Thursday, March 17, 2011

Dryers, Animals, and Other Housing Failures

Call it confirmation bias if you will, but I seem to have unusually bad luck with drying machines and animal infestations.

A couple terms ago, I made the (rather glaring, in retrospect) mistake of moving into a house where the washing machine and dryer would be "replaced soon" by the landlord (they weren't there when we moved in). The appliances did eventually get put in, but it would be a stretch to say they were new. In fact, the dryer was missing its exhaust vent, which is a rather important thing to have. Now, exhaust vents aren't that hard to get or install and eventually we did install one ourselves, but the process of doing this was all sorts of awful (most of them involving abuses of duct tape) since the pipe the landlord had supplied didn't fit the mangled attachment points.

The next term, in a different house, we had a bat somehow get into the house. I was fairly apathetic about this but one of the other guys in the house (a veteran from the dryer disaster) went mildly insane and plastered black garbage bags over every doorway in the house to prevent the bat from attacking us in our sleep and giving us rabies, or histoplasmosis, or something. The next day saw a bathunt with a bunch of twenty-year-old guys armed with broomsticks and an almost comical fear of giant leathery bugs. We never did find the bat.

Today, I was working on plotting out an essay for my philosophy class (topic: what is it like to be a bat?), when I heard a persistent fumbling sound coming from the laundry room. At first, I assumed one of my roommates was doing some incredibly clumsy laundry, but after half an hour or so, this hypothesis seemed increasingly and distressingly unlikely. No, there was clearly something stuck inside the dryer vent; something alive and possibly terrified.

After considering all the ways I could ignore the problem and hope for a resolution that did not require my intervention, I came to the sad realizations that (a) there was no way the thing was getting out on its own, (b) furry animals and exhaust vents are probably a fire hazard and animal cruelty, (c) anyone attempting to do laundry would be a very bad thing, and (d) people sometimes do laundry from which we can conclude that (e) having clean clothing is overrated and (f) I would have to talk the other residents of my house out of doing laundry for a while.

A dramatized reconstruction of this talk follows:
Me: So... have you ever thought about what it would be like to be a squirrel?
Guy: ...
Me: Say you were a squirrel stuck in a dryer exhaust.
Guy: Seriously?
Me: Um, yeah.

To shorten a lengthy tale into a slightly more condensed form of a lengthy tale, the Laundry Avoidance strategy didn't seem to adequately address the long-term implications of the Animal Stuck In Appliance scenario. What we decided to do was take apart the exhaust vent; sure, we'd have to get some duct tape and fix the damn thing later, but at least we could get on with life.

At this point, I was the only one who had heard the squirrel/bat/chipmunk thing inside the vent. If the bat and dryer experiences had taught me anything it was that wild animals can be bloody difficult to find and dryer vents aren't fun. Nonetheless, we did what we had to do: we unwrapped the duct tape holding the vent in place and we waited for stuff to come out.


We took out the other side: still nothing. There was nothing in the vent. At this point, you probably think that this blog post is about how I let my prior experiences impede my judgement. You might think that I'm slightly insane. You'd probably be right on both counts.


As I went back to planning my essay (maybe "problems with sense perception" would be a better topic than that bat nonsense), there was another fumbling sound from the laundry room. The laundry room that did not contain a squirrel stuck in a dryer vent. The laundry room that we had just conclusively proven (causing some amount of material damage in the process) did not contain a squirrel stuck in a laundry vent. The laundry room that had just as many squirrels in laundry vents as Area 51 had aliens facing human molestation charges and... the fumbling continued. I grabbed a video camera.

I shot a minute long video of an indistinct shape scrambling up a plastic dryer vent, trying to leap up a long vertical stretch of metal tubing, and failing miserably. Armed with this evidence, I set out to convince my earlier accomplice that I was still sane.

The resulting conversation was sufficiently awkward that I feel no need to immortalize it here, but to his credit my partner-in-dryer-destruction returned to the scene of the crime for a second look. Once again, the dryer vent was quiet when we arrived.

Pulling out my video camera, I played back the video I had taken. I had been so excited by the feeling of actually-having-proof-this-time that I had forgotten that most of the video consisted of silence.

"It gets better," I said.

And suddenly it did: a faint scampering could be heard from the video and almost simultaneously the real exhaust vent started shaking up again.

"There," I said, prodding at the screen, "you can kind of hear it there! Here, I'll rewind..."

It turns out that the live performance next to me was more convincing than my recording, so rewinding was unnecessary. We got our animal trapping gear back in place and I triumphantly removed the bottom of the vent and placed it into our designated cardboard box. I'm not even going to bother building this up, because obviously it didn't work. It couldn't work. There was nothing in the freaking vent!

"Huh," we said.


Can you figure out the case of the ghost squirrel?

PS: my philosophy essay is not about any of the topics listed here. I would say what it's actually about, but I don't want TurnItIn to think I plagiarized myself.

EDIT: The true conclusion to this shocking story of paranormal activity is here.

Wednesday, March 2, 2011

Nomograms for Synbio

I've always really liked nomograms. They're basically a set of axes drawn on a page in such a way that each axis represents one (or more) variables and by drawing lines between the various axes, it's possible to find unknown variables graphically.

One of the most basic nomograms possible simply adds two numbers:
From this simple beginning, it's possible to make other analog computation devices that are much more sophisticated. By using logarithmic axes, you can perform multiplication, since log(x) + log(y) = log(xy).

Nomograms are rather outdated, now that computers can perform numerical calculations much more easily and with far greater accuracy than anyone can measure by hand. The reason I'm looking into nomograms again is because they can be distributed on paper more easily than a computer program, they are relatively intuitive, and they allow very complex systems of equations to be solved by people who don't know math. There are also some iGEM outreach events coming up... we'd like to be able to show people mathematical modelling stuff that's related to synthetic biology, but it's hard to come up with stuff that's interesting, learnable in minutes, and true. I think it's possible to condense some tricky work into a graph:

The above graph shows a setup that could calculate the concentration of a molecule and its isomers given a reaction rate constant (provided the axes were properly scaled). This is a fair amount of work (for the creator of the nomogram) when you could just plug "exp(-k*t)" into a calculator, but it's hard to beat the connect-the-dots simplicity of a nomograph. The other nice thing about this type of graph is that it really emphasizes the fact that it's easy to 'cheat' and start with the desired final answer and work backwards to get inputs... ie, design the system analytically.

Unfortunately, the irreversible isomerization reaction is still rather lame and even with an easy method of calculating it, it's still not particularly exciting. What would be cool would be to get a system of equations that describes an optimization problem and have a graph visually represent design trade-offs (like the triangular graph on this page), but that sounds like it might be too ambitious for me to tackle in a couple of spare hours.