MadSci Network: Physics |
Tiago, I'm not sure what you mean by "probability clouds of subatomic particles". I will consider the electron cloud around the nucleus of an atom as a specific example. For atoms in free fall, such as hydrogen atoms in space, the only gravitational effect on the electron cloud is a tidal force. http://en.wikipedia.org/wiki/Tidal_force The tidal force will elongate a body in the direction of the attracting mass and squeeze a body perpendicular to this direction. However, the tidal force is a manifestation of the difference in the force of gravity across the extent of the body and for a body as small as a atom, the tidal force will be negligibly small unless we consider an extreme gravity environment like a black hole. Here the enormous tidal effect is called "Spaghettification". http://en.wikipedia.org/wiki/Spaghettification For example, the Moon's gravitational force is measurably different between the side of the Earth nearer the Moon and the side of the Earth facing away from the Moon. This difference causes ocean tides. But you do not experience a tidal force due to the Moon because your body is small compared with the distance over which the Moon's gravity changes. One of the Mad Scientists here at madsci.org thinks that you may be referring to an effect called "electron sag" proposed in 1966 by the Stanford theoretical physicist Leonard I. Schiff and his Ph.D. student Maurice V. Barnhill (now a physics professor) to explain the experimental result of F. C. Witteborn and W. M. Fairbank that electrons had no free-fall acceleration inside a copper tube. Schiff and Barnhill thought that given a conductor like copper in a gravitational field, the conduction electrons would sink to the bottom while the positive ion cores in the crystal lattice (metals like copper are crystalline) would remain rigidly in place and unaffected by gravity. http://prola.aps.org/abstract/PR/v151/i4/p1067_1 The rigidity assumption is not realistic. Two years later Dessler, Michel, Rorschach, and Trammel in one paper, and Herring in another, used an elastic lattice to account for the effect of gravity on the ion cores and found an effect 100,000 times larger and in the opposite direction to Schiff and Barnhill. That is, they said the conduction electrons should rise to the top of the copper. In 1969, Schiff himself said that his own theory could not account for the Witteborn-Fairbank free fall results. http://prb.aps.org/abstract/PRB/v1/i12/p4649_1 A. J. Dessler et al., Gravitation-Induced Electric Fields in Conductors, Phys Rev 168, 737, (1968) Conyers Herring, Gravitation-Induced Electric Field near a Conductor and its Relation to the Surface-Stress concept, Phys. Rev. 171, 1361 (1968) So who was right? Unfortunately, the quantum mechanical description of macroscopic solid state systems like a large copper pipe in a gravitational field is very complicated and the experiments to test the theories are very delicate. The issue is still not completely resolved, but "electron sag", abandoned by its creator, is not very likely. --Dr. Randall J. Scalise http://www.physics.smu.edu/scalise
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