Izzy Asher recently gave me a gift of a bolo tie. He'd wanted to give me one with stars in it. That sounded cool, and when I saw it, it was indeed pretty cool. And then he explained how it was a one of a kind. He'd made it out of an old TV picture tube and a bag with holograms of stars on it. “Recycled”, he said. Wow.
So staring at those holographic stars got me to thinking about holograms. Holograms are a special kind of “image” where lasers are used to capture information onto some kind of material. The laser light is set up so that it is split so that part of the light goes directly to the “recording medium” while the rest of the light is scattered off the object and some of that light reaches the recording medium.
Because of the complex way that the two beams interact (interference, etc.) the hologram actually records three dimensional information about the object. And this was one of the things that made them exciting. I remember being in museums where there were three dimensional holographic images on display. The color was usually odd, since holograms don't really work in color.
Another feature of holograms, is that the whole image is recorded in each part of the hologram. As I understood it, early holograms where created on glass plates (just like many forms of early photography). So when you broke that glass plate each piece had the whole image in it. Of course, some information was lost, but that just made the image fuzzier, so you lost some detail, but you could still see the image.
Now this feature of holograms has been used as an analogy in some scientific theories. One deals with the so called “holographic universe” where the universe we live in is actually information that has been “printed” on a two dimensional membrane. Which sounds kind of weird. But a hologram contains three dimensional information printed onto a two dimensional recording medium. So it might be a reasonable analogy. And it might be testable. Which is important in science. No matter how odd a theory might sound, if there is a way to test it it can be sound science. So we'll wait and see if the gravity wave detectors see any signs of a holographic universe.
Another place where the hologram is used as an analogy is in the theory of the “holographic mind”. (It is also called holonomic) In this theory the mind works on interference patterns like holograms do. Our memories are formed by various waves in the brain forming interference patters that encode the events and images around us.
One consequence of this might be that memories are encoded in a way that makes memories available from small pieces of a memory. Which seems odd to me given how much my memory seems to lose even the fuzzy images of many events I should remember. But maybe when they test the theory out they'll find some truth in it, despite my doubts.
But I do have a holographic bolo tie that I can look into and see the stars. And I'm going to use it to remember when Izzy Asher gave me some stars.