Tikalon Header Blog Logo

Lightning Generated Antimatter

February 17, 2011

The Star Trek universe is fueled by antimatter, quite literally. The warp drives on the Starship Enterprise and other spacecraft are powered by the annihilation of matter by antimatter.[1] As all Trekkies and physicists know, mixing matter and antimatter causes a total conversion of mass to energy, giving a much bigger bang to E = MC2 than mere uranium fission or hydrogen fusion. There's only about a tenth of a percent change in mass during uranium fission, and about three-quarters of a percent during hydrogen fusion. What this means is that these fictional warp engines produce about 135 times the energy per pound of fuel than our Sun, and we all know that a pound of the Sun produces a lot of energy. After all, the sun has been "burning" hydrogen for almost five billion years, and it's expected to continue for another seven billion.[2]

We're so comfortable with mass-energy conversion nowadays, that it's hard to believe that just a hundred and fifty years ago physicists were still grappling with the problem of how the Sun shines and for how long it has shone. Most biologists at that time thought that the Sun must have been shining on the Earth for at least a few hundred million years. That's so there would have been enough time for evolution to proceed to the biological diversity we now see. Before the atomic nucleus had been discovered and Einstein proposed his famous equation for mass-energy conversion, physicists believed that gravitational contraction heated the Sun; but, this process would not endure for the long times biologists needed for evolution. This didn't deter William Thompson, a.k.a. Lord Kelvin, who didn't believe Darwin and thought that an original and continual infall of meteors would have fueled the Sun for twenty million years.[3]

Theorists, including Dirac, had been thinking about antimatter for a time before it was discovered in 1932 by Carl D. Anderson. Anderson found tracks indicating positrons, the antimatter doubles of electrons, in cloud chamber photos of cosmic rays. Anderson, who shared the 1936 Nobel Prize in Physics, followed up on his discovery by showing the reverse of E = MC2; namely, the creation of electron-positron pairs by gamma rays - the creation of mass from energy.

Cosmic rays, as Anderson found, contain positrons. Particle accelerators, such as the Large Hadron Collider at CERN in Switzerland, produce small quantities of positrons as well. As it turns out, these exotic particles can be produced by lightning. NASA's Fermi satellite, which is a gamma-ray observatory, found that powerful bursts of positrons are produced by lightning and are beamed into space.[4-11] The Fermi satellite was designed to detect extraterrestrial gamma rays, but it detected the positrons by the characteristic 511 keV gamma ray energy produced when a positron hits an electron on the satellite and they annihilate each other.

Positron flux originating from a thunderstorm.

Gamma rays (purple) can turn into focused matter/antimatter beams (yellow). This simulation is for 1.98 milliseconds after the gamma-ray producing lightning event, and the electron-positron beam has reached Fermi's altitude. (Image: NASA/Goddard Space Flight Center/J. Dwyer, Florida Inst. of Technology)


As could be expected, Fermi witnessed such positron events when it was directly above a storm, but there was one interesting exception. On December 14, 2009, there was an event recorded when the satellite was over Egypt and there was a storm about three thousand miles away. The storm, in Zambia, was below the satellite's horizon. The positrons had traveled with the Earth's magnetic field around a significant arc of Earth's atmosphere to impact Fermi; then, 23 milliseconds later, an echo signal was detected from positrons that had looped back from what's called a mirror point.[4,6]

Such evidence of positron production by lightning is quite compelling. About 500 terrestrial gamma-ray events are thought to occur worldwide, daily.[10] Some of these will produce positrons.

It was known prior to Fermi that lightning can produce gamma rays, After all, a lightning discharge is caused by a very intense electric field, and such a field can accelerate electrons to produce gamma rays, a so-called terrestrial gamma-ray flash (TGF). It was never expected that this gamma radiation could be energetic enough to produce electron-positron pairs.

Scientists would not have been surprised if a few positrons appeared, but back-calculating from Fermi's observations indicates that some storms will produce a hundred trillion (1014) positrons.[5] What's still a mystery is that not all thunderstorms produce gamma rays. Steven Cummer, an electrical engineer at Duke University who specializes in atmospheric electricity, is quoted by the BBC as saying,[8]

"The idea that any planet has thunderstorms that can create antimatter and then launch it into space in narrow beams that can be detected by orbiting spacecraft to me sounds like something straight out of science fiction..."

