1. UW
Daily Update Monday Nov. 23
a. Grab
a egg sandwich at Motosurf, then take final physics midterm. It's fairly easy.
b. Go
to the SPS lounge and write my portfolio statement for Honors 100.
c. The
lunchbox seminar is about some small steps towards
“artificial life”. Our professor has designed particles that bind
together using the “lock-and-key” model. Larger spherical particles with
semispherical dimples fit together very closely with smaller spherical
particles. (These particles were large macromolecules made of many small linked
monomers.) When a large particle and a small particle fit together, they bind due
to what is known as “osmotic pressure”. The particles are floating in solution,
so on their own they experience constant pressure from all sides, due to both
water and larger molecules in solution. But when their surfaces get close
enough that there are some water molecules between them, but the larger
molecules can’t fit in the gap, the surfaces facing outwards experience
pressure from both the water and the other particles in solution, whereas the
surfaces facing inwards only experience pressure from the water, so the
lock-and-key particles experience a net force towards each other and bind the
rest of the way. This is called “depletion binding” since the inner large
molecules need to be depleted before it can occur.
d. But,
I hear you ask, as I asked, don’t the larger molecules displace the water, so
that when the larger molecules are forced out of the gap between the surface
and they are replaced by water, the water pressure inside increases by the same
amount the pressure due to the larger molecules decreases? The professor, being
a physicist, not a chemist or biologist, gave a entropic explanation rather
than a mechanical one. The total entropy of the system is lower if the larger
particles are stuck together, because then there is more volume available to
all the molecules floating in solution outside the particles, and this means
more possible states for these molecules and hence more entropy. (The professor
stated (I can’t give the derivation) that entropy = c*number of molecules*ln(volume
available to each molecule).)
e. Anyway,
the professor used the larger particles’ ability to side-link to create chains
of particles to seed the “reproductive” process by which the particles linked
with the smaller spherical particles, which then linked with larger particles
that naturally lined up in the same order; if the larger particles were
small-dimple-big-dimple-small-dimple, they would link to small-sphere-large-sphere-small-sphere,
which would in turn link to small-dimple-big-dimple-small-dimple. (There were
multiple sets of locks and keys; a given type of smaller particle only fit one
size of larger particle) These secondary chains would then split off, since the
interactions between the locks and keys were relatively weak, and you’re left
with the original chain and a copy. Sometimes a wrong molecule would bond,
creating a mutated copy that would compete with the original one.
f. The
most remarkable thing that occurred during the seminar: a young woman studying
biology, Rachel, whom I knew from Go club had come into the physics lounge to
study with no idea that the lunchbox seminar was going on. I told her the topic
of the seminar, and she was very excited. During the seminar, she jumped up to
discuss a new technology, helical protein bundles, with the professor, since it
would solve many of his technical issues. At first, he was skeptical, but she
pressed on. I caught myself holding my breath at one point. After many
questions, the professor asked Rachel for citations, which she readily agreed
to provide. It was awesome.
g. I
discussed a little bit with Gorm, the tutor graduate student I had met at my
first seminar, then left for lunch.
h. I
read a fascinating Ribbonfarm article at lunch, then went to CS class, where
Reges gave the clearest exposition on abstract classes I had yet received.
Reges is such a good lecturer that he strengthens topics I thought I had
solidly covered.
i. I
dropped by the Commuter Commons, a place for off-campus students to hang, to
try to get advice on how to get to the airport for my family’s Thanksgiving
visit to extended family in California. I gained some good information and
readied myself to take public transit the next day.
j. Went
to SPS lounge again, this time for Go club. Played a quick game of 9x9 with
Rachel. I played pretty well, but messed up a corner invasion. Learned a little
bit more about her—she hopes to go to grad school at Stanford, but fears her
application will be denied since she can’t put her current research on yet. I
want to tell Eleanor I’ve found a second Natasha J.
k. Earlier
in the day, I saw a flyer in the SPS lounge for “Effective Altruism
Informational Meeting: altruism supported by evidence-based reasoning” in the
Haggett South study room, run by one of my floormates Issa Rice. I decide to
go, feeling thoroughly Leroy. I fear that the group will be dominated by
passionate social justice advocates or people who advocate some stilted version
of rationality to an irrational extent. But I get extremely lucky, and find a
group that consists of very reasonable people. The head of the Seattle group,
John, who came to help Issa with the meeting, is an Amazon programmer; half of
the others are CS majors and programmers, while the rest are STEM majors. The
regulars dismiss ideas that they think are irrational (in each case, I agreed)
with politeness, but an almost politically incorrect refusal to hedge their
statements with uncertainty they don’t feel. It feels very refreshing. Everyone
has agreed on values to an extent that allows efficient discourse without
side-stepping around direct assessments. We talk about the Effective Altruism
group in Seattle, some interesting meta-charities, and future meeting topics.
Afterwards, I talk with a mathematician, Tim, who tells me about a flaw with
academia I hadn’t heard articulated: full professors are forced to
simultaneously do research, teach, and manage an army of graduate students, and
many people simply don’t have talents in all three areas.
l.
John provided pizza, so I go straight to my room
without passing “dinner in the HUB”. I finish up my portfolio website and
statement for Honors 100 and turn it in, get Rick’s, do laundry, print my
boarding pass, and write this log.
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