csmyth3025

I may be misundertanding some basic concepts here. As far as I know, a free falling body in a homogenous gravitational field is in an inertial frame of reference in every way identical to the inertial frame of reference of a distant observer. The clocks of both of these observers wiil show the same elapsed time. Am I mistaken about this? Chris

As I understand it, the Milky Way's central massive object is constrained by recent observations and analysis as follows: (ref. http://en.wikipedia....sive_black_hole ) The radius of a 44 million km diameter sphere is 22 million km. This is a little over 1/3 the average distance of Mercury to our sun. Even if we assume that the indicated mass fills the entire volume of this limiting sphere, the escape velocity would be about 220,000 km/s (about 73% c) (ref. http://www.wolframal...E36+kg&x=6&y=10 ) Is it the argument of this thread that there is some as yet unknown mechanism by which such an object will not gravitationally collapse to a smaller size (a sphere about 23 million km in diameter)* that will produce an escape velocity greater than c? *(ref. http://www.wolframal...5E36+kg&x=6&y=9 ) Chris

The following webpage will provide you a nice image and links to research papers and publications which should answer your question: UCLA Galactic Center Group Chris

Thanks for the link. It's obvious that the answer to my question is much more complicated than the deceptively simple statement of the question itself. This, of course, leads to another question (and, perhaps, another thread): Can this question be answered in any meaningful way? Chris Edited to correct spelling error

Hello DrRocket! Fancy meeting you here! This thread has been very interesting but, as you know, my ability to appreciate the nuances of the arguments presented here is limited - to say the least. To simplify things (for me), let me take a question posted elsewhere in another thread and pose it here in the hope that the answer might help me differentiate the various definitions you good folks have been debating. If I take a 1 kg mass, pick it up off the floor and place it on a shelf 2 m high, what - if anything - changes. From what I've read here I'm guessing that the rest mass and the invariant mass remain the same. Of course I could be wrong about that. That reduces the question to: Does the relativistic mass or equivalent energy content (whichever term you prefer) increase, decrease, or remain the same relative to the Earth? It's my understanding that these last two terms are always relative to something else. Best Regards Chris Edited to correct spelling error

Hi all. I'm Chris. I'm interested in physics - particularly SR & GR.