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The inner ear is the principal organ responsible for
making
sure that various animals are able to orientate
themselves
in a useful manner. Otherwise entropy takes over and all
the world's giraffes are on their sides. The system is a
series of tubes bent around, full of liquid. I don't know
exactly what the liquid is, but I do know biology, so I'm
guessing it's salty water. The point of the liquid is to sort
of stay still while the ear moves around it. You get the
same effect if you turn a bowl full of liquid. The
periphery
of the inner ear is lined with sensors to detect the
movement or the liquid relative to the inner ear.
Problems
arise, because the system can't know whether the ear is
moving of the liquid. So if you slosh your head about
enough, you can easily overwhelm the inertia of the
water,
then you have a mess.
Now, we can improve this: replace the water with
mercury, which, rather pleasingly is 13.6 fold denser.
That's 13.6 fold better at staying still. It is a little more
viscous than water, but only a tad.
The net result should be more sensitive balance, a robust
resistance to spinning fairground rides and insanity.
Endo and Perilymph composition
http://www.cochlea....lea/cochlear-fluids
[bs0u0155, Jul 01 2015]
[link]
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Metallic Mercury injected into the cranium ... what's not to like ? |
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//That's 13.6 fold better at staying still.// |
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Can you elaborate on this section me old fruity? |
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This is a very excellent idea. [+] |
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//Can you elaborate on this section me old fruity?// |
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Yes. So, objects don't accelerate unless you apply a force.
How much acceleration you get depends on how much
mass there is. F = ma or a = F/m in that example.
Mercury has 13.6 times more mass per unit of volume. So
you need proportionally more force. With solids, it's
simple. Push it, the whole thing moves. With fluids it's
more complex because it's not held in a rigid matrix. If
you push it, the bit near your finger moves, the rest of
the liquid will be affected, how much depends on the
viscosity.
Now, make a coffee, leave it to settle for a couple of
mins* and splash in a little milk. Don't stir it, because who
has time for that? You can use the milk as a marker of
what's going on in the liquid. If you rotate the cup, the
liquid MOSTLY stays still. It moves a little bit, because the
interface between the cup and liquid provides some
friction. That friction is able to transfer enough force to
accelerate the mass a little bit. Now, if the cup were
filled with mercury, the interface would still be
transferring only a small amount of force, but would have
13.6 fold more mass to move, so the acceleration of the
mercury would be proportionally lower. The balance
sensing in the ear, places sensors** at the interface to
detect the difference in movement between the liquid
and their anchor. The denser the liquid, the bigger the
signal to noise ratio and the better the sensitivity. |
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*conversation about the misuse of the word
"optogenetics" optional. |
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**mechanically gated potassium and calcium channels...
amazing, I didn't know about cellular potassium INflux,
normally sodium is the overwhealmingly dominant
extracellular ion. |
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//pleasingly is 13.6 fold denser// Argh-huff-sigh: the end
of the world approacheth! Your abuse of mathematics and
language, it will destroy us all! Or at least some of us.
OK, annoy, rather than destroy. |
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//13.6 fold denser// --> 12.6 fold denser
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[by an underemployed pedant with an infected tooth] |
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ah, yes, well done, I was wondering who would spot that
first. Ahem. |
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Uh, I hate to be the clever one here, but if the
density of mercury is 13.6g/cm3, and the density of
water is 1g/cm3, then mercury is 13.6 times denser
than water. |
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But I digress. It turns out that cave-dwelling swifts
(who fly about in near-total darkness) have their
balance organs filled with a liquid which is saturated
with potassium chloride, and considerably denser
than water whilst being not much more viscous. |
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13.6 times denser than water
(13.6 * 1.0) + 1.0 = 13.6? No, that would be 14.6... |
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//by an underemployed pedant with an infected tooth//
Rather lame excuse if you ask me. |
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//have their balance organs filled with a liquid which is
saturated with potassium chloride, and considerably denser
than water whilst being not much more viscous// |
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It turns out that all of the balance organs are like this. The
composition is almost exactly the same as the intracellular
fluid, with a slight boost so that potassium influx can occur
at relevant rates. Fascinating stuff <link>. |
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And there I was thinking I was making this shit up. |
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//13.6 times denser than water
(13.6 * 1.0) + 1.0 = 13.6? No, that would be 14.6
/// |
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OK, here's the deal. I will give you two one-pound
coins. In return, you will offer me one one-pound
coin. I will say "no, I need two times as much as
that",
and you will offer me three one-pound coins. |
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We will continue this process until you understand. |
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"two times as much", that's 2*1, and isn't the same as "two
times more than that". |
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In what version of English does "as much as" mean the same thing as "more than"? |
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I still am suspicious. If it was harder to get moving, it would also be harder to stop. |
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Because the inner ear must have channels to maintain the fluid, could drugs be used to alter the channels and increase the fluid density? No big needles or mercury necessary. |
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Like g-string, g-spot, or gigging |
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//In what version of English does "as much as" mean
the same thing as "more than"? // |
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"It costs two times as much as that" is generally
considered equivalent to "it costs two times more
than that". |
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We have a similar issue in a certain art or exercise of which I partake. A sequence of operations is to be enacted, say, three times in succession. The sequence is written out in full once; and then (to save space) the instruction "repeat twice" Cue much pedantry over whether "twice" should or should not be excised and be replaced with "three times". |
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If you said "repeat twice", it would technically mean
that you should do the exercise two more times
(three in total). If you said "repeat three times", it
would technically mean that you would do it a total
of four times. However, given the lamentable lack of
pedantry and verbal precision amongst the great
unwashed, this might not work. |
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It would be clearer to say "repeat twice more". |
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That is a clever solution but I think it would be ruled as "cheating". |
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//Fill the inner ear with Mercury...// |
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"Ah, Mr. Zeugma, we've got the results of your MRI
back and... I said 'WE'VE GOT THE RESULTS...'" |
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