This is certain, that it must proceed from a cause that penetrates to the very centres of the sun and planets, without suffering the least diminution of its force; that operates not according to the quantity of the surfaces of the particles upon which it acts (as mechanical causes use to do), but according to the quantity of the solid matter which they contain, and propagates its virtue on all sides to immense distances, decreasing always as
the inverse square of the distances....
A spherical gravitational source has an external gravitational field that falls off precisely as
the inverse square of the distance from the sphere's center.
# 331, Mark, keep in mind that gravitational force decreases as
the inverse square of distance, so about the only object in the solar system that has any influence would be Jupiter — and that is probably negligible.
Not exact matches
The study also considered an estimate
of the waste dumps which was performed using the
Inverse distance squared method.
Remember the
inverse square law — if you double the
distance between the light and the seedlings, you reduce the light by a factor
of four.
The scientists relied on the
inverse -
square law
of physics, which states that the intensity
of light drops off according to the
square of the
distance between the light source and its target.
Their curse was the
inverse square law, which states that the intensity
of electromagnetic radiation is inversely proportional to the
distance from the emitting source.
The brightnesses
of stars does decrease with greater
distance (remember the
inverse square law) BUT there are more stars further out.
The
distances to very luminous objects can be derived using the
inverse square law
of light brightness if their luminosity is known.
Re 392 Chris Dudley — I don't understand what you mean by R ^ 2T ^ 4 — and there should be something about how optical depth is proportional to R, and also, if you're going a significant
distance toward the center
of such an object, there is the issue
of spherical geometry; if the optical thickness is large enough across small changes in radius, then you don't need to account for the spherical geometry in the calculation
of the flux per unit area as a function
of the temperature profile and optical thickness; however, the flux per unit area outward will drop as an
inverse square, except
of course within the layers that are being heated through a different process (SW heating for a planet, radioactivity, latent and sensible heat loss associated with a cooling interior, gravitational potential energy conversion to enthalpy via compression (adiabatic warming) and settling
of denser material under gravity (the later both leads to compression via increased pressure via increased gravity within the interior, and also is a source
of kinetic energy which can be converted to heat)...
«
Inverse -
square law The intensity (or illuminance or irradiance)
of light or other linear waves radiating from a point source (energy per unit
of area perpendicular to the source) is inversely proportional to the
square of the
distance from the source; so an object (
of the same size) twice as far away, receives only one - quarter the energy (in the same time period).»
Re 51 Tom P — Okay, I'll look at those, but while I have the time now: yes, center
of mass is shited in proportion to mass and
distance, whereas gravity follows an
inverse square law, which is roughly why I wouldn't expect all the planets or the sun to orbit the barycenter — well, at least not neatly as if all the mass was concentrated at the barycenter (perhaps I misunderstood what you meant).
Many
of the stories that we hear about the alleged problems caused by wind turbines at considerable
distances go entirely counter to the
inverse square law.