Prompt Cast
The Mystery of the Most Powerful Cosmic Ray Ever Observed
TLDR In 1991, a cosmic ray detector in Utah observed a cosmic ray with more energy than anything ever observed before, leading to a complete reappraisal of what was known about cosmic rays. The origin of this "oh my god" particle, as well as other ultra-high energy cosmic rays, remains unknown, raising questions about their nature and potential sources.
Timestamped Summary
00:00
On October 15th, 1991, a cosmic ray detector in Utah observed a cosmic ray with more energy than anything ever observed before.
02:10
In 1991, an observation of a high-energy cosmic ray required a complete reappraisal of what was known about cosmic rays and the theories used to describe them.
04:05
The energy contained in cosmic ray particles, measured in electron volts, is the focus of this episode, with the most energetic particles being very rare and reaching up to 13.6 tera electron volts, and particle colliders like the Large Hadron Collider are used to observe what happens when particles collide.
06:09
The Fly's Eyes Cosmic Ray Detector observed a cosmic ray with an energy equivalent of 320 quintillion electron volts, which was about 40 million times greater than the most powerful particle that could be accelerated in the Large Hadron Collider, leading to it being named the "oh my god" or OMG particle.
08:24
The OMG particle traveled at an incredibly high speed, near the speed of light, and had an energy that exceeded the theoretical limit for a proton by six-fold, leading researchers to initially question the validity of the observation.
10:50
The OMG particle, although initially met with skepticism, became less implausible as more observations of ultra-high energy cosmic rays were made, and in 2022, a Whopper 244 exa-electron volt cosmic ray was observed, raising questions about the nature of these particles and their potential sources, such as neutron stars with strong magnetic fields.
12:52
The origin of the OMG particle, which remains the most powerful cosmic ray ever observed, is still unknown, but it is unlikely to have come from the active galactic nucleus of Centarius A.
