What makes mirrors shiny

And what are they doing in the water?! Basically, anything with a smooth surface that reflects almost all of the light that hits it — with only very little light absorbed or scattered — can be a mirror. The key factor is a smooth surface, because rough surfaces scatter light instead of reflecting it.

When photons — rays of light — coming from an object your smiling face, for example strike the smooth surface of a mirror , they bounce back at the same angle.

Your eyes see these reflected photons as a mirror image. The mirror image is reversed , which you can easily see if you stand in front of a mirror with a shirt with words on it. The words on the shirt appear backwards in the mirror. Of course, not all smooth surfaces act as mirrors. If a smooth surface absorbs the photons, they can't bounce back and there will be no reflection.

Although calm , dark water has been used as a mirror since the beginning of time, people started making mirrors thousands of years ago. The first mirrors were likely polished stones, such as obsidian a type of volcanic glass.

Large pieces of polished metal , such as brass, were also used as mirrors, although these were very expensive. The modern mirrors you're familiar with are much more recent.

European glass makers began developing a process of coating clear glass with a thin layer of reflective metal in the 15 th and 16 th centuries. Today, mirrors are usually made of clear glass that has been coated on one side with a thin film of metal, such as silver or aluminum.

The mirrors in most bathrooms are these types of mirrors, known as plane mirrors. They are flat and reflect the objects in front of them accurately , maintaining the same relative size and position of the objects reflected. In addition to helping you make sure your hair looks nice before you head out to school or off to work, mirrors serve many important functions.

For example, rear-view mirrors on a car allow you to see what's behind you before you back up. Mirrors are also important parts of telescopes and microscopes. Mirrors can even help you watch television.

Today's high-definition televisions often rely upon millions of microscopic mirrors to display those beautiful, crisp images you enjoy watching so much! Up there in the sky! It looks a bit like a cloud. Find out more tomorrow in Wonderopolis! Ready to have some fun with mirrors? For today's activities, you'll need to find a couple mirrors to use.

Make sure you get permission to use a mirror if it belongs to someone else. Ask a couple friends or family members to join you as you reflect on today's activities:. We're sorry you feel like that, Naomi. You can always explore Wonders to find something more educational for you.

So glad you enjoyed learning something new with us! We LOVE learning new things. That's too bad, Yoyo. We encourage you to check out our Explore Wonders page and we bet you will find something that interests you. I appreciate the information on how a mirror works. I had no idea that some mirrors were actually made of silver or even aluminum really, I always thought it was some sort of plastic underneath the glass.

My niece has been asking about how mirrors work and how they can reflect so good, I will be sure to share this with her. Hi, Ben! We are so glad that you learned something new with us on this Wonder! We deleted your link only because we don't publish links from users as a general policy.

Yeah, Trinity, really as long as smooth, reflective surfaces have been around, then mirrors have been around. Do you think dinosaurs were checking their reflection in a mirror to see how they looked? We're glad you are our Wonder Friend, Chloe!

We bet your mom wants to make sure you take breaks from using computers and tablets, to make sure you get exercise and to give your eyes a break from the screens.

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Thanks so much for commenting today! Thank you Wonderopolis, you have changed my life. I have worked in the mirror industry for 30 years now, and I have always wondered how they work. With this amazing article it broke it down for me in every detail.

I have a grandson who is working on a science fair project about optical illusions, and I told him their would not be an optical illusion without a mirror, so he asked me how do mirrors work, so I searched it up, and it led me to this wonderful article.

Thank you so much Wonderopolis, and I will always be wondering with you. Thank you so much, Tbone! We are thrilled that your Wonder Journey led you to Wonderopolis! We are so glad to have you as a Wonder Friend, and we're happy to help you learn more about mirrors! We are undergoing some spring clearing site maintenance and need to temporarily disable the commenting feature. Thanks for your patience.

Drag a word to its definition. Scientific mirrors are designed with virtually no imperfections or distorting qualities whatsoever. Materials technology drastically affects the quality of a mirror. Light reflects best from surfaces that are non-diffusive, that is, smooth and opaque, rather than transparent. Any flaw in this arrangement will detract from the effectiveness of the mirror.

Innovations in mirror making have been directed towards flattening the glass used and applying metal coatings of uniform thickness, because light traveling through different thicknesses of glass over different parts of a mirror results in a distorted image.

