The times dispatch. [volume] (Richmond, Va.) 1903-1914, 1905-09-05
THE ABSOLUTE ZERO.
Significance Of the Phrase-Ar'
litter Absence of Heat.

Tho confusion which OFTEN cAtste 49,
Tho term Zero necessitntes q "oru y
explanation. In graduating tner..iol,r
eter two points are taken as tnc s SUN.
~ ,,o,nts these are the melting point
~ loo and the boiling point Of water
In tho centigradc, or Celsius. thermome-
,ar and in tho Reaumur Thermometer,
now rarely used, the former OF these Is
recognized as zero, or o; but In the ran
r.nheit thermometer, most commonlS
usod for ordinary temperatures, " - 10
ma rl1el SO degrees, SO that the fchrenEei'
zero is 80 Fahrenheit degrees oeioW INC
| ccnt,gradc and Reaunur zero. i,ut
degrees differ and measurement peins
| dependent upon the number into Whicl !.
1.-THE space between the melting poiht ol
lice and the boiling point OF water as n ~,
dicated by the thermomctric BODY IN me
thermometer tube Is divided IN mo
oontirrade Thermometers this Is divided
INTO 100 degrees In tho Reaumur INTO
81 degrees, and In tho Fahrenheit, lSo
degrees, so that the. boiling point when
Is called ! 900 degrees on the centigradc
rends 2l2 degrees on the Fahrenheit scare
The term zero" therefore, is very
indefinite one, but absolute zero IS
yerv definite one, for 1t means the ehllre
absence OF heat, or the absolute impos-
slbillty Of obtaining mechanical action
by cooling. Measured in terms OF either
the centgrade scale or tho Fehrenheit'
1t has mathsnatical expression Whictl
Is capable OF being conceived Possibly
the following, from the American lnVcn-
tor, may give some idea Of IT:
Dr. James Dewar recently ~ d ae.lyerea
| at the Royal Institute. Lyndon. ils
subject was New Low Temperature
Phenomena.' Sir James name has been ,. 9,
constantly before the public n !, ! eohne g,
few scientists have accomplished SO many
| new results in It's use. But Sir James
has been able to attain far lower tom.
peratures than that OF ia " b or c s,,c
eee'd am in liqyuifyng every known gas
With the single exception OF helium. a n.
has reached n temperature OF minus 20.
degrees cen,grHae Mhet re- 200 whieh i
the me'''gw Ren this see attned Ser
is little ditlcuty In obtaalnnng fr g5e,
i hydrogen for short period; as "n nh
the liquid hydrogen eyaporates y 40
stracts. heat from. the portion remaining
and SO temporarily freezes II. IN ~. " -
fashion temperature OF minus w do
srees ccntigrade has been se iwncano rnei
this or any other figure y we though
that there was no limit to the degre
TO which bodies can be cooled. But "
| snail SnOrtlyT sec lH&il lIlCLC - "AA
and that Sir James has very nearl
II heat he DO n form Of energy, or
mode OF motion. and cold be simply tn
relative absence OF heat, It Is plain thf
| bodies cannot be cooled indefinitely, siDt
| the amount OF heat energy within the
| must be finite. There must be. then; q
absolute zero OF temperature. Whit
| bodies will have reached when all AZ
heat has been taken out Of them. III
| follows inevitably from the modern co..
ception Of heat as q "node of motion
The determination Of the degree TO Whlt
| a body must be cooled 80 as to DO abs
| !utely cold would appear Impossible, ID
| ii is not 30 Considerations OF variol
| kinds notably those relating to y
| shrnkage In gas rs II Is cooled hay
| led physcans to agree that the abs
| lutte zero must be at minus 273 degree
| centgrade. But nowadays physicians q
| ceaning to use the centiErade Hcnles-L
| alone the rldlculously obsolete Fahrc
heit. to which the conservative poop
adherc-but are following the adyi
originally given by Lord Kelvin. to ma!
The absolute zero the zero OF their seal
Thus We say that the temperature
| lIaud hydrogen Ii about 20 degrees q
soute and that Professor Dewar y
| probably touched temperature AZ lc
as seven or eight degrees absolute,
even little lower still.-Current Lite
IslI lrA 4 " . 1"