FROG3D Posted May 24, 2006 Share Posted May 24, 2006 How can you move in space when there's no matter to push on? Any ideas? And I was also wondering what kind of force or technique can escape a black hole? Thanks, FROGGIE Link to comment Share on other sites More sharing options...
ydoaPs Posted May 24, 2006 Share Posted May 24, 2006 How can you move in space when there's no matter to push on? Any ideas?throw stuff away from you in the opposite direction you want to move. And I was also wondering what kind of force or technique can escape a black hole?it's not possible. if it were, it wouldn't be a black hole Link to comment Share on other sites More sharing options...
Cap'n Refsmmat Posted May 24, 2006 Share Posted May 24, 2006 How can you move in space when there's no matter to push on? Any ideas? yourdadonapogos is right. You may want to look up Newton's Third Law to see what he means; rockets are based on this principle. And I was also wondering what kind of force or technique can escape a black hole? Thanks' date=' FROGGIE[/quote'] Nothing can escape a black hole when it gets too close. There's an imaginary line known as the "event horizon" that simply says "if you go past this line, you will never get out." Link to comment Share on other sites More sharing options...
dirtyamerica Posted May 24, 2006 Share Posted May 24, 2006 How can you move in space when there's no matter to push on? Any ideas? Do what I would do.....flatulate. Seriously. Link to comment Share on other sites More sharing options...
ydoaPs Posted May 24, 2006 Share Posted May 24, 2006 Do what I would do.....flatulate. Seriously. not enough mass or acceleration to do any good.....unless... Link to comment Share on other sites More sharing options...
dirtyamerica Posted May 24, 2006 Share Posted May 24, 2006 not enough mass or acceleration to do any good.....unless... ....hehe, if you only knew. A small push by a fart would propell a body through space. You'd probably just end up doing back flips though. Link to comment Share on other sites More sharing options...
ydoaPs Posted May 24, 2006 Share Posted May 24, 2006 VERY slowly Link to comment Share on other sites More sharing options...
concrete_hed Posted May 24, 2006 Share Posted May 24, 2006 How do satellites stay pointing in the correct position? In movies, it seems as if a small amount of gas is released in one direction to move the satellite in the other direction. Could you build an engine to work in space that uses compressed air? Link to comment Share on other sites More sharing options...
sabbath Posted May 24, 2006 Share Posted May 24, 2006 don't satellites maintain orbital speed so they don't get out of orbit? it's basically gravity and the right acceleration keeping it afloat...umm right? Link to comment Share on other sites More sharing options...
concrete_hed Posted May 24, 2006 Share Posted May 24, 2006 Yes but im talking about the direction that the satellite is pointing, eg the solar panels have to be pointed towards the light source. Link to comment Share on other sites More sharing options...
insane_alien Posted May 24, 2006 Share Posted May 24, 2006 Yes but im talking about the direction that the satellite is pointing, eg the solar panels have to be pointed towards the light source. they use an RCS (reaction control system) for this or have the pannels on a gimbal system if the sattelite has to point down at earth(telecommunication systems) if it doesn#t then the sattelite will not rotate much if left alone. Link to comment Share on other sites More sharing options...
swansont Posted May 24, 2006 Share Posted May 24, 2006 Do what I would do.....flatulate. Seriously. Only helps if you aren't wearing a spacesuit. If you are, I imagine it's ghastly. Link to comment Share on other sites More sharing options...
timo Posted May 24, 2006 Share Posted May 24, 2006 Yes but im talking about the direction that the satellite is pointing, eg the solar panels have to be pointed towards the light source. I don´t know much about that but at least I remembered a name associated to steering of satelites, so maybe start your search from here: http://en.wikipedia.org/wiki/Control_Moment_Gyroscope Link to comment Share on other sites More sharing options...
Neil9327 Posted May 24, 2006 Share Posted May 24, 2006 How can you move in space when there's no matter to push on? Any ideas? And I was also wondering what kind of force or technique can escape a black hole? Thanks' date=' FROGGIE[/quote'] It should be noted though that if the type of motion you want to achieve is a rotation (rather than a linear motion) this can be done without anything to push against. As an example of this, try dropping a cat upside-down from a height. It will right itself and land on its feet using this principle. (no DON't try this yourself. Your cat may be stupid) Link to comment Share on other sites More sharing options...
swansont Posted May 24, 2006 Share Posted May 24, 2006 It should be noted though that if the type of motion you want to achieve is a rotation (rather than a linear motion) this can be done without anything to push against.As an example of this' date=' try dropping a cat upside-down from a height. It will right itself and land on its feet using this principle. [/quote'] Not exactly. Linear motion doesn't require anything to "push against" either — that's not the principle involved in a rocket. It's conservation of momentum, and action/reaction, from Newton's third law. And rotation has its own application of Newton's laws. Absent any torque, angular momentum is conserved. A nonrotating rigid object cannot start spontaneously rotating. A cat, however, is not a rigid object; it does its reorientation without having any angular momentum by twisting different parts of its body having different moments of inertia. The rotation of part of an object, like a satellite, can be achieved by rotating another part in the opposite direction, which conserves angular momentum. Link to comment Share on other sites More sharing options...
