Wouldn't the light pulses only return at the same time if you also were at the center of the sphere?
On Fri, Sep 23, 2011 at 11:12 AM, Stephen A. Lawrence <sa...@pobox.com> wrote: > In fact, the questions aren't nonsense; they just need to be carefully posed > to get sensible answers out of them in a universe where SR applies. > > There is a "distinguished frame" for the universe: The rest frame of the > three degree background radiation. There just is one inertial frame of > reference in which that's isotropic -- in all other frames it's red shifted > in one direction, blue shifted in the other. That frame is (presumably) the > frame which is at rest relative to the primordial fireball. > > Furthermore, if the universe is a compact manifold and "folds back on > itself" -- such as the surface of a sphere -- then there is an intrinsic > "rest frame" as well, which can be found by sending pulses of light > simultaneously in opposite directions. If the universe is closed, and the > light eventually comes back to the emitter, then there is just one inertial > frame in which the two pulses will arrive back at the emitter > simultaneously. > > More obscurely, if the universe is closed, then the frame just mentioned is > the one in which the Sagnac effect is null. All other frames are (in > effect) rotating (going 'round and 'round the universe). > > > On 11-09-23 01:53 PM, Mauro Lacy wrote: > > Vorts, > > So, when I first heard about zero point energy years back, I assumed > it was something I had already theorized myself when struggling with > the concepts of relativity (which still bugs me, for the reasons I'm > about to list) as I was mentally using the term Zero Point already. > Imagine my dissapointment... > > > Anyways, I'm a biologist and chemist more than a physicist, so PLEASE, > correct me where I am wrong. As the velocity of an object increases, > its apparent mass increases, and time slows, for that object, yes? > And the time dilation and mass increase is "relative" to the velocity > based upon the observer being a zero point. For 3 objects moving in a > straight line in the same direction, one at .1 c, one at .2 c, one at > .8 c, time dilation will be different for the .8 c object when vied by > the other two objects, yes? because its traveling at .7 c compared to > one, and .6 c compared to the other, correct? > > If that is the case, is there a zero point? is there an intrinsic > velocity that pretty much EVERYTHING in the galaxy/universe shares? > If so, what happens to mass and the flow of time as you approach that > zero point? > > The "velocity of the vaccum". Does the vacuum moves? At which speed? And > in relation to what? the immobile vacuum? > Einstein's SR disregards all those questions as nonsense, or better said, > "metaphysics". Speeds are only to be measured between material bodies, and > not correlated against any absolute reference, because that absolute > reference cannot be measured or determined. > Does something that cannot be measured or determined exists? In which > sense, or "where", it exists? > > >
