Abreast. – 1. Side by side, with breasts in a line ; as, two men could hardly walk abreast. 2. In navigation, side by side ; also, opposite ; over against ; on a line with a vessel’s beam.
Abridgement. – The act of abridging, or the state of being abridged ; lessening ; reduction, or deprivation; as, an abridgement of expenses. Abrupt. – Without notice to prepare the mind for the event . sudden , hasty ; unceremonious.
Abscissa. – The horizontal coordinate in a two – dimensional system of rectangular coordinates, usually denoted by X.
Absolute. – A term applied to a system of magnitudes when all are defined in terms of the fundamental units without the introduction of multiples or sub – multiples.
Absolute Angle of Attack. – In aircraft, the angle of attack of an airfoil, measured from the attitude of zero lift.
Absolute Ceiling. – The maximum height above sea level at which a given airplane would be able to maintain horizontal flight under standard air conditions.
Absolute Expansion. – The expansion of a liquid, regardless of the dimensions of the receptacle which contains it.
Absolute Permissive Block System. – A system of automatic single track railway signaling designed to afford: a, full overlap protection for opposing movements, and b, protection same as on double track for following movements.
Absolute Pressure. – That measured from the true zero or point of no pressure. It is equal to the pressure indicated upon the gauge, plus that of the atmos phere, which is usually taken as 14.7 or 15 lbs. Thus 68 lbs. gauge pressure is 82.7 or 83 lbs. absolute.
Absolute Strength. – In mechanics, the actual breaking strength of a bar or structure, as distinguished from the safe or working load.
Absolute Temperature. – In physics, the actual temperature of anything. reckoned from absolute Pero. It is taken as the temperature indicated by t he thermometer or similar instrument, to which is added 273° centigrade or 460° Fahrenheit. the difference between absolute zero and the zeros of the respective thermometric scales, which are arbitrarily fixed.
Absolute Units. – A system of units based on the smallest possible number of independent units. Specifically, units of force, work, energy and power not derived from or dependent on gravitation.
Absolute Zero. – In physics, tempera tuna or the heat which it represents is regarded as a manifestation of molecular activity in any substance, the higher the temperature, the greater the motion or vibration among the molecules of which every solid, liquid or gaseous body is composed. Experiments have demonstrated that a gas expands when at the freezing point and under constant pressure about 1/492, of its volume for each increase of 1° Fahr. in pressure. This tends to show, that at some point about 492° – 32° or 460° below zero of Fahrenheit’s scale, the volume of the gas would have become zero or it would have lost all the molecular vibration which manifests itself as heat. The temperature of this absolute zero point, from which all temperatures of gases (are reckoned, is estimated at – 273.1° C’. or – 459.4° F.