What might a Gliesian be like?

[Spidey88]

Re: What might a Gliesian be like?

 

On the subject of exoskeletons:

 

The real issue with an exoskeleton in a terrestrial environment is growth. Above a certain size, Earth arthropods will be crushed under their own weight if they moult (as a soggy, not-yet-dried exoskeleton won't support its body a whole lot). Of course, alien creatures with exoskeletons may have a significantly different system that doesn't require periodic moulting - or they could overcome this limitation by being amphibious or aquatic (moulting underwater, where the body is more supported, worked just fine for 10-foot-long eurypterids).

 

Terran insects' size is also limited by the method by which they respire - but an alien insect analog would not necessarily have the same problem.

 

 

On the subject of locomotion:

 

At 1.6 Gee a fall does about 60% more impact...so a fall of say 10 feet goes from Ouch! To "is there a doctor in the house?" I'd assume that evolution would favor the most conservative design. Though evolution does seem to play a few jokes along the way.

 

I'd be suprised to see a biped at 1.6 gees, but maybe a biologist can explain exactly how wrong I am....

 

 

As a biologist - to be honest, I'd be slightly surprised to see a biped under any circumstances, independent of G-forces.

 

We've got a rather inflated opinion of the humanoid form, IMHO. Unstable and inefficient locomotion (though other bipeds pull it off a lot better). Bipedal organisms in general are fairly uncommon when you think about it - the most successful organisms on our planet have six or eight legs. Almost all mammals, amphibians, and reptiles are quadrupedal - birds are the big anomaly, having need of a pair of limbs for flight. Humans are in the same boat, needing a pair of limbs for manipulation (it's much easier to convert existing limbs to new uses than to create new ones out of nowhere). All exclusively bipedal organisms that we've got here have evolved from quadrupedal ancestors.

 

In general, Earth vertebrates are really rather limb-deprived when you look at the bulk of the species on the planet - I'd assume we'd be on the low end of the galactic scale with but four major appendages (It might have something to do with our evolutionary origins in an aquatic environment, which is far more limiting for fast-moving critters with lots of appendages due to hydrodynamic factors). High-G environments are most definitely not a requirement for more than four walking limbs! Roboticists tend to agree that bipedal robots are a pain to deal with - between four and eight legs are easiest and most stable - so you could use that as additional justification when constructing an organism from scratch. Any more than eight walking limbs, and you tend towards wasted energy and redundancy (though there are some critters with lots of legs that move mighty quick, as any Scutigera centipede will prove). Any less than four, and stability takes a lot more effort.

 

In a nutshell? I think a likely sentient alien would be quadrupedal or hexapedal, with at least one pair of limbs dedicated to manipulatory purposes. Under 1.6 Gs, it'd likely be fairly stocky, esp. if it was of a reasonable size. Its legs would probably be planted under it in a vertical fashion, as opposed to being splayed out to the sides like an insect or reptile (too much strain under its own mass).

[Badger]

Re: What might a Gliesian be like?

 

I was thinking in the event one side is always dark, one side always light. Wouldnt it be likely we would get 2 separate species. One developed 2 survive in the light/heat. And the other specifically in dark/cold. Not an expert in biology so, I might not be of much help.

[Sundog]

Re: What might a Gliesian be like?

 

I was thinking in the event one side is always dark' date=' one side always light. Wouldnt it be likely we would get 2 separate species. One developed 2 survive in the light/heat. And the other specifically in dark/cold. Not an expert in biology so, I might not be of much help.[/quote']

 

Eminently possible. However, I'd say we'd be dealing with two species in a connected ecosphere, rather than two separate ecologies, as I'd think it likely that life would develop in the Twilight Band, and spread from there.

 

However, I wouldn't consider it likely. Too much specialisation would be required to survive in the cold or heat zones to make development of intelligence likely - consider how environmentally unspecialized humans are. We're great on the plains, but we function perfectly well in every niche save the aquatic and the aerial.

[Dr. Anomaly]

Re: What might a Gliesian be like?

 

Thinking along the lines of having to deal with changes from very hot to very cold and light/dark... the need to shed excess heat quickly or conserve it in the cold... and about possible IR sensors for dealing with the night/cold side...

 

WE are hotter than our environment. So we can dump heat into our environment for cooling. Now, if you're an organism that spends part of your time in an environment that's HOTTER than you are, dumping heat into the environment is something you can't do, so how do you get rid of your excess waste heat?

 

Or is it something you can't do?

 

All you really need to be able to dump heat, is a way for heat to flow from a hotter area to a colder area. If you're cooler than your environment, that's where the problem comes in.

 

Unless.

 

Posit these creatures having a kind of internal heat reservoir... perhaps a container or "bottle" of some kind, insulated, deep inside their bodies that acts as a heat dump. The fluid in this reservoir is at a much higher temperature than the rest of their normal body functions. You could use a kind of organic heat pump to cool the rest of the organism by driving the fluid in the reservoir to a higher temperature than the normal "operating temperature" of the organism.

 

This could have several useful effects.

 

First, it would allow you to vent your waste heat into the environment, even on the hot side... all you have to do is make sure that you concentrate enough waste heat in your reservoir to make sure IT is hotter than the environment, then provide some means to vent the heat into the surroundings. If nothing else, squirting out a stream of high-temperature liquid through an insulated tube could do the trick.

