1. UW
Daily Update Monday Nov. 17
a. Armed
with peanut butter and raisins stuffed in my coat pockets, I head to the
Motosurf truck and grab a very reasonably priced, generous serving of oatmeal.
I head to the physics tables and chow down.
b. Class
feels like mostly review.
c. Work
on lecture homework. Get bogged down in loads of erroneous algebra. The problem
is simple in concept and could conceivably be done any number of ways, but the
art of the thing is to frame the problem in a way such that symmetries cause
forces to cancel, resulting in simple math. I do it the hard way, and even then
I could have solved it, but I make annoying mistakes.
d. Walking
to the Lunchbox Seminar, I mull over the advantages my awesome code editor has
given me and resolve to procure a copy of Mathematica, to see if an interactive
environment will do as much for math as it does for coding.
e. I
go to the engineering website, and Mathematica is free, but I have to wait a
couple of days for student verification information to be processed, since I
restricted release of my student directory information. Frustrating!
f. The
Lunchbox Seminar is fascinating as always. It’s the first time we have a female
lecturer. She’s working on the properties of so-called “low-dimensional”
materials like graphene, thin sheets of carbon 1 atom thick. As always, I feel
like I need to have a better grounding in quantum mechanics to understand
what’s really going on, but I get a lot of interesting stuff.
g. Her
research includes the following:
i. Putting
molecules on sheets of graphene to understand how the electrons react.
ii. Using
a capacitor to add excess electrons to thin sheets of material, then observing
how properties like the distribution of charge on the material change with
instruments that take advantage of quantum tunneling of electrons to measure
average charge.
iii. Sandwiching
together sheets of different materials and figuring out how these very
precisely defined contact interactions affect the materials.
iv. Measuring
the conductivity of sheets of graphene, which usually contain defects which
result in (resistance? Without the defects, would graphene be a superconductor
with negligible resistance?)
h. Graphene
can be synthesized in neat ways.
i. You
may have heard this already, but pieces of graphene can be obtained by applying
adhesive tape with just the right amount of stick to graphite and peeling off
the tape. Then when you stick the tape down on a substrate more attracted to
the graphene than the tape is, you can deposit the graphene on the substrate.
Graphene obtained this way actually exists in square-micron size blotches of
pure graphene interspersed between pieces of carbon several atoms thick, and
places where no carbon was deposited. But the blotches of graphene can be detected
and isolated for study.
ii. You
can react a sheet of copper with methane (CH4), then use hydrofluoric acid (I
think? Don’t really understand this) to react away the hydrogens, leaving just
the carbon on the copper in very large sheets of pure graphene. Sheets the size
of tablecloths have been synthesized this way.
iii. Graphene
can be cut atom by atom using advanced equipment. Some catalysts actually cut
graphene naturally along regular patterns. (In the presence of nickel ion,
graphene severs jaggedly J
)
i. Neat
stuff! Also, if graphene between a charge source and a charge drain is cut so
that the middle is slimmer than the ends, like a constricted portion of a
river, the electrons will behave as they would in a river, speeding up in the
constricted portion (or so I gathered).
j. After
the Lunchbox Seminar, I eat lunch at the HUB (two small slices of pizza is not
enough for me). Wander into Hannah and chatted with her while I ate.
k. Go
to CS, where we discuss parallel processing as a side topic and some list methods
I’d already seen.
l. Return
to dorm and get computer science assignment working. Resolve some inner
confusion about whether I need to use a pattern that’s a fundamental feature of
C++, but a hack in Java. If I pass a variable pointing to a list as a parameter
to a method in Java, and tell that variable inside the method to point to a
different list, the actual variable passed in (outside the method call) doesn’t
now point to the different list. To get this to happen, I have the method
return the different list, and tell the variable pointing to the original list
to point to the result of the method where I pass in that variable. This is
known as the x = change(x) pattern. I figure out where I needed to use it and
where it was extraneous.
m. Go
to Go club. Play a training game and learned some neat stuff. Rachel challenges
me to a game for next meeting, saying (intimidatingly) she enjoys judging
people’s strength.
n. Eat
pizza and read physics at the 8.
o. Play
badminton. I feel like I’m really improving!
p.
Return to dorm, shower, do physics hw, write
log.
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