how does gravity travel & how fast is it?
443153
In physics, the graviton is a hypothetical elementary particle that transmits the force of gravity in most quantum gravity systems. In order to do this, one theory posits that gravitons have to be always-attractive (gravity never pushes), work over any distance (gravity is universal) and come in unlimited numbers (to provide high strengths near stars). In quantum theory, these requirements define an even-spin (spin 2 in this case) boson with a rest mass of zero.
123056
The Earth would immediately leave it’s orbit in a direction tangential to the current orbital plane at a velocity equal to it’s current orbital velocity, roughly 11 km/s.  The final path will be modified by the gravitaitonal force of the other solar system bodies, but since the Sun’s gravitational attraction is much greater than the others,  the solar system would just fly apart.  \n\nThere’s no delay in gravity force propagation, so the effects will be instantaneous the moment the gravity is “turned off”.\n\nEDIT:  \n\nmrjeffrey 321:  It is correct.  The information of the sun's gravitational field really does travel faster than the speed of light.  I don't have any vested interest in any particular theory, I prefer to look at the facts and the experimental data.  Ask any astronomer who performs astrometric or planetary position calculations using celestial mechanics.  The positions of the planets are always calculated using instantaneous gravity.  The positions are then corrected for aberration, the visual position error caused by the fact that light is speed limited.  So, we really calculate the actual positions of the planets, and then we correct for where we actually see the light coming from these planets, delayed by the speed of light.\n\nIn fact, if you model the solar system by adding in a delay for "gravity propagation" at the speed of light, the orbits of the planets in the solar system begin to slowly deteriorate.  This is most obvious with observations of certain binary double stars, where any delay in gravity would cause the star pairs to fly apart.  According to actual ephemeris measurements, the Earth is being accelerated to point about 20 arc-seconds ahead of where the sun appears in the sky.  This is because gravity is pulling us instantaneously towards the true position of the sun, not the apparent position we see in the sky.\n\nI'm not an expert on relativity, so I'm not going to argue fine points about what general  or special relativity either does or doesn't say or is interpreted to say.  What matters is the actual evidence, and the evidence says that the effects of gravity are instantaneous.\n\nNote that there was a paper published back in 2003 regarding the measurement of the speed of gravity, which resulted in it being very close to the speed of light.  There are several errors in this paper that were pointed out after publication.  The calculations used were shown to be incorrect.\n\nAn interesting question on this subject is black holes.  If we agree that gravity is a particle or wave, and we agree that nothing, no information, can escape a black hole, then how is it that black holes exhibit gravity? If they are truly so massive that they warp the very fabric of space-time, then how is it that gravity waves can escape when light cannot  If we accept the fact that black holes are "information holes" in the sky, how can they reveal themselves through gravity?
87899
The earth is say assumed to be a perfect sphere.\nSince it rotates around itself, so every point on its surface moves with the same speed which is v say.\nIt traces its whole circumference in 24 hrs.\nIts radius is about 6400 km\nSo maximum distance traced is 2 * 3.14 * 6400\n                           =  40192 km.\n\nFor a plane of mass say m and let mass of earth be M\nvelocity of plane (V) is given by centripedal force.\n\nSo V = (gR)^(1/2)  ...... I agree that this is a bit physics. This is a reference to newton's gravitation law.\ng is acceleration due to gravity. R is radius of earth.\n\nI didn't quite get the second part of your question which involves the plane. But i hope a bit physics may help you. Post your question again systematically. I hope the first part of your question is answered satisfactorily.
537369
If your mass is m, multiply it by g to convert it to N, where, g is the acceleration due to gravity of the place where you currently are.\nFor most of the places on earth, we take the average value of g = 9.81 (m/s)/s.
554157
Here's the rub - nothing can travel through space faster than the speed of light - but since escape velocity (the speed which a body must attain to break free of a gravitaional field) depends on density, if a body of matter is sufficiently dense, the its escape veolcity can exceed the speed of light - meaning that light itself is captured in its gravitational field and cannot break free.
