

For Cats, a Big Gulp With a Tiny Touch of the Tongue - hornokplease
http://www.nytimes.com/2010/11/12/science/12cats.html

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philwelch
"The project required no financing. The robot that mimicked the cat’s tongue
was built for an experiment on the International Space Station, and the
engineers simply borrowed it from a neighboring lab."

It's mindblowing enough that it took until the year 2010 to figure out how
cats drink water. How do we live in a modern world with all the unimaginable
wonders of science and integrated circuits and space travel, with more people
studying exotic data from space probes and particle accelerators than there
were scientists of any variety 500 years ago, and yet until now a cat drinking
water was a complete mystery to us? The fact that figuring it out was a side
project using borrowed equipment is a punchline.

~~~
mechanical_fish
This _is_ a wonder of the modern world: Extreme high-speed digital cameras,
the kind of stuff that Harold Edgerton became renowned for a mere fifty years
ago, are now so cheap, easy to use, and sensitive that some guys at MIT can
afford to aim one at their cats for extended periods of time on a whim.

Back in Edgerton's day you had to take ultra-high-speed photographs using
extremely bright strobe lighting. I don't know for sure that he never
photographed a cat lapping, but I can't imagine that the typical cat was happy
to sit around drinking when strobes were going off and a high-speed film spool
was cranking nearby. Plus, there was probably a crazy backlog of other, more
serious things to film. So it was probably hard to collect enough data to be
sure you knew what was happening.

I helped a lab shop for one of these high-speed cameras a few years back. They
were not cheap, but they were cheaper than some cars, and they've probably
gotten even cheaper since. When these things get to the point that we can all
afford one, we are going to have some serious fun.

All hail the semiconductor optics folks! Buy one a drink today! ;)

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jbail
Calculating the balance between opposing gravitational and inertial forces is
yet another reason why cats are awesome.

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hartror
_Calculating the balance between opposing gravitational and inertial forces is
yet another reason why_ evolution is awesome.

Fixed it for you.

edit: Really? Downvotes for promoting evolution? Just because I did it in an
amusing way?

~~~
teilo
No, more likely because you did it using a Slashdot meme, which, while some
might find it funny, most here find it obnoxious.

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skoob
It's interesting that this is quite different from how dogs drink:
[http://bethesignal.org/blog/2009/06/13/how-do-dogs-drink-
wat...](http://bethesignal.org/blog/2009/06/13/how-do-dogs-drink-water/) They
scoop up the water with their tongues by curling it _backwards_.

~~~
eru
It looks like there's also a column of water involved, like with the cats.

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eru
> The lapping frequency should be the weight of the cat species, raised to the
> power of minus one sixth, and multiplied by 4.6.

I wonder how mass^(-1/6) has the same unit as frequency.

~~~
colanderman
I'd presume that the 4.6 has some units attached to it that the reporter
missed. (Which unfortunately is important since we're given no other
indication what units of mass are to be used.)

1/6 sort of makes sense though. Mass is directly proportional to volume, and
it's probably the length of the tip of the tongue which is important, so
there's a cube root right there. Throw in a square root for good measure
(those tend to show up in physics problems) and invert it since the frequency
presumably decreases w/r/t mass and you're at mass^-1/6.

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aaronbrethorst
I wonder if this will take next year's Ig Nobel prizes in both veterinary
medicine and physics...

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cowpewter
My cat is too lazy for math. She lays next to water bowl with her chin resting
on the edge and her paw dangling into the water, then just rotates her wrist
to bring her wet paw up to her mouth and licks the water off her paw. Repeat.

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benjaminashley
>The cat laps four times a second — too fast for the human eye to see but a
blur

I'm pretty sure that's not true.

I mean, the 4 Hz thing is probably true, but my eyes have little trouble
discerning 4 Hz.

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ent
well it would very much depend on 4 Hz of what. It's really easy to notice
flickering white light at 4 Hz but it's alot harder to see something that
moves a long distance back an forth at 4 Hz.

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meric
I can see my cat move her tongue back and forth four times a second just fine.

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sliverstorm
The fact that they lap at precisely the right frequency... Darwin's theory is
so perfect, and I just figured out how to put in words why it is. _feedback_.

Feedback really is king.

~~~
tspiteri
I agree that evolution did play the crucial part in developing the drinking
method for cats, which is now part of their instinct, but the precise
frequency can be learned during their lifetime, it does not have to be
instinctive. Cats train their drinking technique daily for long stretches of
time, so they have plenty of chance to optimize their drinking frequency. And
the thing is, that is feedback as well: cats, being quite impatient, try to
drink water as fast as they can, so they try to move their tongues faster,
only to discover that they are spending more time getting their drink, so they
slow down their tongues again, and get more water.

~~~
ars
The only way to find out is have a cat drink at reduced (not zero) gravity.

New mission for NASA: "Cat on the moon."

"I believe that this nation should commit itself to achieving the goal, before
this decade is out, of landing a cat on the Moon and watching him drink."

~~~
DannoHung
Huh... if it is evolutionarily ingrained, then that means that Dogs would be
far better space-pets.

