Relativity theory changed Newton's Universal gravity constant/?is there a space time constant?
598835
Newton's gravitational constant (G) hasn't changed one bit because of Relativity (and is in fact one of only two constants in GR the other being the cosmological constant (Λ) which was thought to be zero but is now known not to be).\n\nThough I don't think there would be any meaning of a ratio between G and Λ
5325
Gravity changes the structure of space-time continum..Thus the linear propagation of light is affected by gravity..\n Light don,t have mass.It changes it's path in a gravitational field not due to it's mass but due to the total change in the space-ime structure.
484177
In simpler words: special theory of relativity is just a special case of the general theory!\n\nGeneral theory of relativity deals with accelerated frames of reference. In other words when we have the 'acceleration not equal to zero' (e.g. gravitational acceleration), we use general theory. That is why this is mainly a 'theory of gravity'. One special case for this can easily be when acceleration = 0, and that is the case of special relativity! This is the basic difference between the two theories.\n\nThe other differences could be seen in the postulates of these two theories:\nSpecial theory of relativity postulates:\n1. A frame of reference moving with a constant velocity (i.e., no acceleration) with respect to an inertial frame, is also an inertial frame.\n2. Speed of light in vacuum remains constant in all inertial frames of reference.\n\nGeneral theory of relativity postulates:\n1. In an accelerated frame of reference (with respect to an inertial frame) the spacetime is warped. \nOr, Gravity warps spacetime. \n2. In an accelerated frame of reference (with respect to an inertial frame) the time is dilated. \nOr, Gravity dilates time.\n\n***\nInertial frames: A given region (or coordinate system) where Newton's laws are valid.\nSpacetime: The region in space and time.\nWarped: Distorted\nDilated: Slowed down.
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Nope - Einstein created his cosmological constant in order to preserve the idea of a "static" universe, he felt that a changing (expanding or contracting) universe was unnatural as supported by his equations of gravity, so he created the constant specifically to maintain gravitational equilibrium through the universe as a whole.\n\nNewton's big "G" is just a constant relating the strength of the (far field) gravitational force to the chosen set of units.\n\nAlso, I'm not quite sure which version of the cosmological constant you are citing, as genrally the constant that comes out of the metric goes as:\n\nCosmological Constant = 8(Pi)*(G)*(energy density)
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SPECIAL RELATIVITY (1905) - \n..the laws of physics are the same in all inertial reference frames\n..time dilation\n..length contraction\n..speed of light is invariant\n..e=mc^2\n\nGENERAL RELATIVITY (1907) -\n..theory of gravity\n..acceleration and gravity are equivalents\n..gravity bends the path of light\n..mass curves space-time\n\nGod should be spelled B-I-G B-A-N-G\nPBrax@netscape.com
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Visit this link for a good explanation:\n\nhttp://en.wikipedia.org/wiki/Theory_of_relativity
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Here's some basic background covering how mathematical models of space and time have evolved since ancient times, from the Pythagorean Rule to Newtonian mechanics, Special Relativity and General Relativity.\nhttp://www.theory.caltech.edu/people/patricia/st101.html\n\nEinstein and Special Relativity give us a mathematical model for spacetime that reflects the observed behavior of Nature in that nothing can go faster than the speed of light. (At least not anything observed in a laboratory or in outer space as of yet.) \n\nIn Einstein's time they were already learning about differential geometry, but Einstein motivated this field of mathematics even more when he came up with an equation relating the curvature tensor of the spacetime distance function to the distribution of matter and energy in spacetime, encoded in a tensor Tuv called the stress-energy tensor. \n This equation is now called the Einstein equation: \nRuv - (1/2) guv R = (8 Pi G/c4) Tuv \n This equation (or actually, set of equations, for there is an equation for every combination of tensor indices u and v) models a lot of phenomena in the Universe that was impossible to describe with mathematics just using Newton's law of gravity. For example, observations of the bending of light by gravity, gravitational radiation emitted by pulsars, new observations of black holes and the observed expansion of the visible Universe can all be modelled rather successfully using this elegant formalism uncovered by Einstein.
