Mirrors and reflections

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FIn summary, the conversation discusses the concept of mirrors and reflections and how they work. It mentions the role of metallic bonding in allowing electrons to be free of atoms and how this results in the reflection of light at the same frequency. The conversation also touches on the confusion surrounding the reflection properties of non-metallic surfaces, such as plastic, and how gold is able to reflect light while also adding a gold color to it. The conversation also delves into the physics behind mirrors and why they reverse left and right but not up and down. Overall,
  • #1
tom12519
I have been pondering for a while upon how mirrors and reflections work. In a standard shiny metal, metallic bonding allows electrons to be free of atoms and thus occupy any energy level. This means that electrons can absorb the photon and re-emit it as the same frequency. However, I still do not understand how a non-metallic surface (for example a thin sheet of plastic at a very low angle) can reflect light as well as how gold manages to reflect light but also have a gold colour apparently added to the light simultaneously.

Any responses/references to reading material would be greatly appreciated.
 
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  • #2
tom12519 said:
I have been pondering for a while upon how mirrors and reflections work. In a standard shiny metal, metallic bonding allows electrons to be free of atoms and thus occupy any energy level. This means that electrons can absorb the photon and re-emit it as the same frequency. However, I still do not understand how a non-metallic surface (for example a thin sheet of plastic at a very low angle) can reflect light as well as how gold manages to reflect light but also have a gold colour apparently added to the light simultaneously.

Any responses/references to reading material would be greatly appreciated.
The highlighted section is incorrect, specular reflection is due to the response of atoms on a surface excited by an EM wave and is a non-resonant process. In other words, you need to think of the atoms acting as little antennae, rather than bound electrons jumping up and down energy levels.

Claude.
 
  • #3
I believe that gold reflects infrared better than does aluminum. This is why the solar reflectors on space suit helmet lenses are covered by a thin layer of gold. This does offer increased efficiency for a solar power reflecting device.
 
  • #4
minorwork said:
I believe that gold reflects infrared better than does aluminum. This is why the solar reflectors on space suit helmet lenses are covered by a thin layer of gold. This does offer increased efficiency for a solar power reflecting device.

Is it something to do with the softness of gold?. Gold is easily made to very thin plates.
 
  • #5
I couldn't say why. Around the gas crunch in the early 70s I was building reflector molds and the Physics and Chemistry Handbook showed gold reflecting better. Right now I don't know where the wife has hid it. Gold is the most malleable of metals. Pretty dense too.

Mirrors mess me up anyway. Why do they reverse right and left and not up and down?
 
  • #6
minorwork said:
I couldn't say why. Around the gas crunch in the early 70s I was building reflector molds and the Physics and Chemistry Handbook showed gold reflecting better. Right now I don't know where the wife has hid it. Gold is the most malleable of metals. Pretty dense too.

Mirrors mess me up anyway. Why do they reverse right and left and not up and down?

I am still very confused about reflection property of metal and other material. Why only very smooth surfaces reflect better?, why graphit doesn't reflect well? etc..
As for your question of mirror : left-right and up-down, it only because the mirror turn your image 180 degrees compared to you. When you turn, your up is still up, down is still down, but your left turn to right and vice versa.
 
  • #7
You are right. I looked some stuff up and a mirror reverses symmetry. Humans are bi-
lateral symmetric. That is we are not symmetric top and bottom. Thought I saw a similar question to yours somewhere on this site with a pretty good explanation. If I find it I'll mention it.
 
  • #8
Mirrors show lateral inversion because of the fact that the distance the image is behind the mirror is the same as the object is infront so think of a letter F infront of a mirror, pick some points on the letter F to the left of the mirror and think where their image would appear to be in the mirror then join these point up to reconstruct the letter and you will see it have been left to right reversed.

F ¦
 

1. How do mirrors create reflections?

Mirrors are made of a thin layer of metal, usually silver or aluminum, that is applied to the back of a glass surface. When light hits the mirror, it bounces off the metal layer and creates an image that we see as a reflection.

2. Why do mirrors reverse images horizontally but not vertically?

This phenomenon is known as the "mirror reversal effect." It occurs because when light reflects off a mirror, it follows the law of reflection, which states that the angle of incidence (incoming light) is equal to the angle of reflection (outgoing light). This results in a horizontal flip of the image, but the top and bottom remain in the same position.

3. Can mirrors create infinite reflections?

Yes, mirrors can create infinite reflections, also known as an "infinite mirror effect." This occurs when two mirrors are placed facing each other, and the reflections bounce back and forth between them. The reflections appear to continue on forever because the light is constantly bouncing back and forth between the two mirrors.

4. Do mirrors work differently for different wavelengths of light?

Yes, mirrors reflect different wavelengths of light in different ways. For example, mirrors may reflect visible light very well but absorb infrared light. This is why some objects may appear differently in a mirror (such as looking darker or lighter) compared to how they look in natural light.

5. Can mirrors be used to create 3D images?

Yes, mirrors can be used to create 3D images. This is typically done using a technique called "anamorphosis," where a distorted image is reflected in a cylindrical or conical mirror, and when viewed from a specific angle, it appears as a 3D image. This technique is commonly used in funhouse mirrors and street art installations.

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