Wednesday, February 25, 2009

Trope-ing the light fantastic (life-sign detectors)

What is life? How can we identify it?

Those are tough questions. Every time one scientist thinks he's discovered signs of life on, say, Mars, another scientist offers an alternate explanation for the data. The pattern began with the Viking missions in the 1970s and continues to, most recently, the localized methane eruptions recently spotted by both terrestrial telescopes and a current Mars satellite mission.

Fictional life-sign detectors (LSD) have none of these difficulties. Like universal translators, an LSD is a great device for moving along a plot. No need to rendezvous with a derelict ship to see if the crew is living, ailing, or dead. No need to explore a whole freaking planet to find suspected castaways or your missing crew mates.

What, exactly, is the LSD detecting -- and across great distances, and often even across vacuum? Intracellular chemical reactions? Implausible (and wouldn't they be different for every species?). Respiration? Body heat (aka infrared)? Perhaps the coldblooded need not apply. Other electromagnetic emissions? Doubtful: It's not like human bodies transmit radio waves. Motion? Nope, the fictional LSD always manages to detect comatose creatures in need of rescue.

None of the above seems remotely plausible. None seems reliable -- even if I could imagine a sensitive enough detector -- to recognize life forms from a never-before-encountered biology.

Which leaves what? A "life force" unknown to today's science that an LSD may detect. IMO, that's medieval superstition, or parapsychological gibberish, or total handwavium.

Bottom line: The life-signs detector is a trope (or LSD, indeed).


Catreona said...

Awh, c'mon, Ed. You don't need no stinkin' life signs detector. All you need to do is look down and see the canals and towers. And, maybe you'll spot some aliens, (or should that be natives?) zipping along on their flying carpets. Haven't you ever read The Martian Chronicles? LOL

Well, how are hitherto unknown species discovered here on Earth? Seems like new extremophile bacteria and such are always being found. How is that done? Would the method work elsewhere throughout the universe?

Admittedly, any such method would probably not detect the sort of aliens one could interact with (with one's handy dandy universal translator). But, it might be a very good thing to be able to detect bugs that would eat or dissolve or otherwise ingest your spaceship if you landed.

Edward M. Lerner said...

The state of the art in life-signs detection is clearly quite short range, or we wouldn't need to explore deep-ocean vents and arctic oceans to find new species.

Long-distance Life-signs Detector would better have made my point -- but then the acronym wouldn't be LSD. Gotta allow me my wordplay :-)

Trope LSDs find a particular errant crewperson or unconscious alien pilot across distances of hundreds, even thousands, of miles, often across vacuum. THAT is what seems like an acid trip to me.

Catreona said...

I agree that detection such as you describe seems tantimount to majic.

On the other hand, trying to stick to the strictures of the laws of Physics can produce major plot problems. For instence, in my current project (not going well BTW your humble SF writer anticipates imminent baldness), I needed my spacecraft to have shirtsleeve gravity and to be able to traverse a given distence in hours rather than days. After much reading and consulting and brain cudgling, I gave in and let the needs of the storyline superceed the known laws of Physics. It's far future, on a distent planet. If people from Earth were clever enough to get their, they might well be clever enough to figure out how to create artificial gravity and FTL travel, at least locally between the planet in question and it's L1 station and it's habitable moon. What's a little hand waving among friends. Got a hero with telekynetic powers too. Maybe I should call it a Fantasy Romance rather than an SF Romance. *sigh*

Edward M. Lerner said...

What's a trope or two among friends?