Saturday, May 12, 2007

Star Treck to dragonflies

Its funny how one's mind jumps from one thing to another isn't it? I heard on the news that 'Scotty' of Star Trek fame had recently died and they were sending some of his ashes up in a rocket. I was a great fan of Star Trek and still like science fiction.

As I thought about Star Treck I remembered the Kligons. The Kligons, an alien race, could mask or cloak their spacecraft, which they did when engaging in battle. I always wondered how they could do that, even if it was imagination one would assume the writer would have some explanation of how this was accomplished.

Then I remembered that in 1995 it was discovered that dragonflies do this cloaking or hovering technique that masks them from their prey. As so often happens science fiction writers imagine the improbable that becomes the possible and later becomes fact. Real life truly is stranger that fiction. Since the program was written some time before 1995 it was unlikely the writer of Star Trek was privy to the following information.

This is a rather clinical description of Motion Camouflage

Motion camouflage, first described by Srinivasan & Davey (1995), is a stealth technique that allows a shadower (e.g. a predator) to approach a moving shadowee (e.g. the prey) whilst appearing to remain stationary. To achieve this, the shadower follows a path such that it always lies on the line connecting the shadower and fixed point. If the shadower is a predator approaching its prey, ignoring the movement of limbs (etc) in biological organisms, the only visual cue to the shadower's approach is its looming (i.e. the increase in the shadower's image size as the distance between shadower and prey decreases). In contrast with any non-camouflaged approach, the prey perceives no lateral or vertical movement away from the direction of the fixed point. The fixed point could be an existing landmark in the background (against which the shadower is camouflaged) or possibly the initial position of the shadower (in which case the shadower appears not to have moved from its starting point).


latt├ęgirl said...

I didn't understand a word of that, but it was fascinating anyway. :)

Cherry said...

You have those dragonflies (it's dragonflies or dragonFILEs ?) at your neighborhood ?

It's amazing that such insect has an ability to camouflage. Human sadly is the best creature at camouflaging, they can say nice things in front of you while actually you are his prey.

PS: Can you edit my link address to ? I moved to new domain.

Thanks a lot

Jeni said...

The only dragonflies in my vocabulary these days pertain to the little images on the front of my granddaughter's pullup pants! And, when she needs a fresh clean pair she will sometimes mention "want dragonfly" - her lovely cue there unless the aroma has already hit ya!