…An electron can pass from the orbit of one nucelus to another’s without passing through space between. It occupies no particular position in space when its velocity is under observation; when its location is fixed, its speed is indeterminate. At times an electron behaves like an object: when it hits a TV cathode tube it has weight and produces a pulse of light. But objects can only be in one place at one time. Not the electron.
In a famous experiment, one was fired at a metal sheet with two holes; the result- at least in the only words we have to express it- was that it passed through both of them simultaneously. In particle physics the notion of linear causality has been pulverized by quantum theory, velocity position uncertainty, and relativity. And other elementary particles make the electron seem conservative; to begin to describe them taxes the capabilities of language.
—Anna Mary Robertson “Grandma” Moses (American; Naïve Art, Primitivism, 1860-1961): Catching the Thanksgiving Turkey, 1943.—Physicists have suspected the existence of a mysterious, undetected form of matter since 1933, when Swiss astronomer Fritz Zwicky noticed an apparent discrepancy between two methods of estimating the mass of distant galaxies. The mass of galaxies as measured by the light emitted from them was less—far less—than the galaxies’ mass measured by applying Newton’s theory of gravity to their relative motions. To move as fast as observed, the galaxies had to contain more matter.
Observations over the past 80 years have confirmed Zwicky’s discovery, leading physicists to a startling conclusion. The universe, it seems, contains a large amount of invisible matter, and so far we’ve never been able to catch it on Earth.—Read More:http://www.symmetrymagazine.org/article/april-2012/dark-matter-search-goes-deep-underground-in-south-dakota
Perhaps the weirdest elementary particle of all is the neutrino. It is a ghost. It has no magnetic field and no charge and no mass. It interacts with something else under the rarest circumstances- specifically, when a neutrino produced by the breakdown of boron-8 nuclei hits a chlorine atom, the collision may produce an atom of radioactive argon. Otherwise, neutrinos are imperceptible; they pass through the earth as if it weren’t there. So the neutrino hardly exists for us; but then, we do not exist for it. The chances against it showing up by direct collision as it glides through the earth at the speed of light are about ten thousand million to one. Like beau Brummell at the bore’s soiree, it is distinguished by its immense absence.
—Gustave Caillebotte, “Willows by the Yerres”, 1872, oil on board, Private Collection—Physicists, of course, do have theories about what dark matter might be. The leading candidate is the “weakly interacting massive particle,” or WIMP. More than a dozen research teams on three continents are hunting WIMPs, among them the Xenon 100 experiment at the Gran Sasso National Laboratory in Italy, which already is operating a detector using 100 kilograms of liquid xenon. LUX, with 350 kilograms of xenon, will take that search to a new level. Read More:http://www.symmetrymagazine.org/article/april-2012/dark-matter-search-goes-deep-underground-in-south-dakota
However, much of the energy released from the core of the sun is in the form of neutrinos. Unlike other forms of energy, which take thousands of years to work their way out to the solar surface, the neutrino shoots straight out and keeps going forever. Neutrino emission is therefore an important part of the energy loss that stars, including our sun, suffer while cooling; at one time, one of America’s chief instruments for solar study was a 100,000 gallon tank of perchloroethylene, a dry-cleaning fluid, lodged in a blind, rock-walled cave one mile below the ton of Lead, South Dakota. Now and then, a neutrino went into the tank en route throgh the earth, hit a chlorine atom, and unmasked itself. ( to be continued)…
ADDENDUM:
(see link at end)…the most recent of which is the LUX dark matter detector being constructed nearly a mile below the surface in an abandoned South Dakota mine, which will up the detection sensitivity threshold by several orders of magnitude. Given the many, many brains currently working on the direct detection problem, today’s publication of a new study in the journal Monthly Notices of the Royal Astronomical Society finding, indirectly, more dark matter around the Sun than previously thought should deliver some hope.
So, let’s recap dark matter real quick. In the 1930s, Swiss astronomer Fritz Zwicky noted that the observed movements of galaxies weren’t adding up. There was something invisible there exerting a gravitational force, a very large something. Right about the same time, Jan Oort in the Netherlands discovered that there was a much higher density of matter around the Sun than could be explained by all of the observable stuff (gases and stars). The explanation for the disparities became what we now call dark matter, a theorized ghostly something that makes up most of the matter in the universe, yet interacts hardly at all with the observed universe beyond gravity. While we observe it fairly easily in the movements of galaxies, the global race is still on to detect it directly.Read More:http://motherboard.vice.com/2012/8/9/new-research-we-live-in-a-cosmic-cave-full-of-dark-matter–2
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