THE ABSOLUTE ZERO

Dominion, Volume 3, Issue 828, 28 May 1910, Page 7

THE ABSOLUTE ZERO

MINUS 459 DEGREES FAHRENHEIT.

What is the coldest possible temperature? . The question is a timely one, (says an English Journal) for it has seemed at times during this last .winter «g it the bottom of the temperature scale must surely bo struck—providing there is a bottom. Is there, then, any limit to the degree of coldness that can be obtained or imagined? As we know of no definite upper limit to possible temperatures why should there be a lower?

Wo might speculate and'BTguo as long, as we please on the reasonableness of this last point but all to no avail, tor science steps in and says with great positivencss that there is a definite limit to tho lowet conceivable temperature, and that this may lie placed with considerable accuracy at 459 degrees below zero on the Fahrenheit scale. Wo suppose that at all temperatures above this "absolute zero" particles of matter, either solid or gaseous, are in a state of vibration, the more rapid vibrations corresponding to the greater degree Df heat. All such vibrations would cease entirely at absolute zero, and ail gases would liquofy and even solidify before reaching this point. Tho gradual approach in scientific experimpnts to this lowest possible temperature reminds ono of the various "farthest north" expeditions. Liquid air, with its 312 degree.? ■ below zero, was a great advance on previous records, although still over a hundred degrees above this'absolute zero. Liquid hydrogen at minus 422 degrees, or 37 absolute, was a still greater advance, and when this was frozen into solid hydrogen "ice" at 432 below zero or 27 degrees absolute, it seemed as if science had done its best in this direction.

But only a little over a year ago tho rttro pas helium was liquefied ar. minus •151 degrees. When this was boiled under reduced pressure a temperature of minus 454 was reached, or only 5 degrees above absolute zero, and this will probably remain our "farthest north" point for some lime to come. Slightly lower temperatures than this can undoubtedly 1» reached ; but there is small hope of our ever attaining absolute- zero any more than thovo is of reaching perfection in anything.