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previous home next PDF Michael Fowler, University of Virginia A Magnetic Puzzle… Suppose we have an infinitely long straight wire, having a charge density of electrons of – λ coulombs per meter, all moving at speed v to the right (recall typical speeds are centimeters per minute) and a neutralizing fixed background of positive charge, also of course λ coulombs per meter. The current in the wire has magnitude I = λv (and actually is flowing to the left, since the moving electrons carry negative charge).
A 5-micrometer glass bead levitated in air by a single laser beam from below. This optical trap is formed by the scattering force from the laser beam and the gravitational force on the bead. Tongcang Li, et. al. used a similar optical trap to study the Brownian motion of a trapped bead in air with ultra-high resolution. Their paper is published in Science. Credit: Tongcang Li. AUSTIN, Texas—A century after Albert Einstein said we would never be able to observe the instantaneous velocity of tiny particles as they randomly shake and shimmy, so called Brownian motion, physicist Mark Raizen and his group have done so.
Classical physics could not explain the spectra of black bodies. It predicted that the intensity (power emitted at a given wavelength) of emitted light should increase rapidly with decreasing wavelength without limit (the "ultraviolet catastrophe"). In the figure below, the curve labeled "Rayleigh-Jeans law" shows the classically expected behavior. However, the measured spectra actually showed an intensity maximum at a particular wavelength, while the intensity decreased at wavelengths both above and below the maximum.
Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time. Stanford and NASA researchers have confirmed two predictions of Albert Einstein's general theory of relativity, concluding one of the space agency's longest-running projects. Known as Gravity Probe B , the experiment used four ultra-precise gyroscopes housed in a satellite to measure two aspects of Einstein's theory about gravity. The first is the geodetic effect, or the warping of space and time around a gravitational body.
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Structure of the Universe Does the Universe have an edge, beyond which there is nothing? Are the galaxies arranged on the surface of a sphere? Why can't we see the whole universe?
Physicists Slow Speed of Light By William J. Cromie Gazette Staff Light, which normally travels the 240,000 miles from the Moon to Earth in less than two seconds, has been slowed to the speed of a minivan in rush-hour traffic -- 38 miles an hour. An entirely new state of matter, first observed four years ago, has made this possible.
The Antihydrogen Laser Physics Apparatus (ALPHA) at the CERN particle physics laboratory announced that they have been able to hold 309 atoms of antihydrogen in a magnetic trap for 1000 seconds, approximately 10,000 times longer than before. When they experimented with the anti-atoms last year they verified that they were in fact antihydrogen atoms by releasing them from the trap and observing them being annihilated by hydrogen atoms. During that experiment they were only able to contain the atoms for 170 milliseconds. They have repeated this experiment, but have made a few changes.
Why I Criticize Religion - Sam Harris http://www.facebook.com/ScienceReason ... Why I Criticize Religion - Sam Harris @ Big Think (Part 1). --- Please SUBSCRIBE to Science & Reason: • http://www.youtube.com/FFreeThinker •…
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Einstein for Everyone Nullarbor Press 2007 revisions 2008, 2010, 2011, 2012, 2013 Copyright 2007, 2008, 2010, 2011, 2012 John D. Norton Published by Nullarbor Press, 500 Fifth Avenue, Pittsburgh, Pennsylvania 15260 with offices in Liberty Ave., Pittsburgh, Pennsylvania, 15222
"How strange is the lot of us mortals! Each of us is here for a brief sojourn; for what purpose he knows not, though he sometimes thinks he senses it. But without deeper reflection one knows from daily life that one exists for other people -- first of all for those upon whose smiles and well-being our own happiness is wholly dependent, and then for the many, unknown to us, to whose destinies we are bound by the ties of sympathy. A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving...
@ ledzep23 : "I was referring to the effects of particles combining after the Big Bang!(If any) That's one of the things they're trying to do, right?" Particles combine(d) in different ways at different times after the Big Bang. The LHC is working at an energy scale that is close to the Big Bang but not close enough for quantum gravity effects to be significant. "They're trying to find the Higgs Boson and something that has to do with Anti Matter, etc."