Faster than Light

Pentcho Valev

Georgina,

Let the stationary observer measure the frequency to be f, the speed of the light c, and the wavelength L:

f = c/L

As he starts moving towards the source with speed v, the measured frequency becomes f'=(c+v)/L, the speed of the light relative to him c', and the wavelength L':

f' = (c+v)/L = c'/L'

So we don't have much choice. Either

(A) c' = c+v ; L' = L (end of relativity)

(B) c' = c ; L' = cL/(c+v)

A is reasonable - it is valid for all other 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."

B is obviously absurd - it implies that the motion of the observer miraculously changes the wavelength of the incoming light.

Pentcho Valev

Georgina Woodward

Hi Pentcho,

What I have found from various sources is the relevance of Maxwell's wave equation. Which is about the specific requirements for an electromagnetic wave rather than any other kind of transverse wave such as ripples in a moving rope or ripples on a pond.

I don't have LateX so in words that is: c is equal to 1 over the square root of permeability times the permitivity. Permeability is the resistance to the setting up of an electric field and permitivity is the ability to support a magnetic field. It can be seen that these phenomena have nothing to do with moving sources or observers.

From this finding came the development of special relativity that gives the mathematical explanation of why the constant speed of light is seen to be so. If one takes space-time to be the external reality then as something moves it is not only moving in space but also time. That makes comparison of the experience of each different (inertial frame) observer different from the simple calculation in (Newtonian) space with absolute passage of time. The different observers will not agree about what is synchronous. Taking SR into account it can be shown that the speed of light is the same for each inertial frame.

The being at different apparent times is easy to accept if one considers the observer running towards the distributor is rapidly obtaining more and more recent sensory data from which his present experience is fabricated. The slow walker is fabricating his present experience from older sensory data. They are not experiencing being in the same present.

The special relativity requirement does not apply to transverse waves other than the electromagnetic kinds as EM waves are travelling at light speed which makes the minuscule difference significant whereas it is irrelevant at the much slower speeds of visible waves such as the rope and water ripples.

Georgina Woodward

I think that last paragraph could be improved. Important points as I see it are :

1. We use electromagnetic data to fabricate our experienced present. Different (more or less recently produced) data input gives a different present.

2. light travels a long way at speed of approx. 299 792 458 meter / second in a tiny amount of time. So a tiny time discrepancy between the inertial frames is enough to give the observed measurable spatial differences.

3. In the same tiny time interval there will be no perceivable difference in location of the rope wave or water wave, as the are travelling so very much more slowly.

4. The speed of light is slightly different in air compared to a vacuum.Air has a refractive index of 1.0003 "Notice that the index of refraction of air differs from the index of refraction of vacuum by a very small amount. For applications with less than 5 digits of accuracy, the index of refraction of air is the same as that of vacuum, n= 1.000." from The Speed of Light and the Index of Refraction, www.rpi.edu

Pentcho Valev

Georgina,

Note that the equation f'=(c+v)/L=c'/L', which is acceptable to both relativists and antirelativists, has only two posssible solutions for c' and L', and one of these solutions is fatal not only for Einstein's relativity but for theoretical physics as a whole. So please let us first choose between the solutions (A) and (B) before discussing anything else:

(A) c' = c+v ; L' = L (end of Einstein's relativity)

(B) c' = c ; L' = cL/(c+v) (Einstein's relativity is saved but the shift in wavelength caused by the motion of the observer is absurd)

Pentcho Valev

Georgina Woodward

Hi Pentcho ,

there are eight different formula for dealing with Doppler shift. They can be found listed here- Doppler shift formula, tutorvista.com Just close the tutor box to look at the formulas un-interupted. f is frequency, f' is apparent frequency, which makes clear that the frequency of the source is not changed but from the observer's perspective it seemingly does change.

Georgina Woodward

Seeming change of wavelength is not absurd. Consider a boat on the sea being rocked by regular waves. The frequency, speed and wave length of the waves can measured as they pass by. However if the boat travels with the waves at their speed it will not be rocked but will stay at the same height travelling in a trough or riding a crest for example. Now seemingly the frequency is 0 and so is the wavelength, (even though the sea has not changed). It is as if, from the boats perspective, it is travelling on still water.

Pentcho Valev

Georgina,

"Seeming change of wavelength is not absurd. Consider a boat on the sea being rocked by regular waves. The frequency, speed and wave length of the waves can measured as they pass by. However if the boat travels with the waves at their speed it will not be rocked but will stay at the same height travelling in a trough or riding a crest for example. Now seemingly the frequency is 0 and so is the wavelength, (even though the sea has not changed)."

