Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1912-03-29
THE LIMIT OF COLD
Absolute Zero and the Way 1t Is
Defined by Science.

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 81 de-
grees and its boiling point at 212. |
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 cent?
grade scale, with its boiling point at
100 degrees and its 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 fer its measurements,
which has a theoretically correct zero
point. This scale is called the abso-
lutte scale. with it's zero point 273 de-
grees below the zero of the centigrade
scale and 1894 degrees below that of
! the Fahrenheit zero. This is what is
meant by the zero of absolute temper
AZURE
Absolute temperature has been de-
! fined. According to science. all mat
| ter is composed of small particles or
molecules in 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 it on the abso-
lutte 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-
Giles.
To illustrate the meaning of this
point and to explain how it was got,
imagine a volume of air Of 2T3 cubic
inches at the temperature of freezing
water on the centigrade scale. Heat
this volume of air to l degree cent?
grade and its volume will have in
creased TO 274 cubic inches. and if
heated to degrees its volume will
original volume be cooled degree be-
low the freezing point of water its
volume will be decreased by one cubic
inch and become 212 cubic inches.
For every additional decrease of
degree the volume will contract one
two-hundred and seventy-third part of
what 1t was to begin with, so that, IL
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 its 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
h to 213 degrees below the centigrade
h zero, where the motion has entirely
ceased and the paths Of the particles
are infinitely short. OF course the gas
under consideration ct -273 degrees
will have volume due to the sum of
b the volume occupied by the molecular
particles themselves.
This 273 degrees then is the abso.
lutte zero. 1t 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 /:
-273 degrees. while the freezing point
- Of 80 on the Fahrenheit scale is -459.4
degrees on IT, The ordinary tempera
ture of a room is about 6S degrees F.
or 527.4 degrees on the absolute scale
On the same scale summer heat I.
about 55s degrees F.
The zero Of absolute Temperature
has nearly been reached In the prepa
ration of solid hydrogen gas and liquiC
helium. The temperature OF liquid
helium Zone Of the rarest of gases Il
only about degrees above absoiut.
zero, so that the individual particle
Of liquid helium have almost becom
motionless. Probably In the nea
neiehborhood of absolute zero this gas
which is the only one that has no
been solldified, will become solid an,
represent matter In its state of moIeC
uIar death.-w. G. Dumas In Chicag
a Record Herald.