In an earlier post we looked at the possible alien sense of sight and possibilities other than sight to produce a picture of the world. Things such as sonar and radar were also discussed. Now on our world some animals have much better hearing than vision, and it seems to serve them well. Dogs and cats have a much higher range of hearing, and dogs can hear rodents running through the ground across a field. In fact dogs can hear four tones for every one we hear, which means that perfectly tuned guitar might sound horribly out of tune to them. Now hearing is best in animals which live in environments where sight might be limited. Sight hounds like Afghans and Greyhounds do not have quite the hearing of their cousins, though it is still very good. But their eyes are much better, since they hunt across open plains. Our hearing is adequate for our purposes, though our eyes are superior in most respects to any other animal. We don’t allocate as much brain area to hearing as we do to sight. Our visual cortex takes up an entire lobe, about a quarter of our brain mass. Hearing a small section of one. But we hear well enough to communicate, and that seems to be enough for a well sighted like us. Speaking about communication, research shows that deaf people are on the whole more depressed than blind people. Seems that the sound of another human communicating to us is important to our psychological well being. But I still always thought I could do better deaf than blind. Then again, as a writer I can work without having to hear anything, while being without vision would be a pure bitch. So what would the hearing be like for another intelligent species? And could it be the dominant sense?
In Star Trek Spock had superior hearing because the atmosphere of Vulcan was thinner than Earth’s. It would make sense for organisms that developed in a thinner atmosphere to have superior hearing to a similar Earth animal for the simple reason that less dense atmospheres conduct sound at a slower and less robust rate. Also, the more stealthy predators there are the better the hearing should be. Now in space hearing is a sense that could be done without. Not that it isn’t useful, but sound doesn’t transmit in a vacuum, and visual displays could handle all communication. So there could be space faring races that are completely deaf, though not having the utility of hearing on a planet’s surface is still a detriment. Having something sneak up on you that isn’t really stealthy, because you can’t hear, would be an embarrassing way to die. Of course another sense like 360 radar sense or vision might compensate, but if the creature has to sleep hearing is a good sense for picking up the approach of an intruder and waking one up.
So what about for communication? Visual signals or scents might do the job, but good old talking, yelling whatever covers a good distance and goes around corners. Hearing seems like to useful a sense to leave out of the package for most creatures. So will there be intelligent creatures that are deaf, or at least don’t possess hearing organs, depending on picking up vibrations in other ways? Probably, but I would still put my money on most of them having hearing organs of some type, and picking up sounds for communications and survival purposes. They might have hearing organs like we do, and two seem to do a good job at giving us a directional sense of hearing, but hearing vibrations through the skin might do the job. Hearing in the lower ranges might do as well as hearing across all ranges, but there is a reason that animals with sensitive hearing have such a good range, much higher than our own. And of course we would expect intelligent creatures to not have as good a sense of hearing as lower animals on their world, or would we. There are all kinds of possibilities, and I don’t think we can rule any out just based on our own world examples.
Senses
All posts tagged Senses
Will aliens have different senses than we have? If so, what form will they take? Our own senses seem to serve us well, the old vision, hearing, odor, sense of touch, and taste. I would suspect that they would serve aliens on other worlds just as well, but there could possibly be exceptions. The exceptions may be better suited to some really bizarre environments. They may not translate well into other environments. Let’s start with vision, probably the most important of our human senses. Not to say that people can’t survive without seeing, and can’t develop other senses to take over if necessary. But try to drive a car or fly an airplane without vision and you are in real trouble, if not dead. Now our vision operates within what we call the visible spectrum because it is what we see. On either side are the Ultraviolet and Infrared waves that we can’t see, though some other animals can see in them. Species from planets with more of either wave impacting their planet may also see more into those ranges of the spectrum. We have good color vision, better than most other animals, and very good discrimination, also better than the great majority of animals. Our motion detection and night vision aren’t as good, which seems to be the trade off we have made to have eyes that function really really well in the daytime. Infrared might serve us better at night if we had it, but in some situations is worse than useless, like in a heat filled environment where living creatures are not always the hottest things out there.
Now our sense of vision also serves us very well in environments other than the surface of the Earth. In the vacuum of space electromagnetic waves are still transmitted, and we can still see most things. We don’t see all the xrays, cosmic rays, ultraviolet and such, but we can work around that by developing devices to see those for us and translate them into something we can see. We can see through transparent substances that look out into hostile environments without problem, whether it is the vacuum of space or the crushing waters of the ocean depths. If the atmosphere is too opaque, such as a dense fog bank or permanent murky atmosphere we might have problems, but we can still develop things to let us see what’s there. There have been many representations of alien vision in the infrared or ultraviolet, one coming to mind is Predator. I really wasn’t impressed by the visual acuity shown, and would much prefer our own eyes in most cases.
What about other senses that might take the place of sight? There are some possibilities, all with weaknesses that, in my opinion, make them a much less effective in the long run, especially when the species gets into a space environment. Sonar is one possibility, where an organ is used to pick up sounds from the environment and interpret them. This was portrayed in the movie Pitch Black. Sonar might make a good substitute on a totally dark or murky atmosphered planet. However, it does have series drawbacks. Other sounds can mask the sounds the creature is interested in, like something it wants to eat or that wants to eat it. There is also the problem of the sound waves giving away the generating creature. It would be kind of hard to sneak up on something you are beaming continuous sound waves at. It gives new meaning to the saying “feeling the eyes of something on you.” Now maybe the sound could also be used as a stunning weapon, which brings in whole new possibilities. What about passive sonar? Only using the sounds generated around you as the means to locate. Works well with things that make noise. Not so well with the trunks of large plants or rocks. Chasing down a prey animal while running through a forest could lead to serious bodily harm. Radar is another possibility, if an organ could be developed that sent out radio waves to bounce off a target. Same limitations and problems as sonar though. In space sonar would be just about useless, as sound does not travel in a vacuum. Any space faring sonar race would have to develop devices that turn electromagnetic waves into sound so they could be interpreted by the creature. Radar using races would have the advantage of being able to use their sense in a vacuum, but the disadvantage of giving themselves away to whatever they’re trying to get a look at, if that thing has the ability to detect radio waves. If not then it is just as good as our kind of vision, and better in an obscuring atmosphere.
So if vision is so superior, will it be developed to the exclusion of any other kind of primary image sensing ability? Not a definite. Evolution works kind of randomly, with organisms surviving to reproduce due to their fitness or adaptation to the current conditions. Again, if in an environment where vision does not do a great deal for survival, then non vision techniques will predominate. Or if be chance sonar develops first and all animals that develop eyespots, the precursors of eyes, are eaten to extinction, then eyes will not develop and rule the world. But the eyes have it as far as overall utility goes, and I would expect that among intelligent space faring races, most would have eyes, at least two, since this helps with depth perception, which is a useful survival trait. I have seen some stories in which some modification of a single eye had depth perception, so that is not something that couldn’t happen. And more than two eyes is a distinct possibility, though I doubt the compound eyes of insects would dominate due to their lack of acuity and confusing visual pattern (they are more suited to picking up movement from a large visual field) but again not impossible. Later I will discuss the next major sense, hearing.
