Oh-My-God particle

This article is about the cosmic ray. For particle also known as God particle, see Higgs boson.

The Oh-My-God particle was an ultra-high-energy cosmic ray (most likely a proton)[1] detected on the evening of 15 October 1991 over Dugway Proving Ground, Utah, by the University of Utah's Fly's Eye Cosmic Ray Detector.[2][3] Its observation was a shock to astrophysicists (hence the name), who estimated its energy to be approximately 3×1020 eV (3×108 TeV, about 20 million times more energetic than the highest energy measured in radiation emitted by an extragalactic object and approximately 100 quintillion times the energy of visible light);[4][5] in other words, an atomic nucleus with a kinetic energy of 48 joules, equivalent to a 5-ounce (142 g) baseball travelling at about 93.6 kilometers per hour (60 mph).[6]

This particle had so much kinetic energy it was travelling at 99.99999999999999999999951% the speed of light. This is so near the speed of light that if a photon were travelling with the particle, it would take 220,000 years for the photon to gain a 1 centimeter lead.[1]

The energy of this particle is some 40 million times that of the highest energy protons that have been produced in any terrestrial particle accelerator. However, only a small fraction of this energy would be available for an interaction with a proton or neutron on Earth, with most of the energy remaining in the form of kinetic energy of the products of the interaction. The effective energy available for such a collision is √2Emc2, where E is the particle's energy, and mc2 is the mass energy of the proton. For the Oh-My-God particle, this gives 7.5×1014 eV, roughly 30 times the collision energy of the Large Hadron Collider.[7]

Since the first observation at least fifteen similar events have been recorded, confirming the phenomenon. These very high energy cosmic ray particles are very rare; the energy of most cosmic ray particles is between 10 MeV and 10 GeV. More recent studies using the Telescope Array have suggested a source for the particles within a 20-degree "warm spot" in the direction of the constellation Ursa Major.[3][8]

See also

References

  1. 1 2 "sci-fact: The fastest object ever recorded was... - Science Llama". the-science-llama.tumblr.com. Retrieved 2016-01-29.
  2. ↑ "The Fly's Eye (1981-1993) -- The Highest Energy Particle Ever Recorded". cosmic-ray.org.
  3. 1 2 "The Particle That Broke a Cosmic Speed Limit". Quanta Magazine. 2015-05-14.
  4. ↑ the blazar Markarian 501, measured in 1997
  5. ↑ "Electronvolt". Wikipedia, the free encyclopedia.
  6. ↑ Open Questions in Physics. German Electron-Synchrotron. A Research Centre of the Helmholtz Association. Updated March 2006 by JCB. Original by John Baez.
  7. ↑ CERN bulletin November 2015
  8. ↑ "Physicists spot potential source of 'Oh-My-God' particles". sciencemag.org. 8 July 2014.
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