seriously disabled Posted March 1, 2010 Share Posted March 1, 2010 Hi everyone, I have a question relating to gafferuk's but probably a more fundamental one. Don't get me wrong. My math skills are completely lacking in this area and I still haven't reached the chapter of trigonometry and vectors in my college algebra textbook. So please if you could provide an answer which is not mathematically rigorous as possible that would be appreciated. According to Newton's first law, it takes a force to make a massive object to start moving from a rest position. If an object starts moving by a force from a rest position, it will keep moving unless stopped or slowed down by some kind of force such as friction or gravity for example. So my question is this: How did the planets, the sun and the galaxies start moving, rotating and spinning around their axes in the first place? An object with such a high mass such as the sun surely needs a huge amount of energy to start moving at the speed it does now. Even we, as advanced as we are, don't have an energy source so great as to move a star as large as the sun in such a great speed. So what is the current accepted theory of how the sun, the planets and galaxies started moving in the first place and how did they reach such great speeds? Link to comment Share on other sites More sharing options...
Mr Skeptic Posted March 1, 2010 Share Posted March 1, 2010 The gist of it is that the solar system formed from a rotating cloud of debris. This is why the spin of individual planets is in the same direction as the spin of the system overall. Link to comment Share on other sites More sharing options...
Sisyphus Posted March 1, 2010 Share Posted March 1, 2010 You have a Newtonian force in gravity. Unless the entire universe is precisely uniform and balanced, gravity will get things moving. And a big cloud of dispersed matter can build up a whole lot of acceleration as it collapses over huge distances, and conservation of angular momentum means things get spinning fast as they get more compact, like a figure skater pulling his arms in, only multiplied by billions of times. Link to comment Share on other sites More sharing options...
seriously disabled Posted May 3, 2010 Author Share Posted May 3, 2010 Questions like this have always bothered me: why the universe is the way it is and not some other way. Some of these questions are, for example: What is the reason behind inertia (Newton's First Law of motion)? Why are the electron and proton opposites and why do opposites attract at all? Why is the electron's charge -1 and the proton's +1? What tells light that it always needs to travel at speed c? Link to comment Share on other sites More sharing options...
PaulS1950 Posted May 3, 2010 Share Posted May 3, 2010 The problem here is that you have to accept that it was already in motion before it formed. The rotation began as the system started to compress from a gas and debris cloud into a solar system. Link to comment Share on other sites More sharing options...
seriously disabled Posted August 17, 2010 Author Share Posted August 17, 2010 You have a Newtonian force in gravity. Unless the entire universe is precisely uniform and balanced... What do you mean by 'uniform and balanced'? How exactly did gravity cause the sun and the planets to gain so much angular momentum? Link to comment Share on other sites More sharing options...
bob000555 Posted August 17, 2010 Share Posted August 17, 2010 Questions like this have always bothered me: why the universe is the way it is and not some other way. You’re falling into a common fallacy regarding probability. It’s the same fallacy used by religious types to argue that there must be a God and it goes along these lines: “This particular arrangement of mater and of the laws of physics is incredibly unlikely.” This is, of course, true, but the problem comes when we attach a certain reverence to this importability. The religious use it as proof of a plan which the use to imply a creator. The fact is, even though this particular arrangement of the universe is unlikely it had to have some arrangement and each arrangement is equally unlikely. Think of it as a raffle with many entries: one of them will win even though each one is unlikely to win. The one that ends up winning was no more or less unlikely to win then any other. What do you mean by 'uniform and balanced'? How exactly did gravity cause the sun and the planets to gain so much angular momentum? A uniform and balanced universe would be a homogeneous universe with all areas having the same density. Even in such a universe given enough time areas of higher relative density would emerge via Brownian motion. These areas would then exert a gravitational force and attract surrounding material becoming even more dense and making their gradational fields even stronger leading to a snowball effect of sorts. Link to comment Share on other sites More sharing options...
TheTheoretician Posted August 17, 2010 Share Posted August 17, 2010 Well, the correct answer to the first question in the OP will never emerge from science. I'm dissing myself as a scientist as I write that, but there's no way around it. Only the correct theory will answer it. And very few, upon hearing the True Answer, are willing to accept it. Peace, Ik Link to comment Share on other sites More sharing options...
pioneer Posted August 17, 2010 Share Posted August 17, 2010 The answer has to do with an exothermic output caused by the lowering of gravitational potential. The original cloud of stella gas has a very high level of entropy or disorder. The force of gravity lowers this high level of entropy by increasingly restricting the matter into zone(s) of space/time. The result is a release of the energy that was in the higher starting entropy. This energy output increases the entropy elsewhere within the system and shows up as rotations and orbits. An orbit means kinetic energy that can counter gravity; acts like pseudo-antigravity. Once the system reaches steady state, inertia within the motion keeps the orbits and rotations going, unless they are acted upon by a force. Link to comment Share on other sites More sharing options...
swansont Posted August 18, 2010 Share Posted August 18, 2010 The answer has to do with an exothermic output caused by the lowering of gravitational potential. The original cloud of stella gas has a very high level of entropy or disorder. The force of gravity lowers this high level of entropy by increasingly restricting the matter into zone(s) of space/time. The result is a release of the energy that was in the higher starting entropy. This energy output increases the entropy elsewhere within the system and shows up as rotations and orbits. An orbit means kinetic energy that can counter gravity; acts like pseudo-antigravity. Once the system reaches steady state, inertia within the motion keeps the orbits and rotations going, unless they are acted upon by a force. Um, no. To pretty much all of this. Link to comment Share on other sites More sharing options...
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