View Full Version : gravity
07-13-01, 07:15 PM
Gravity is the glue of the known universe bonding pretty much everything together...so what is it?
I was just curious to know if anyone knows anything and /or everything about the latest theorys on what gravity is, where it comes from, why its here...etc. Or even websites about gravity.
It is just one of those things that drives a person mad thinking about its presence. Any help would be fantastic, Thanks.
Do a Google search on Gravity, Graviton, Super String Theory - you will have plenty to read over the weekend. Then you can comeback and add your spin on things.
Good Luck. Happy Reading....
07-23-01, 11:42 PM
Duplicate post erased.
07-24-01, 12:00 AM
Gravity is, so far, claimed to be one of four primary forces. Forces are usually described in terms of what they do instead of what they are, as the latter is still quite a mystery. However, Einstein managed to describe gravity as a secondary consequence of a curve, or deviating metric, in space around material bodies. Since a curve is not a very apt name for a three dimensional shape, I find it necessary to substitute the phrase, "a graduated decrease in density of space approaching material bodies" (but heed Josharuni's modification in a post below).
However, since your profile describes you as a sophomore in college, with an interest in all physics related fields, I'm pretty sure you must have already delved into, or been presented with, the current theory of gravity. If you might like to contemplate a possible alternative theory of gravity I will present one here, but be sure not to let it interfere with your learning of the accepted theory.
I, personally, am inclined to believe that gravity is only a secondary force, like that of the force of the wind. I believe in the existence of an ether (something comparable to an extremely thin gas) pervading all space. I further believe this ether is dynamic, and descends vertically onto, and into, the earth, in some dynamic process we have not yet caught on to. If this is the case the ether would have escaped detection by the Michelson-Morley team back in 1887 because their equipment (and premises) was orientated for horizontal detection only. They left it up to the rotation of the earth to provide them with all the other possible orientations. However, they missed the vertical possibility, but a steady descending ether still would not have shown up in the type of test they where using.
Since the Michelson-Morley team got the Nobel prize for their failure to detect an ether, there have not been any further attempts to do so that I know of. As a matter of fact I was searching the web using the word "ether" to see if I could find any radical thinkers on the subject when I was stirred on to Sciforums.com. No luck so far. However, there is a very interesting book which forthrightly incorporates the ether into an explanation of the single particle, two slit, diffraction pattern phenomenon. This book doesn't just allude to the ether in theory, but illustrates the testing procedures used by some Japanese researchers into the single particle, two slit, diffraction pattern phenomenon, showing that a ghost particle is apparently formed in the ether, and how they identify it. The name of the book, slightly inappropriate, because it does not elaborate very much about the general nature and "habits" of the referenced ether, is "Return of the Ether". The author is Sid Deutsch, an electrical engineer, and Fellow of the Institute of Electrical and Electronic Engineers. The book is published by Scitech Publishing, and can be had through regular channels, or at www.scitech.com, for about 25 dollars.
It's rather hard, I think, for anyone to put the current theory of gravity into a nut shell on a web discussion forum. There are many good books which come near to doing that though, of which one is The Elegant Universe, by Brian Green, for about 15 dollars.
I hope I have provided you a little food for thought about gravity even though I haven't provided you with any positive instruction you can build on.
Decent, knowledgeable post, Fairfield.
Welcome on board.
07-24-01, 01:35 PM
According to the book "The elegant universe," special reletivity describes gravity as a curving of time and space. Any mass in space will curve time and space - the more massive the more distortion. Most people have to notion that gravity is a specific force, like push and pull, due to the lingering newtonian theory of gravity which conflicted with Einstein's theory of relativity.
yeah.... like fairfield said, read the book...
I'd like to nuance your post a bit: Gravity *isn't* the curvature of spacetime, it is described as the curvature of spacetime. Einstein's theory of general relativity is a theory, not a fact.
(That's what happens if you start saying Newtonian gravity is just a theory ;)).
07-30-01, 12:53 AM
Thanks for catching me napping regarding gravitational force. I did like you said, and (re)read parts of Brian Greene's book. I also reread Einstein's book, Relativity (for the general public). They're not the same.
My statement that "Einstein had managed to describe the force of gravity as a secondary consequence of a change in the metrics of space around material bodies" was an erroneous statement based on my lazy minded interpretation of Brian Greene's interpretation of an alleged Einsteinian theory of the cause of gravity. Furthermore, my translation of "curved space" into a graduated decreasing density of space was also a lazy minded error because that was neither a proper translation of Greene's intended meaning, nor an accepted version, by anybody, of the metrics of space in a gravitational field.
However, it appears to me that Brian Greene's version of Einstein's work with gravity is also false, because in my rereading of Einstein,s book, "Relativity" I can find no statement regarding the cause of gravity, only statements regarding an improved theory of the metrics of gravity. In the entire book Einstein uses the word "curved", in reference to space, only once, and that in an Appendix. There he encloses the word in parentheses to indicate that it is used only as a figure of speech.
I size up the gravity information picture like this:
Gravitational Force at point x = Its Mass X Distance of motion ["space"] /Time (squared). In Newtonian physics only Distance was considered to be a variable. In Einsteinian physics all three factors are considered to be variables, and it takes a particular formula to work them out.
Since, in both cases, there are identifiable quantities of force involved, you can't say there is no longer any old fashioned "Newtonian" push-pull involved, because these terms are just common, or primitive, substitute words for the word force.
If some people want to say that gravitational force is due to some alterations of space around material bodies, that's ok. Newton never proved that gravity originated inside of bodies. So pick your own preference. Personally, I'm currently betting on a vertically descending dynamic ether wind.
I am only a casual observer of the physics scene, so I welcome corrections.