![]() ![]() That is, light with shorter wavelengths -blue, green, indigo, and violet -is scattered more strongly than is light with longer wavelengths -red, orange, and yellow. When white light from the sun collides with molecules of oxygen and nitrogen, it is scattered selectively. The process of scattering is responsible for the fact that humans observe the sky as blue. Light that bounces off small objects is not reflected uniformly, but is scattered in all directions. ![]() The green light remains at this moment because the light rays of shorter wavelength -blue and violet -are scattered by the atmosphere. The green light is the very last remnant of sunlight refracted by Earth ’s atmosphere, still observable after all red, orange, and yellow rays have disappeared. That term refers to the fact that in the moment following sunset or sunrise,Ī flash of green light lasting no more than a second can sometimes be seen on the horizon on the upper part of the sun. One of the most dramatic examples of sunlight refraction is the green flash. The closer a star is to the horizon, for example, the more its apparent position is displaced from its true position. The same situation is true for any astronomical object. That is, the sun ’s apparent location is displaced by some angle from its true location. The eye sees the path of the light as it is bent and assumes that it has come from a position in the sky somewhat higher than it really is. Light from the sun enters Earth ’s atmosphere at an angle and is refracted. No refraction occurs, and no change in the sun ’s apparent position takes place.Īs the sun approaches the horizon, that situation changes. When the sun is directly overhead, the light rays it emits pass straight through Earth ’s atmosphere. Perhaps the most common example of an atmospheric effect created by refraction is the displacement of astronomical bodies. Light waves passing through water and then through air are bent, causing the eye to create a visual image of the object. The process of refraction accounts for the fact that objects under water appear to have a different size and location than they have in air. Refraction is the bending of light as it passes at an angle from one transparent material into a second transparent material. The color of a rainbow can partially be explained in terms of internal reflection. Of a transparent material (such as a water droplet), is reflected off the inside surface of the material, and is then reflected a second time out of the material. During internal reflection, light enters one surface One form of reflection -internal reflection -is often involved in the explanation of optical phenomena. For example, an object that appears to have a green color does so because that object absorbs all wavelengths of white light except that of green, which is reflected. Reflection can explain the origin of color in some cases, because certain portions of white light are more easily absorbed or reflected than are others. Reflection occurs when light rays strike a smooth surface and return at an angle equal to that of the incoming rays. That interaction takes one of three general forms: reflection, refraction, and diffraction. The fact that colors appear in the atmosphere is a consequence of the way that white light is broken up into its component parts -red, orange, yellow, green, blue, indigo, and violet (the spectrum) -during its interaction with materials in the atmosphere. Such phenomena include a wide variety of events ranging from the blue color of the sky itself to mirages and rainbows to sundogs and solar pillars. Atmospheric optical phenomena are visual events that take place in Earth ’s atmosphere as a consequence of light reflection, refraction, and diffraction by solid particles, liquids droplets, and other materials present in the atmosphere. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |