Einstein's breakthrough was far deeper, more philosophical than assumedThey did find relativity before Einstein. With all the formulas. In particular, what Einstein said about simultaneity and synchronization of clocks was straight from what Poincare said five years earlier.
Relativity is about general, qualitative principles, not about light or particular objects and gadgets
Some days ago, we had interesting discussions about the special theory of relativity, its main message, the way of thinking, the essence of Einstein's genius and his paradigm shift, and the good and bad ways how relativity is presented to the kids and others. ...
Did the physicists before Einstein spend their days by screaming that the simultaneity of events is absolute? They didn't. It was an assumption that they were making all the time. All of science totally depended on it. But it seemed to obvious that they didn't even articulate that they were making this assumption. When they were describing the switch to another inertial system, they needed to use the Galilean transformation and at that moment, it became clear that they were assuming something. But everyone instinctively thought that one shouldn't question such an assumption. No one has even had the idea to question it. And that's why they couldn't find relativity before Einstein.
Einstein has figured out that some of these assumptions were just wrong and he replaced them with "new scientific dogmas".
Motl repeats the widespread belief that Einstein found relativity by repudiating conventional wisdom and introducing new dogmas. That is not true at all. The most widely accepted theoy on the matter was Lorentz's 1895 theory. Lorentz had already received a Nobel prize for it in 1902.
Einstein's big dogmas were that the speed of light is constant and motion is relative. Einstein later admitted that he got the constant speed of light straight from Lorentz. He also got the relativity postulate from Lorentz, although it was Poincare who really emphasized it, so maybe he got it from Poincare.
Einstein did later argue against rival theories, such as Abraham's, but he never claimed that Lorentz or Poincare were wrong about their relativity theories. Other authors referred to the "Lorentz-Einstein theory", as if there were no diffence.xxc Even when Einstein was credited with saying something different from Lorentz, he insisted that his theory was the same as Lorentz's.
Einstein did sometimes pretend to have made conceptual advances in his formulation of special relativity, such as with the aether and local time. But what Einstein said on these matters was essentially the same as what Lorentz said many years earlier.
The formulation of special relativity that is accepted today is the geometric spacetime version presented by Poincare and Minkowki, not Einstein's. Poincare and Minkowski did explain how their view was different from Lorentz's.
What about E=mc^2? Wasn't that Einstein's contribution alone, which makes his contribution unique?ReplyDelete
On the simultaneity of events in SR, taking the thought experiment of the train and the platform and the 2 lightflashes :ReplyDelete
The front lightflash trajectory to reach trainguy is shorter than the back lightflash. Obviously, because the train moved towards the point of the front flash origin.
So trainguy may experience this as non-simultaneous (platformguy gets both flashes simultaneously), but trainguy intellectually understands beyond any doubt that the 2 flash impacts at the origins happened at one instance only, and that is the physical reality.
So please can we get rid of the unnecessary, uselessly confusing extrapolations.
The light travels independently of the train and trainguy, that's all. Trainguy has a perfectly decent set of braincells to grasp the meaning of this characteristic of light.
Completely separated from the above description, there is the fact that trainguy's clock runs slower than that of platformguy in accordance with the Lorentz factor.
It does not appear to run slower, it runs slower because after the experiment the remnant of lost seconds is actually found on the one clock compared to the other, it's real.
These are the facts, proven by experiment, nothing less and nothing more.
This does not mean that there is an absolute time though, because we can easily imagine how both clocks on earth run slow compared to a clock on the sun for instance.
P.S. Both flashes impacted on the moving train in this example, 'chalk marks' were placed accordingly on the platform.ReplyDelete
In the same article, Motl says :ReplyDelete
" Massless objects (photons implied here) simply must move by the speed of light. "
This is one of the most persistent misinterpretations of what photons could be. Massless object do nothing, they don't exist, so something is missing in our understanding of the phenomenon here.
So here's a proposition to resolve that apparent contradiction:
Light as a series of consecutive momentum transfer of the constituents of a physical (unified) field. Comparably to the desktop toy Newton's Cradle, where elastic collisions of the spheres actually induce an impact at the end, at high 'propagation' speed, but without actually moving anything from position A to B. No impact would mean no stirring of the eye receptors.
I have included this concept mathematically and geometrically in the context of a more comprehensive theory.
Those interested can look here.
(Pages 13&14 spec.on the propagation of light)
(Pages 18&19 spec.on the propagation of light
I am well aware that 'mechanical explanations' are considered 'outdated'. But think about why we concluded that. It's only because we became more and more confronted with experimentally inaccessible scales, no more low hanging fruit.
'Stuff' determines the laws of physics, not math. Math is the language to express on an abstract level, how the stuff behaves, it merely reflects symptoms.
And it requires efficient creativity to
imagine,model and then mathematically formalise, how that stuff behaves.
Efficient creativity has its own know how by the way, built over 50 years of experience, in the department of Design Sciences. But one has to be prepared to look over the hedge to expand one's skills.
Nice post! I'm a year 13 Physics student and recently did a course on special relativity. I now want to learn a bit more about classical electrodynamics developed by the likes of Maxwell and Lorentz. Do you know any good books or online courses etc.. that I could use to learn about this? My maths is strong so I would prefer something that included equations. I also have a blog Hi, I'm a year 13 physics student hoping to study Physics at university. These kind of topics about the universe as a whole and there being a theory of everything are really what interests me and so I wanted to know how I should go about learning the prerequisites to things like string theory, general relativity, dark energy etc.. Are there any good books you recommend or online courses? My maths is quite good as I took the A-Level a year early and am taking further maths in the coming year so if the course/book is maths heavy thats fine by me. I also have a blog of my own https://alexdoesphysics.blogspot.com/ where I post about things I've read regarding physics and maths. where I've been sharing my journey learning about special relatvitiy along with some other things.ReplyDelete