Michel Jullian wrote: > I didn't understand your reply, would the elementary particle (any particle, e.g. a neutron, a quark) lose something while falling towards a planet?
Basically you're asking what sustains such particles. To perhaps provide you with a different POV, here's an analogy even though all analogies are imperfect, but they server to make a point. The electro-magnet represents the particle. The source of power (current source) that sustains the electro-magnet would represent "Space." We agree energy is being moved from the battery when two electro-magnets accelerate toward each other in magnetic attraction. We agree such energy is moved from the battery to KE and an increase in B-field. In the case of permanent magnets, we both agree that energy of "some sort" is moving to the magnets in way of KE in addition to a net increase in B-field. You refer to such an energy source as PE. I am pointing out very obvious patterns in nature that indicates such energy is not yet another different aspect. That such PE is not yet another separate type. We see PE popping its head in QM and Classical equations. IMHO PE should *not* be some magical glue to bond and balance mathematical theories together. You might ask as to what patterns in nature am I referring to. Anything from springs to electro-magnets. Long ago people probably looked at the spring and could only imagine where such energy was being stored, where it was going to and coming from. Today the spring is no mystery. We know about atomic bonds. :-) When humanity discovers an electro-gravity coil then do you truly believe it will require *no* energy when objects accelerate toward such a coil while it is on? We already know what happens when the electro-magnet coil attracts magnetic materials. It requires energy. > BTW, I wonder if PE shouldn't be viewed as a property of the universe rather than of an object. That's exactly what you seem to believe. As two iron atoms accelerate toward each other we know it gains KE and a net increase in magnetic field. You believe nature has a back door of energy, figuratively speaking. A hidden storage compartment that cannot be seen or analyzed while in storage. Such a theory is fine if one has nothing else, or until we begin to perceive such aforementioned patterns in nature, or until we analyze the equivalent of the magnetic dipole moment, which we call the electro-magnet. Also, such a concept of PE is very ugly as far as simulation programs are concerned. It's difficult enough simulation known energy. > BTW2, the universe is all that exists, by definition. Parallel "universes" should be called something else. I believe you are confusing Omniverse or Multiverse with the word "universe." You cannot say the universe is all there is if you accept parallel universes. It's just a definition anyway, which I often call "all there is" as Nature, but sometimes I prefer Omniverse. Regards, Paul ____________________________________________________________________________________ Don't get soaked. Take a quick peak at the forecast with the Yahoo! Search weather shortcut. http://tools.search.yahoo.com/shortcuts/#loc_weather