Radio age (Jan 1927-Jan 1928)

RADIO AGE for May-June, 1927 25 I Current Science | Mining Gold With Bubbles Children's PlayThing Has Important Role in Mining Industry — Bubble Study Reveals Properties of Light HAVE you ever studied a soap bubble? Perhaps when you were a child you were fond of playing with a dish of suds and a clay pipe, but the bubble is more than a toy, for grown up scientists at the U. S. Bureau of Standards in Washington have been studying them, even to the point of shooting bullets through them, and photographing them as they break. The photographing has been done by Dr. Philip P. Quayle, and uses light furnished by an electric spark, so that the bullet and half broken bubble are photographed as clearly as if they were at rest. And from these photographs it has been found that the bubble is not the simple thing that we used to imagine it, but some very complicated processes go on within its walls. Some of these are of considerable practical use, as in the mining industry, where they are used STEEL BALL DROPPED IN A SOAP BUBBLE. This photograph, made about a hundredth of a second after the ball first touched the bubble, shows that it has not yet begun to break, but extends down around the ball like an elastic membrane DR. PAUL R. HEYL, head of the Sound Laboratory at the U. S. Bureau of Standards, in Washington, who tells of some of the wonders of the soap bubble. Dr. Heyl has also been engaged in a long series of researches to determine the exact force of gravity to separate precious metals from the ore. Dr. Quayle's work has been in the sound laboratory of the Bureau, which is under the direction of Dr. Paul R. Heyl, whose studies along a different line in a subterranean vault under one of the Bureau's buildings have given a more accurate value of the mass of the earth. "When a bubble once gives way its complete disappearance is so rapid as to lead to the common impression that it is instantaneous," said Dr. Heyl. "The very rapid spark photographs taken of a breaking bubble by Dr. Qualye shows that the bursting of a bubble is a progressive process, though a very rapid one. Photographs have been obtained of a bubble which has had a bullet fired through it. For a few millionths of a second (long enough to be photographed) the bubble stands as if in amazement with a hole in each side. The holes rapidly increase in size, the water film spraying off at the edges into fine drops, until in a thousandth of a second or so the bubble is gone. "One of the first things to catch the attention when a bubble has been successfully blown is the shimmering play of colors reflected from its surface. These colors, we notice, are formed somehow in the act of reflection of the colorless light of day from the surface of the bubble. It is possible, with a little practice, to detach the bubble from the pipe by which it was blown, and to catch it upon a piece of cloth, where it may remain for some time. If we closely examine the distribution of colors on such a quiet bubble we may be fortunate enough to see colored bands moving downward from the top of the bubble to the bottom. The north pole of the bubble seems to be the storehouse whence the bubble draws these colors in succession. And if we are excep THE BULLET AND THE BUBBLE phtogr aph made in the sound laboratory of the U. S. Bureau of Standards by means of an electric spark, by Philip P. Quayle, showing a soap bubble through which has been fired a rifle bullet. The bullet has passed out of the bubble, but it still stands, with a hole in each side. The lines extending from the front of the bullet are sound waves