 

Second, that mechanism gives a ready-made method of attack or defense. It probably wouldn't be that physically damaging to something that could survive the heat of the "day" side already... but if used on the night side, it might temporarily "flash blind" a predator's IR vision, perhaps acting a bit like an octopus' ink... splashing high-temperature fluid all over the surroundings, and making it impossible for a predator to "see" anything in the vicinity.

 

Thirdly, it could be used as a way to "tank up" on heat before venturing into the night side, reversing the organic heat pump when in a cold environment to trickle heat away from the reservoir and through the tissues to replace heat lost to the cold nightside environment.

 

And as to the problem of exoskeletons, weight, and so on vs. the benefits of osseous extremities to act as heat insulators (both from ground too cold or too hot) you don't need to have an entire exoskeleton to do that. Just some form of... what we might regard as extremely exaggerated hooves or claws could provide the sort of "dead" osseous material for insulation of the ends of the extremitites, without the need for encasing the entire creature in armor.

[Mister E]

Re: What might a Gliesian be like?

 

I'd make them only slightly smaller on average' date=' but stocky, kind of like Stallone or Schwartzenegger. [/quote']

 

Schwarzenegger says he's about 6'2".

[Nyrath]

Re: What might a Gliesian be like?

 

As a biologist - to be honest' date=' I'd be [i']slightly[/i] surprised to see a biped under any circumstances, independent of G-forces.

 

We've got a rather inflated opinion of the humanoid form, IMHO. Unstable and inefficient locomotion (though other bipeds pull it off a lot better). Bipedal organisms in general are fairly uncommon when you think about it - the most successful organisms on our planet have six or eight legs. Almost all mammals, amphibians, and reptiles are quadrupedal - birds are the big anomaly, having need of a pair of limbs for flight. Humans are in the same boat, needing a pair of limbs for manipulation (it's much easier to convert existing limbs to new uses than to create new ones out of nowhere). All exclusively bipedal organisms that we've got here have evolved from quadrupedal ancestors.

 

In general, Earth vertebrates are really rather limb-deprived when you look at the bulk of the species on the planet - I'd assume we'd be on the low end of the galactic scale with but four major appendages (It might have something to do with our evolutionary origins in an aquatic environment, which is far more limiting for fast-moving critters with lots of appendages due to hydrodynamic factors). High-G environments are most definitely not a requirement for more than four walking limbs! Roboticists tend to agree that bipedal robots are a pain to deal with - between four and eight legs are easiest and most stable - so you could use that as additional justification when constructing an organism from scratch. Any more than eight walking limbs, and you tend towards wasted energy and redundancy (though there are some critters with lots of legs that move mighty quick, as any Scutigera centipede will prove). Any less than four, and stability takes a lot more effort.

 

In a nutshell? I think a likely sentient alien would be quadrupedal or hexapedal, with at least one pair of limbs dedicated to manipulatory purposes. Under 1.6 Gs, it'd likely be fairly stocky, esp. if it was of a reasonable size. Its legs would probably be planted under it in a vertical fashion, as opposed to being splayed out to the sides like an insect or reptile (too much strain under its own mass).

Very interesting! Of course before I read your post, the first thing that popped into my head was the aliens from Hal Clement's classic SF novel MISSION OF GRAVITY. They look like large centipedes, with four pincher tipped arms, two at each end. There is an artist conception on the book cover here:

http://www.hour25online.com/Hour25_Previous_Shows_2003-06.html

(scroll down).

 

Keeping in mind that Hal Clemet was a physicist, not a biologist, and the Mesklinites were living on a planet with a surface gravity up to 500 g, not 1.6.

[Dr. Anomaly]

Re: What might a Gliesian be like?

 

Peak at 667g, I believe... though he later said that may have been too high by a factor of 2.

[BobGreenwade]

Re: What might a Gliesian be like?

 

Schwarzenegger says he's about 6'2".

As does the IMDB. I stand corrected.

[Dr. Anomaly]

Re: What might a Gliesian be like?

 

As does the IMDB. I stand corrected.

 

Actually, being BobGreenwade, you hang upside down corrected... but I suppose that's beside the point...

[Spidey88]

Re: What might a Gliesian be like?

 

"Mission of Gravity" was a great book. Hal Clement's really good for creating very interesting nonhuman characters that seem somewhat realistic biologically. He definitely gave a lot of thought to the creatures he created, and how they're adapted to their environments.

 

His book "Nitrogen Fix" has a really neat character named "Bones" that has a totally alien mindset and motvations (often rather sinister in a detached sort of way), but still manages to be a huge help to its human "friends".

[Dr. Anomaly]

Re: What might a Gliesian be like?

 

I love Hal Clement's works...

[Drhoz]

Re: What might a Gliesian be like?

 

I love Hal Clement's works...

 

*nods happily* the last line of Mission of Gravity had me cheering and punching the air

[Cancer]

Re: What might a Gliesian be like?

 

The sequel to Mission of Gravity, Star Light, is a good breakdown-in-communications story. Not so much raw joyful world-creation, unfortunately.

[Dr. Anomaly]

Re: What might a Gliesian be like?

 

Unfortunate but true. I do prefer Mission of Gravity to Starlight.