At least for waves other than light waves, it is universally accepted that, when the observer starts moving relative to the source, both frequency measured by him and speed of the waves relative to him change but apparent wavelength remains unchanged (most scientists suggest, implicitly of course, that this is valid for light waves as well):

Doc Schuster: "The wavelength is measured the same by everybody." (see my discussion with Doc Schuster)

"Thus, the moving observer sees a wave possessing the same wavelength (...) but a different frequency (...) to that seen by the stationary observer."

"vO is the velocity of an observer moving towards the source. This velocity is independent of the motion of the source. Hence, the velocity of waves relative to the observer is c vO. (...) The motion of an observer does not alter the wavelength. The increase in frequency is a result of the observer encountering more wavelengths in a given time."

Pentcho Valev

Georgina Woodward

"The motion of an observer does not alter the wavelength. The increase in frequency is a result of the observer encountering more wavelengths in a given time." Pentcho

That I agree with.

Re the motion of the boat; when it is traveling with the waves it is not changing the wavelength of the sea waves at all but as I said the wavelength is seemingly 0. The boat is not encountering any waves. I'm sorry but if no wavelength is experienced it can't be the same as experience of a unchanged wavelength.

Derivation of Doppler Effect Wavelength Equations, by Ron Kurtus

Pentcho Valev

Georgina,

The observer walks along the fence. Relative to him, the posts have speed c, and the frequency he measures is f=c/λ, where λ is the distance between the posts. Now the observer starts running along the fence and his speed increases by v. Relative to him, the speed of the posts shifts from c to c'=c+v. This shift in the speed of the posts (relative to the obsevrer) causes the frequency he measures to shift from f=c/λ to f'=c'/λ. Neither the real not the apparent distance between the posts changes of course.

99,99% of scientists derive the Doppler frequency shift (moving observer) analogously, for all kinds of wave - only in the case of light waves they "forget" to mention the equation c'=c+v:

"Sound waves have speed c, and f and λ are related by c=λf. 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'/λ."

"The Doppler effect - changes in frequencies when sources or observers are in motion - is familiar to anyone who has stood at the roadside and watched (and listened) to the cars go by. It applies to all types of wave, not just sound. (...) Moving Observer. Now suppose the source is fixed but the observer is moving towards the source, with speed v. In time t, ct/λ waves pass a fixed point. A moving point adds another vt/λ. So f'=(c+v)/λ."

As for Ron Kurtus, he belongs to the 00,01% of scientists who teach otherwise. If you wish, we could discuss his mistake.

Pentcho Valev

Georgina Woodward

Hi Pentcho,

I understand your point that motion doesn't change the length of something but we are talking about perception. The output of sensory data processing is no longer the source of the data it is something else -a manifestation. The same applies to the barn pole type paradoxes.

I chose Ron Kurtus' page because he is talking about wavelength rather than frequency which I have found is a lot more unusual to come across. He provides his credentials, which I looked at before linking the site.

I accept that Ron Kurtus knows and understands and is a lot more experienced regarding the subject than me. Teaching is one of the best ways to really grasp a subject. On that previously linked site he does say " Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible." So perhaps you should address your identification of a mistake in his presentation to him, as he is far more likely to understand whether it is he or you that are mistaken. I would be interested in his response.

I found this article that shows, at least, I have been thinking about this too simplistically. It has an equation showing angle between observer and a beams direction.Also it talks about increasing intensity when traveling towards the source which makes a lot of sense as photons will be being received more quickly.Then it talks about different kinds of eye and the output they will 'see'. Which I think is interesting because there seems to me to be a lot of more focus on the input IE what that should be but not so much on the outputs generated by processing,

Real-time simulation of aberration and Doppler eï¬€ect of light

Georgina Woodward

It is a mistake to regard the here and Now /present, IE What is seen to be here-Now or what is seen to be present, as a singular time in space. That's because it is amalgamated from poly temporal data (easier to say than multi- temporal). Far more intuitive when astronomic observation is included. Near cat on wall, more distant trees and a night sky for example. Each sample of sensory data is a sub set of all of the sensory data spread out in space over time (IE over iterations of the object universe)from an observed object, being only that part received by the observer. The sensory data received together, does not all have the same temporal origin in space, giving an output with images representing different uni-temporal times (iterations of the Object universe). The differences in sizes of objects when close to observer and far from observer are an indication that the amalgamated output image is formed from projected sensory data. Visual angle determining size of image on retina and visual cortex and hence perceived size. Wikipedia, Visual angle. A meter ruler appears smaller as it is moved away from the observer as the visual angle decreases. In the case of human stereoscopic vision two amalgamated images are mentally combined to give the effect of 3D. It is clear that neither the sizes experienced nor the temporal mixture of the image are an identical representation of the object reality, the actual substantial source objects themselves existing externally to the observer. And being what it is, a fabricated output from an amalgamation of data originating at different distances and hence also times, it is altered by motion of observer or motion sources of data input, both of which alter the way in which the observer receives sensory data from which to fabricate the observed present. Where something is seen in uni-temporal time (IE related to which iteration of the Object universe) does alter as does apparent size.

