Bradyon
Encyclopedia
A bradyon, also known as a tardyon or ittyon, is a particle
that travels slower than light
. All known particles that have mass are bradyons. The term "bradyon", from (bradys, “slow”), was coined to contrast with "tachyon
", from (tachys, “swift, quick, fast, rapid”), which refers to hypothetical particles that travel faster than light.
Assuming that tachyon
s do not exist, 'bradyon' is a synonym for 'mass
ive particle' (i.e. a particle having a non-zero mass
). Any bradyon has a real rest mass
, whereas any luxon has zero (both real and imaginary) rest mass. Tachyons (if they exist) have imaginary rest masses.
The words "tardyon" and "bradyon" are neologisms and are not yet in wide use, even within the field of physics
.
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
that travels slower than light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
. All known particles that have mass are bradyons. The term "bradyon", from (bradys, “slow”), was coined to contrast with "tachyon
Tachyon
A tachyon is a hypothetical subatomic particle that always moves faster than light. In the language of special relativity, a tachyon would be a particle with space-like four-momentum and imaginary proper time. A tachyon would be constrained to the space-like portion of the energy-momentum graph...
", from (tachys, “swift, quick, fast, rapid”), which refers to hypothetical particles that travel faster than light.
Assuming that tachyon
Tachyon
A tachyon is a hypothetical subatomic particle that always moves faster than light. In the language of special relativity, a tachyon would be a particle with space-like four-momentum and imaginary proper time. A tachyon would be constrained to the space-like portion of the energy-momentum graph...
s do not exist, 'bradyon' is a synonym for 'mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
ive particle' (i.e. a particle having a non-zero mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
). Any bradyon has a real rest mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
, whereas any luxon has zero (both real and imaginary) rest mass. Tachyons (if they exist) have imaginary rest masses.
The words "tardyon" and "bradyon" are neologisms and are not yet in wide use, even within the field of physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
.