Just some interesting news from PhysOrg.com
The onset of electrical resistance "Motion of electrons (blue) and holes (red) in an electric field (video) This is exactly what scientists at the Max-Born-Institute in Berlin recently did in a semiconductor material and report in the current issue of the journal Physical Review Letters [volume 107, 256602 (2011)]. Extremely short bursts of terahertz light (1 terahertz = 1012 Hz, 1 trillion oscillations per second) were used instead of the battery (light has an electric field, just like a battery) to accelerate optically generated free electrons in a piece of gallium arsenide. The accelerated electrons generate another electric field, which, if measured with femtosecond time resolution, indicates exactly what they are doing. The researchers saw that the electrons travelled unperturbed in the direction of the electric field when the battery was first turned on. About 300 femtoseconds later, their velocity slowed down due to collisions." Note the statement, ".indicates exactly what they are doing". So determining exactly what the electrons are doing, which I assume means location (and velocity?) should give Heisenberg heartburn? Or are they only obtaining position info? -Mark
