The physics technical term massive particle refers to a massful
particle
In the physical sciences, a particle (or corpuscle in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass.
They vary greatly in size or quantity, from s ...
which has
real non-zero
rest mass
The invariant mass, rest mass, intrinsic mass, proper mass, or in the case of bound systems simply mass, is the portion of the total mass of an object or system of objects that is independent of the overall motion of the system. More precisely, ...
(such as
baryonic matter
In particle physics, a baryon is a type of composite subatomic particle that contains an odd number of valence quarks, conventionally three. Protons and neutrons are examples of baryons; because baryons are composed of quarks, they belong to ...
), the counter-part to the term
massless particle. According to
special relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory of the relationship between Spacetime, space and time. In Albert Einstein's 1905 paper, Annus Mirabilis papers#Special relativity,
"On the Ele ...
, the velocity of a massive particle is always less than the
speed of light
The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time i ...
.
When highlighting relativistic speeds, the synonyms bradyon (from , ''bradys'', "slow"), tardyon
or ittyon
are sometimes used to contrast with
luxon (which moves at light speed) and hypothetical
tachyon
A tachyon () or tachyonic particle is a hypothetical particle that always travels Faster-than-light, faster than light. Physicists posit that faster-than-light particles cannot exist because they are inconsistent with the known Scientific law#L ...
(which moves
faster than light).
See also
*
Elementary particle
In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles—twelve fermions and five bosons. As a c ...
References
{{particle-stub
Particle physics