You’ve picked a really fun example and I’m glad you asked! You are exactly correct; the value of the speed of light is not science because it cannot be refuted

You’ve picked a really fun example and I’m glad you asked! You are exactly correct; the value of the speed of light is not science because it cannot be refuted. (Although this was not always true!) You see, in 1983 the definition of the length of a meter was changed to be the distance that light travels through vacuum in 1/299,792,458 of a second, precisely. Or to put that differently, that the speed of light through vacuum is pinned at 299,792,458 meters per second, precisely. Not “by current technological standards”; that’s the exact value of the speed of light in SI units, and presumably always will be. So light now always travels at that speed because we’ve defined it that way, and if (when) we develop better methods to more accurately measure how far light travels over a period of time, it changes the length of a meter, not the speed of light. Light would still be travelling at 299,792,458 m/s; those meters would just be a little longer or shorter to compensate for whatever errors we discovered. (And similarly, if we discovered that our measurements of certain specific vibrations of caesium-133 atoms were wrong, it doesn’t change the measured length of a second; it changes the length of a meter. The duration of a second relative to the caesium-133 atoms is fixed by fiat, the same way that the speed of light is fixed by fiat) But if you’d asked before 1983, then I’d have said that yes, the value of the speed of light was easily refutable, simply by following the standard everyday process of science. (and in fact this happened in 1972, 1958, 1950, 1926, 1907, etc and so on all the way back to the mid-1600s) If you wanted to ‘refute’ the currently accepted speed of light, then all you had to do was run an experiment to measure the speed of light and find out that it had a different speed than everybody thought previously. Once you did that, you of course needed to get a bunch of other scientists to inspect your methodology and results and then repeat your experiment and do other variations of your experiment, and eventually come into agreement with your new, improved measurement. Boom! Refuted. Science, bitches. :D The whole point of science is that every single one of its findings can be refuted if new experiments determine that our previous understanding was incorrect. If something can’t be refuted, it’s not science. By definition. That’s the core distinguishing feature between science and dogma/opinions/whatever. But yeah. The speed of light? Not science any more. We’ve declared a value by fiat and no experimental results can change it from here on out.