What this Universe would have been if there were no gravity?
in [Relativity]
|
Prev: A nomenclature puzzle about gradients, divergences and fields
Next: Newton's law of gravitational attraction
From: Jonah Thomas on 26 Sep 2009 11:14 BradGuth <bradguth(a)gmail.com> wrote: > w/o gravity atoms would still be atoms. Obviously you got a problem > with that. It makes sense that we'd get some kind of universe if we didn't have the visible effects of gravity. But what about the invisible effects we don't understand? We really aren't in a position to decide about those. It's like, in euclidean geometry you can remove any one of the axioms and then you can have different geometries, that are different in fundamental ways. But if you remove a theorem and not the axioms that prove it then you have problems.... Is gravity more like an axiom or is it more like a theorem? Is it something that gets tacked on separate from everything else important or is it a consequence of something more fundamental? I don't know the answer to that, so I don't know how the universe would be different without it. This is a variation on a fundamental question which is very hard to answer in general. "How would the world be if it was different from the way it is now?" Historical science fiction is dedicated to this question. What would have been different if Lincoln had not been shot but everything else to that point was the same? What if the south had won the civil war? What if the nazis had developed the atomic bomb? What changes would inevitably have to happen if something was different? Libertarian science fiction also deals with this. Given a society which is not a libertarian utopia, which government action has done most to prevent us from being a libertarian utopia? How does government prevent people from freely cooperating? How would a libertarian society inevitably work if government was not there to prevent it? The question of what the world would have to be like if it was different has inspired a lot of deep thinking.
From: Sanny on 26 Sep 2009 12:20 > w/o gravity there is no such thing as up or down, not that atoms or > whatever matter of zero gravity would care. > > w/o gravity, perhaps solar systems and galaxies would be more like > large atoms, instead of forming flat disk like. Perhaps everything > becomes round, spherical or balloon like. Without Gravity the Universe would be like Spiders web. As Gravity pulls masses and joins them. Without gravity everything will be like gaseous state. Just like Gases has little effect of gravity. They move arround. Simmilarly every object will fly. More like an astronaut in SpaceShip flying. Bye Sanny The Computer chats like Humans. Believe it???:http://www.GetClub.com Now you believe it. What do you say?
From: BradGuth on 26 Sep 2009 12:46 On Sep 26, 8:14 am, Jonah Thomas <jethom...(a)gmail.com> wrote: > BradGuth <bradg...(a)gmail.com> wrote: > > w/o gravity atoms would still be atoms. Obviously you got a problem > > with that. > > It makes sense that we'd get some kind of universe if we didn't have the > visible effects of gravity. > > But what about the invisible effects we don't understand? We really > aren't in a position to decide about those. > > It's like, in euclidean geometry you can remove any one of the axioms > and then you can have different geometries, that are different in > fundamental ways. But if you remove a theorem and not the axioms that > prove it then you have problems.... > > Is gravity more like an axiom or is it more like a theorem? Is it > something that gets tacked on separate from everything else important or > is it a consequence of something more fundamental? > > I don't know the answer to that, so I don't know how the universe would > be different without it. > > This is a variation on a fundamental question which is very hard to > answer in general. "How would the world be if it was different from the > way it is now?" > > Historical science fiction is dedicated to this question. What would > have been different if Lincoln had not been shot but everything else to > that point was the same? What if the south had won the civil war? What > if the nazis had developed the atomic bomb? What changes would > inevitably have to happen if something was different? > > Libertarian science fiction also deals with this. Given a society which > is not a libertarian utopia, which government action has done most to > prevent us from being a libertarian utopia? How does government prevent > people from freely cooperating? How would a libertarian society > inevitably work if government was not there to prevent it? > > The question of what the world would have to be like if it was different > has inspired a lot of deep thinking. You mean the undetectable effects that we don't currently understand would likely be as unknown and/or misunderstood as they are now. Big deal, and thus no great loss. ~ BG
From: BradGuth on 26 Sep 2009 12:49 On Sep 26, 9:20 am, Sanny <softtank...(a)hotmail.com> wrote: > > w/o gravity there is no such thing as up or down, not that atoms or > > whatever matter of zero gravity would care. > > > w/o gravity, perhaps solar systems and galaxies would be more like > > large atoms, instead of forming flat disk like. Perhaps everything > > becomes round, spherical or balloon like. > > Without Gravity the Universe would be like Spiders web. > > As Gravity pulls masses and joins them. Without gravity everything > will be like gaseous state. > > Just like Gases has little effect of gravity. They move arround. > Simmilarly every object will fly. > > More like an astronaut in SpaceShip flying. > > Bye > Sanny > > The Computer chats like Humans. > Believe it???:http://www.GetClub.com > Now you believe it. What do you say? There would still be solids, fluids and gaseous forms to deal with. Just the shaps and densities of most everything would become different w/o gravity. ~ BG
From: Jonah Thomas on 26 Sep 2009 14:12
BradGuth <bradguth(a)gmail.com> wrote: > Jonah Thomas <jethom...(a)gmail.com> wrote: > > BradGuth <bradg...(a)gmail.com> wrote: > > Is gravity more like an axiom or is it more like a theorem? Is it > > something that gets tacked on separate from everything else > > important or is it a consequence of something more fundamental? > > > > I don't know the answer to that, so I don't know how the universe > > would be different without it. > You mean the undetectable effects that we don't currently understand > would likely be as unknown and/or misunderstood as they are now. Big > deal, and thus no great loss. No, I mean the unknown connections. It's like, say you asked what would be different about the earth if its orbit around the sun was rectangular instead of elliptical. You could make a list of what differences that would make. Like, the seasons would be special at the corners. There might be some dislocations in angular momentum then, too. But you could figure that the earth wouldn't be radically different, even if the moon had a rectangular orbit too, the effects would be kind of subtle. But the changes in the laws of physics that would support rectangular orbits -- are you up to figuring out the implications of that? And do you think they would be no big deal just because you don't understand them? If gravity is something you can just turn off and nothing else changes, then you might predict what the result would be. But if turning off gravity means you have to adjust everything else to get a universe where fundamental particles still have charge but do not have gravity, then there's no particular reason to assume those adjustments would be undetectable. Just unknown. If we knew how to do it then we'd know what difference it made. But we don't. |