Robert Seeberger wrote: > As I understand Relativity, it states that there are no privileged > frames of reference. Therefore, there can be no "absolute velocity" > since the velocity of an object is completely dependent on the frame > of reference of an observer.
Absolutely. ;-) Everything is indeed relative, unless you believe in way-out stuff like Mach's Principle. That darn German hippie. > Further, it seems questionable to me to relate the expansion of > "space" to the velocity of objects. The expansion of space is not the > same thing as the movement of objects within it (though related), and > while space expands the objects within it (atoms and galaxies) do not. > So I also see a conflation of expansion and velocity. Perhaps this is > an artifact of the kinds of metaphors used to explain relativity? > > This causes me to pose a question: What causes space? (This is the > simplest way to state the question I can think of) What causes space? Um... Good question! Would space exist if there was nothing in it? Somebody like Mach would probably say no, things like inertia and gravity are caused by the presence of matter and energy, so without them present all you've got is a lot of nothingness without physical laws - but everyone ignores him these days. A modern physicist might say that space-time was created with the Big Bang, and has an existence of its own. That is, if you could somehow magically break the conservation laws and remove all the matter and energy from the universe, there would *still* be something called space-time left behind where physical laws would continue to function. There wouldn't be any gravity without mass, but if you inserted a test object into the newly depopulated universe, it would still bend space, experience inertia when moving, and so on. So I guess the answer would be (imo) that the Big Bang "gave birth" to space, and space-time now continues to exist as an independent thing of its own. Space-time (again imo) isn't a construct generated by matter or energy, it's a thing that's as real as either of them. The Fool wrote: > But what if the apparatus is cooled to very close to absolute 0? Like > some kind of bose-einstein condensate? I suspect that the theoretical lower limit of cooling would still fall short of the kind of stillness needed to get an interesting displacement in space. But I don’t know, maybe the math would say different. Kevin Street -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.338 / Virus Database: 267.10.10/73 - Release Date: 8/15/2005 _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
