How Will You Define Gamma Ray?

Scientists define Gamma ray as an electromagnetic ray, a packet of electromagnetic energy with the shortest wavelength and highest energy in the electromagnetic spectrum.

(Researchers identify light as another sort of electromagnetic radiation, but it has a longer wavelength.)

Gamma-ray photons typically have energies greater than 100,000 electron volts (eV). They possess wavelengths shorter than 0.1 nanometers (or 1 angstrom). They consist of photons, meaning they carry no electrical charge or rest mass.

Gamma rays travel at the same speed as light and can pass through most materials, including human tissue, with enough force to pass through 25 cm (1ft) of metal and require thick lead or concrete to stop them.

Radioactive elements give off gamma rays. Unstable atomic nuclei emit them as they transition to a lower, more stable energy state.

Supernovae, neutron stars, and solar flares originate them in space, and astronomers study them. Pair annihilation creates them when an electron and a positron collide and vanish.

Gamma rays can be harmful, so scientists keep the radioactive elements that emit them in thick metal containers. These containers protect the people handling the elements from the radiation.

Doctors use gamma rays in medicine to diagnose illnesses and to treat cancer, and engineers equip some artificial satellites with gamma-ray telescopes.

Content for this question contributed by Steven Firestine, resident of Venetia, Washington County, Pennsylvania, USA