233240
To answer this, it's necessary to review something of the landscape. \n\nForces in the universe have been quite successfully treated as gauge forces, using gauge theories. \n\nSo each of the following forces is a gauge force, as shown by the very successful gauge theories that have been developed to describe them. \n\nstrong nuclear force\nweak nuclear force\nelectical charge force\n\nA 'force transmission particle' (or particles), has been found for each of these, and it is the exchange back and forrh of them which seems to "be" the underlying force between two particles. Some of these particles have mass, some have charge, some have spin, ... Finding these things, and understanding how they work, has earned many a Nobel Prize. \n\nFor gravity, the particle which transfers the force has been called the 'graviton'. But, none (and no sequela attributable only to them) has been observed to date. Gravity should have some wave properties, which might tell us something more about it, but gravity waves have not been observed either. Two large experiments are running now which might turn some up so stay tuned. \n\nEinstein's General Relativity treats gravity as an alteration of the character of spacetime itself, and the alteration is stronger closer to the mass. But, there is no limit on the distance of the alteration in the theory, nor in observational reality, as may be seen by gravitationally predictable behavior across galactic and more than galactic distances. Our Local Cluster of galaxies is an example, as they seem to be responding to each others' gravitational influence.  \n\nIf gravity is a gauge force, and the graviton exists, then gravity may have a transmission speed, and if so, there's some reason to believe it cannot be faster than light transmission. If it is not a gauge force in the manner of the others, we are dealing with something which may not have a top speed at all. If so the example of the Earth's orbit not noticing the disappearance of the Sun for about 10 minutes might not be very applicable. \n\nShort answer, we don't know how 'fast' gravity is as compared to light, and are still trying to understand fundamental things about gravity and its behavior. Merely being able to send exploring probes to Neptune and Jupiter's moons and Mars and such is not really evidence that we understand the fundamentals involved. \n\nAfter all, there has been quite recent work on the fundamental nature of friction which may turn out to be, finally, an actual understanding of how it works. We've been able to use it for a very long time, even if we didn't really understand quite what it is. Every basketball player understands friction well as a practical matter of not sliding into the crowd, and hockey players manipulate it very carefully to move quickly, or stop more or less quickly, but neither understands much about its fundamnetal nature. After all, we've only just in the last year or so understood how zinc compounds in oil reduce bearing friction (as in car engines) as they most certainly do. \n\nObviously, science has quite a long ways to go in explaining even some everyday phenomena. It's the nature of the beast.
605786
When a spacecraft is in orbit it needs no energy. That's the simple answer. However, you need to get it into orbit in the first place, and this means accelerating the object to the speed it needs to orbit the earth - around 18,000 mph. How much energy you need then depends on the mass of the object or spacecraft - this can be calculated from 1/2 mv^2. \n\nTo escape the earths gravity altogether the spacecraft needs to go faster, about 25,000 mph or 7 miles per second. So if you were going to Mars for example, once you achieve that speed you need no more energy.
426497
Everything travels in a straight line unless acted upon by an outside force.\n\nMore precisely, everything travels at the same velocity (speed and direction) unless acted upon by an outside force.
172926
The others gave the correct answer overall, but got the details wrong.  All objects accelerate, when dropped in free fall near the surface of the earth, at 9.8 meters/second/second (not 9.8 inches/s or 9.8 miles/hour).\nThe reason heavier object don't fall faster is that, although they have more weight, i.e. more gravity pulling on them, they also have more mass, i.e. more "inertia", which is the resistance of objects to being accelerated.  The two things exactly cancel out; isn't that convenient?  \n\nBtw, the reason why they cancel out, that is, the reason why the mass that shows up in the formulas for gravity is the same quantity that shows up as inertia in Newton's laws, was not fully solved until Einstein, but the fact that they do was known to Galileo.
1044543
General Theory of Relativity:\n\nA mass in space creates an indention much like a bowling ball on a trampoline.  Its this indention that is the cause of gravity.  If a marble were to roll across the trampoline into that indention, it would take a curve path and eventually fall into the bowling ball.  This is what happens when you fall to the Earth: your body is in a sense sliding on the curvature of space-time.
