New posts in Reference Frames

In a general physical sense, is the position of a particle really a vector?

Is the speed of light in all media independent of reference frame?

Newton's Third law of Motion, who can tell me how to deduct below?

If there is no absolute time, how can we say the Big Bang was 13.8 billion years ago?

Clarification on circular motion and pseudo-forces

Ground → ship Wi-Fi bandwidth in my fast moving spaceship

Why are observers/reference frames able to see themselves moving through time but not through space?

Does the wavelength of a particle depend on the relative motion of the particle and the observer?

What's the physical meaning of the standard base vectors?

Is there any physical evidence for motion?