Super Genius
Posts: 1,132 
Location: Montreal
Location: Montreal
August 28th, 2007, 07:09 PM
Geez that's almost addicting... but it does help me understand gravity...
Quoting hermanntrude
Here's a fun little flash game
Geez that's almost addicting... but it does help me understand gravity...
Super Genius
Posts: 1,132
Location: Montreal
Location: Montreal
August 28th, 2007, 07:14 PM
So most of the posters seem to agree gravity is not a force but rather the result from spacetime curvatures...
I heard about a theory concerning gravitons... Anyone know about this? It seems to suggest their would actually exist some massless particles that are responsible for gravity... What does that have to do with spacetime curvatures?
Does anyone really know what gravity is?
So most of the posters seem to agree gravity is not a force but rather the result from spacetime curvatures...
I heard about a theory concerning gravitons... Anyone know about this? It seems to suggest their would actually exist some massless particles that are responsible for gravity... What does that have to do with spacetime curvatures?
Does anyone really know what gravity is?
Genius
Posts: 929
August 28th, 2007, 11:59 PM
By the way, what is the goal of that game? It's fun to try to get a few of them in orbit around the middle one, and then smash into eachother.
Quoting s_lone
Wow, that really is addictive.
Geez that's almost addicting... but it does help me understand gravity...
By the way, what is the goal of that game? It's fun to try to get a few of them in orbit around the middle one, and then smash into eachother.
Super Genius
Posts: 1,132
Location: Montreal
Location: Montreal
August 29th, 2007, 12:30 AM
If you play around with the parameters you can really get some weird cosmic dancing going... Makes you wonder what kind of weird cosmic choreographies are going on out there...
Quoting gc
I don't think there's any goal apart from doing godly experiments...
Wow, that really is addictive.
By the way, what is the goal of that game? It's fun to try to get a few of them in orbit around the middle one, and then smash into eachother.
By the way, what is the goal of that game? It's fun to try to get a few of them in orbit around the middle one, and then smash into eachother.
If you play around with the parameters you can really get some weird cosmic dancing going... Makes you wonder what kind of weird cosmic choreographies are going on out there...
Clever Clogs
Posts: 519
May 9th, 2008, 08:12 PM
Gravitons are also supposed to move at the same speed as photons, meaning if the sun suddenly dissappeared the Earth would still orbit around the center of the solar system for about 8 minutes then shoot off into interstellar space.
Quoting s_lone
I think gravitons are the force carrier for gravitation just like photons are the force carrier for electromagnetism.
So most of the posters seem to agree gravity is not a force but rather the result from spacetime curvatures...
I heard about a theory concerning gravitons... Anyone know about this? It seems to suggest their would actually exist some massless particles that are responsible for gravity... What does that have to do with spacetime curvatures?
Does anyone really know what gravity is?
I heard about a theory concerning gravitons... Anyone know about this? It seems to suggest their would actually exist some massless particles that are responsible for gravity... What does that have to do with spacetime curvatures?
Does anyone really know what gravity is?
Gravitons are also supposed to move at the same speed as photons, meaning if the sun suddenly dissappeared the Earth would still orbit around the center of the solar system for about 8 minutes then shoot off into interstellar space.
Knows No Bounds
Posts: 3,398 
Videos: 2
Location: 50° 30' N, 104° 38' W
Videos: 2
Location: 50° 30' N, 104° 38' W
June 24th, 2008, 01:39 AM
No, I think nobody *really* knows what gravity is. Actually I think that in a fundamental sense nobody really knows what anything is, all we've really got is mathematical descriptions that work within certain limits . Newton conceived of gravity as a force related to the masses and distances involved, but was never happy with the "action at a distance" that his formulation implied, though his analysis has been spectacularly successful and is still widely used. Einstein resolved Newton's concerns by conceiving it as a warping of space caused by the presence of mass: mass changes the shape of space and objects moving in response to gravity are simply following space's contours, much as you have to follow the contours of the land when you drive or walk around on it.
