Active Scanning, Why Not?

For my first course of meat n' potatoes I'll ruminate on Active Scanning.

Scanning and perception are more or less synonymous. Things of alls sorts be detected with our five senses without any special means, this is passive scanning, or everyday perception. Humans can't passively scan anything when there isn't enough energy to detect anything. This is darkness to the eye, silence to the ear, cold to the touch, and so on.

This brings in active scanning. If there is something that you can't detect passively through your senses, it is always because the energy from the thing isn't reaching your eyes, ears or whatever. A great way to overcome this obstacle is to some how get appropriate energy to bounce off of whatever you want to detect, so that you can observe the energy as it bounces back and hits you. What "appropriate" is depends on what sense you use to detect the thing. If you want to see it, shine light. If you want to feel it, make it warm. If you want to hear it, throw sand or water or something else on it, and you'll hear where it is.

For the sake of argument, I'm going to call the energy that is used to bounce off something as the Probe, and the thing that is to be detected the Target. The returning energy-information I'm going to call the Resolution.

This occured to me when I was watching CSI, that burgeoning bastion of realistic ragamuffins. Marg Helgenberger had a flashlight semen scanner with a special bulb with another filter attached to it. Like this:


In this case, our Target is semen. Marg can't see the semen because our average everyday Probes, indirect sun, incandescent or flourescent light, when shined on semen, mostly pass through it and bounce off whatever the semen has landed on, ususally a patterned blanket or sheet. Sure, minor discoloration might appear, but it's hard to tell at a glance if you're detecting semen or not.

So Marg uses a special Probe that doesn't pass through the Target and bounces right off of it, UV light. That blue filter on her scanner changes the incandescent light of the flashlight bulb to UV light.

After the UV hits the semen, the Resolution bounces all over the place, including Marg's eye. But there's another problem, the eye can't see UV any better than it can see dried-out semen, UV passes through our visual centers without much bouncing into our brains. That's when the purple part of the scanner comes into play. While the blue part changes incandescent light to UV, the purple part changes UV to bright orange, which does bounce into Marg's brain.

So Marg wants to detect a Target, but the random Passive Probes don't bounce off of the Target. So she prepares a Probe that does. Unfortunately this Probe creates a Resolution that she still can't detect. So she prepares the Resolution to be detectable.

I'm sure this whole thought process is more effective for her than Lion Face Lemon Face.

This represents a very sophisticated (if simply constructed) Active Scanning device. Sophisticated because all of the Probe/ Target interaction is invisible, yet utilized. Simple because her methods use silicates and purified elements to create homogenous compounds without moving parts, wear and tear or any other maintenance issues.