"2+2 doesn't always equal 4 [...] Suppose you switch on a flashlight. The light moves at, well, the speed of light. And as you know the speed of light is the same for all observers. We learned that from Albert Einstein. Yes, that guy again. Now suppose I switch on the flashlight while you come running at me at, say, ten kilometers per hour. At what velocity is the light coming at *you. Well, that’s the speed of light plus ten kilometers per hour. Right? Erm, no. [...] So, if you add something to the speed of light, the speed of light doesn’t change. If you come running at me, the light from my flashlight still comes at you with the speed of light." http://backreaction.blogspot.com/2021/06/22-doesnt-always-equal-4.html

John Stachel: "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." http://www.aip.org/history/exhibits/einstein/essay-einstein-relativity.htm

"Seems to be nonsense" is a red herring. Einstein's constant speed of light is OBVIOUS NONSENSE. Frequency and speed of light pulses vary proportionally for the moving observer https://youtube.com/watch?v=bg7O4rtlwEE, in accordance with the formula

(frequency) = (speed of pulses)/(distance between pulses)

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Richard Feynman: "I want to emphasize that light comes in this form - particles. It is very important to know that light behaves like particles, especially for those of you who have gone to school, where you probably learned something about light behaving like waves. I'm telling you the way it does behave - like particles. You might say that it's just the photomultiplier that detects light as particles, but no, every instrument that has been designed to be sensitive enough to detect weak light has always ended up discovering the same thing: light is made of particles." QED: The Strange Theory of Light and Matter p. 15 https://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691024170

Feynman UNWITTINGLY suggests:

1. The speed of light varies as per Newton's theory.

2. Variable wavelength of light https://youtube.com/watch?v=xsVxC_NR64M is an unrealistic concept. (In resurrected, Einstein-free physics, the wavelength of light will be CONSTANT for a given emitter.)

Banesh Hoffmann, Einstein's collaborator, admits that, originally ("without recourse to contracting lengths, local time, or Lorentz transformations"), the Michelson-Morley experiment directly proved Newton's variable speed of light and disproved the constant speed of light:

"Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether." Banesh Hoffmann, Relativity and Its Roots, p.92 https://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768

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