But I don't think that really makes it any clearer to anybody. And there's a fundamental problem. General relativity and quantum theory are deeply inconsistent. All quantum interactions mathematically take place in the flat Minkowski space-time of special relativity, which according to general relativity is not the true shape of space, and general relativity implicitly assumes that all physical quantities, like mass and energy and time and distance and whatnot, are infinitely divisible, while quantum theory says that's not so, the universe is grainy on the smallest scales. Yet every testable prediction both theories make has been borne out by experiment to an unprecedented level of accuracy. Quantum theory strongly implies there should be a graviton, a particle that mediates gravitational effects just as photons mediate electromagnetic effects, but gravitons and their associated waves, which quantum theory also strongly implies must exist, have never been detected.
Clearly we're missing something. Some version of string theory may or may not resolve this, the jury's still out on that, but my personal feeling is that reality, whatever it is, is fractal in nature, in the sense that it'll display the same degree of complexity no matter what scale we inspect it at. It's already clear from quantum theory, for instance, that reality is what the physicists describe as "non-local," which in practical terms means that some information somehow gets around at effectively infinite speeds, but there's no way to use it for signaling. Google for Bell's Theorem, for instance, and you'll see what I mean. Or if your mathematical sophistication is up to it, look at the equations of quantum theory and relativity, or just take my word for it, and you'll see that time has no preferred direction except in a few very specific and rare quantum interactions. Positrons (=the anti-matter versions of electrons), for instance, which unquestionably exist, mathematically are equivalent to an electron with negative mass and energy moving backwards in time.
There are deep mysteries here, and there is much we do not understand. Maybe Niflmir can figure it all out for us...
No, I think nobody *really* knows what gravity is. Actually I think that in a fundamental sense nobody really knows what anything is, all we've really got is mathematical descriptions that work within certain limits . Newton conceived of gravity as a force related to the masses and distances involved, but was never happy with the "action at a distance" that his formulation implied, though his analysis has been spectacularly successful and is still widely used. Einstein resolved Newton's concerns by conceiving it as a warping of space caused by the presence of mass: mass changes the shape of space and objects moving in response to gravity are simply following space's contours, much as you have to follow the contours of the land when you drive or walk around on it.
But I don't think that really makes it any clearer to anybody. And there's a fundamental problem. General relativity and quantum theory are deeply inconsistent. All quantum interactions mathematically take place in the flat Minkowski space-time of special relativity, which according to general relativity is not the true shape of space, and general relativity implicitly assumes that all physical quantities, like mass and energy and time and distance and whatnot, are infinitely divisible, while quantum theory says that's not so, the universe is grainy on the smallest scales. Yet every testable prediction both theories make has been borne out by experiment to an unprecedented level of accuracy. Quantum theory strongly implies there should be a graviton, a particle that mediates gravitational effects just as photons mediate electromagnetic effects, but gravitons and their associated waves, which quantum theory also strongly implies must exist, have never been detected.
Clearly we're missing something. Some version of string theory may or may not resolve this, the jury's still out on that, but my personal feeling is that reality, whatever it is, is fractal in nature, in the sense that it'll display the same degree of complexity no matter what scale we inspect it at. It's already clear from quantum theory, for instance, that reality is what the physicists describe as "non-local," which in practical terms means that some information somehow gets around at effectively infinite speeds, but there's no way to use it for signaling. Google for Bell's Theorem, for instance, and you'll see what I mean. Or if your mathematical sophistication is up to it, look at the equations of quantum theory and relativity, or just take my word for it, and you'll see that time has no preferred direction except in a few very specific and rare quantum interactions. Positrons (=the anti-matter versions of electrons), for instance, which unquestionably exist, mathematically are equivalent to an electron with negative mass and energy moving backwards in time.
There are deep mysteries here, and there is much we do not understand. Maybe Niflmir can figure it all out for us...
