The Bridgeport evening farmer., 1912-04-08
THE LIMIT OF COLD
Absolute Zero and the Way It Is
 Defined by Science.
POINT OF MOLECULAR DEATH

At 45e.4 Degrees Below the Fahrenheit
 and 273 Degrees Below the Centi-
 grade Zero There Is No float, No En-
 srsy and No Motion Within Matter.
 Few people have any definite idea of the meaning of absolute zero. When temperatures or degrees of heat are mentioned 1t is natural for most people to think of these degrees as given on the household or Fahrenheit scale. with it's freezing point at g. de grees and it's boiling point at PIP. The space on the Fahrenheit thermom- eter below the freezing point of water is divided into thirty two equal spaces down to zero. The other thermome- ter scale in common use Is the centi- grade scale. with its boiling point at 100 degrees and it's freezing point at zero. The zero points on these two scales are not the zero of absolute temperature or absolute zero, but are only two relative points.
 Temperature as used and spoken of In ordinary practice Is only relative and Is measured in reference to two points-the boiling and freezing points of water at sea level. But science and scientific investigation requires another scale for it's measurements. which has theoretically correct zero point. This scale is called the abso- lute scale. with its zero point 273 de- grees below the zero of the centigrade scale and 459.4 degrees below that of the Fahrenheit zero. This is what Is meant by the zero of absolute temper ature.
 Absolute temperature has been de fined. According to science. all mat ter is composed of small particles or molecules ia ceaseless vibration in the spaces between them. This molecular motion. as it Is called. is much greater in gases than it is in liquids or solids. and the ultimate particles are farther apart. The idea of absolute zero and the place assigned to 1t on the abso- lute scale Is based on this property of matter-motion. In gaseous forms of matter the motion is greater because of the greater space between the parti- cles.
 To illustrate the meaning of this point and to explain how 1t was got. imagine volume of air of 273 cubic inches at the temperature of freezing water on the centigrade scale. Heat this volume of air to 1 degree centi- grade and it's volume will have in. creased to 274 cubic inches. and if heated to degrees it's volume will be 275 cubic inches. Likewise. if the original volume be cooled degree be- low the freezing point of water it's volume will be decreased by one cubic inch and become PIP cubic inches. For every additional decrease of 1 degree the volume will contract one two-hundred and seventy-third part of what it was to begin with. so that, if the cooling is carried far enough. it is easy to see that at 273 degrees below the freezing point of water the volume will become nothing.
 The volume of a gas is due to the real volume of it's individual particles. together with the volume of the spaces between these particles. At ordinary temperatures these particles are in swift motion. But for every degree of cooling this motion is slackened, and the paths of vibration become shorter. This motion continues down to 273 degrees below the centigrade zero. where the motion has entirely ceased and the paths of the particles are infinitely short. Of course the gas under consideration at -273 degrees will have a volume due to the sum of the volume occupied by the molecular particles themselves.
 This 273 degrees then Is the abso- lute zero. It is the point of molecular death. No heat is there. no energy and consequently no motion. Matter at this point is entirely motionless within itself.
 The thermometer scales of the world should be based on 1t as the logical starting point. The freezing point of water. which is zero on the centigrade scale. referred to the absolute scale is -273 degrees. while the freezing point of 32 on the Fahrenheit scale is -59.4 degrees on it. The ordinary tempera ture of room is about 6S degrees F.. or 527.4 degrees on the absolute scale. On the same scale summer heat Is about 558 degrees F.
 The zero of absolute temperature has nearly been reached in the prepa- ration of solid hydrogen gas and liquid helium. The temperature of liquid helium lone of the rarest of gases) is only about degrees above absolute zero. so that the individual particles of liquid helium have almost become motionless. Probably in the near neighborhood of absolute zero this gas which is the only one that has not been solidified. will become solid and represent matter in it's state of molec uIar death.-W. 0. Dumas in Chicago Record-Herald.