Since the light strikes different parts of the surface at different angles, it is reflected in many different directions, or diffused. Diffused light is what allows us to see a sheet of paper from any angle, as illustrated in Figure 3. Many objects, such as people, clothing, leaves, and walls, have rough surfaces and can be seen from all sides.
A mirror, on the other hand, has a smooth surface compared with the wavelength of light and reflects light at specific angles, as illustrated in Figure 4. When the moon reflects from a lake, as shown in Figure 5, a combination of these effects takes place.
Figure 2. Light is diffused when it reflects from a rough surface. Here many parallel rays are incident, but they are reflected at many different angles since the surface is rough. Figure 3. When a sheet of paper is illuminated with many parallel incident rays, it can be seen at many different angles, because its surface is rough and diffuses the light.
Figure 4. A mirror illuminated by many parallel rays reflects them in only one direction, since its surface is very smooth. Only the observer at a particular angle will see the reflected light.
Figure 5. If the glass is translucent then some is reflected back while some frequencies pass through.
Ultraviolet is blocked by glass. Some object appears to be shiny due to the wave nature of light. The bending of light as it passes an object causes the object to appear shiny due to its reflection. The most shiny metal is aluminum. There are also some other metals which are shiny and they include iron and silver among others. Because plant waxy cuticle present in shiny leaves.
For some trade IDs-for a shiny tentacool level 1 is 14f5e39dd93d55 and for a shiny staru is 14f5ed4. Log in. Study now. See Answer. Best Answer. Some lights and torches have a shiny back in order to reflect the light better. Study guides. More answers. Q: Why do some lights and torches have a shiny back? Write your answer Related questions. Why do some light and torches have shiny? Where do you find wolves in Minecraft? In most flashlights, the lamp is either a tungsten filament incandescent bulb or a light emitting diode solid state bulb , also known as an LED.
The tungsten filament or LED glows when electricity flows through it, thus producing visible light. Tungsten is a natural element and the tungsten filament is a very thin wire. Tungsten lamps must be replaces when the tungsten filament breaks. An LED contains a very small semiconductor diode that is encapsulated in epoxy and this part emits light when electricity flows through it.
LED's om flashlights are widely considered "unbreakable" and not replaced — a lifetime lamp. Phosphors are substances that give off light -- or fluoresce -- when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons jumps to a higher energy level, causing the atom to vibrate and create heat.
When the electron falls back to its normal level, it releases energy in the form of another photon. This photon has less energy than the original photon, because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum -- the phosphor gives off white light we can see. Black lights work on this same principle. There are actually two different types of black light, but they work in basically the same way. In both of these light designs, the emitted UV light reacts with various external phosphors in exactly the same way as the UV light inside a fluorescent lamp reacts with the phosphor coating.
The external phosphors glow as long as the UV light is shining on them. In the next section, we'll see what kinds of objects contain phosphors, and we'll look at some interesting uses for black lights. If you walked around all night with a portable black light, you would discover that there are phosphors all over the place.
There are lots of natural phosphors, in your teeth and fingernails, among other things. There also a lot of phosphors in manmade material, including television screens and some paints, fabric and plastics. Most fluorescent colored things, such as highlighters, contain phosphors, and you'll find them in all glow-in-the-dark products. Clubs and amusement parks use special black light paint that glows different colors. You can also buy fluorescent black light bubbles , invisible black light ink, fluorescent black light carpet and even fluorescent black light hair gel.
In addition to making people and fluorescent posters look cool, black lights have some practical applications. For example:. Most of these uses, as well as dozens of others, follow a common theme -- the black lights make the invisible visible or isolate one specific substance from everything around it. When you think about it, there are dozens of situations where you could put this phenomenon to work. The applications are potentially endless!
For more information on black lights and other sorts of light energy, check out the links on the next page. Sign up for our Newsletter!
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