Thursday, July 14, 2011

Energy Consumption

Apparently US data centers consumed 61 billion kWh in 2006 (according to this EPA report (PDF)). That sounds like a big number, but I like to judge these things by my favourite Big Energy metric: how much mass would you have to completely annihilate to get that much energy?

Well, assuming I crunched the numbers correctly (ie, assuming I can blindly trust Google's calculator), that amount of energy can be expressed as 2.196*(10^17) joules, which, when divided by the speed of light squared yields: 2.44 kilograms.

Given that the same EPA report claims that this energy usage statistic accounts for 1.5 percent of the total US electricity consumption, that means that to power all of the US for a year, you would need to annihilate 2.44 divided by 0.015 = 163 kg of matter.

That strikes me as a remarkably high number. It means that if I were to encounter my antimatter twin (and both of us weighed somewhere around 68 kg), even if we did fully annihilate each other and even if all the energy from this event were captured (and stored perfectly until needed), this would only power the US for somewhere around 300 days.

This saddens me, because it means that my human-antihuman power supply will require a disturbingly large number of sacrifices to keep running.

Wednesday, June 29, 2011

Quality Wasted Time

When I first started this blog, its mandate was to talk about engineering-lifestyle things, like freaking out about midterms and being jealous of MIT. I've strayed a bit from that ideal over the years, but I'd like to get back to it now with a discussion about the quintessential student pastime of wasting time on the internet.

Now, since you're reading my blog, I'm going to take it for granted that you already appreciate the benefits of spending time on online activities that are not, strictly speaking, useful. With that in mind, we can skip the moral questioning and get straight to the fun stuff: did you know you can download parts of Wikipedia as books?

It's true. I'm not referring to WikiBooks either, which are notoriously incomplete and haphazardly edited, but actual PDFs/ODT files/ZIM files/physical books made from the content of Wikipedia itself.

This might not sound like that much of a time waster, because navigating Wikipedia the conventional way is probably even more of a time waster due to all the link-hopping. Reading a book of encyclopedia articles could also be considered a constructive use of time. To both of these objections I present: this six hundred page book of chess variants. Clearly this is a waste of time and something I would never have wasted time on before it became possible to load onto an e-reader.

So you now have a couple thousand new books to read (starting, perhaps, with Philosophy of Science, Neuroscience, LGBT themes in science fiction, fantasy and horror, Consciousness, Complex Dynamics, or University Genetics). Interestingly, Creationism and Intelligent Design is one of the larger books, probably because the arguments, lawsuits, and politics involved are distressingly entertaining.

Moving along, I've also taken to wasting a fair amount of time on the Khan Academy site. Again, studying mathematics through a tutoring site (an incredibly good tutoring site with video tutorials from one instructor spanning topics from basic addition to vector calculus) might seem like a benign time waster, but I assure you it is quite possible to spend far too long there.

For one thing, the Khan Academy has discovered that the future is games and uses a gaming-inspired reward system to motivate students to study more. This only affects people who log into the site (with a Google or Facebook account) but should you be so unwise as to do so, you'll suddenly have the option to gain lots of points by watching video lectures and answering simple interactive math tests. Since the tests are aimed more at the elementary level than the university level, it is quite possible to gain ludicrous amounts of utterly meaningless points in the span of a few hours if you're willing to answer lots of arithmetic questions. I don't personally recommend doing this but, having done it, I have a renewed appreciation for not having to manually multiply dozens of three-digit number pairs together for homework anymore.

Seriously though, Khan Academy has a lot of good stuff for anyone who wants to learn stuff (mostly math, but there's a couple biology, chemistry, and history videos available for good measure). It's a similar type of time waster as watching lots of TED talks and you can even combine the two by watching a TED talk about Khan Academy.

In other news, I have a free unlimited internet connection and am really good at arithmetic again for no apparent reason.

In actual other news: brains, concepts, plasticity, self-organizing, going to CogSci 2011 woohoo, Shad BrainLab, iGEM, software, interfaces, coding Saturday, going to be awesome, can't say much about any of these things, but they're all awesome.

Wednesday, April 6, 2011

Best day... ever?

I was hoping to write a proper post about this, but I am somewhat too tired to do so, so I'll resort to posting a schedule of the day.

9:00 AM: Brain Day starts, introductions to talks by...

9:15 AM: Sebastian Seung (MIT) [I am my connectome TED Talk, on Youtube].

10:45 AM: Peter Strick (Pittsburgh): Motor control and basal ganglia / cerebellum topography.

1:30 PM: Jonathan Cohen (Princeton): Adaptive cognitive control.

3:00 PM: Ned Block (NYU, Philosophy) [On Consciousness Youtube clip].

[End of Brain Day]

7:00 PM: Perimeter Institute lecture by Roger Penrose [Discover Magazine article]

10:00 PM: Read web comics. There was a good crop today!

EDIT: Apparently Ryan North of Dinosaur Comics was also at the Perimeter Institure lecture. I'm kinda disappointed I spent too much time listening to the lecture to notice this.

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.