Neil deGrasse Tyson mercilessly brainwashes the gullible world:
Neil deGrasse Tyson: "One of the towering great achievements of the human mind in our understanding of the universe is Einstein's theories of relativity. [...] It makes only two assumptions: that the speed of light in a vacuum is constant no matter who is doing the measurement and no matter in what direction you are moving or how fast. You always get the same measurement for the speed of light. That's Assumption 1 which by the way the experiment has shown to be true. [...] Given those two tenets, extraordinary spooky phenomena derive from them. For example: As you travel faster [...] time ticks more slowly for you than it does for other people who are not."
Two blatant lies in the above performance:
1. "The experiment" has shown that Einstein's constant-speed-of-light postulate is true.
2. Time ticks MORE SLOWLY for the moving observer.
No experiment has shown that Einstein's constant-speed-of-light postulate is true. In 1887 (prior to FitzGerald and Lorentz advancing the ad hoc length contraction hypothesis) the Michelson-Morley experiment UNEQUIVOCALLY confirmed the variable speed of light predicted by Newton's emission theory of light and refuted the constant (independent of the speed of the light source) speed of light predicted by the ether theory and later adopted by Einstein as his special relativity's second postulate:
"To it, we should add that the null result of the Michelson-Morley experiment was unhelpful and possibly counter-productive in Einstein's investigations of an emission theory of light, for the null result is predicted by an emission theory."
"Emission theory, also called emitter theory or ballistic theory of light, was a competing theory for the special theory of relativity, explaining the results of the Michelson–Morley experiment of 1887. [...] The name most often associated with emission theory is Isaac Newton. In his corpuscular theory Newton visualized light "corpuscles" being thrown off from hot bodies at a nominal speed of c with respect to the emitting object, and obeying the usual laws of Newtonian mechanics, and we then expect light to be moving towards us with a speed that is offset by the speed of the distant emitter (c ± v)."
"The Michelson-Morley experiment is fully compatible with an emission theory of light that CONTRADICTS THE LIGHT POSTULATE."
Banesh Hoffmann, Relativity and Its Roots, p.92: "There are various remarks to be made about this second principle. For instance, if it is so obvious, how could it turn out to be part of a revolution - especially when the first principle is also a natural one? 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. If it was so obvious, though, why did he need to state it as a principle? Because, having taken from the idea of light waves in the ether the one aspect that he needed, he declared early in his paper, to quote his own words, that "the introduction of a 'luminiferous ether' will prove to be superfluous."
As for the second blatant lie, "Time ticks MORE SLOWLY for the moving observer", it is contradicted by other Einsteinians:
David Morin, Introduction to Classical Mechanics With Problems and Solutions, Chapter 11, p. 14: "Twin A stays on the earth, while twin B flies quickly to a distant star and back. [...] For the entire outward and return parts of the trip, B does observe A's clock running slow..."
"The Twin Paradox is a scenario that, at first glance, seems to make nonsense out of Einstein's theory of special relativity. The situation is that a man sets off in a rocket travelling at high speed away from Earth, whilst his twin brother stays on Earth. [...] What happens is that the twin on Earth, viewing himself as stationary and his brother as moving at high speed, sees his brother experiencing time dilation and thus ageing more slowly. At the same time, the twin in the spaceship considers himself to be the stationary twin, and therefore as he looks back towards Earth he sees his brother ageing more slowly than himself."
According to special relativity, time ticks FASTER, not MORE SLOWLY, for the moving observer - he will discover this by comparing his (moving) clocks with stationary clocks. In order to completely confuse the brainwashed world, Tyson is teaching the opposite to what Einstein's relativity predicts! Flat Earthers are unable to practice such subtle doublethink - they are much less insane than Neil deGrasse Tyson.