125809
The struggle here is that you provide too little information to recognize this problem as coherent.\n\nWe may assume that the acceleration of gravity is 9.8 m/s/s or 32 ft/sec/sec.\n\nThe velocity(V) of an object is equal to its initial velocity(v) plus its acceleration(a) times time(t). \nV = v + at or V = v - 32t (in feet per second)\n\nYour object will reach maximum height when the velocity is zero or when the initial velocity is equal to 32 ft/sec/sec * time. With your list of times, you'd just multiply by 32 to solve for the initial velocity, if that is what the problem is actually looking for. There are many other permutations of this data, but hopefully that is a start for you.\n\nGood luck.
343175
the surface of earth moves at a very high speed. (~ 1674 km/h)\n\n(2 * pi * 6400 km)/ 24 hours\n\nBut the atmosphere surrounding the earth also moves with same speed. So it keeps us dragging the person who jumps and make sure he falls "vertically" at the same place.\n\nIf there is no atmosphere around a planet and if you jump there from helicopter, you can feel the difference.\nOn this planet, if you jump from ground, you will move along with planet because of Newton's first law. (similar to throwing a ball up in a travelling car. the ball will travel along with car)
943563
I have no clue of any, but I know that the escape velocity of Earth (the speed of which it takes to escape Earths gravity) is 25,000 mph. Try launching six and a half tons 25,000mph!=)
844498
You have uncovered one of the secrets of the universe. Simple Harmonic Motion (SHM) surrounds us in every aspect of the universe. It is the lowest common denominator. Even Newton got it slightly wrong in his First Law where he said that a body will continue in uniform motion until an external force acts upon it. There is nowhere in the known universe that gravity does not exist.\n\nConsider an air table which is flat and which extends in all directions by a million miles, and it rests on the earth. place a puck on it and give it a gentle nudge. It will move off in the direction you push it at an apparently constant velocity, however it will eventually stop and return to the point where it started because of the earth's gravitational field. It will shoot past and head off in the opposite direction until it stops again, being pulled back by the earth's gravitational field. It will continue this way forever (ignoring all friction), oscillating in simple harmonic motion. \n\nNewton's problem was that he was restricted to observing a very small portion of the SHM path, so it seemed linear.\n\nAnyway, congratulations, you are on the path to unlocking the secrets of the universe.
303004
I've just read that the gravity on the sun is 28 times greater than the Earth.\n\nIt is gravity that keeps satellites and space stations in an orbit around the Earth, at least if that orbit does not intersect the Earth, because then they would crash, and if that orbit isn't too low above the Earth, because then they'd be slowed down by friction with the outermost layers of the atmosphere of the Earth, and then they'd fall down after all. Gravity also keeps the Moon in its orbit around the Earth, and the Earth and the other planets and comets and asteroids in an orbit around the Sun, and the Sun in an orbit around the centre of the Milky Way Galaxy.
1043854
This is a cool question.  If you were able to tunnel through the Earth, and fall through, your speed would keep increasing until you reached the graviational center.  At that point, the net gravitational force is zero, because all of the forces cancel.  However, you wouldn't just stop because of your inertia.  You would go right through, but then you would begin to slow down, until you reached the other hole.  Depending on how high you started from the first hole, and lets say you jumped five feet above the hole, you would come to a complete stop five feet above the second hole.  Then you would fall back through and continue that cycle.  (Of course we aren't considering air resistance, which screws everything up! ;0)\n\nGuess how long it would take to make it to the other side of the Earth through that tunnel?  Approximately 42 minutes!  Not a bad way of traveling.\n\nThe other cool thing is, if you were to tunnel from say New York to Berlin, which means the tunnel isn't obviously through the middle of the Earth, it would still take you 42 minutes!
475251
If I remember correctly from my high-school physics class, it's a combination of gravity and one of Newton's laws of motion - the one that says "an object in motion stays in motion unless acted on by an outside force." So that force keeps it moving around and gravity keeps it from just flying off into space.