Comments by "Taxtro" (@MrCmon113) on "Special Relativity: This Is Why You Misunderstand It" video.

@HowardS185 I don't think that does it. It has to be the case that you can tell that you're accelerated without ever having known any other state. It must be immediately accessible. And you have to draw the same conclusions whether you're accelerated by a spaceship or stuck against a planet.
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@stylis666 That "acceleration" is absolute should be extremely alarming. That means acceleration isn't just the second time derivative of position. It's fundamental. And it looks exactly like gravity. Why?
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The "acceleration" thing doesn't entirely do it for me. Let's say Bob's already moving away from Alive from the start and instead of turning around he passes Bob2 (and for the sake of symmetry Alice is handing over her clock to an Alice 2). I'm not sure what the best intuition here is.
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silverrahul I've come around to understand that acceleration is not just the second derivative wrt to velocity. No acceleration is actually a fundamental feature of the universe, measured by accelerometers and it defines inertial frames for us.
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