Show A SOAP BUBBLE the relation of its varying thinness to the colors it shows the extreme thinness of the bubble is indeed wonderful it is estimated that the film in some places is anly one three millionths of an inch in thickness probably few of us can conceive of such thinness let me express it in another way the old and the new testament contain some 3 of letters now one three millionth is such a part ifan inch filch as the first letter of the bible is a part of the sum of all of its letters the bubble however is not of equal thickness at all points and it is dorthis for this reason that it has the various colors for il instance istance wherever the film is orange red it measures about three mil liontos of an inch where it is blue eighty one millionths of an inch and at a point where lemon yellow is prominent about twenty one millionths of in an inch perhaps you wonder why the colors change from one part of the soap bubble a to an another other this is because the film filin of the soap bubble evaporates and grows thinner but unequally so at different portions A greenish blue with a pale rose red spot near it indicates an extreme thinness and at such a point the film is ready to give way at the least jar you will he be glad to know th the a source of the beautiful colors V everyone very one is delighted with them even if not inhere interested ts by the explanation of their origin we may say that they come from the light light gives color to all objects but not exactly as it does to the soap bubble white light from the s sun ran can be broken into the seven colors which behave seen in the rainbow in that instance the raindrops separate it into its parts A glass prism will do the tha same as you may prove by looking through a glass pendant from a h hanging anding lamp when the light reaches the surface of the soap bubble a part is reflected from it and we see images on its surface as if it were a curved mirror another portion of the light however enters the film and is ie separated so that parts of the seven colors are thrown into the bubble and we can see them at various portions of the opposite surface another part of the light after being broken by the film is reflected by its inner surface back to our eyes so that wo we see colors at the point where the light enters jacob P F bucher in st nicholas |