Andalite tail blade density.

[esplin]

Let us assume that the Andalite tail blade is made of some sort of bone.
Did anyone else noticed how strong they are? Slicing through thin metal very easily and almost any amount of bone.

In book 33 Ax uses his tail to remove a man hole cover. 

Anyone else think this was strange/awesome/unlikely.

[DinosaurNothlit]

Alien bone is very unlikely to be of the same composition of bones on earth.  Actually, even on earth, creatures have evolved many different kinds of hard substances; chitin, keratin, bone, cellulose, calcite, etc.

Vertebrate bone is actually mostly composed of a mineral called apatite, which scores a 5 on the Mohs scale of hardness used for most minerals (out of 10).  Considering that you could use almost any mineral to make a hypothetical bone (depending, of course, on the elements available on the planet you're from), you could have bones ranging from the hardness of calcite (which composes the shells of most shellfish), which is a 3 on the Mohs scale, to apatite (5), on up to theoretically harder minerals, like quartz (7) or feldspar (6.5, I think).  I don't think we have anything harder than apatite bones on earth, but that doesn't mean it's impossible.

So no.  I agree with you on 'awesome,' but not on 'strange' or 'unlikely'.

[Essam 293]

^^ If that's not a +1 answer, then I don't know what is.

[Chad32]

I never really thought much about it, but they are quite strong and sharp. Does Ax ever mention how he keeps the blade sharp? Most animals I believe sharpen horns and such by rubbing them against something. Maybe he has an exercise where he sharpens it on a large rock.

[ChimichangaChupacabra]

Yeah, agreed, it was kind of dumb.

They'd be bone, as with the Hork-blades.  So, yeah, fine for slashing up soft fleshy humans and big bag-of-goo worms, but whenever they'd be cutting down trees or slicing through sheet-metal, it induced the eye-rolling.

[morfowt]

In book 33 Ax uses his tail to remove a man hole cover. 

I don't think that has to do with the tail blade, but the muscles in the tail, which we know for a fact, are very strong.

Alien bone is very unlikely to be of the same composition of bones on earth.  Actually, even on earth, creatures have evolved many different kinds of hard substances; chitin, keratin, bone, cellulose, calcite, etc.

Vertebrate bone is actually mostly composed of a mineral called apatite, which scores a 5 on the Mohs scale of hardness used for most minerals (out of 10).  Considering that you could use almost any mineral to make a hypothetical bone (depending, of course, on the elements available on the planet you're from), you could have bones ranging from the hardness of calcite (which composes the shells of most shellfish), which is a 3 on the Mohs scale, to apatite (5), on up to theoretically harder minerals, like quartz (7) or feldspar (6.5, I think).  I don't think we have anything harder than apatite bones on earth, but that doesn't mean it's impossible.

it could also have to do with speed. with enough speed, anything thin is a pretty sharp blade.

[ChimichangaChupacabra]

Different densities doesn't mean you can just throw reason out the window.  Andalites obviously operate under a similar level of gravity and environmental force as our own, it's extremely unlikely their bones are made out of something hard enough to slice steel and trees.

[Estelore]

I live in tornado alley, and I've personally seen a single piece of hay that has passed cleanly halfway through the trunk of a sapling oak. I couldn't pull it out bare-handed, it was so deeply wedged there. Sufficient velocity makes even very flimsy substances shockingly effective as sharp-edges.

As for the obviously-their-gravity-is-similar thing, ChimiChupa... why is that obvious? Obviously, their gravity is no WEAKER than ours, but why could it not be stronger? A larger planet, perhaps, and they would need stronger muscles to support themselves. They would NEED to be quadrupeds. Perhaps they encounter Earth's weaker gravity and find it easier here.

[morfowt]

I live in tornado alley, and I've personally seen a single piece of hay that has passed cleanly halfway through the trunk of a sapling oak. I couldn't pull it out bare-handed, it was so deeply wedged there. Sufficient velocity makes even very flimsy substances shockingly effective as sharp-edges.

oh good. so I wasn't just pulling bits of info from tv shows and misunderstanding my teacher...
(yeah I wasn't so sure what I was saying was true, but it sounded true...)

[Estelore]

*nods*

Throwing cards, paper cuts, aluminium-foil-accidents... very weak materials can be quite dangerous, in correct circumstances.

[ChimichangaChupacabra]

Yes, yes, I know all that.  They're all more or less freak accident examples, though.  I doubt a species would evolve on the gamble that "hey, if they have sharp bones on their tails, they'll be unstoppable".  There are other better defense mechanisms out there.  As totally rad as the Andalites are, they're pretty frickin' implausible.

[morfowt]

well andalite aren't exactly unstoppable... a primitive human gun could kill one. and so could 3 or 4 hork-bajir

[ChimichangaChupacabra]

Not what I meant.  Obviously.

[morfowt]

... then what did you mean?

[musicman88]

Cutting metal with just about anything other than heat is a pretty large task.  I find it hard to believe that anything could cut something as think as a manhole cover no matter how fast it was going or what it was made out of.