...Just like warp drives. This study was published in the January 20, 2011, issue of the journal, Geophysical Research Letters.[11]

US Lightning Density Map 1996-2000

Forget the tinfoil hat. You need lead underwear! Not really, since positrons rarely reach ground level; but you can see where lightning is more common from this figure (Reformatted from original NOAA image)


References:

  1. "Matter-antimatter reaction," from Memory Alpha Wiki.
  2. K.-P. Schröder and Robert Connon Smith, "Distant future of the Sun and Earth revisited," Monthly Notices of the Royal Astronomical Society, vol. 386, no. 1 (May, 2008), pp. 155-163.
  3. John N. Bahcall, "How the Sun Shines," Slac Beam Line, Winter, 2001, pp. 2-12.
  4. Thomas H. Maugh II, "What's in a thunderstorm? Antimatter, for one," Los Angeles Times, January 11, 2011.
  5. Richard A. Lovett, "Thunderstorms Shoot Antimatter Beams Into Space," National Geographic News, January 11, 2011.
  6. Tony Phillips, "Thunderstorms Make Antimatter," Science@NASA, January 11, 2011.
  7. NASA's Fermi Catches Thunderstorms Hurling Antimatter into Space, NASA, January 10, 2011. Fermi Mission home page is here.
  8. Jason Palmer, "Antimatter caught streaming from thunderstorms on Earth," BBC News, January 11, 2011.
  9. Johanna Miller, "Gamma rays made on Earth have unexpectedly high energies," Physics Today, vol. 64, no. 1 (January, 2011).
  10. Spacecraft catches thunderstorms hurling antimatter into space, American Geophysical Union Press Release No. 11–01, January 10, 2011.
  11. Michael S. Briggs, Valerie Connaughton, Colleen Wilson-Hodge, Robert D. Preece, Gerald J. Fishman, R. Marc Kippen, P. N. Bhat, William S. Paciesas, Vandiver L. Chaplin, Charles A. Meegan, Andreas von Kienlin, Jochen Greiner, Joesph R. Dwyer and David M. Smith, "Electron-positron beams from terrestrial lightning observed with Fermi GBM," Geophys. Res. Lett., vol. 38 (January 20, 2011), L02808 (5 pages).
  12. Kate Ravilious, "Lightning Creates Particle Accelerators Above Earth," National Geographic News, April 20, 2010.

Permanent Link to this article

Linked Keywords: Star Trek; universe; antimatter; warp drive; Starship Enterprise; annihilation; matter; antimatter; Trekkies; physicist; mass; energy; mass–energy equivalence; E = MC2; uranium; fission; hydrogen; fusion; Sun; mass-energy conversion; biologist; Earth; evolution; biodiversity; biological diversity; atomic nucleus; Einstein; gravitational contraction; William Thompson; Lord Kelvin; Charles Darwin; meteor; Paul Dirac; Carl D. Anderson; positron; cloud chamber; cosmic rays; Nobel Prize in Physics; gamma ray; particle accelerator; Large Hadron Collider; CERN; Switzerland; lightning; NASA; Fermi Gamma-ray Space Telescope; Fermi satellite; extraterrestrial; Goddard Space Flight Center; J. Dwyer; Florida Inst. of Technology; electric field; thunderstorm; Steven Cummer; electrical engineer; Duke University; atmospheric electricity; BBC; Geophysical Research Letters; tinfoil hat.

RSS Feed

Google Search


Latest Books by Dev Gualtieri

LGM by Dev Gualtieri
LGM by Dev Gualtieri, paperback LGM by Dev Gualtieri, Kindle

Thanks to Cory Doctorow of BoingBoing for his favorable review of Secret Codes!

Secret Codes & Number Games by Dev Gualtieri
Secret Codes & Number Games by Dev Gualtieri, paperback

Other Books

Other Books by Dev Gualtieri