Notice: session_start(): ps_files_cleanup_dir: opendir(/var/lib/php5) failed: Permission denied (13) in /home/astro/websites/astronomynet/htdocs/sitewide.php on line 4 Re: What Causes Gravity? - an Astronomy Net Blackholes2 Forum Message

 Blackholes2 Forum Message Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
 Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...The Space and Astronomy Agora Re: What Causes Gravity? Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response ToPosted by Wayne/">Wayne on November 15, 1999 02:00:28 UTC

: Gravity is not the geometry of space-time, that is merely our mathematical way of describing it. General relativity is not an explanation of gravity, it is a description only, and it is also an incomplete description. General relativity describes the macroscopic effects of gravity through two fundamental postulates, those being the constancy of the speed of light and the Equivilance Principal. To do this you need geometry, since light "wants" to travel in straight lines; hence one ends up with general relativity. The "geometry" of gravity exists only in our description of it, it is merely a simple consequence of the way light (and all objects under uniform motion) likes to travel in straight lines, but the force of gravity causes that motion to bend and not be straight. That is what the geometry describes, and it is what we use to predict the motion of something in a gravitational field. Also, maybe you have not heard, but General relativity and its "geometry" is a classical theory, meaning it does not take into account quantum mechanics and does not and can not explain where gravity comes from on a sub-nuclear scale. Also, M-theory is at this point HIGHLY speculative, and is not well formed and also lacks the observational evidence to support it, and may always lack the evidence because it requires too much energy to confirm. You shouldn't be so quick to beleive everything you read.

Joe, Thanks for the input. This clearifies some points for me.

 Web www.astronomy.net