ralfcis » 29 Aug 2017, 16:01 wrote:There can be no aging difference between 2 inertial frames in a flyby even though the ship has flown by the 4ly miarker in 3 of its years.
And the other party of the "2 inertial frames in a flyby" has flown by the ship's 4 lyr marker in 3 of its years. Completely reciprocal, as it should be for any two fully inertial frames.
This appears to be so broad a definition of the word ‘speed’ as to include even jargon uses of the word that differ from ‘velocity’ such as the ‘speed’ of a trip to the store or the operating ‘speed’ of a computer.
----For a speed to be a speed it has to be the speed of something that is physically observable and all speeds correctly identified obey the rule of the composition of velocities where velocities can be added or subtracted from other velocities relative to differently moving observers but light does not qualify by this definition.
phyti » October 22nd, 2017, 1:23 pm wrote:
In the 1600's Ole Romer discovered light required a finite time to move a finite distance, while making astronomical observations of Jupiter and its satellites, thus eliminating the idea of instantaneous propagation.
phyti » October 22nd, 2017, 1:23 pm wrote:
Light has no inertial/rest mass, and only a constant propagation speed, that is independent of the source. The 2nd and 3rd properties prevent it from following the original vector addition of velocities, resulting in time dilation. The effects of motion on the measurements of time and space, both involving em processes, i.e. light speed, provides a self preservation of c.
To say that light has “a constant propagation speed, that is independent of the source” violates the Galilean principle of relativity. How can anything have the same speed relative to all possible sources independent of their varying individual velocities?
bangstrom » 23 Oct 2017, 02:25 wrote:To say that light has “a constant propagation speed, that is independent of the source” violates the Galilean principle of relativity.
phyti » October 24th, 2017, 1:19 pm wrote:
Galileo was wrong.
The measured speed of light is constant because perception is altered resulting in that conclusion.
BurtJordaan » October 24th, 2017, 3:41 pm wrote:bangstrom » 23 Oct 2017, 02:25 wrote:To say that light has “a constant propagation speed, that is independent of the source” violates the Galilean principle of relativity.
I think it's the other way round. If the observed propagation speed of light was not the same in every inertial frame and/or dependent on the source speed, it would have violated the Galilean principle of relativity. The principle states that there is no physical way to differentiate between a body moving at a constant speed and an 'immobile' body. A difference in the observed propagation speed of light would have made it possible to make that differentiation.
bangstrom » 25 Oct 2017, 07:30 wrote:How would an observed difference in the propagation speed of light make it possible to distinguish between a moving body and an ‘immobile’ body in violation of the Galilean principle?
Consider some other fast moving particle such as an electron or muon, or better yet, a neutrino if you could easily detect them.
BurtJordaan » October 25th, 2017, 1:58 am wrote:bangstrom » 25 Oct 2017, 07:30 wrote:How would an observed difference in the propagation speed of light make it possible to distinguish between a moving body and an ‘immobile’ body in violation of the Galilean principle?
If a proper one-way measurement of the propagation speed of light comes out differently in relatively moving frames of reference, the laws of physics must be different in those two frames, in violation of Galilean relativity. The secondary consequence would have been that we could have detected the "absolute frame", which we know we cannot (by experiment).
BurtJordaan » October 24th, 2017, 3:41 pm wrote:bangstrom » 23 Oct 2017, 02:25 wrote:To say that light has “a constant propagation speed, that is independent of the source” violates the Galilean principle of relativity.
I think it's the other way round. If the observed propagation speed of light was not the same in every inertial frame and/or dependent on the source speed, it would have violated the Galilean principle of relativity. The principle states that there is no physical way to differentiate between a body moving at a constant speed and an 'immobile' body. A difference in the observed propagation speed of light would have made it possible to make that differentiation.
bangstrom » 25 Oct 2017, 22:08 wrote:The problem is that no moving objects respond to an “absolute frame” and even high speed particles with variable speeds through space (electrons, muons, and possibly neutrons) can not be used to distinguish between a moving body and an “immobile” body because none of these respond to an absolute frame.
How can anything have the same speed relative to all possible sources independent of their varying individual velocities?
The value of ‘c’ has all the properties of a dimensional constant
For a speed to be a speed it has to be the speed of something that is physically observable
phyti » October 26th, 2017, 12:15 pm wrote:
A recent example on another forum. The poster argues that when A and B observe a moving clock running at two different rates, he argues the clock can't be in two different states simultaneously. I agree with him, since it's not about the clock, it's about different perceptions.
phyti » October 26th, 2017, 12:15 pm wrote:
“Bangstrom:The value of ‘c’ has all the properties of a dimensional constant.”
'dimensionless' constant, a scalar by definition. So is g, 1 sec to 10 m, and there are many others.
phyti » October 26th, 2017, 12:15 pm wrote:
Light is modeled as a photon, a packet of energy, and can be manipulated many various ways. We are aware of it indirectly.
phyti » October 26th, 2017, 12:15 pm wrote:
Lrt’s assume light motion is instantaneous and use the earlier time vs space graph.
An em signal that reflects from the moon’s surface, would be shown as a horizontal line at t=0 and a second horizontal line at t= 2.5. Now we have to explain the gap. Is it the time to turn the light around ?
Experimenting with more distant objects, planets, etc, someone might detect a pattern, that the time gap increases with the distance, and theorize that it’s nothing but transit time!
phyti » October 26th, 2017, 12:15 pm wrote:
Galileo was correct for moving matter, since each component of a composite object had the same velocity. If you subtracted that velocity from each component, you are left with a static object. Galileo was not aware of the behvior of light, so didn’t know its speed was independent of its source, and did not add as velocities of material objects. He also therefore would not know what compensates for this difference, such that all inertial frames behave as rest frames.
