words that we use, seem to us familiar, familiar from childhood and understandable.We think that we always know what we say and what we mean.But if you try to find out from any passerby on the street, for example, the word "ray", one can hardly expect a quick and correct answer.Really, what is it?
etymology
will understand to start with the origin of the word.According to the dictionary of the Russian language, the beam - a stream of light that comes from any source, or a narrow band of light coming from the glowing object.For example, the rays of the setting or rising sun.
exact origin of the term is unknown, but presumably, it originates from the Latin word for "light."In Slavic languages, the word is found everywhere.In Russian it got their Old Slavonic.
meaning and scope
word "Ray" in the first place is associated with sunlight.How many times have all heard the expression: "sun rays" or "ray of light".But in fact, this word has a direct relationship to the geometry.Ray - it's part of the line, which originates on the point, and on the other - is infinite.
have any ray is an extreme point.This is the beginning of the beam.Since it has no end, it is usually denoted by a single letter.Moreover, the beam - is one of the simple geometric shapes such as a line or a broken line.
beam concept also used in physics, but only in acoustics and geometric optics.There beam - is the line along which light energy is moving.
main feature geometric and light beam - is their straightness.But this is true of light only when its propagation in a uniform transparent medium.Otherwise it becomes curved.
How
see the light of this experience is very pleasant to children, it clearly show them what a ray of light.This requires simple cooking.It is necessary to darken the room and put on the table any flashlight.A beam of light is now barely visible, but if you squeeze sharply prefab plastic bottle of talcum or baby powder as powder particles, once in it, begin to glow.Now, children can see that the light beam - a strip of light from a flashlight and continuing into infinity.Why is this happening?The fact that light can not be seen until it is not reflected by any surface.Particles of talc, hitting a beam of light, making it clearly visible.
