Exotic matter

Exotic matter

In physics, exotic matter is a term which refers to matter which would somehow deviate from the norm and have "exotic" properties. There are several uses of the term.

  • Hypothetical particles which have "exotic" physical properties that would violate known laws of physics, such as a particle having a negative mass.
  • Hypothetical particles which have not yet been encountered, such as exotic baryons, but whose properties would be within the realm of mainstream physics if found to exist. It has been speculated that by the end of the 21st century it may be possible by using femtotechnology to create new chemical elements composed of exotic baryons that would eventually constitute a new periodic table of elements in which the elements would have completely different properties than the regular chemical elements.[1]
  • States of matter which 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 which are poorly understood, such as dark matter.

Contents

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 completely inconsistent with a common-sense approach and the expected behavior of "normal" matter, negative mass is completely 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. 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.

E = \frac{mc^2}{\sqrt{1 - v^2/c^2}}

If the rest mass is imaginary, then the denominator must be imaginary since the total energy 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., among others, special relativity implies that tachyons, if they existed, could be used to communicate backwards in time[2] (see Tachyonic antitelephone article). Since 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.[citation needed]

In quantum field theory, imaginary mass would induce tachyon condensation.

See also

References

  1. ^ Kurzweil, Ray The Age of Spiritual Machines 1999
  2. ^ G. A. Benford, D. L. Book, and W. A. Newcomb (1970). "The Tachyonic Antitelephone". Physical Review D 2: 263. Bibcode 1970PhRvD...2..263B. doi:10.1103/PhysRevD.2.263. 

Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Exotic — can mean:*In mathematics: **Exotic R4 differentiable manifold homeomorphic but not diffeomorphic to the Euclidean space R4 **Exotic sphere differentiable manifold homeomorphic but not diffeomorphic to the ordinary sphere*In physics: **Exotic atom …   Wikipedia

  • Matter — This article is about the concept in the physical sciences. For other uses, see Matter (disambiguation). Matter is a general term for the substance of which all physical objects consist.[1][2] Typically, matter includes atoms and other particles… …   Wikipedia

  • Exotic baryon — Exotic baryons are which are bound states of 3 quarks and additional elementary particles. This is to be contrasted with ordinary baryons, which are bound states of just 3 quarks. The additional particles may include quarks, antiquarks or… …   Wikipedia

  • Matter creation — is the process inverse to particle annihilation. It is the conversion of massless particles into one or more massive particles. This process is the time reversal of annihilation. Since all known massless particles are bosons and the most familiar …   Wikipedia

  • Exotic atom — An exotic atom is an otherwise normal atom in which one or more sub atomic particles have been replaced by other particles of the same charge. For example, electrons may be replaced by other negatively charged particles such as muons (muonic… …   Wikipedia

  • Exotic star — An exotic star is a compact star composed of something other than electrons, protons, and neutrons, balanced against gravitational collapse by degeneracy pressure. These include strange stars (composed of strange matter) and preon stars (composed …   Wikipedia

  • Exotic particle — An exotic particle is a kind of theoretical particle said to exist by some areas of modern physics, and whose alleged properties are extremely unusual. The best known example is probably the tachyon, a particle that always travels faster than… …   Wikipedia

  • Degenerate matter — is matter that has such extraordinarily high density that the dominant contribution to its pressure is attributable to the Pauli exclusion principle.[1] The pressure maintained by a body of degenerate matter is called the degeneracy pressure, and …   Wikipedia

  • Dark matter — Not to be confused with antimatter, dark energy, dark fluid or dark flow. For other uses, see Dark Matter (disambiguation) …   Wikipedia

  • Dark matter in fiction — Dark matter is defined as hypothetical matter that is undetectable by its emitted radiation, but whose presence can be inferred from gravitational effects on visible matter. It has been used in a variety of fictional media, including computer and …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”