ReRelativity is a physical effect. It affects clocks and meter sticks and all forms of inanimate objects such as satellites and stars. An observer moving towards a clock sees the clock moving faster because the amount of space and time between him and the clock is decreasing. The opposite is true for an observer moving away from the same clock. This is an objective physical effect and not a matter of cognition.
I said ‘c’ has all the properties of a dimensional constant… not a dimensionless constant. One second for 300,000 km is a dimensional constant.
The photon is a model for light. It is an imaginary particle. A. F. Kracklauer calls the photon a paradigm and a folklore. The photon represents a quantum of energy in an EM event but its presence between signal and sink is purely conjecture.
The gap is the distance to the moon measured in seconds rather than units of length. Units of space and time are interchangeable and this is the meaning of the constant c. C tells us that there is one second of time in every 300,000 km of space so the distance to the moon is 1.25 secx300,000 km or 375,000 km. The implication of this requires a non-Newtonian understanding of time much like in the Limerick about the young fellow named “Sprite” who could travel much faster than light.
Anything remote from your location is separated from you by spacetime. Space and time are essential aspects of the same thing “spacetime” and we can’t separate one from the other. This view places the surface of the moon I.25 seconds in our past.
An instant signal from the Earth to the moon arrives on the moon 1.25 seconds into the moon’s future. All EM signals are moving forward in time. A bounce-back signal from the moon to the Earth arrives an additional 1.25 seconds into our future so we need to wait a total of 2.5 seconds to receive the return signal.
This is quite counter intuitive but it is consistent with experiments in QM such as entanglement and quantum teleportation and, when applied to SR, it eliminates the familiar paradoxes and the only violation is of Einstein’s second postulate where c is
defined as the speed of light. It makes no difference to the math because c has the same numerical value whether you call it a speed or a dimensional constant.
If light carries energy, why does it have no mass and why doesn’t the speed of its source add to the speed of light?
phyti » October 30th, 2017, 12:57 pm wrote: How can the clock have three different frequencies simultaneously? The answer is the same for all the supposed contradictions. It's not about the clock, it's the perceptions. Physical laws prevent such states for objects, but do not prevent multiple perceptions.
Why didn't you include observers in your list of affected things?
phyti » October 30th, 2017, 12:57 pm wrote:The photon is a model for light. It is an imaginary particle. A. F. Kracklauer calls the photon a paradigm and a folklore. The photon represents a quantum of energy in an EM event but its presence between signal and sink is purely conjecture.
Signals can be encoded for communication, therefore the return signal verified as the response to the one sent. This is part of the protocol for electronic communications and encryption. When the lunar module was behind the moon, there was no communication since the signals were blocked! Kracklauer should do more research.
phyti » October 30th, 2017, 12:57 pm wrote: Expressions like 'a days ride', 'a 2 day march', 'a 40 min trip', are common expressions used in the past and today, with time and distance used interchangeably. Nothing new here.
phyti » October 30th, 2017, 12:57 pm wrote: Nothing moves in time! That's the lines on paper version of SR.
phyti » October 30th, 2017, 12:57 pm wrote:
If the second postulate is violated, so is the first.
phyti » October 30th, 2017, 12:57 pm wrote:
One could speculate that space has a structure which determines the behavior of light, and possibly gravity.
How does a blocked signal make photons real?
There is nothing new about c is being a conversion factor for converting between units of space and time. Herman Bondi interpreted the meaning of c as a constant ratio of length-units to time-units in our observational projections of optical phenomena, analogous to the constant 39.37 inches to the meter in the measuring of length, and 2.2046226 pounds to the kilogram in the measuring of weight.
The conversion factor for converting inches to meters is not a length and the conversion factor for converting pounds to kilograms is not a weight so why insist on calling the conversion factor for converting units of time to units of distance a “speed”?
Also, the constant , c^2 relating units of mass and energy which, like c, and other constants in general, is obviously the same for all observers in all states of motion or rest.
Also, what meaning can be found when you square a speed?
Everything moves in time.
The lines on spacetime diagrams of SR are highly artificial but, like good maps, they describe an observed reality and the uniformity of the diagrams describes the scalar nature of c.
Einstein’s first and second postulates are unrelated so how can violating the second violate the first.
Changing the definition of c from a speed to a dimensional constant does not change the numerical value so the math remains the same.
The structure of space is such that every interval of space includes an interval of time. Any two otherwise simultaneous events separated by space are also separated by an interval of time equal to one second for every 300,000 km of space. That determines the behavior of both light and gravity.
phyti » November 2nd, 2017, 11:04 am wrote:Bangstrom;How does a blocked signal make photons real?
-------------
It shows something moves between emitter and receiver, and it can be blocked. An experiment involving photons can easily show they exist in intermediate locations other than emitter and detector. Photons are as real as any particle.
phyti » November 2nd, 2017, 11:04 am wrote:Although Minkowski generalized time as a mathematical dimension, removing any independent identity, there were two beneficial effects for graphics. The nature of time vs space is eliminated thru the use of complex notation (ict), time is restored to a measurement of distance (which it was throughout history, and the scaling by c results in meaningful graphs for extreme speeds. The graphics now plot vt vs ct or v/c, a history of speed. In this setting 'c' becomes a conversion constant. It also
simplifies calculation when assigned a value of 1 as a standard.
phyti » November 2nd, 2017, 11:04 am wrote:---------
1. Light propagation in space can be considered as a physical process regulated by the laws of physics, thus constant in all frames, and included in the 1st postulate.
2. You can derive the 1st postulate using the 2nd, showing x'/t =x/t,
phyti » November 2nd, 2017, 11:04 am wrote:---------
If using SR graphics, 1 time unit ct = 1 space unit x. Measuring the speed of light does not explain how or why it has that specific value.
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