Is the speed of light in a vacuum an assumption, not a certainty ?

@allygator18 reservoir of what ?

😉@allygator18

@Convivial Great, you arrived at the right answer, well done. A good approximation can be a kin to an assumption.

@Messi no... An assumption is something you assume without any foreknowledge...

@Convivial it is also "the act of taking possession or asserting a claim". To assume anything is to state something as exact without knowing if it is exact or not

@Confined ludicrous, now!

@froggtongue The isotropic one way speed of light was never attempted

@Messi i've only heard of one possible way to test for it. But i don't have any hopes of finding that the speed is dependent upon direction.

@froggtongue Some physicists do not seem to be aware of that only the round-trip speed of light has been very well-tested. The round-trip speed of light is indeed isotropic and is represented by the constant c. To measure the round-trip speed of light, we only need one clock and because of this we are not dependent on any clock synchronization procedures. In general, this is not the case when setting up experiments for measuring the one-way speed of light.

@PurpleHearts that depends on whether you turn the light on first before you both travel

@SpaceJesus raspberries I bet

Schnozzberries 😆 @caPnAhab

@SpaceJesus @SpaceJesus astronauts aboard the ISS have reported that they notice a metallic aroma – like the smell of welding fumes – on the surface of their spacesuits once the airlock has re-pressurised.

@SW-User yes

@stratosranger They can you know

😳@Messi