When I was younger, a lot of my science fiction dreams were about alien species, and I was obsessed with the idea of aliens having different senses than ours. The problem is that making up a new sense (“We perceive things through fleen”) is not very interesting. What does it mean to have a sense you have never had? Trying to describe that in a science fiction story is like trying to explain color to a blind person. And that’s not a simile. Isolating what it means to fleen things is a difficult task.
To help science fiction writers, here is my proposed method of looking at senses. Although I can’t describe to Dan Brown, for example, what it’s like to have taste (har har), I can isolate features about taste that differentiate it from other senses. For example, taste has a very short range. Sight can see the Andromeda Galaxy, but no one has ever tasted the Andromeda Galaxy, at least not from earth. Taste, like most of our senses, is localized to one organ, while touch, for example, is spread out not only across all of your skin, but also most of your internal organs (obviously a “technically” person could winge that technically touch is “localized” to the body, and those parts of the body that exclude the brain, the “Moreau spot” on the thigh, etc.; but we are striving for utility at the expense of precision).
Here’s a sample chart of some useful specific qualities of the five* human different senses:
|Sight||Bajillions of miles||Yes||Yes||Yes (Eyes)|
|Hearing||A mile?||No||No||Yes (Ears)|
|Taste||Contact||N/A||Sort of||Yes (Tongue)|
A few explanations: Distance depends on intensity, of course, and for sight many things are invisible at a few feet or yards, but seeing something almost a billion miles away is a daily (and seeing many things bajillions of miles away a nightly) occurrence. Most things we hear are closer than a mile, but airplanes, air raid sirens, etc. could be a mile away and heard without it being weird. It’s possible to smell things pretty far away, but it’s rare enough to freak people out. And while things like heavy bass can be felt from a distance, or air can have a bad taste, these things are “technicallys”; generally something must tough you or your tongue to be felt or tasted.
The straight line column should be clear. You can smell and hear things around corners, while you’d need unusual apparatus or atmospheric events to see around a corner.
Plugging your ears and holding your nose are not a very efficient way to repress senses, and touch is obviously even harder to repress, at least without drugs or ice or mastery of forbidden fighting techniques. Closing your eyes is trivial, and we do it all the time, and while not perfect (which is why we shut the lights off when we sleep, no?) it works pretty well. It’s also easy not to taste things, in the sense that the tongue is habitually kept hidden behind a row of sharp teeth. If it touches the tongue you will (barring precautions) taste it, but this is analogous to an eye if you peel back the eyelid.
There are other potential columns, of course. The medium through which sense data is delivered, for example: sound requires air, which sight does not; or ways of negating a sense: sight is useless in the dark; precision; frequency of use; etc.
If an alien can “taste” at a distance, is that still taste? You can violate some entries on the chart without creating a new sense: A cricket hears with its knees (different localization), but we’re not shy about calling its sense hearing, just as an alien that could see around corners is still, we all agree, seeing. But if you met an alien who said it could taste things miles away, only not around corners, you might start to wonder if taste was the right word. Maybe if it could only taste spicy things miles away? Maybe if it used something that looked like a tongue?
The thing being perceived is probably the most important part of any sense. A platypus can detect the electric impulses in the muscles of its prey, and that brief description gives an idea of what it’s like to be a platypus in muddy water. But often the thing being perceived is the hardest thing to describe, and saying that fleen, the most alien of senses, perceives the apparently unrelated characteristics of sequence, amplitude, fuzztone and grift is perhaps less useful than knowing that it has a range of thirteen rods and is localized to the snib. Perhaps not. At the very least. making a similar, or larger, chart and juggling its cells around should generate alien (although sometimes nonsensical) perceptions.
*Uri Geller, alone of humans, has a sixth sense that lets him feel only humiliation and shame.