how is einstein's theory of relativity similar to and different from galilean-newtonian relativity?

Question

how is einstein's theory of relativity similar to and different from galilean-newtonian relativity?

Answer 1

Some of the assumptions and properties of Newton's relativity theory are:
1) The existence of infinitely many inertial frames. Each frame is of infinite size (covers the entire universe). Any two frames are in relative uniform motion. (The relativistic nature of mechanics derived above shows that the absolute space assumption is not necessary.)
2) The inertial frames move in all possible relative uniform motion.
3) There is a universal, or absolute, time.
4) Two inertial frames are related by a Galilean transformation.
5) In all inertial frames, Newton's laws, and gravity, hold.

In comparison, the corresponding statements from special relativity theory by Einstein are:
1) Same as the Newtonian assumption.
2) Rather than allowing all relative uniform motion, the relative velocity between two inertial frames is bounded above by the speed of light.
3) Instead of universal time, each inertial frame has its own time.
4) The Galilean transformations are replaced by Lorentz transformations.
5) In all inertial frames, all laws of physics are the same (this leads to the invariance of the speed of light).

Notice both theories assume the existence of inertial frames. In practice, the size of the frames in which they remain valid differ greatly, depending on gravitational tidal forces.

In the appropriate context, a local Newtonian inertial frame, where Newton's theory remains a good model, extends to, roughly, 107 light years.

In special relativity, one considers Einstein's cabins, cabins that fall freely in a gravitational field. According to Einstein's thought experiment, a man in such a cabin experiences (to a good approximation) no gravity and therefore the cabin is an approximate inertial frame. However, one has to assume that the size of the cabin is sufficiently small so that the gravitational field is approximately parallel in its interior. This can greatly reduce the sizes of such approximate frames, in comparison to Newtonian frames. For example, an artificial satellite orbiting around earth can be viewed as a cabin. However, reasonably sensitive instruments would detect "microgravity" in such a situation because the "lines of force" of the earth's gravitational field converge.

In general, the convergence of gravitational fields in the universe dictates the scale at which one might consider such (local) inertial frames. For example, a spaceship falling into a black hole or neutron star would be subjected to tidal forces so strong that it would be crushed. In comparison, however, such forces might only be uncomfortable for the astronauts inside (compressing their joints, making it difficult to extend their limbs in any direction perpendicular to the gravity field of the star). Reducing the scale further, it might have almost no effects at all on a mouse. This illustrates the idea that all freely falling frames are locally inertial (acceleration and gravity-free) if the scale is chosen correctly.


Maxwell's equations governing electromagnetism possess a different symmetry, Lorentz invariance, under which lengths and times are affected by a change in velocity, which is then described mathematically by a Lorentz transformation.
Albert Einstein's central insight in formulating special relativity was that, for full consistency with electromagnetism, mechanics must also be revised such that Lorentz invariance replaces Galilean invariance. At the low relative velocities characteristic of everyday life, Lorentz invariance and Galilean invariance are nearly the same, but for relative velocities close to that of light they are very different.



In the sophisticated approach to the Galilean plane, say that taken by Isaak Yaglom or V.V. Kisil, there is a study of parabolas called cycles which generalize the concept of a circle to the peculiarities of Galilean geometry, particularly its theory of angle.

Answer 2

Galilean Relativity

Answer 3

Relative motion was put in perspective by Galileo Galilei. He formulated the Principle of Relativity. It was upon this Principle that Einstein first Relativity Posulate was based upon.
The Second postulate of Einstein Relativity was that the speed of light could not exceed a certain limit of the speed of light that was measured relative ot the local frame of reference of the Earth. Hence ,it stated that the speed of light is constant and everyhere the same in the Universe.
Newton and Galileo had no instruments to measure the Speed of light on earth. Galileo did try to measure it and he concluded the velocity is instantaneous.So Newton and Galileo thought of light as being infinitely fast.
So the postulates of Einstein relativity theory differ from Galiean relativity only about the speed of light.

Neverthe less it has never been proven that the velocity of light as measured relative to local space of the Earth is the only velocity magnetude of Light in the Universe.

Answer 4

It is similar to because it includes the Newtonian theory. For low masses and low velocities both melt together.

It is different in terms of Einsteins theories base on constance of speed of light in vacuum (special relativity) and the principle that laws of physics must have the same form in all kinds of coordinate systems (even accelerated systems like a rocket traveling around earth)

There are more differences, but then it gets quickly very, very complex.

Answer 5

Einstein's relativity and Galileo's relativity share in common the first postulate according to which the true laws of physics are the same in all inertial reference frames in relative motion. Einstein's special relativity adds to that a second postulate according to which light propagates in empty space with the same speed c relative to all inertial reference frames in relative motion. It seems that in Galileo's relativity light propagates with infinite speed.In Galileo's relativity the space time coordinates of the same event detected from two inertial reference frames in relative motion with speed V are related by
x=x'+Vt'
t=t'
whereas in Einstein's one by the so called Lorentz-Einstein transformations you can find in the most introductory textbooks!

Answer 6

It is similar both use coordinate system.

It is different since einsteins relativity uses the speed of light constant (c)

Answer 7

Newton knew that gravity is a rigidity at the same time as Einstein took a step forward by applying announcing that warps and curves could desire to be the source of the rigidity. products moving via area could have a tendency to fall into each and each others warps of "area-time" (Einstein's area-time warp). Newton (did no longer see the warp) sees the falling/attracting behaviour a rigidity.