The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1905-07-19
THE ABSOLUTE ZERO.
Significance of the Phrase-An Utter
Absence of Heat.

The confusion which often exists
about the term zero necessitates a
word of explanation. In graduating
thermometer two points are taken as
the standard points. These are the
melting point of ice and the boiling
point of water. In the centigrade, or
Celsius, thermometer and in the Reau-
muir thermometer, now rarely used, the
former of these is reekoned as zero, or
0 deg; but in Fahrenheit thermometer,
most commonly used for ordinary tenn
peratures, it is marked 81 degrees, so
that the Fahrenheit zero is 81 Fab
renheit degrees below the contigrade
and Reaumur zero" But degrees Diff
fer in measurement, being dependent
upon the number into which the space
between the melting point of water, as
indicated by the thermometric body in
the thermometer tube, is divided. In the
centigrade thermometer this is divided
into 100 degrees, in the Reaumur into
80 degrees, and in the Fahrenheit $50
degrees, so that the boiling-point which
is called 1000 degrees on the centigrade
reads PIP degrees on the Fahrenhe1t
scale. The term Zero" therefore, is a
very indefinite one, but absolute zero"
is a very definite one, for it means the
entire absence of heat, or the absolute
impossibility of obtaining mechanical
action by cooling. Measured in terms
of either the centigrade scale or the
Fahrenheit, it has a mathematical ex-
preston which is capable of being con-
c6lN6Q. POSSIBLY the lOIlOWlli6s 11Ol1l IAAO
American Inventor may give some idea
of It:
DR.. James Dewar recently delivered
his first lecture of a series of discourses
at the Royal Institute, London HIS
subject was, New Low Temperature
Phenomena Sir James name has been
constantly before the public in connec-
ton with liquid air demonstrations, and
few scientists have accomplished so
many new results in its use. But Sir
III 2ff tot f1r
temperatures than that of liquid or even
solid air. By it's means he has succeed
! ed in IiQuefying every known gas, with
| the single exception of hellum, and has
| reached a temperature of minus 253 de-
grees centigrade chat is, 253 degrees be-
| low the centigrade Zero which is the
melting point of ice) with liquid hydro
gen. When this is attained there is lit
| tie difficulty in obtaining frozen hydro
gen for a short period; as when the
LIQUID hydrogen evaporates it abstracts
| heat from the portion remaining and so
temporarily freezes it. In this fashion
| a temperature of minus 265 degrees
centigrade has been reached. There
would be no particular significance in
this or any other figure if we thought
/ that there was no limit to the degree
to which bodies can be cooled. But we
shall shortly see that there is q limit,
and that Sir James has very nearly
reached it.
If heat be a form of energy, or a
mode of motion. and cold be simply
the relative absence of heat, it is
plain that bodies cannot be cooled in
definitely. since the amount of heat
energy within them must be finite
There must be. then. an absolute zero
of temperature, which bodies will
have reached when all the heat has
been taken out of them. This fol-
lows inevitably from the modern con-
Ception Of heat as mode of mo-
ton" The determination of the de-
gree to which a body must be cooled
so as to be absolutely cold would APP
pear impossible, but it is not So
Considerations of various kinds. not
ably those relating to the shrinkage
in gas as it is cooled. have led physi-
clans to agree that the absolute zero
must be at minus 273 degrees cent?
grade. But nowadays physicians are