<Valcrum_x> Posted May 24, 2006 Share Posted May 24, 2006 Not exactly. Linear motion doesn't require anything to "push against" either — that's not the principle involved in a rocket. It's conservation of momentum' date=' and action/reaction, from Newton's third law.[/quote'] I agree with swansont, it's a simple matter of action-reaction, as stated in Newton's Third Law...Eventhough space is "Empty" it's not a vacuum and therefore has "matter to push against". Perhaps a more simplified example of the action-reaction is the recoil of a gun when it's fired, the speed at which the bulllet leaves the gun woul cause an equally large reaction opposing the original action. Link to comment Share on other sites More sharing options...
Genecks Posted May 24, 2006 Share Posted May 24, 2006 Should this be in biology? Despite the aeronautical and physical concepts, one would need a type of thrust. Such a thrust would come from an external device, unless one could manage to move the human body very quickly. In such a scenario, however, the human body would not get any where any time soon. Since planets are light-years away, the closest possible area to get to would most likely be a satellite of a planet or some rock somewhere, in some place in space. I would believe that a type of push, from an external device, would be very necessary. Link to comment Share on other sites More sharing options...
FROG3D Posted May 24, 2006 Author Share Posted May 24, 2006 Thanks guys! Wow, those were great! I'm still wondering if my organism can escape the black hole? It doesn't have to be perfect, but it has to make SOME kind of sense. Can quantum tunnelling work? Thanks again, FROGGIE Link to comment Share on other sites More sharing options...
Mach Posted May 24, 2006 Share Posted May 24, 2006 ^ i really dont think so because the force is so immense that not even light can escape Link to comment Share on other sites More sharing options...
Genecks Posted May 24, 2006 Share Posted May 24, 2006 One would have to reach past multiple stages of mental enlightenment. This has not really been recorded scientifically; therefore, it is not possible to escape a black hole as of lately; this is according the the individual being alone in space without external devices. Or at least not many people know about a current possible scientific procedure. Link to comment Share on other sites More sharing options...
Neil9327 Posted May 25, 2006 Share Posted May 25, 2006 Not exactly. Linear motion doesn't require anything to "push against" either — that's not the principle involved in a rocket. It's conservation of momentum' date=' and action/reaction, from Newton's third law. And rotation has its own application of Newton's laws. Absent any torque, angular momentum is conserved. A nonrotating rigid object cannot start spontaneously rotating. A cat, however, is not a rigid object; it does its reorientation without having any angular momentum by twisting different parts of its body having different moments of inertia. The rotation of part of an object, like a satellite, can be achieved by rotating another part in the opposite direction, which conserves angular momentum.[/quote'] But the point I'm trying to make is that the cat IS able to turn in mid air to change the direction it is pointing in space. Which is relevant to the original poster's question. Do a google on "drop cat feet angular momentum" for explanations as to how the cat's angular momentum remains at zero while it spins its feet one way and turns its body the other etc. Link to comment Share on other sites More sharing options...
bascule Posted May 25, 2006 Share Posted May 25, 2006 throw stuff away from you in the opposite direction you want to move. This isn't the only way. For example, you could use an inertial drive Link to comment Share on other sites More sharing options...
ydoaPs Posted May 25, 2006 Share Posted May 25, 2006 One would have to reach past multiple stages of mental enlightenment. :confused: Link to comment Share on other sites More sharing options...
Genecks Posted May 25, 2006 Share Posted May 25, 2006 The metaphysical side of person biology. The inquiry was about how an individual could move in space. However, the topic was set in biology and not engineering, physics, or other. Therefore, I gave a response that would be attributed to the humans on the planet. ..oh.. it moved to the physics board. Link to comment Share on other sites More sharing options...
SkepticLance Posted May 25, 2006 Share Posted May 25, 2006 How does one move in space? As others have said, by throwing something in the opposite direction - the principle of the rocket. The force from this is equal to mass times velocity squared. Mass. the more you throw, the more you move. Velocity. the faster you throw, the faster, squared, you move. What this means, is that the best means of moving in vacuum is to fire mass in the opposite direction at enormous speed. Current Earth to orbit spacecraft tend to work the wrong way. They depend on lots of mass rather than lots of velocity in their exhaust (what is thrown away). A really efficient space craft will fire lots of mass, but at enormous velocity. The fastest speed achievable, for the matter thrown away, is close to the speed of light. Thus, the best rocket for the vacuum of space is a linear accelerator, that fires heavy atoms such as Xenon at close to the speed of light. Over a period of time, this will permit the rocket to accelerate in the opposite direction to very high speed. How does one escape a black hole. As the very first reply said, it is impossible. To be in a black hole, by definition, means being inside the event horizon. Once you are there, you are gone. In fact, you will be torn apart by tidal forces as you spiral down into the singularity. Link to comment Share on other sites More sharing options...
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