The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1884-01-07
SCIENCE OF COLD AND HEAT.
The Absolute Zero the Absolute Want
Of all Motion in Things.
What 273 Degrees Below Zero Means-Facts
and Figures that Tend to Mystify
While they Seem to Explain,

Good morning Professor. How is your cor
porosityl Cold, isn't It'll Twenty-Five below
freeze this morning"
THAT is not cold-far from it, In fact, there
is no such thing as cold. Cold is negative-the
mere absence of heat"
'Well, there is a good deal of absence of it
this morning. said the reporter, rubbing his
frosty ears.
That's mere matter of sensation Fact is,
it can get good deal colder than it is now, or
was in 1854 Heat, you know, is motion-noth-
ing more certain. 1t is simply the motion of the
particles of a body. If the particles go fast the
body is hot; if slower it cools The absolute
zero is the point of no motion, and is 273 cent?
grade degrees below the freezing point of water.
Hot and cold are sensations only. We call
bodies that impart warmth to or abstract it from
our own, hot or cold. The various degrees of
heat and cold we call in general temperature,
and few scientific terms are more difficult to de-
fine. The temperature of body is the moving
power of its molecules it is in brief, theirmolec
ular energy. At the absolute zero the molecules
would be in a state of rest"
How big are these molecules that seem to do
all the mischief"
Almost infinitely small. I never saw one.
They are below the power of the best micro
scopes, and that means less than a hundred
thousandth of an inch in diameter. would like
to see one,' said the Professor, musingly, "but
never expect to. But there is no doubt about
their existence. They are the units of the physi-
cist as the stars and planets are the units of the
astronomer. Take this lump of ice, for instance.
1t is made up of countless molecules of water
hydrogen oxide, the chemist calls it. Now,
just as the geoogist tears the earth to pieces so
does the chemist separate the water into its ele-
mentary hydrogen and oxygen; but to the as
tronomer the earth is unit, and so is the mole
Guile to the physicist The chemist, you know,
deals with atoms, the physicist with molecules,
the mechanic with masses the astronomer With
the separate heavenly bodies. Each has his
unit, you know"
The reporter didn't know He remembered
that he went 'tonton the paper at seventeen,
never went through a college except
to report commandments, and left
the public schools before they made the
natural sciences take the place of the three Rs;
but he NODDED assent, and the Professor went on.
Yes we deal with the molecules; we believe in
then-s Heat with us is molecular motion; colds
less of this motion; absolute zero is no motion-a
hypothetical condition. fe c4
but you have not told me how big or how lit
tie these molecules are" said the reporter.
'Oh, you want mathematical expression for
them, |. see Well, Sir William Thompson, of
Glasgow, fixes their limit for water at between
the 250-millionth and 500-millionth of an inch in
diameter, and to give some idea of the coarse
grainedness, so to speak, of drop of water, he
says that if drop the size of pea were magni-
fed to the size of the earth, and each molecule
magnified in the same proportion, the structure
would be coarser grained than heap of small
lead shot, but not so coarse as a heap of cricket
balls. He defines molecules as pieces of matter
of measurable dimensions with shape, motion,
and laws of action, intelligent subjects of scien-
fife investfation"
''Shape and motion, have they7 what shape
are they9"
That we don't know, They are probably
round like the planets. Like, them, they are in
constant motion. In a gas this motion is in
straight lines For instance the air we breathe
is made up of mainly molecules of oxygen and
nitrogen, with now and then of water, or of
carbonic acid. Even in glass globe or room,
these are in constant motion If the gas is hot
they 20 faster if cooler they slow up. Under
like conditions of temperature and pressure
all gases contain the same number of MOLECULES
in the same volume That is. if yon take half
dozen globes like those in the windows of the
When and fillaone with oxygen, lone with ny
drogen,r and one with carbonic acid gas, etc. just
as they have filed them with shot and beans, the
globes would contain exactly the same number
of molecules. lnsoGsT coYsCc
what is that number9" said the reporter This
mind full of new scheme for having the globes
reflled with gases and getting up new deal for
Lady Wills, he to have the inside track ac-
count of his newly gathered and gaseous knowl-
edggeG
temperature and pressure. With the thermometer
at zero, and the barometer at thirty inches, one
cubic inch of every gas. matter what kind,
contains one hundred thousand million million
million molecules. Here it is on paper in
fgures-it equals ten raised to the twenty third
power. In the case of hydrogen gas these mole
cues moving at the rate of 6097 feet per sec
ond as their mean velocity-over mile sec
ondn
''Whewr said the reporter, that is a stiff
breeze"
Eyes, something over 5000 miles in an hour
They act in all directions, producing the perma-
nent tension or pressure of the gas. This ten
sion is low to-day. The air particles are moving
slow, and all the liquids and solids of our bodies
are partaking of this slower motion" Here the
Professor stirred up the fire, to impart as he
said, higher degree of molecular motion to the
molecules of inside atmosphere
Are the molecules of liquids and solids also in
motions" asked the reporter.
'Oh yes; just the same. Only in the gaseous
state the molecules are separated beyond the
sphere of each others influence In liquids
cohesion restraints the molecules within
the mass, though they move among
themselves. Neither liquids nor gases show
any trace of structure, but solids have tenacity
and structure their particles are relatively fixed
But the molecules of neither liquids nor solids
touch each other-they vibrate back and forth
across the intermolecular spaces faster when
heated, slower when cold. You see the eternal
tendency is toward equilibrium of molecular mo-
ton. It has been so always. The moon has
run through her stages, is cooled off has neither
water nor air and of course no life. She is, in
fact, approaching the absolute So is our
earth-Once a gas, now a semisolid, with
aqueous and atmospheric envelopes. She sus-
tains life comfortably only in her temperate and
constantly contracting zones The old earth is
bound to be snuffed out some day--in fact con-
gealed-and the great wave of reduced molecu-
lar vibration which is sweeping over her
fairest zone is a sign of the coming time when
she will be destroyed, not by fire, but for the
want of it"