Monday, July 8, 2024

Posulating the Constant Speed of Light

D V Redžić writes in a new paper:
The historical path to special relativity starts from the second postulate introduced by Einstein in 1905 [10]. Immediately after the publication of reference [10],
No, the historical path starts with Maxwell's 1865 theory, and the motion invariance tests of it by Michelson in the 1880s.

A popular interpretation of the 1887 Michelson-Morley experiment was that the speed of light was the same for all observers.

Newton, and all physicists before Einstein (including Voigt, Larmor, Lorentz and Poincar´e [15-18]), took it for granted that there was only one ‘time,’ absolute Newtonian time, for all observers in motion with respect to one another. Einstein was bold enough to venture that each inertial observer has her/his own absolute Einsteinian time.
No. Moving objects had they own "local time" in Lorentz's 1895 relativity theory. Poincare accepted this, and believed that motion affects time. Not sure about Voigt and Larmor, but they gave equantions for time changing; what else could they have thought?

It is amazing that someone could write a commentary on on the historical path of relativity, and act as if it all started and ended with Eeinstein's 1905 paper.


  1. And they are all wrong. Time is a parameter in QFT. You see the same effects in shallow water. Clocks are made out of fields that get distorted. Rindler's "spaghetti truck" thought experiment illustrates the complex nature of special relativity and the breakdown of rigidity at high speeds. In this scenario, a truck attempts to cross a gap longer than itself by accelerating to near light speed. While the driver perceives the gap as shorter due to length contraction, a stationary observer sees the truck as shortened. The paradox is resolved by recognizing that the truck does fall into the gap, but from the driver's perspective, it deforms like spaghetti due to the finite speed of force propagation within its structure. This example demonstrates how relativistic effects can lead to counterintuitive outcomes, highlights the impossibility of perfect rigidity in special relativity, and suggests that there can be observable differences between reference frames at high speeds, potentially indicating "objective" motion.

  2. When your clock distorts, that doesn't mean actual time is distorting. We like to think clocks measure time, but they do not and never have, we just treat it as such for mental convenience. Clocks measure a rate of some kind of change over another rate of change in a ratio that we like to label 'time' (days of a lunar cycle, sunrise to sunset, stars in their exact location in the sky until the next cycle, marks on a candle, oscillations of an electron), as is evident to anyone who has ever studied various historical time keeping methods. Each successive clock has pretty much improved accuracy of measuring a particular rate of change in a ratio but falls to the same problem "What do you do when you discover that whatever you are using to be your meter of the rate of change actually changes?" The answer is always the same, you remember what a clock is, and stop pretending that it is time that is the problem. The problem is always the clock and how you view the method by which you view the clock (light), that's all you have to work with, and all you can muck about with.

    If time could change rate, you also would not be able to tell, as all processes rates of change would also change lockstep. Light is not time, light is merely used to measure and observe rates of change. Stop conflating one for the other with Reductio ad Absurdum. This would not be any different than if you were wrongly surmising the siren on the police car were actually changing pitch (a rate of change) as it drove around in various directions from you instead of it merely sounding as if it did because of the propagation speed of sound.

    Folks also don't like to talk about the problem of physics and time distortion games. If time is actually changing locally, so is acceleration (which is used to calculate distances) and every calculation you use to make measurements with that depends on a period of time to calculate a rate of change (which is everything). Everything that folks like to get excited about with time distortion comes back to "From OUR perspective, it looks like that rate of change over there on that moving object is shifting..." which is where it all goes wrong.

    The light bringing us the data is the source of the distortion, not because the rate of time is changing but because the rate of data being received is changing.