Georgina Woodward

The here and Now /present, IE What is seen to be here-Now or what is seen to be present is not the division between what has existed and what will exist but only the output of that data received and processed by that observer. Another observer moving through space on a different path or moving with a different speed will receive different sensory data and thus have a different present experience. Apparent simultaneity is a question of what data is processed into output together or very close to together.

The division between what has existed, the imaginary substantial past,and the imaginary substantial future is uni-temporal-Now or the one and only existing configuration of the substantial Object universe. That is not the visible universe constructed from received EM radiation data but all that substantially exists simultaneously including all EM potential sensory data within that configuration. All experienced presents, whatever the image content, occur within the uni-temporal Now. There is no other time to exist at. The content of all presents experienced is images of substantial objects and events that have already occurred in Object reality and so the substantial configuration and substantial content of uni-temporal Now precedes the image configuration and content of all presents.

No time travel to the substantial past is possible because the former configurations of substantial matter and particles are not perpetual but are changed into the new configurations of the new uni-temporal Now. Disallowing Grandfather type paradox. Though if it was possible to receive light long after it was emitted it would be possible to see images of the past, reflection echo like is a possibility or collection of the signal and replay back to its source. Without faster than light speed it isn't possible to outrun em signals, slow to below light speed and then view the events of the past. With faster than light speed that would be possible but is not time travel,its just receiving different potential sensory data and making a different experienced present,still within uni-temporal Now the existing configuration of the substantial Object universe. Just as viewing ancient star light is not time travel but is making a manifestation or Image from ancient em sensory data.

Georgina Woodward

Interestingly the explanatory framework with two different facets of reality, Object and Image reality, implies a wave matter duality underlying that. The matter component is the substantial objects made of atoms, where as the wave component is the potential sensory data produced through interaction of the object with the surrounding environment.

The given framework has a place for atoms unlike the theoretical space-time continuum that is missing one complete facet of reality. Both are compatible with non simultaneity of observedevents.

Georgina Woodward

Nowadays we are not limited to drawing flat diagrams on paper but have the advantage of being able to represent matters as CGI. Computer generated representation of 3 dimensional space that can be orientated by the viewer can be used to represent changing configurations of Object realty.

Light sensory data can be depicted spreading out from the substantial Source objects. Different colours can be used to represent the iteration in which each set of sensory data had its origin IE the "time" represented by the data.

A suitable interval between colour changes can be selected to give the best, clearest representation although it should for accuracy probably be the limit of human discrimination between individual images that can be slowed down for the purpose of gleaning what is occurring within the representation. The data received for each observer line of sight (the angle of his visual field as he is not receiving data from all 360 degrees around him ) can be shown by what colour data from which sources intersects his location within the visual field, at any particular uni-temporal -Now.

The colour used to depict the observer will always be the colour of the youngest iteration which is uni-temporal -Now but the data he is receiving, that changes with his position and orientation in space, is of different colours.

The historical view, what the observer has been seeing can be reviewed by looking back over his different coloured existences, as individual uni.-Now times. Or it can be reviewed as a movie showing evolution of the sensory data distributions and from that the evolution of the observers experienced present.It would be interesting to not only replay his experienced present but to also select to show, superimposed, the coexisting Object reality by showing the location of all objects (without showing their sensory data output, that have the same uni-temporal-Now colour as the observer.

Two different observers can be put into the space simulation and their data selection and hence experienced presents compared. The temporal spread within each experienced present will be clear from, the different colours of data received and the non simultaneity of events between two different observers will be clear from the differences in the colours of their respective received data.

I think that is quite clearly explained but I am happy to answer questions on it. I could try to create that simulation but it will take me a long time as I am new to 3D modeling. Perhaps putting together a professional CGI presentation for public presentation and educational purposes is something FQXi might consider worthy of a grant. I would be very happy to work with professional CGI modeler/s on that project, though in the meantime I might be able to generate a simple prototype for basic illustrative purposes.

Georgina Woodward

I'd just like to add that with this CGI representation it will also be easy to show that moving towards a source Object coincides with receiving younger potential sensory data giving a more recent (advanced ) present output; whereas moving away from a source object older sensory data is received giving an older(retarded) present output. Both outputs showing different apparent presents potentially co-existing within the youngest, only existing configuration of the Object universe, uni-temporal -Now.

This is an important step taking the explanatory framework from a philosophical basis to a mathematically demonstrable model. Showing the emergence of experienced space-time from the configurations of uni-temporal space. It will also be possible to extract Mathematical descriptions of what is occurring from the CGI model putting it on par with other mathematical frameworks.

