posted on Feb, 13 2008 @ 01:40 AM
Lasers and light need something to bounce off of to be seen by us.
Here are the variables and rules:
* Given a continuous/homogeneous mist or humidity, all light beams will be visible as soon as it leaves the source and then spread and lose brightness
the farther it gets from the source. In that case you will see the beam all the way back to the device making the lightshow.
* As the density of water mist increases, so does the absorption of light
* As the power of light increases, the normal humidity/mist in the air will reflect light back to our eyes.
* To get a good hologram that hangs in air and is lifelike, you need a 2D sheet of VERY FINE mist that has more density then the surrounding humidity
so that the lasers have a sheet to project onto (for 2D objects). For 3D objects, you need a 3D mass of very fine mist and lasers set 360 degrees
around the object so that you can see all the way around the object with no dead spots. They can not really make 3D mist in the shape of sea monsters
or even planes and they can't make them move that fast even if they could as the mist would leave a trail you could see.
* If you have a very powerful laser or light and want to make a very bright hologram in the daylight, it may be so powerful that the normal humidity
will make the beam visible all the way to the laser device
* As the distance from the hologram and the laser increases, the hologram will look more fuzzy and thus, less life like. This is due to the first rule
and because of areas of temperature differences in the air (makes light look wavy like the air above something hot).
* Daylight holograms can be seen through since the light on the object behind the hologram is bright enough to see at the same time as the hologram.
If you can't see through it, and you know its done using light and lasers, then its not a hologram, its a projection onto a screen that can be seen
otherwise.
* The only 3D image that does not need mist is one where they use a VERY powerful laser to make a point of plasma in mid air. They do this by focusing
the light to a very small point in mid air, thus making the air ionize. If the lasers used to make those dots are red, green, blue or anything BUT UV
or IR you will see the beam (red laser=red beam). The dot will always be a blue/white dot no matter the colour of laser, this is due to air being
comprized of mainly nitrogen. Lasers of this power will blind you and might conduct lightning as well.
* Any and all holograms will look like light on a wall if its projected with a laser, you can not fool people with a hologram even if you didn't need
mist as a medium. They will shimmer and wave about due to those temperature differences.
* Lasers that can make bright hologram are VERY expensive
* [edit] Also Lasers projected on coulds will take the shape of the coulds
There are 3 types of holograms
* The plasma dot type, not for real looking images.
* Laser/light projected onto mist or some other semi-solid/solid medium.
* Lasers shone onto an object that is to be photographed, then the end result is a 2D photo that looks 3D depending on the angle you look at it. The
photo is the medium, without it, you will not get the effect.
[edit on 13-2-2008 by XL5]
spelling
[edit on 13-2-2008 by XL5]