Can someone explain equivalence of gravity and inertia?
..if there are more stars on one half of the sky, does it mean that a thrown object will travel faster in that direction?
If the object is at the edge of the universe, does it mean it will not be able to move anywhere except towards the stars?
atyy said:A mass m can have arbitrary electric charge, but it cannot have arbitrary gravitational charge. Its gravitational charge is always equal to its inertial mass.
Crazy Tosser said:Thank you very much, it makes sense now. I guess I was just confused by the wording :)
P.S. I blame Gardner's book on relativity :P
atyy said:Actually, maybe Gardner was thinking of Mach's Principle, which postulates that inertial mass, even in eg. an electromagnetic situation, is determined by gravity between that object and the distant stars. Mach's Principle is not precisely formulated, and maybe not true, but it did inspire Einstein. It's the basis for many fun discussions!
Barbour edited a whole book about it:
http://www.platonia.com/index.html
Rovelli discusses it on p35,38:
http://www.cpt.univ-mrs.fr/~rovelli/book.pdf
Crazy Tosser said:Can someone explain equivalence of gravity and inertia?
~Tosser
Pippo said:Put a ball on an elastic surface, trying to move it you can establish that the ball would like to remain in the original position (as the elastic surface has been distorted by the ball), this is the inertia, after that put another second ball on the same surface, you may see that the two balls move toward each other, this effect is the same as the gravity.
Now remove the term "elastic surface" and replace it with "space".
(a) the Earth's gravitational field will overpower the effects of the entire universe(that's why you don't fly off Earth and into space and
Crazy Tosser said:............
But anyway, now I understand that what it says is: how much an object resist changes in motion and how much it attracts other objects is, in the lamest terms, the same thing :)
The equivalence of gravity and inertia is a concept in physics that states that the effects of gravity and acceleration are indistinguishable. This means that an observer in a gravitational field would experience the same effects as an observer in an accelerating reference frame.
The concept was first proposed by Albert Einstein in his theory of general relativity, which was published in 1915. Einstein realized that the acceleration caused by gravity is not a force, but rather a result of the curvature of spacetime caused by massive objects.
The equivalence of gravity and inertia can be explained by the principle of equivalence, which states that the laws of physics are the same for all observers in uniform motion, regardless of their reference frame. This means that the effects of gravity and acceleration are indistinguishable because they are both manifestations of the same spacetime curvature.
One example is the experience of weightlessness in an orbiting spacecraft. The astronauts inside the spacecraft are in a state of constant free-fall, experiencing the same effects as if they were in an accelerating reference frame on Earth. Another example is the bending of light by massive objects, such as stars, which can be explained by the curvature of spacetime.
Understanding the equivalence of gravity and inertia is crucial for our understanding of the fundamental laws of the universe. It also plays a key role in modern technologies, such as GPS systems, which rely on precise measurements of both gravity and acceleration. Additionally, the concept has significant implications for the study of black holes and the search for a unified theory of physics.