How to relate Newtonion concept to Modern one?

Question

Acc to Newton, Gravitational force is the force acting between two centers of bodies like the centre of the earth and the moon. We also know gravitons are responsible for Gravity. If we equate the two it means gravitons orginate from the centre of any body. Where is the assumption worng?

Answer 1

Well, in this case, the gravitons are virtual particles being exchanged between every atom in the Earth and every atom in the Moon. Gravitons are particles that communicates the force of gravity between any two particles with "mass" (which could be electrons or quarks).

The reason you can't relate directly Newtonian physics on gravity to "gravitons" is because Newtonian physics describes gravity at large distances and for macroscopic bodies, whereas gravitons are describing behavior of gravity at very short distances (10^-13 cm or less) and between sub-atomic particles.

The same is true for Einstein's Theory of General Relativity. Einstein's theory is a theory of gravity at very large distances that is applicable to planets, stars, galaxies, and the Universe. But it failes miserably at microscopic length scales relevant to sub-atomic particles like electrons and quarks, where behavior of gravitons are important.

Answer 2

You can think of the classical (Newtonian) view as an overall average picture of what is going on in an unimaginably large nuber of fundamental microscopic interactions.

Actually, this is sort of what Newton himself did. He found that, if every bit of matter attacts every other bit of matter according to the inverse-square law, then the net result of the particles in one big piece acting on another big piece would be an attraction between their centers of mass.

The quantum mechanical twist to this is that the interactions can be thought of as the exchange of particles (gravitons) which have certain measurable properties, and since this happens in little packets the force fluctuates a bit around its average value.

The whole graviton thing is in fact not quite settled yet. The issue is that we have a very good geometrical description of gravitation (the General Theory of relativity) which is much more precise than the Newtonian theory. The trouble is that in this theory space itself can be thought of the mediator of the gravitational force--that masses are just responding to and causing distortions of space-time. So a full theory of gravitons seems to require some way to talk about space in little packets which is just extremely weird--even weirder than quantum mechanics.

Answer 3

We dont actually know if gravitons exist yet,its a hypothetical particle described in quantum field theory so we cannot know if they are responsible for Gravity yet.

Answer 4

Gravity is just the warping of space. Gravitions haven't been shown to exist whereas the warping of space can be demostrated.