Origins of the “Oh-My-God Particle”

The 2023-06-03 issue of New Scientist contains an article by Jonathan O’Callaghan, “We are finally closing in on the cosmic origins of the ‘OMG particle’ ”, which describes the history and current research into the origins of ultra-high-energy cosmic rays, defined as particles with energy greater than 10^{18} electron volts.

Some of these particles far exceed this threshold, with one famous exemplar, observed on 1991-10-15 by the Fly’s Eye detector in Utah, having an energy of 3.2\times 10^{20} electron volts, or about fifty-one joules, roughly the energy of an American baseball travelling fifty-five miles per hour or, in the words of one physicist, “a brick falling on your toe”.

The “OMG Particle” in the title refers to the nickname “Oh-My-God Particle” given to the event. I was one who named it.

On the night of 15 October 1991, Fly’s Eye spotted the flash of a cosmic ray with a whopping 320 EeV of energy. The researchers sat on the result for more than a year, only announcing it in 1993 once they were convinced it was real. The discovery was initially called the “WTF particle”, but after going public, a new name was coined by a now-retired engineer called John Walker. That same year, a book about the then-hypothetical Higgs boson, called The God Particle, had been published. “Something with the energy of a brick landing on your toe seemed a lot more impressive [than the Higgs],” says Walker. “So I called it the ‘Oh-My-God particle’.” Walker wrote about it on his website and the name stuck.

In January 1994 I wrote an article, initially circulated on USENET and later on my Fourmilab Web site when it was launched in December 1994, titled “The Oh-My-God Particle”. I had recently read Leon Lederman’s book The God Particle about the search for the Higgs boson, and I decided this particle, moving so close to the speed of light (0.9999999999999999999999951 c), so fast that an observer travelling along with it would experience only 3.5 minutes of proper time in travelling the 2.18 million light years to galaxy M31 in Andromeda, deserved a suitably exalted name. The name quickly caught on, but the attribution was for a long time one of those “friend of a friend” urban legends (you know, like the self-reproducing animal guessing program), but finally the truth (or blame) will out.

“[N]ow-retired engineer”…hrrmph!

The New Scientist article is behind a paywall, but if you read the jail-broken copy on Shining Science, I won’t tell. I do think they deserve a raspberry, however, for stripping the source and author’s name from the article and attributing it to “Editorial Team”.


At least they did not ask ChatGPT for your bio and declare you deceased.


The other two articles highlighted in the upper right of the cover do not inspire confidence in the quality of the content.


New Scientist has for many years tended toward the “popular” end of the “popular science” genre. These days, with Scientific American (or, as I started calling it after the German conquest in 1986, Scientific Enquirer) engaged in a race to the bottom, it isn’t clear who’s left holding up the “science” end of the tent.

In 2006, science fiction writer Greg Egan wrote that “a sensationalist bent and a lack of basic knowledge by its writers” was making New Scientist’s coverage “constitute a real threat to the public understanding of science".

In March 2021, New Scientist was bought for £70 million by the Daily Mail and General Trust, which owns the Daily Mail and The Mail on Sunday tabloids. New Scientist was promised “editorial independence”, but methinks this is not a good sign.


If laser-pumped-plasma-acceleration of electrons (1GeV/cm) could be extended 10 lightseconds (microscopic by galactic dimensions), it could produce something at the OMG level of energy.