
Self-assembly of a lipid bilayer - amelius
https://www.youtube.com/watch?v=ckLQ_5UH7K0
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mkoryak
I have no idea what I just saw. Can someone care to explain what this is, and
why this is cool?

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tantalor
Your cell membranes are made of these little molecules, however they are not
bound together. So how does the membrane stay together? The molecules have 2
ends, one hydrophobic and the other hydrophilic. The membrane is made of 2
layers of the molecules (like a sandwich), with the hydrophilic ends of the
molecules (the bread) on the outside of the membrance and the hydrophobic ends
touching inside. This happens because the two sides of the membrane (the
outside and inside the cells) are water, which the hydrophobic ends hate
(because they are fat/oil).

The question becomes, does this layering occur naturally? Or do the molecules
have to be coerced into this arrangement. Of course the answer is, yes, it
happens naturally. This video is simply a physical simulation and
visualization.

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DennisMoore
Very cool! Were the evenly spaced nine structures at 0:30 a result of non-
random starting positions? Was it simply emergent?

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klarh
If you look carefully, everything for the whole video is replicated 9 times.
These simulations typically use periodic boundary conditions: if something
goes out the left side, it is put in at the right side, and so forth. This
significantly decreases boundary effects that would arise from putting
interfaces into the simulation. Only one of the 9 cells is really being
simulated, but they replicate it once in each direction for visualization so
you can see what is happening through the boundary conditions.

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DennisMoore
Gotcha! I've done some basic 2D simulations of blood vessels using COMSOL, but
those only took minutes to run. This must have required some beefy hardware or
some really good code. It's really quite amazing how well simulations can
match reality.

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justifier
*(philic|phobic) properties seem capable of allowing cellular automata to construct boundary forming multicellular automata

