Inverse square law

[Lucy Skywalker]

jacmac, I think you are right. Apples to oranges, it is the geometry to both beware and be aware.

fosborn, thanks for that video link, it was absolutely fantastic.

My internet is down for 4 weeks at least, one of those one-in-a-million situations , will try to post again later but currently have limited time.

[jjohnson]

There's a discussion of this on the Electric Universe section at the top of the Index page, on "What's up with this 1/r^1 vs 1/r^2 thing?", started by Nereid. It is a fair question, and it is a geometric thing. The falloff of field potential with distance depends on "how large" and "what shape" the field's source subtends as viewed from the receiver's position.

Mathematically it is the integral of dA elements ("point sources") over the spherical angle subtended by the source. If the source of light or gravity or magnetism or sound is an infinite plane, there is no falloff with distance away from the plane. If it subtends what is essentially a "point source" only, the energy potential at the observer has fallen off in proportion to the inverse square rule, 1/r². If it's a long, "linear" source, it's just 1/r. Source with characteristics different to these will have lying in the range of 0 to 2. It is as true of gravitational sources as of electromagnetic sources.

The difficulty arises not because the gravitational force is intrinsically far less strong than the EM force. It is because of the markedly different manners of expression of the two forces. The real world case is not simply whether the gravity force or the EM force controls or dominates the motion of an electron and a proton. There is a fraction of the atoms and molecules in a cosmic filament, say, that is ionized and therefore they are charged particles, and that leaves some that are not.

Charged or not, every single particle exerts an attracting gravitational force on every other particle in the collection. Without fail. Charged particles exert no forces (other than collisions) on charge-neutral atoms and molecules. Charged particles exert repelling or attracting forces on like-charged and unlike-charged particles respectively, although intervening particles can proved electromagnetic "shielding" so that the infinite EM force can be reduced or stopped in a way that gravity cannot. Some otherwise neutral atoms, molecules, and small agglomerations (perhaps sticking together in a mass as a piece of dust or a small grain via Van de Waals intermolecular forces) which can attract loose electrons and this become charged "clumps", creating dusty, grainy or chunky plasmas.

Simulating all these various attracting and repelling forces at different distances among the group, as they move and collide and the motions change the relative strengths of various EM charge forces, and Debye shielding occurs but only at certain characteristic distances, and gravity is a constant unshielded force but its field is constantly changing with the motion of all the particles, charged and uncharged, and waves occur, is so difficult that even parallel computing and huge memory cannot keep track of enough particles to provide a really faithful, complete simulation.Because of that difficulty, most scientists believe that there is not sufficient foundation to quantify and accurately simulate the hypotheses presented by the EU way of thinking. Just because you cannot simulate something huge in all its complexity does not mean that you can't observe it happening and draw plausible conclusions about what is going on.

Fortunately, more and more of astrophysics observations are concerned with the plasma physics of many astronomical observations and data sets, and schools are devoting research time and measurements and theorizing to the solution of long-standing questions, observations and mysteries not explicable by conventional interpretation and theory. On the down side, IMHO, there are still too many leaders pointing the way along the Cold Dark Matter path and its convolutions and difficulties and lack of direct observations. That model seems not much less difficult to master than simulation of cosmic plasma events. We in the EU and plasma physics world are still at baby steps. Call it Door Number two. That's the one I pick to have the prize behind it.

Jim