This collection of quotes is being compiled by Lo Snöfall

30 June 2012





Field lines of a point dipole of any type, electric, magnetic, acoustic, …

http://en.wikipedia.org/wiki/Dipolar_theism In process theology dipolar theism is the position that in order to conceive a perfect God, one must conceive It as embodying the "good" in sometimes-opposing characteristics, and therefore cannot be understood to embody only one set of characteristics.
http://en.wikipedia.org/wiki/Dipole 
In physics, there are several kinds of dipoles:
  • An electric dipole is a separation of positive and negative charges. The simplest example of this is a pair of electric charges of equal magnitude but opposite sign, separated by some (usually small) distance. A permanent electric dipole is called an electret.
  • A magnetic dipole is a closed circulation of electric current. A simple example of this is a single loop of wire with some constant current flowing through it.[1][2]
  • A flow dipole is a separation of a sink and a source. In a highly viscous medium, a two-beater kitchen mixer causes a dipole flow field.
  • An acoustic dipole is the oscillating version of it. A simple example is a dipole speaker.
  • Any scalar or other field may have a dipole moment.
Dipoles can be characterized by their dipole moment, a vector quantity. For the simple electric dipole given above, the electric dipole moment points from the negative charge towards the positive charge, and has a magnitude equal to the strength of each charge times the separation between the charges. (To be precise: for the definition of the dipole moment one should always consider the "dipole limit", where e.g. the distance of the generating charges should converge to 0, while simultaneously the charge strength should diverge to infinity in such a way that the product remains a positive constant.)
In addition to current loops, the electron, among other fundamental particles, has a magnetic dipole moment. This is because it generates a magnetic field that is identical to that generated by a very small current loop. However, to the best of our knowledge, the electron's magnetic moment is not due to a current loop, but is instead an intrinsic property of the electron. It is also possible that the electron has an electric dipole moment, although this has not yet been observed (see electron electric dipole moment for more information).
The only known mechanisms for the creation of magnetic dipoles are by current loops or quantum-mechanical spin since the existence of magnetic monopoles has never been experimentally demonstrated.
 With respect to molecules, there are three types of dipoles:
  • Permanent dipoles: These occur when two atoms in a molecule have substantially different electronegativity: One atom attracts electrons more than another, becoming more negative, while the other atom becomes more positive. See dipole-dipole attractions.
  • Instantaneous dipoles: These occur due to chance when electrons happen to be more concentrated in one place than another in a molecule, creating a temporary dipole. See instantaneous dipole.
  • Induced dipoles: These can occur when one molecule with a permanent dipole repels another molecule's electrons, "inducing" a dipole moment in that molecule. See induced-dipole attraction.

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