Holography

So what is holography......wouldn't you like to know:) Its a crazy photography that you have probably seen today but may not have noticed. It is used in so many different ways today that you would be quite surprised.

Holography is "lensless photography" in which an image is captured not as an image focused on film, but as an interference pattern at the film. Typically, coherent light from a laser is reflected from an object and combined at the film with light from a reference beam. This recorded interference pattern actually contains much more information that a focused image, and enables the viewer to view a true three-dimensional image which exhibits parallax. That is, the image will change its appearance if you look at it from a different angle, just as if you were looking at a real 3D object. In the case of a transmission hologram, you look through the film and see the three dimensional image suspended in midair at a point which corresponds to the position of the real object which was photographed.

Well, a hologram is like a picture. Sort of. You see, when you look at a picture -- like a photograph -- it is flat. If you took a regular picture of a big marble, and it had a smaller marble behind it, you would not be able to look around the big marble to see the little one.
With a HOLOGRAM, you would be able to look around the big marble and see the little one behind it. It's true. That's because a hologram is in 3-D. The letter "D" in "3-D" stands for the word "dimension". The "3" in "3-D" stands for how many "dimensions" something has.

A photo, a piece of paper -- or even this computer screen -- is 2-D, or two dimensions: up and down and left and right. When something has 3-D, like the world in which we live -- or a hologram -- it has an added dimension: up and down, left and right and forwards and backwards. When talking about dimensions, we call forwards and backwards "depth". So . . . when we say that a hologram has 3 dimensions, it means we can see up and down, and left and right, just like a picture or photo . . . but we can also look "into" the hologram because the hologram, and the objects that it contains, has depth.

Looking at a certain types of holograms is just like looking at something that is really in front of your eyes. In fact, some holograms are so real that you want to take your hand and touch the object in it -- but your hand goes right through thin air. Imagine getting up to get a soda while you're watching a holographic Super Bowl. When you walk across your living room, you'd walk right through the players. You could try to kick the ball, but your foot would pass right through it.

Well, someday everything that we look at will be holographic images. In fact, all of those "really cool" special effects that you love in the movies today . . . would you believe that someday you will actually LAUGH at them? One day in the future, 3-D holographic images will be sent into our homes and we will see all the action as if it is taking place right in our own living rooms.

We do not have it now because we are not as advanced in science and technology as we sometimes like to think we are. If you have an antenna, cable TV, or a sattelite dish, you know that what you watch on TV has to get there somehow. It's OK for us to send regular pictures to a TV, but we cannot send a hologram. In fact, we are not even close to being at the point where we can send a hologram and have it show up in someone's house. It's going to take a lot of clever minds (like your own) to make this happen. But it will happen. And maybe, yes maybe, you'll be part of it.

With holography, we can test all kinds of things . . . from automobile engines, to aircraft tires, to artificial bones and joints. This type of holography is called "interferometry", and the resulting hologram is called an "interferogram". Holography is also used in medical imaging where doctors can look at a 3-dimensional cat scan and actually go in and take measurements within the holographic image.

Very simple (and colorful) holograms are used on consumer packaging materials such as cereal and toothpaste boxes, and a host of other items. Holograms are used for security for credit cards and for identifying manufactured objects such as clothing to help cut down on conterfeiting.
Holographic Optica Elements (HOE's) are used by airplane pilots for navigation. It allows them to keep their eyes on the sky or runway, while still being able to read their instrumentation . . . which appears to float in front of their cockpit window. This feature is already available as an option on several automobiles. Holographic lenses and contacts can make one lens provide several different functions, such as correcting regular vision and also act as magnifiers for reading -- all in the same lens, and throughout the entire lens at the same time. Holograms can be made into portraits of people, pets, etc. Artists use holography to express their creativity and are shown in galleries around the world. They are used in printing for magazine and book covers. National Geographic as well as Sports Illustrated (Michael Jordon) have been famous examples. They can be used for point-of-purchase advertising, taking the place of a photograph of a product or service in a store or supermarket. Holograms can be used for data storage such as holographic hard drives. The entire contents of the library of congress can be stored in the area the size of a sugar cube.

As the technology grows and develops we will see holographic television and motion pictures as mentioned earlier. So yeah that was alot of information but I hoped you learned something new. Actually this was probably all new to you, because it was definitely all new to me:) Oh I thought this picture was cool.