receiver), in violation of special relativity:"

I agree, except that you're lumping in the 'interpretation' of SR with the postulates. I'm pointing out that no matter how much nonsense the former is, the postulates can survive and be consistent with your first proposition; c is relative to each observer. But I point out that rationally that's only valid if it changes speed to the new datum for c ON ARRIVAL and interaction. Not before.

That is also consistent with Eckard's statement that "Doppler blue or red shift does not change the speed c of propagation." Just as with sound, there is an unrecognised difference between propagation and relative speeds.

Even Newton found that, but like Einstein (and most today) couldn't successfully rationalise it. It's the DATUM rest frames, represented by co-moving bodies that change. It'll just be 'unfamiliar' at first.

Eckard,

There's no such thing as a 'seeming' speed! (all speeds found 'seem' to be c anyway!) All physically measured speeds are real local ones. It is RELATIVE speeds that are not directly measurable that are 'arbitrary'.

Contrary to your assumption about space there is of course ALWAYS a local reference frame; It is the nearest or dominant massive 'body', whether a planet, sun, galaxy, or bunch of electrons. That is always the reference datum. If you try applying that (each side of the astrophysical shock or near field TZ surrounding all bodies) you will find the fully consistent logic.

Best wishes

Peter

Peter,

If the observer starts moving with (small) speed v towards the light source, the speed of the light relative to him shifts from c to c', the wavelength shifts from L to L' and the frequency he measures shifts from f=c/L to f'=(c+v)/L (experimentally confirmed Doppler frequency shift). Also, we have: f'=c'/L'.

We are to choose between:

c' = c+v ; L' = L (fatal for relativity),

and

c' = c ; L' = c/f'.

Any speculations that go beyond the above choice are irrelevant.

Pentcho Valev

Pentcho,

Stand beside the start of a travelator and time the walkers passing by as they step on to it. All walk at 5kph (we'll call it 'c'), so they are effectively meeting and propagating in a new inertial system, i.e. in a new 'inertial frame'.

Now I'll show you that you are locked into a belief system that has blinded you to what really happens in nature, the exact mistake also made by mainstream!! Carefully visualise and analyse this scenario from your fixed reference frame.

Before the walkers (we'll call them 'photons') step on they are 1 metre apart (wavelength).

After they step on they are 2 metres apart if the travellator moves at 5kph. So WAVELENGTH HAS INCREASED. OK?

What about their speed? Has that also increased wrt YOU? YES of course! It has doubled to 10kph! i.e. It has changed reciprocally /inversely with wavelength. OK.

Now your eureka moment. Enjoy it; Check their relative 'frequency' of passing you by. You will find IT HAS NOT CHANGED!

It's only if you yourself CHANGE FRAME and jump onto the travelator that you find their frequency has changed (halved) but not only is that not the relevant case but THEN you find their speed c has stayed the same!

The big mistake mainstream have made is treating 'frequency' as a real physical scalar like wavelength. It's not. it's only a metaphysical 'derivative'. You have been falling into the same trap.

The interpretation of SR is false because light changes to the new LOCAL c on arrival, because the datum systems of propagation are in relative motion.

Nothing can be 'measured' until it 'arrives! and that new 'discrete' field.

Shocking at first. But all anomalies are entirely unlocked.

Peter

Peter,

Your travelator scenario is irrelevant - it is not analogous to the Doppler frequency shift. The Albert Einstein Institute offers a nice scenario with animations - just analyse it (if you can) and see if the speed of the light pulses (relative to the receiver) is constant or not:

Albert Einstein Institute: "Here is an animation of the receiver moving towards the source:

stationary receiver

moving receiver

(...) By observing the two indicator lights, you can see for yourself that, once more, there is a blue-shift - the pulse frequency measured at the receiver is somewhat higher than the frequency with which the pulses are sent out. This time, the distances between subsequent pulses are not affected, but still there is a frequency shift: As the receiver moves towards each pulse, the time until pulse and receiver meet up is shortened. In this particular animation, which has the receiver moving towards the source at one third the speed of the pulses themselves, four pulses are received in the time it takes the source to emit three pulses."

Pentcho Valev

Pentcho,

if I start moving forwards led by a block of glass or lens material to intercept light, I can't measure the light until it does so. It is then propagating within the lens medium (eye ~n=1,38) at c/n wrt the lens state of motion.

That is the exact case for all measurements of light speed and frequency. Despite mainstream beliefs and intellectual failure the frequency doesn't change with the wavelength, its the speed of light that changes. But only the light that ARRIVES!

Peter

Akinbo,

That over-simplified view has fooled everybody so far. Now upgrade it to faithfully model reality;

Put the essential measurement tool, a lens with non zero thickness, at the start of the blue detector. Then put a processor behind it, and a wire or optic nerve between them. (the 'Shannon channel') (There can be NO 'frequency' computed until the signal enters the 'processor' and it calculates against time).

It is the 'processor' that produces the "measurement" of frequency. So now study the wavelength in the lens and channel. THAT is the ONLY wavelength the processor has access to.

In the case of the emitter moving through a medium the wavelength has already changed on entering the medium to propagate at c!

DFM, QED.

