WHAT MAKES A SOAP BUBBLE?

Northern Advocate, 10 November 1934, Page 6

WHAT MAKES A SOAP BUBBLE?

Have you ever stopped to think how bubbles are formed? They are simply hollow balls of water, with air inside. You see, when air gets into water It always tries to force its way up through the water to escape, and in such a way as to form the bubble. The air inside the bubble, and the water that forms its case are struggling against each other. The air wants to rise, and the water wants to fall; but because the air is the stronger, the bubble rises and floats. The water casing round the bubble is very thin, and the water keeps running down to 1 the bottom of the ball, where you can watch it form into drops. Soon 'this .continual dripping will make Die walls of the water bubble so thin that the air is able to force its way through the water, and that is why the bubble bursts. The soap bubbles that we used to have such fun with when we were very small always lasted very much longer than any other kind of bubble. That was because the soap makes the walls of the water ball that comes out of the. pipe tougher than usual, so that the air finds it very much harder to force its way through. The soap keeps the water in the bubble walls from running down to the bottom of the ball for a time, and that is why the soap bubbles will float in the air for quite a while. The colours we see on the soap bubbles are made by the sun’s rays striking on the bubble and reflecting them back to us in colours very like those of the rainbow. And now we come to the reason. The bubble is always round because the air inside the water walls presses with equal force against all sides of the bubble at the same time.