Georgina Woodward

The correct explanatory framework, correctly portrayed will dictate the mathematics that emerges from it.

Pentcho Valev

How Einstein Embraced the Bizarreness

Robert Scherrer, Professor and Chair of Physics and Astronomy at Vanderbilt University: "And what's even more bizarre is that if you are moving at 99% of the speed of light, and your friend is standing still, both of you will see the light moving away at exactly the same speed. (...) Instead of trying to explain away this bizarreness, Albert Einstein embraced it."

Einstein wrestled with his conscience for a while but in the end found it profitable to embrace the bizarreness (absurdity):

Pentcho Valev

World Science Festival: "Time is of the essence ... or is it?"

MODERATOR: Jim Holt PARTICIPANTS: David Z. Albert, Vijay Balasubramanian, Carlo Rovelli, Lee Smolin DATE: Sunday, May 31, 2015 TIME: 2:00 PM-3:30 PM VENUE: The Gerald W Lynch Theater at John Jay College

Buy Tickets

What is time? The question has preoccupied philosophers and scientists for centuries. Isaac Newton described time as absolute, but Einstein proved that time is relative, and, shockingly, that time and space are intricately interwoven.

_________________________________

[end of quotation]

Did Einstein PROVE that "time is relative, and, shockingly, that time and space are intricately interwoven"? No. He just disfigured time (and space) in order to vindicate the absurd idea that the speed of light (relative to an observer) is independent of the speed of the observer:

John Stachel: "But here he ran into the most blatant-seeming contradiction, which I mentioned earlier when first discussing the two principles. As noted then, the Maxwell-Lorentz equations imply that there exists (at least) one inertial frame in which the speed of light is a constant regardless of the motion of the light source. Einstein's version of the relativity principle (minus the ether) requires that, if this is true for one inertial frame, it must be true for all inertial frames. But this seems to be nonsense. How can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam? Einstein states that he wrestled with this problem over a lengthy period of time, to the point of despair. We have no details of this struggle, unfortunately. Finally, after a day spent wrestling once more with the problem in the company of his friend and patent office colleague Michele Besso, the only person thanked in the 1905 SRT paper, there came a moment of crucial insight. In all of his struggles with the emission theory as well as with Lorentz's theory, he had been assuming that the ordinary Newtonian law of addition of velocities was unproblematic. It is this law of addition of velocities that allows one to "prove" that, if the velocity of light is constant with respect to one inertial frame, it cannot be constant with respect to any other inertial frame moving with respect to the first. It suddenly dawned on Einstein that this "obvious" law was based on certain assumptions about the nature of time always tacitly made."

Pentcho Valev

"On 29 April, Nasa scientists wrote an article on Nasa Spaceflight that they had tested British scientist Roger Shawyer's controversial electromagnetic space propulsion technology called EmDrive and were unable to disprove their results, indicating that the technology worked. However forum users looking at the experiment results also found that when lasers were fired into the EmDrive's resonance chamber, some of the laser beams had travelled faster than the speed of light..."

"Thrust measurements of the EmDrive defy classical physics' expectations", said the researchers, who have been testing the highly controversial electromagnetic space propulsion technology. They posted on the Nasa Spaceflight forum that when lasers were fired into the EmDrive's resonance chamber, some of the laser beams had travelled faster than the speed of light..."

"Nasa Spaceflight forum" above is a link in the paper but it leads to no information about laser beams travelling faster than the speed of light. Could the dangerous posts have been removed from the forum?

Pentcho Valev

[deleted]

Interesting stories Pentcho. It may be a problem that the device relies upon special relativity principles. Special relativity being,it seems, about appearances and not changes to the underlying Object reality of matter.

I took a quick look at nasaspaceflight.com EM drive discussions. There is a variety of discussion about time travel there including talk of altering light cone orientations. One chap is talking about travelling really fast to Alpha centuri which he likens to going back in the past from the Earth's point of view. It is interesting because with uni-temporal passage of time it isn't possible to go back into the past, as it has no substantial existence. But in this scenario he could go and then be at a position in space to witness events before they are seen much later at his earlier spatial origin -making it seem that he was in the past, according to a distant Earthbound observer's much later observation.

However the sensory data produced from events near Alpha centuri will later form a part of the distant observers present. In that regard it is the pre-written future (future as in not yet but will be present). So he is seeing distant observer's present earlier; and in that respect has advanced 'forward' in apparent time (receiving younger sensory data, seeing 'the past' sooner) compared to the distant observer.

In both descriptions the substantial space traveler is always at unitemporal -Now neither travelling to past or future, its all about appearances.

Georgina Woodward

Anonymous replied on May. 15, 2015 @ 02:10 GMT is me, Georgina

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