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One way mirrors are a common sight in many police interrogation rooms, airports, and convenience stores. But what is it about these seemingly fragile pieces of glass that allow certain people to see out while the rest of us can’t see in?
In order to understand what makes this possible, you need to first learn a bit more about how light works. For starters, we know that a beam of light is comprised of photons… particles of light with no mass and very little energy. These photons pass through various materials, such as glass, and cause them to vibrate. Because the vibrations are so small you can’t hear them, but they can be felt.
When light passes through a medium, it scatters off the electrons in that medium. If the material isn’t too dense it will scatter off just one electron: if it’s denser than that laser light may not be able to pass through, and instead will gain energy in an attempt to continue its journey. Thus a beam of light could never go from one point A to another point B without losing some of its original energy first.
However, there is a loophole for these photons… if they are given one final shove. One mirror can act like a tiny particle accelerator that accelerates all the photons in its path. In fact, if you put a mirror so far back in the room that it actually is a particle accelerator, then there is no way for light to penetrate it.
A simple experiment will show how this works. If you shine a laser into two small pieces of aluminum foil, scatter off the foil’s electrons and then shine a flashlight at them, you will notice that instead of seeing the beam where it came from, you will see almost all of the light projected on to one piece of foil (about 70%).
The Shortlist...
how to make a one way mirror
Place the thinly livered mirror in between the two rooms
Adjust the lighting in one of the rooms so that is dim in one room and very bright in the other room
Look through the mirror while in the bright room
Look through the mirror now while in the dim room with very little light on the mirror. This will help you see through the mirror
how can you tell a one way mirror?
It is easy..place your finger on the mirror. If there is a gap between your nail and the mirror, it is a genuine mirror.
can light pass through a one way mirror?
Some light can pass through but not much
do one way mirrors work at night?
No they do not. Both sides can be seen at night, especially if you look into mirrored office buildings.