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Discovery of the positron. This cloud chamber image was taken during the 1932 work by US physicist Carl David Anderson (1905-1991) that led to the discovery of the positron. This particle is the opposite of the electron and the first antimatter particle to be discovered. The image shows the curved track of a positive particle entering the cloud chamber from below. The particle is known to be positive because of the direction in which it bends in the chamber’s magnetic field. The track is too faint to be caused by a proton, and is more like an electron’s track, hence it had to be the predicted positron. These results were published in 1933

Discovery of the positron. This cloud chamber image was taken during the 1932 work by US physicist Carl David Anderson (1905-1991) that led to the discovery of the positron. This particle is the opposite of the electron and the first antimatter particle to be discovered. The image shows the curved track of a positive particle entering the cloud chamber from below. The particle is known to be positive because of the direction in which it bends in the chamber’s magnetic field. The track is too faint to be caused by a proton, and is more like an electron’s track, hence it had to be the predicted positron. These results were published in 1933

Filed under physics dirac positron antymatter experiment science

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skepttv:

Cool Effect: Dropping a neodymium magnet down a copper pipe

Check out what happens when you drop a neodymium magnet down a copper pipe.

The movement of the magnet induces an electric current in the copper and with electric current comes a magnetic field, which makes the magnet attracted to it. The magnet doesn’t stick to the wall as it falls because the induced current, and its corresponding magnetic field, are perfectly distributed so that the magnet feels magnetic force equally from all sides.

The magnetic field slows the magnet, but can’t stop its fall because if the magnet stopped moving, the induced electric field would go away and the magnet would start falling again.

(Source: geeksaresexy.net, via skeptv)

Filed under physics science electromagnetism faraday

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Antiproton ring found around Earth


ANTIPROTONS appear to ring the Earth, confined by the planet’s magnetic field lines. The antimatter, which may persist for minutes or hours before annihilating with normal matter, could in theory be used to fuel ultra-efficient rockets of the future.

Charged particles called cosmic rays constantly rain in from space, creating a spray of new particles - including antiparticles - when they collide with particles in the atmosphere. Many of these become trapped inside the Van Allen radiation belts, two doughnut-shaped zones around the planet where charged particles spiral around the Earth’s magnetic field lines.

Satellites had already discovered positrons - the antimatter partners of electrons - in the radiation belts. Now a spacecraft has detected antiprotons, which are nearly 2000 times as massive.

Filed under physics antimatter antiproton Astronomy Astrophysics Van Allen science

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Copenhagen interpretation Principles A system is completely described by a wave function ψ, representing an observer’s subjective knowledge of the system. (Heisenberg)[citation needed] The description of nature is essentially probabilistic, with the probability of an event related to the square of the amplitude of the wave function related to it. (The Born rule, after Max Born) It is not possible to know the value of all the properties of the system at the same time; those properties that are not known with precision must be described by probabilities. (Heisenberg’s uncertainty principle) Matter exhibits a wave–particle duality. An experiment can show the particle-like properties of matter, or the wave-like properties; in some experiments both of these complementary viewpoints must be invoked to explain the results, according to the complementarity principle of Niels Bohr. Measuring devices are essentially classical devices, and measure only classical properties such as position and momentum. The quantum mechanical description of large systems will closely approximate the classical description. (The correspondence principle of Bohr and Heisenberg.) Photo: Description: Niels Bohr and Werner Heisinberg at a Bohr Institute conference, Copenhagen.Date: 1934 or 1936Credit: Photograph by Paul Ehrenfest, Jr., courtesy AIP Emilio Segre Visual Archives, Weisskopf CollectionNames: Bohr, Niels Henrik David; Heisenberg, Werner

Copenhagen interpretation

Principles

  1. A system is completely described by a wave function ψ, representing an observer’s subjective knowledge of the system. (Heisenberg)[citation needed]
  2. The description of nature is essentially probabilistic, with the probability of an event related to the square of the amplitude of the wave function related to it. (The Born rule, after Max Born)
  3. It is not possible to know the value of all the properties of the system at the same time; those properties that are not known with precision must be described by probabilities. (Heisenberg’s uncertainty principle)
  4. Matter exhibits a wave–particle duality. An experiment can show the particle-like properties of matter, or the wave-like properties; in some experiments both of these complementary viewpoints must be invoked to explain the results, according to the complementarity principle of Niels Bohr.
  5. Measuring devices are essentially classical devices, and measure only classical properties such as position and momentum.
  6. The quantum mechanical description of large systems will closely approximate the classical description. (The correspondence principle of Bohr and Heisenberg.)

Photo:

Description: Niels Bohr and Werner Heisinberg at a Bohr Institute conference, Copenhagen.
Date: 1934 or 1936
Credit: Photograph by Paul Ehrenfest, Jr., courtesy AIP Emilio Segre Visual Archives, Weisskopf Collection
Names: Bohr, Niels Henrik David; Heisenberg, Werner

Filed under Copenhagen copenhagen interpretation physics quantum mechanics Bohr heisenberg Born Schrödinger science