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The general theory of relativity is much more complex and difficult to understand than the special theory. It proves the force of Gravitation, as proved by Sir Isaac Newton, wrong. According to Newton, gravity was a force between two bodies, which depends on their respective mass and the distance between them. \nThe basic idea of general relativity can be illustrated with the help of an imaginary experiment as performed by Einstein.  Suppose a lift is at rest in space.  If a ball is released within the lift, it will float in space and not fall.  If the lift accelerates upward, an observer within the lift will see the ball fall to the floor exactly as it would under the pull of gravity.  The ball appears to fall because the floor of the lift, as seen from outside the lift, it accelerates upward toward the ball.  All the effects we associate with gravity would be seen by the observer in the lift.  Einstein called the phenomenon shown in this experiment the Principle of Equivalence. This principle states that it makes no difference whether an object is acted on by a gravitational force or is in an accelerated frame of reference.  The result in both cases will be the same.  From this principle, Einstein reasoned that matter in space distorts or "curves" the frame of reference of space. The result of this curvature is what we experience as gravity. The Euclidian or flat geometry was unable to explain the curve, so Einstein used geometries called Riemannian geometry to explain the effect. \nAccording to Newton's theory, a planet moves around the sun because of the gravitational force exerted by the sun.  According to the theory of general relativity, the planet chooses the shortest possible path throughout the four-dimensional space- time, which is deformed by the presence of the sun. This shortest possible path is called a geodesic.  This may be compared to the fact that a ship or an aeroplane crossing the ocean follows the section of a circle, rather than a straight line, in order to travel the shortest route between two points.  In the same way, a planet or light ray moves along the "shortest" line in its four-dimensional world. \nSo far, three things have been discovered in which Einstein's theory of general relativity receives experimental proof as opposed to the theories of Newton.  These differences are not great, but are measurable.  In the first place, according to Newton's theory, the planet Mercury moves in an ellipse about the sun.  According to Einstein's theory, Mercury moves along an ellipse, but at the same time the ellipse rotates very slowly in the direction of the planet's motion.  The ellipse will turn about forty-three seconds of an arc per century (a complete rotation contains 360 degrees of an arc and 360 X 60 X 60 seconds of an arc).  This effect is rather small, but it has been observed.  Mercury is nearest to the sun and the relativistic effect would be still smaller for other planets.  \nIf we take a picture of part of the heavens during an eclipse of the sun and near the eclipsed sun, and then take another picture of the same part of the heavens a little later, the two photographs will not show identical positions for all the stars.  This is so because, according to general relativity, a light ray sent by a star and passing near the rim of the sun is deflected from its original path because the sun's gravity curves space.  The effect of gravity on light is also the reason why black holes are invisible.  The gravitation in a black hole is so strong that light cannot escape from it. \nPhysicists have known for more than a hundred years that when some elements are heated to incandescence they give off a pattern of spectral lines (coloured lines), which can be examined through a spectroscope.  According to the Einstein theory, the wavelength of light emitted from a massive object will become longer because of gravitation.  This results in a shift of the spectral lin
611971
Mass is a constant; weight varies by gravitational pull.
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http://en.wikipedia.org/wiki/Gravitation#Newton.27s_law_of_universal_gravitation
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Newton just claimed that was true.  We have made millions of measurements which support the theory.  But I know no way of proving it.  A separate question is whether inertial mass equals gravitational mass.  Again, all the measurements we've ever taken support the idea, but we know no way to prove it.
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d is the most correct answer, yes.  \n\nHowever keep in mind that despite g being the "gravitational constant", acceleration caused by gravity DOES change depending on the the distance from the earth.  When we're talking about the difference of a table, there is practically no difference, however keep in mind that it does change.
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Simple Relativity\n\nAlbert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" introduced the special theory of relativity. Special relativity considers that observers in inertial reference frames, which are in uniform motion relative to one another, cannot perform any experiment to determine which one of them is "stationary". This is known as the principle of relativity. While this principle was not new to Albert Einstein's work, he found that including electromagnetism in this principle required a new formalism with many surprising consequences. In particular, it required the speed of light in a vacuum to be the same for all these observers, regardless of their motion or the motion of the source of the light.\n\nOne of the strengths of special relativity is that it can be derived from only two premises (although Albert Einstein did not derive it this way):\n\nThe speed of light in a vacuum is constant (specifically, 299,792,458 meters per second). \nThe laws of physics are the same in any inertial frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed by an observer who is stationary in the laboratory. \n\nGeneral relativity\n\nGeneral relativity was developed by Einstein in the years 1911 - 1915. General relativity is a geometrical theory which postulates that the presence of mass and energy "curves" spacetime, and this curvature affects the path of free particles (and even the path of light). It uses the mathematics of differential geometry and tensors in order to describe gravitation without the use of the force of gravity. This theory considers all observers to be equivalent, not only those moving with uniform speed.
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no idea...but I think you use the formula (Gravitational constant x mass 1 x mass 2) / distance squared
814715
no. \nthe stress-energy tensor tells us how the energy is spread, and moves, across spacetime.\nthe gravitational constant is a parameter that determines to what degree 1 kg of mass (for instance) will "warp" the spacetime. \n\nso, you can't derive it from the einstein equation.\n\nin fact, relativists usually set the gravitational constant to = 1, so that they don't have to deal with it. although it's essential when you're trying to determine exactly what your physical predictions will be, it's not really an active element of einstein's theory. it just kind of sits there.
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Special Relativity?\n1) Laws of physics do not depend on reference frame\n2) Speed of light is independent of reference frame\n\nGeneral Relativity?\nAs above, but also that uniform acceleration in free space cannot be distinguished from uniform free fall due to gravity.\n\nTo get anything else other than these basic precepts you need a lot of maths. (Especially to a high level! 4-vectors :-)
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'G' is representation for Gravitational constant, by defination it is universal constant, it does not change.\n\n'g' on the other hand is used for accelaration due to gravity. Never write it as G, it is always in miniscule. g force is given by the formula\n\ng = G*m/r, \n\njust put in the values of G (6.6742 x 10^-11 m3 kg-1 s-2), mass of sun (1.9891×10^30 kg) and radius of sun (1.392×10^6 km). Where ^ means, raised to the power. I'd love to solve it for you but I am not sure it might be your homework. Anyway, do let me know what the answer is.