Archive for October, 2008

Hip Hop and Error Analysis

There’s sixteen ounces to a pound, twenty more to a ki

–Mos Def, “Mathematics”

Crack cocaine has long been a scourge of America’s inner cities, and as such, often makes its way into hip hop lyrics.  For whatever reason, drug dealers measure large amounts of cocaine in kilograms (usually abbreviated as a “kilo” or a “ki”), while smaller amounts are measured in ounces (“O’s” or an “O-Z”).  This leads to some pretty unusual unit conversion, as illustrated above.

How close is this conversion?  Well, 36 ounces is 2.25 pounds, while a kilogram is approximately 2.2 pounds.  This is about a 2.3% excess, so somebody’s getting ripped off here.  My hunch is that it’s the user who gets the short shrift.  Maybe we can dub 36 ounces the “drug dealer’s kilo,” along the same lines as a baker’s dozen being equal to 13.

Another example of shady unit conversion:

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I’ve been grading lab reports for the class that I TA this week.  Sometimes I don’t know how teachers handle it… seeing the same mistakes repeatedly just gives you a terrible outlook on the abilities of undergrads, and by extension, the whole world.  PhD comics has had a running commentary on my thoughts about this:

(I hope this qualifies as fair use of this image.  If not, I will take it down and link to the page.)

Now, in reality I know that they’re not really that bad (the ones I’ve taught, anyway), but grading will make you lose sight of this, at least temporarily.  That’s why I found it was a bad idea to grade for an hour and a half before going to teach my lab.  Doesn’t quite put you in a “go get-em” sort of mood.  I got over it, though.

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Killing Trees: The Never-Ending Quest for Scrap Paper

Early on in this blog, I wrote about reducing my carbon footprint, linking to a calculator that estimates your enviornmental imact.  One section they should have had: “Are you a physics grad student?  If so, we will increase your carbon footprint to take into account all the trees that you will kill doing homework sets this year.”

Physics homework sets are notorious for taking multiple pages per problem (although they’re not as bad as some of the math classes that I’ve taken).  And this is just for the final finished solutions — don’t forget the paper that I waste on the false starts and dead-end approaches to problems.  Another factor that contributes to my tree-killing is that I typically work through an assignment in a very nonlinear fashion: starting a problem, getting stuck, starting a new problem, hitting a wall, going back to an earlier problem, etc.  Because of this, I may end up with each problem on its own separate sheet(s) of paper.  I feel bad about wasting paper, but there’s really no other way to work through the problem sets.

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