Question Hello! Just can't seem to fit Newton's Bucket into my head. I've long been committed to the idea that ALL motion is relative but the concavity of the water's surface seems to fly in the face of that. So! Without asking for an explanation I may never understand, please feel free to simply settle my confusion with a simple "yes" or "no":
DOES Newton's Bucket Argument establish that rotational motion is *SPECIAL*, occurring with respect to an absolute-rest-state which is invisible to all non-rotational relative motions?
Thanks in advance! -JMM
Answer The core of the matter is Mach's principle. http://en.wikipedia.org/wiki/Mach%27s_principle Rotating bodies are in motion relative to their other parts and accelerating relative to their other parts, so yes they are special. Take a wheel, for example. Points on opposite sides (and all other locations) are moving relative to their attached parts and accelerating relative to them. Establishing that the whole universe isn't also rotating somehow is relatively immaterial and leads to over-thinking these problems...leading to thought experiment after thought experiment. Don't let it drive you crazy. Motion relative to the distant stars in the universe is relative, but rotation according to observation of the entire group (i.e. the universe) is absolute.
I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.
I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.
Education/Credentials Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.