The circle in the middle of the trefoil represents an atom and the blades represent the three common types of ionizing radiation emanating from it — alpha (α), beta (β) and gamma (γ). The symbol was ...

To reduce the strength of incoming gamma rays by a billion, you need 13.8 feet (4.2 meters) of water, 6.6 feet (2 m) of concrete or 1.3 feet (0.39 m) of lead, according to the radiation protection ...

Gamma rays are the most energetic form of electromagnetic radiation. In just a few seconds, a gamma-ray burst blasts out the same amount of energy that the Sun will radiate throughout its entire life.

For context, one of those visible wavelengths carries an energy of about 1 electron volt. The gamma rays Nisa and fellow researchers witnessed, by contrast, exuded about 1 trillion electron volts.

When gamma rays collide with air in our upper atmosphere, they explode into a fountain of subatomic particles in an air shower, leaving behind a signature that the HAWC detects.