massless

[ mas-lis ]

adjective

, Physics.

1. pertaining to an elementary particle having zero rest mass, as a photon.

Other Words From

• massless·ness noun

Word History and Origins

Origin of massless¹

First recorded in 1875–80; mass + -less

Example Sentences

New simulations of these events show hot neutrinos -- tiny, essentially massless particles that rarely interact with other matter -- that are created during the collision can be briefly trapped at these interfaces and remain out of equilibrium with the cold cores of the merging stars for 2 to 3 milliseconds.

From Science Daily

But while his classification system is accurate for particles with mass, it produces inaccurate results for massless particles, like photons.

From Science Daily

"Qin and I showed that using topology," Palmerduca said, "we can modify Wigner's classification for massless particles, giving a description of photons that works in all directions at the same time."

From Science Daily

In 1964, Higgs figured out how otherwise massless particles could gain mass by interacting with a quantum field consisting of Higgs bosons lurking in the vacuum of space.

From Science Magazine

The otherwise massless W and Z interact with it to acquire energy and, hence, mass.

From Science Magazine