You always see yourself in a mirror. Have you ever wondered what the color of a mirror is? It’s a tricky but interesting question. The mirror reflects light at the same angle and direction from which it arrives. It is called specular reflection, which creates an image of whatever is in front.
The “specular” means “mirror” in Latin. Different images depend on how you look at the mirror with this type of reflection. The image changes as we move around a room. It gives the illusion of a window into some mirror universe.
What is the color of mirror?
The word reflection comes from the Latin “reflectere,” meaning “to bend backward.” They bend the light backward but in very different ways. They’re going to end the same, aren’t they? Even under a microscope, a mirror is incredibly smooth, so the surface always faces the same direction. The light still obeys the law of reflection at each spot, but different spots face different directions, so the light scatters instead.
Do you think it is white or silver? If you think so, you are wrong; if you think it is colorless, you are wrong. So what’s the color? Before starting, here’s a question for you.
First of all, we need to know how anything reflects any color. It is the wavelength of all the reflected ways with maximum intensity from the object and color. Let’s take the example of grass. The grass is green in color, but why? It’s because grass absorbs all the color except green and reflects it.
White light contains seven colors. If seven color falls on grass, why only see it as green? When all seven colors force grass, grass absorbs all the colors except green. That green is reflected in the grass, which appears green.
Do you know that black is not a color? When an object can absorb all seven colors of white light, it appears black. Black is the absence of color. When an object reflects all colors, it becomes transparent. Now back to the topic, if you take yellow paper and shine pink light on it, it will try to reflect as much yellow as possible. Also, it will try to absorb all pink colors. But it can absorb only up to a limit.
The same happens when you eat as much as possible and reject the remaining food. The paper will absorb all pink colors and reject yellowback. As Pink light is more than yellow, it reflects pink more than yellow. This is also why laser light strength gets lighter after reflecting from one wall to the other.
So the mirror reflects all the colors. So shouldn’t it be white? No, as mentioned earlier, it is not white. A mirror may look white or silver as it is usually depicted. The mirror reflects in a wavelength of 510 NM, green in color. You cannot see the wave with your eyes because it is tiny, 5.1 x 10 negative 7 meters. Don’t believe it? You can prove it yourself with the help of a mirror tunnel or an infinite mirror.
A mirrored tunnel is basically to mirror put facing each other. It creates an image inside an image, and so on. It is endless. Here a question will come to your mind why is it getting smaller? It is because of the distance between the two mirrors. Why does the image getting a little blurred? It is because the mirror not only reflects but also absorbs little light. It is like I give you an apple. You eat a little of it and pass it back to me.
Why is the mirror green?
Now you will also see, at last, it appears green. But why green? It is because common mirrors have a layer of glass soda. It is normally soda-lime glass and has iron oxide impurities which give it a slightly greenish color. If you don’t feel able to see, don’t worry. Your mirror may be too polished.
The mirror is made of atoms, usually silver or shiny metal. We like to imagine that light interacts with the atoms on top, but there are spaces between those atoms that the light can fit through. Scattering can happen off many layers of atoms and still contribute to the reflected light. The mirror-like reflection in this plastic is from the surface atoms. The color is from the layers underneath. That’s not even considering the wave nature of light. If we do that, each atom sends its light in all directions, including the material.
Ultimately, those light waves cancel except in two specific directions. The incoming beam splits in two at any surface. It doesn’t have to be transparent. Some of the light will reflect. How much is reflected or transmitted depends on many things: the materials involved, the incoming angle, the frequency of the light, etc.
- Because of transparency, the light is about 5% reflected and 95% transmitted for an air-glass boundary. For a mirrored surface, it’s the other way around.
There’s always some transmitted light, even for a mirror.
What makes these materials different is how far that transmitted light can go. It’s something called Penetration Depth. This penetration depth depends on four things:
- The electric and magnetic field properties of the material.
- The frequency of the incoming light.
- The electrical resistance the material can provide.
A silver mirror, it’s 1.4 nanometers. That’s drastically different from glass. So it goes that far and stops? Well, no. The light intensity drops off exponentially. A penetration depth of 1.4 nanometers means that for every 1.4 nanometers, the light goes into the silver. At one penetration depth, the intensity is 37% of the original. At five penetration depths, the intensity drops below 1%.
For the silver mirror, that’s still only 7 nanometers. That transmitted light is going nowhere fast. Based on this equation, transmitted light won’t go as far in electrical conductors. That’s what gives metals that distinctive metal coloring we all recognize. The light barely penetrates.
Atoms can absorb light in two ways: Resonant Absorption and Dissipative Absorption. Resonant absorption is when a single electron absorbs a single photon with the energy needed to bump the electron to a higher energy level. This is the absorption that results in things like fluorescence and phosphorescence. It is not the absorption that creates reflected and transmitted light beams. When this happens, the electron usually doesn’t have a chance to re-emit that light.
Fluorescence and phosphorescence are special exceptions. Reflected and transmitted beams come from the other type of absorption: Dissipative Absorption. This type doesn’t require quantum mechanics. It is a very classical effect. An atom is minding its own business when some light comes along. As the atom is made of charge, the light’s electric field drives the atom’s motion. They are also responsible for the green color of the mirror.
Frequently asked questions
What is a mirror made of?
About five thousand years ago, mirrors were made of highly polished metal discs such as bronze, copper, and super-rich gold. A mirror was a highly prized symbol of status and wealth. But then, around the first century Common Era, another style of mirror arrived, the metal-backed glass mirror.
By the 16th century, glass artisans in the Republic of Venice had become good at silvering. That’s the process of coding glass with a thin layer of metal. The only thing one metal used in this process is mercury, also known as one of the most toxic metals in the world.
Then in the mid-1800s, German chemist Justus von Liebig figured out how to use actual metallic silver in his silvering process. A mirror begins as a large sheet of plate glass is first cleaned with hot demineralized water, and then the layering begins. First comes a layer of liquid tin and silver, though some manufacturers will use aluminum instead.
In either case, these metals react or harden. You have a reflective surface. Covering this sewing with a couple of layers of protective paint is relatively simple. It is then baked to cure or set that coating. Underneath the layer of glass, the silver ring will never need polishing and will never dull.
What are the two types of mirrors?
There are two major types of mirrors. One is a curved mirror, and the other is a flat mirror.
Why do mirrors flip left?
You’ve probably noticed that words look backward in a mirror but aren’t upside down. Mirrors don’t flip left and right or up and down. If you look carefully at a scene in a mirror, you’ll notice that everything on the left stays on the left, and everything on the right stays on the right. Also, everything up stays up, and everything down stays down.
What does get flipped in the direction into or out of the mirror? The things closest to us end up farthest away, and those farthest from us end up closest. Mirrors flip not left and right, nor up and down, but depth – they flip in and out. Also, mirrors invert in and out because they reflect light according to the principle of specular reflection: light coming into the mirror at a given angle bounces back off at the same angle.
M. A. Kallistratova. “Physical grounds for acoustic remote sensing of the atmospheric boundary layer.” Acoustic Remote Sensing Applications.
Fioratti, Helen. “The Origins of Mirrors and their uses in the Ancient World.” L’Antiquaire & the Connoisseur.