It is due to these irregularities that some mirrors make you look thinner and some fatter than normal. If the metal backing on a mirror is scratched or thin in spots, the brightness of the reflection will also be uneven. If the coating is very thin, it may be possible to see through the mirror. This is how one-way mirrors are made. Non-opaque coating is layered over the thin, metal backing and only one side of the mirror the reflecting side is lit.

This allows a viewer on the other side, in a darkened room, to see through. Glass, the main component of mirrors, is a poor reflector. It reflects only about 4 percent of the light which strikes it. It does, however, possess the property of uniformity, particularly when polished. This means that the glass contains very few pits after polishing and will form an effective base for a reflective layer of metal. When the metal layer is deposited, the surface is very even, with no bumps or wells.

Glass is also considered a good material for mirrors because it can be molded into various shapes for specialty mirrors. Glass sheets are made from silica, which can be mined or refined from sand. Glass made from natural crystals of silica is known as fused quartz. There are also synthetic glasses, which are referred to as synthetic fused silica. The silica, or quartz, is melted to high temperatures, and poured or rolled out into sheets.

A few other types of glass are used for high-quality scientific grade mirrors. These usually contain some other chemical component to strengthen the glass or make it resistant to certain environmental extremes.

Pyrex, for example, is a borosilicate glass—a glass composed of silica and boron—that is used when mirrors must withstand high temperatures. In some cases, a plastic substrate will do as well as a glass one. In particular, mirrors on children's toys are often made this way, so they don't break as easily. Plastic polymers are manufactured from petroleum and other organic chemicals. They can be injection molded into any desired shape, including flat sheets and circles, and can be opaque or transparent as the design requires.

These base materials must be coated to make a mirror. Metallic coatings are the most common. A variety of metals, such as silver, gold, and chrome, are appropriate for this application. Silver was the most popular mirror backing one hundred years ago, leading to the coinage of the term "silvering. More recently, before , mirror manufacturers used mercury because it spread evenly over the surface of the glass and did not tarnish. This practice was also eventually abandoned, for it posed the problem of sealing in the toxic liquid.

Today, aluminum is the most commonly used metallic coating for mirrors. Scientific grade mirrors are sometimes coated with other materials, like silicon oxides and silicon nitrides, in up to hundreds of layers of, each a 10,th of an inch thick.

These types of coatings, referred to as dielectric coatings, are used both by themselves as reflectors, and as protective finishes on metallic coatings.

They are more scratch resistant than metal. Scientific mirrors also use silver coatings, and sometimes gold coatings as well, to reflect light of a particular color of light more or less well. Surface regularity is probably the most important design characteristic of mirrors. Mirrors for household use must meet roughly the same specifications as window panes and picture frame glass. The glass sheets used must be reasonably flat and durable. The designer need only specify the thickness required; for example, thicker mirrors are more durable, but they are also heavier.

Scientific mirrors usually have specially designed surfaces. These surfaces must be uniformly smooth within several lOOOths of an inch, and can be designed with a specific curvature, just like eyeglass lenses. The design principle for these mirrors is the same as that of eyewear: a mirror may be intended to focus light as well as reflect it.

The mirror design will also specify the type of coating to be used. Coating material is chosen based on required durability and reflectivity and, depending on the intended purpose of the mirror, it may be applied on the front or back surface of the mirror.

Any subsequent layers of protective coatings must also be specified at this stage. For most common mirrors, the reflective coating will be applied on the back surface of the glass because it is less likely to be harmed there.

The back side is then frequently mounted in a The initial step in mirror manufacture involves cutting and shaping the glass blanks. Cutting is usually done with a saw with diamond dust embedded in the tips. Once the separation occurs, any moisture — even just steam from showering — can begin to cause the black spots to appear. By understanding what causes mirror rot, Calgary homeowners and business owners are in an excellent position to prevent it from ever happening.

The first step is to ensure your glass cleaners are ammonia-free. If a cleaner is responsible for your mirror, instruct them not to use ammonia-inclusive cleaners on your mirrors. When the solution is sprayed on the mirror, it often drips and pools along the edge, increasing the likelihood of the glass layer separating.

By spraying onto a rag instead, there will be no pooling fluid. Finally, protect the mirror from moisture.