Musk buys Twitter

[Not Insane]

Originally Posted by bobabode

Anyone with a high school edumacation who actually paid attention knows that the 'speed of light' roughly 186k per second figure is measured in a vacuum. Not in your bathtub or anywhere near a black hole. https://en.wikipedia.org/wiki/Speed_of_light

I agree. But if it slows down when passing through water it means its speed is not constant. However, if someone says its speed is constant in a vacuum, I'd agree with that statement. Precision of language matters in affairs of science.