

Mindblowing Experiment demonstrating Laminar Flow - wicknicks
http://io9.com/5811236/this-is-the-coolest-science-experiment-youll-see-all-week

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chopsueyar
Awesome.

If you like laminar flow stuff, check out these DIY laminar fountain videos:

<http://www.youtube.com/watch?v=SEqrRV0jMw8>

<http://www.youtube.com/watch?v=7sDs_r91uJE>

<http://www.youtube.com/watch?v=Ijn98G0I99E> (very ad-laden, beware)

If anybody has plans or instructions on how to make a laminar flow sheet of
air (air curtain), please reply.

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Xk
If you were like me and wondered why they had to go back six after going
forward five, it's because they counted wrong.

They go forward six and a half turns, and go back six and three quarters.

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erydo
I noticed it when they miscounted, and it was kind of interesting how it
happened.

The professor talked through a revolution, and then resumed counting from his
previous number. The student who was counting in the background just sort of
reset to the professor's count instead of correcting him, and it seemed
entirely subconscious.

Not mindblowing, but I found that little moment more intriguing than the
laminar flow.

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kenjackson
Could you do that with a spoon in a large bowl? Or does the unmixing need to
be extremely precise?

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wiredfool
The 'mixing' needs to be as pure laminar flow as possible, and that's
generally between two cylinders that are rotating at different speeds. The
speed of the fluid across the space should be a linear function of the
relative distance from each wall. Any variation of that is going to reduce the
reversability. So what they're doing is very carefully not mixing, but
shearing. The fluid here is behaving like a very soft chunk of rubber, not
like any fluid that you're used to dealing with.

If you've got a spoon, there's going to be some turbulence as the flow goes
around the edges and the flow detaches from the surface. Turbulence absolutely
destroys the reversibility.

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kenjackson
Thanks. You just saved me cleaning up a big mess in the kitchen.

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timdorr
So, it's a sort of fluid-based, reversible encryption?

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onedognight
Actually, yes. The path you take to stir the fluid would be your key which
would be verified by getting back to the initial dye state. The key size would
be ideally infinite dimensional (the dimension of the path space), but
practically bandwidth limited by your ability resolve the dye pattern.

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espeed
Is this analogous to the quantum mechanics theory that information cannot be
lost or destroyed and everything is therefore reversible?

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abecedarius
It's an instance of it, though classical physics has the same property.
Feynman introduces this stuff in <http://www.youtube.com/watch?v=_Kab9dkDZJY>

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ahi
Very cool, but it seems they had some trouble counting to 5.

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dhughes
Unblending, pretty amazing.

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malvosenior
Get a damn clamp.

