Community Magazine December 2013

ANSWER: Dear Hanna, When we add soap to water, the water’s surface friction is reduced and the surface of the water becomes much more flexible. The surface stretches and enables us to blow air into it, just as if we were blowing up balloons. What is the function of a cat‛s whiskers? Whiskers expand an animal‛s sense of touch beyond the limits of its body. A cat‛s whiskers consist of particularly stiff hairs. When these hairs are bent, the cat‛s brain discerns the direction and speed of the bending, and is thus able to navigate away from obstacles. A cat that has no whiskers will find it difficult to make its way in the dark or to navigate its course along narrow corridors. Is black a color? True, your crayon box includes a black crayon. However, the truth is that black is not a color! Every ray of light consists of seven colors: red, orange, yellow, green, blue, indigo and violet. The color white is created from the blending of these colors. When a ray of light hits an opaque object that appears to us to be green, for example, that means that the object has absorbed all the colors in the light ray except green, which is sent back to the viewer‛s eye. If the object‛s color appears blue, that means that the object has absorbed all the colors in the light ray except blue. However, if the object‛s color appears black, that means that the object has absorbed all the colors in the light ray and has not sent back any color to our eyes. How does glue stick things together? Like all material in this world, glue is made up of tiny particles called molecules. Glue molecules act like very small magnets; in other words, each glue molecule attracts any molecules in its vicinity, whether they are glue molecules or the molecules of any other substance, such as paper, wood or metal. The “magnetic” or adhesive power of glue increases considerably when the glue dries. At this stage, the glue molecules attract one another and also attract the molecule of the glued materials with great force. Thus, once the glue has dried, the adhesion of the glued portions is very powerful. Why do people blush when they're embarrassed? Blushing is a nervous reaction that causes tiny blood vessels in your skin to widen. This allows more blood to flow to your skin and creates that reddening effect that you seem to know all too well. Blushing just happens to be your way of reacting to a particular situation. Someone else may not visibly blush, but they may very noisily tap their fingers or clear their throat. Everybody is different, but everybody gets embarrassed or nervous sometimes! TEVET 5774 DECEMBER 2013 83