In physics, exotic matter is matter that somehow deviates from normal matter and
has "exotic" properties. A more broad definition of exotic matter is any kind
of non-baryonic matter—that is not made of baryons, the subatomic particles,
such as protons and neutrons, of which the ordinary matter is composed. Exotic
mass has been considered a colloquial term for matters such as dark matter,
negative mass, or imaginary mass. Types of exotic matter
There are several types of exotic matter:
Hypothetical particles that have "exotic" physical properties that would
violate known laws of physics, such as a particle having a negative mass.
Hypothetical particles that have not yet been encountered, such as exotic
baryons, but whose properties would be within the realm of mainstream physics
if found to exist. States of matter that are not commonly
encountered, such as Bose–Einstein condensates and quark–gluon plasma, but
whose properties are perfectly within the realm of mainstream physics.
States of matter that are poorly understood, such as dark matter.
Ordinary matter placed under high pressure.
Negative mass Negative mass would possess some strange
properties, such as accelerating in the direction opposite of applied force. For
example, an object with negative inertial mass and positive electric
charge would accelerate away from objects with negative charge, and
towards objects with positive charge, the opposite of the normal rule that
like charges repel and opposite charges attract. This behaviour can produce
bizarre results: for instance, a gas containing a mixture of positive and
negative matter particles will have the positive matter portion increase in
temperature without bound. However, the negative matter portion gains negative
temperature at the same rate, again balancing out.
Despite being inconsistent with the expected behavior of "normal" matter,
negative mass is mathematically consistent and introduces no violation
of conservation of momentum or energy. It is used in certain speculative
theories, such as on the construction of wormholes and the Alcubierre drive. The
closest known real representative of such exotic matter is the region of
pseudo-negative-pressure density produced by the Casimir effect.
Imaginary mass A hypothetical particle with imaginary
rest mass would always travel faster than the speed of light. Such particles
are called tachyons. There is no confirmed existence of tachyons.
If the rest mass is imaginary this implies that the denominator is
imaginary because the total energy is an observable and thus must be real.
Therefore the quantity under the square root must be negative, which can only
happen if v is greater than c. As noted by Gregory Benford et al., special
relativity implies that tachyons, if they existed, could be used to
communicate backwards in time. Because time travel is considered to be
non-physical, tachyons are believed by physicists either to not exist, or else
to be incapable of interacting with normal matter.
In quantum field theory, imaginary mass would induce tachyon condensation.
Materials at high pressure At high pressure, materials such as NaCl
in the presence of an excess of either chlorine or sodium were transformed into
compounds "forbidden" by classical chemistry, such as Na
3Cl and NaCl 3. Quantum mechanical calculations
predict the possibility of other compounds, such as NaCl
7, Na 3Cl
2, Na 2Cl, and Na
3Cl. The materials are thermodynamically stable at high pressures. Such compounds
may exist in natural environments that exist at high pressure, such as the deep
ocean or inside planetary cores. The materials have potentially useful
properties. For instance, Na 3Cl is a two-dimensional metal, made of
layers of pure sodium and salt that can conduct electricity. The salt layers act
as insulators while the sodium layers act as conductors.
See also Antimatter
Dark energy Dark matter
Gravitational interaction of antimatter Mirror matter
Negative energy Negative mass
Strange matter QCD matter
References External links
Exotic Matter and Negative Energy on YouTube
The Riddle of AntiMatter on YouTube