gameboy1234 wrote:Also, not too sure about relativity mk 1 by Galileo.
Galileo was the first to say that the laws of physics are the same in all inertial frames
. He didn't know about the constancy of the speed of light in all frames and thus the need for Lorentz transformations to make this work (it would be another three centuries before people thought of this) and he didn't have the math to formulate the idea rigorously (that wouldn't come until Newton), so he stated it in the form of a thought experiment. He argued that if you have a ship at rest
and you do some measurements below the deck, you will get the same results as if the ship was moving at a constant speed (you need to be below the deck to avoid the open air). Special relativity kept the idea of the laws of physics being the same in all inertial frames, but it replaced the simple velocity addition used to switch between frames with Lorentz transformations. General relativity went further: it says that the laws of physics are the same in all
frames of reference, whether inertial or not.
Aside: the complexity of the theory grows exponentially along the way. Galilean (or Newtonian, if you prefer) relativity can be mastered by most children in middle school. Special relativity is harder, but not by much: it can be at least partly understood by bright high school students and most undergraduates. General relativity is a royal pain in the neck. The math required is way above the other two and while most physicists have done it at one point or another, I don't think most would be able to solve a problem involving it without refreshing their memory from a book first (I certainly would not).