electron volt

For comparison, the super-energetic protons in the largest particle accelerator on Earth — the Large Hadron Collider — only reach trillions of electron volts.

For comparison, protons in the largest accelerator on Earth, the Large Hadron Collider, reach mere trillions of electron volts.

A search for possible sources of the 38 highest-energy gamma rays, above 398 trillion electron volts, came up empty, supporting the idea that the gamma rays came from cosmic rays that had wandered about the galaxy.