Best wishes

Peter

Peter,

"Put the essential measurement tool, a lens with non zero thickness, at the start of the blue detector. Then put a processor behind it, and a wire or optic nerve between them. (the 'Shannon channel') (There can be NO 'frequency' computed until the signal enters the 'processor' and it calculates against time)."

This is irrelevant. You have killed many discussions so far by introducing things like that.

Pentcho Valev

Pentcho,

"That over-simplified view has fooled everybody so far."

It appears it will continue to fool you while you behave like mainstream by clinging to your beliefs and a narrow closed minded way of seeing things.

It's not "irrelevant". I suggest nothing is more accurate and relevant.

Peter

Peter, I must agree with Pentcho on this one. I have disagreed with him many times in the past so I am not taking sides. Pentcho's animation clarifies a puzzling situation regarding what changes when an observer moves, i.e. wavelength, frequency or speed, ALL three, TWO out of three or NONE? It is worthy to note that dimensionally, time is present in speed (Meter per second) and frequency (cycles per second) but absent in wavelength (Length)

The introduction of a processor, a wire, optic nerve or the 'Shannon channel' is unnecessary. A frequency measurer is merely a counter. Frequency being cycles per second, if you can count faster or slower by delaying or hastening light arrival by your movement, you can change the measured frequency (IMO).

There is also no need to introduce a medium in this case since both emitter, receiver and signal are in the same medium. "...the wavelength has already changed on entering the medium", has no meaning. Where was the wavelength before entering the medium?

There may be issues however for the case when the signal enters a new medium. In that case speed and frequency can certainly change. I am not sure yet whether in that case wavelength can change also. Pentcho may find us a reference or an animation depicting that.

Any answers to my poser, why a Doppler shift or difference in light arrival times is not observed in our spaceship called earth, but is observable for light coming from outside our spacecraft?

If what DFM says is that all light speed is reduced to 'local c', what is local, the observer or the spaceship? If it is observer, then how many local c's are in the ship?

In my pet theory, I think Galilean relativity holds the key as illustrated by Galileo's ship (see The proposal). Light within the ship is not influenced by the spacecraft or ship's motion. For sound, we have air. For light, do we have a possible matter medium (or 'ponderable' matter as Einstein may say) that can also be gravitationally bound to the moving Earth? I think we do.

As usual with these exchanges I discover something new here (relativityoflight.com) which I will read later. Looks interesting.

Regards,

Akinbo

Peter,

Consider Dopler shift (moving observer) for sound waves:

"Sound waves have speed c, and f and L are related by c=Lf. For an observer moving relative to medium with speed u, apparent propagation speed c' will be different: c'=c±u. Wavelength cannot change - it's a constant length in the medium, and same length in moving coordinate system (motion does not change lengths). Observed frequency has to change, to match apparent speed and fixed wavelength: f'=c'/L."

Do you accept this interpretation? If you do, you will probably understand how irrelevant your lens, processors, wires, optic nerves etc. are.

Pentcho Valev

Pentcho, let's not crucify Peter. If you look at page 5 of the lecture you linked. You will see how unfortunately teachers mislead their students. Peter may have attended one such lecture. In that Washington University, a lecturer taught his students that when source is moving, frequency remains constant and wavelength changes (Which is FALSE), but when observer is moving frequency changes and wavelength remains constant.

The correct position should be that frequency remains constant in BOTH cases, but it is 'Observed' frequency that changes in both scenarios consequent on change in relative speed, while wavelength is constant in the medium no matter whether it is source or observer that is moving.

When a source chases its own waves as the lecturer says, the emission frequency remains what it was when source was stationary BUT because the next wave is emitted in a different position than the previous, the 'observed' frequency changes as you showed in your animation.

Regards,

Akinbo

Akinbo,

"a processor, a wire, optic nerve or the 'Shannon channel' is unnecessary."

It'd be interesting to deprive an observer of those elements and see if he can obtain a 'frequency'.

It's not shocking or worrying that you think that way. It's the mainstream view, and in line with my 2010/11 '2020 Vision' essay, where I estimated it's be at least 2020 before any change in understanding.

I'd like to be proved wrong, but can't expect to be.

Best wishes

Peter

Pentcho,

"Wavelength cannot change - it's a constant length in the medium," In each medium yes. Where propagation media are in co-motion at v wavelength demonstrably changes. If the media have the same refractive index it is only that relative v which gives the Doppler shift. All observers made of matter constitute a 'medium' with it's own rest frame.

But at our present stage of intellectual evolution that's difficult to see and rationalise as it need visualisation of kinetic progression. Still a little too difficult it seems.

Akinbo,

The purpose of providing you with that simple table was to help you avoid making the simple error of comprehension above. I promise I never attended any such lectures. The rationale is one step in comprehension above that which you are applying. You can't be blamed, but be aware; That lecturer was correct for the case I outlined above, (which I note you couldn't refute). (perhaps not entirely correct, I haven't seen it).

But don't be concerned about "crucifying" me. I've learned that apparently it's part of my lot.

Peter,

"All observers made of matter constitute a 'medium' with it's own rest frame."

You obviously believe this is a great insight of yours that the world still does not understand. I think it is an obsession that has killed many discussions.

Pentcho Valev