Holograms are something that has been around for a long time, are widely used but are barely understood by the average person. To be fair that is understandable when many technologies like holograms, the internet, tv, and more are barely understood. For example, do you actually know how photographs work? How an image in real life is captured and presented on a film? If you start to ask questions like this you will end up going down a complicated yet fascinating rabbit hole. Today we want to point you in the direction of that rabbit hole.
Holograms are a mystery to most but they don’t have to be. To understand how a hologram works we simply need to understand how a picture is taken, the answer is light. Let’s imagine you have an old camera (new cameras essentially do the same thing but are far more efficient) and you want to take a picture of a shoe. You would simply grab your camera and click the button. The camera would then open the lens and let light through to hit the film. The light travels from the outside environment and imprints an image on the film. Essentially the light travels from the shoe and the table it is on and goes directly towards the camera creating a 2D image of light, dark, and color.
Now imagine you are just looking at the shoe. If you were in the exact same position as the camera you would see almost the exact same image but slightly different. This is because you have two eyes and light is going into your two eyes creating two separate images and your brain is combining them to make sense of it. This allows you to see in three dimensions. If you moved your head the image would change. The light and dark shades of the shoe would alter based on your position and the angle would alter too.
This is where a hologram comes in, it is like taking two viewpoints of the same image. This is done using laser light. As we all know from looking at Pink Floyd albums when you send light through a prism it splits into all the colors of the rainbow. Yet when you split laser light it is stronger and splits to create two lights that are the same color. Scientists use this fact and split laser light with a mirror to send two beams at an object from a different direction. They actually use one mirror to split the laser and two more mirrors to send the two beams back towards an object (the shoe in this case).
This then creates an image of the shoe that changes depending on the light. If you move the hologram the shoe will change position as if viewed from two different angles. While you may think of holograms as only used in gimmick concerts and science fiction movies they are actually all around you. If you have your wallet or purse take out some notes and check to see if there are any holograms in place. If you have a visa card you may be surprised to find a hologram of a dove on the back located on a silver screen.
These are placed there because holograms are incredibly difficult to recreate and therefore help to increase security. If you have ever seen bad counterfeit notes you will remember that they replaced the hologram with a simple picture. The effort to recreate the hologram itself was too much.
One last amazing fact about holograms is that they are divisible. If you cut a picture of a shoe in half you will have two pictures, each of half a shoe. If you cut a hologram of a shoe in half, you will have two holograms both of a full shoe. We don’t recommend cutting your credit card in half to test this theory out, instead search on YoutTube for some great videos that show it in full.