Newton's Law of Universal Gravitation - Problems With Newton's Theory

Problems With Newton's Theory

Newton's description of gravity is sufficiently accurate for many practical purposes and is therefore widely used. Deviations from it are small when the dimensionless quantities φ/c2 and (v/c)2 are both much less than one, where φ is the gravitational potential, v is the velocity of the objects being studied, and c is the speed of light. For example, Newtonian gravity provides an accurate description of the Earth/Sun system, since

\frac{\Phi}{c^2}=\frac{GM_\mathrm{sun}}{r_\mathrm{orbit}c^2} \sim 10^{-8},
\quad \left(\frac{v_\mathrm{Earth}}{c}\right)^2=\left(\frac{2\pi r_\mathrm{orbit}}{(1\ \mathrm{yr})c}\right)^2 \sim 10^{-8}

where rorbit is the radius of the Earth's orbit around the Sun.

In situations where either dimensionless parameter is large, then general relativity must be used to describe the system. General relativity reduces to Newtonian gravity in the limit of small potential and low velocities, so Newton's law of gravitation is often said to be the low-gravity limit of general relativity.

Read more about this topic:  Newton's Law Of Universal Gravitation

Famous quotes containing the words problems with, problems, newton and/or theory:

    I was a wonderful parent before I had children. I was an expert on why everyone else was having problems with theirs. Then I had three of my own.
    Adele Faber (20th century)

    I have said many times, and it is literally true, that there is absolutely nothing that could keep me in business, if my job were simply business to me. The human problems which I deal with every day—concerning employees as well as customers—are the problems that fascinate me, that seem important to me.
    Hortense Odlum (1892–?)

    I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis; and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.
    —Isaac Newton (1642–1727)

    Freud was a hero. He descended to the “Underworld” and met there stark terrors. He carried with him his theory as a Medusa’s head which turned these terrors to stone.
    —R.D. (Ronald David)