Why four digits?
 

Why is it the Na'vi have only 4 digits on each hand...?

Is there some kind of practical application for this? I don't really see why evolving to have 4 digits would be any more practical than having 5, even less so perhaps. So I was just wondering, is there anything that says why they lack that 5th digit?

Well, I don't know why the na'vi have 4 digets. But prehaps the 4 dights were suppose to show that jake and nyteiri were aliens to each other but still loved each other. (some scenes were suppost to show Jake and nyteiri weaving their fingers together.)

For kicks!

Haha, but anyways... There's no particular reason we evolved with 5 fingers, I would say it was just best suited to our environment or something.

Now, a cool thought is that the Na'vi's numerical system would be composed of base 8 rather than base 10 like our own.

Ahh base 8... now there's something I tried to understand. And failed. Miserably. :D

I have said all along that this would be the ultimate scene (or it would make the current scene under the Tree of Voices even better, if that's possible).
As to why they have 4 digits, I have no idea. I think it was donebecause it would seem completely unbelievable that both Na'vi and humans would have similar physical traits like 5 fingers. So this separates them a bit

I also think that the reason was to make na'vi look like more alien :).

Btw the octal numeral system is a lot more practical than our decadic if it comes to computers. It can be converted to binary and vice versa very easily. Not much usefull for na'vi since they don't use this technology, they have eywa that is much better :D.

It's cool, I went to university for computer science for a year and I still can't count with it.

Really? I find it way easier to convert decadic into binary than octal. Maybe it's just because I had way, way more practice doing that though, we didn't use octal extensively.

Well this gonna be little oftopic...
Every 3 binary digits (000-111) equal one octal digit(0-7)
000=0, 001=1, 010=2, 011 = 3 ... 111 = 7.
The best of all is fact that u can do conversion to binary just by using simple rewriting rules mentioned above (in fact u can do similar thing with all numeral system with base of power 2 (2^n) where the binary number has n digits).

So for example binary byte 01011110 = 136 in octal. "Rewriting rules" must be used from right to letf, from the lowest exponent to the highest. So you really don't need any numerical operations here, and can be very easily converted. (btw more usefull nowadays is hexadecimal system...)

Why four digits?
 

I don't know why, but I love the look of their 4-digit hands :D

Why four digits?
 

Haha...no no not going so far :)

Yeah, I was thinking the pinkie is pretty useless anyway. It is actually quite redundant. Perhaps the the Na'vi hand is more efficient with four stronger fingers.

Why four digits?
 

Another question is "why do we have five?"

Why four digits?
 

Evolution is conservative in a way that it won't change properties that work well. Of course there could be beings with less or more fingers, but obviously 5-fingers version survived and this don't neccesary mean any connection with digits count. Maybe it was only coincidence and because 5-digits caused no real troubles it remained unchanged. You can find that many animals have 5-digits...so it it looks like common gene.

See, that makes perfect sense, but I'm still used to thinking in base2/base10 rather than base2/base8 because I never use it for anything, so I still find it more complicated!

It's not unnecessary! We need it so that it can point up when we drink :P

Yeah I understand you tsmukan. Hell...it was strange for me when I was dragged into using it. It's all about "get used to".

Why four digits?
 

So it looks like they are prepared to be more resistent to RDA, because noone else is so devilish.

Pretty much, it's just like problem solving for programming. It's a mental paradigm shift :)

Hahahahaha! Good point!

As far as I know most apes have 5 digits, and apes and humans all share a common ancestor so we must have shared their trait..

It's just evolutionary chance, the same as how there's no reason we have 5 as opposed to 6.

I thought about it... But I would only do it as part of more extensive Na'vi modifications (skin colour, possibly face/nose) which won't happen for various reasons, even if I want it :(

Yeah, I've seen that before.

Main barrier to me becoming more Na'vi is cost. Also, when I considered it, I was thinking more about what other people would think of me, but I no longer care what others think I guess :D
The other problem is just feasibility, as there is still no way to get a good tail or Na'vi ears (plus getting all my skin blue would be expensive, time consuming, difficult and painful...)

What good would simple outward appearance do, when on the inside one would still be same with all the faults of human nature to go with, so what's the point?

We have five digits to be better able to grasp things - the human hand had a lot to do with our own evolution. I am OK with the Nav'vi having for digits - as long as they have thumbs (which are very important), which they do, then it's fine.

Maybe Jake will have his pinkies cut, they mark him as alien and they're in the way :P . It would be painful but he's been through worse.

What? Why? No, I don't want that to happen. :P I don't see how they're in the way. Also, when has he been through worse? Yeah, he had a spinal injury in his human body, but no appendage was removed from his body. That's a little different. :P

The Na'vi have feline like features so maybe the four digits follows this just like cats have four toes (plus the fifth one up their legs, but this isn't used to walking so they technically just only use it for skid control when landing from heights, which doesn't apply to Na'vi since they are bipedial).

Because they can is my answer. Better than being jointless!

I'm more concerned about their flat noses and larger vocal chords (longer, bigger necks) NOT affecting their voices (i.e. a high degree of hypo-nasality [talk while holding your nose] and lower timbre). I know it's because no one wants to listen to Neytiri sound like Andre the Giant with a cold, but it still bothers me. Of course, I'm no voice expert, maybe they have really teeny tiny vocal chords for their size and something funky crazy going on in their sinus cavities... sure, why not

Thanks everyone for the replies.

I realise that, at the end of the day, it's probably four in order to create a subtle aesthetic difference so we can thell they're still aliens despite looking so humanoid but I was coming at it from an evolutionary point of view. I have just got the the part in the Survival Guide about the Prolemuris and reading it made things a little more clear.

Now ^this is something I have also been wondering myself. It was curious that human Jake and Avatar (Na'vi) Jake had exactly the same voice. It would kind of make sense for Neytiri to have the same voice all the time, as we only hear her in one body (Obviously :P) But surely Jake's avatar would have different shaped vocal chords to human Jake so producing a different sound...?

Again, this is most likely just a continuity issue but it still makes me wonder how to explain it.

Jake does have a slightly different voice to his avatar sometimes, but other times it is very similar.

Just explain it as his DNA :P

Perhaps you should be asking why we have five.