An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A quantum mechanical phenomenon where the resistance of certain materials drops dramatically upon application of a magnetic field in certain structures composed of alternating layers of magnetic and nonmagnetic metals. The basis of the GMR is the dependence of the electrical resistivity of electrons in a magnetic metal on the direction of the electron spin, either parallel or anti-parallel to the magnetic moment of the layers. The 2007 Nobel Prize in physics was awarded to the French physicist Albert Fert (1938-) and German physicist Peter Grünberg (1939-) for the discovery of GMR.

→ giant; magneto- combining form of → magnet; → resistance.

To withstand the action or effect of; to strive against, or oppose.

M.E. resisten, O.Fr. resister, from L. resistere "to resist, to stand back, withstand," from → re- "against" + sistere "take a stand, stand firm," cognate with Pers. istâdan, as below.

Baristâdan "to withstand, to stand in opposition," from bar- opposition prefix, → object, + istâdan "to stand," → solstice.
Istâdegi kardan, composite verb, from istâdegi "resistance," state noun from istâdan, + kardan "to do, to make," → -or.

1) General: The act or power of resisting, opposing, or withstanding.
2) Electricity: A property of a conductor by virtue of which the passage of current is opposed, causing electric energy to be transformed into heat. It is the quantity that determines the current that results due to a voltage in a simple circuit. For a fixed voltage, if the resistance increases, the current decreases. It is given by the equation R = ΔV/I, where ΔV is the voltage difference and I the current. Resistance has the SI units volts per ampere, called → ohm.

From → resist + -ance a suffix used to form nouns either from adjectives in -ant or from verbs.

Baristgari, from baristgar, → resistant.
Istâdegi "resistance," state noun from istâdé "stood," p.p. of istâdan "to stand," → resist.

1) Characterized by or showing resistance.
2) A person or thing that resists.

Present participle of → resist, with -ant a suffix forming adjectives and nouns from verbs.

Baristgar, from barist present stem of baristâdan, → resist, + -gar, agent suffix, → -or.
Istâdegigar, from istâdegi, → resistance, + -gar.

Capable of or inclined to resistance; resisting.

From resist, → resistance, + → -ive.

Baristmand, from barist present stem of baristâdan, → resist + -mand possession suffix, → -ist.

A property of a → conductor which is defined as the ratio of the → electric intensity (E) to the → current density (J): ρ = E/J. The greater the resistivity, the greater the intensity needed to establish a given current density, or the smaller the current density for a given intensity. A "perfect" conductor would have zero resistivity, and a "perfect" → insulator an infinite resistivity.

From → resistive + → -ity.

An electrical component used to introduce a known value of resistance into a circuit.

→ resist; → -or.