As pointed out at Slashdot a couple of days ago, there is a pretty interesting converstation going on over at Wikipedia about whether it is ethical for them to include images of Rorschach inkblots. The inkblots are now in the public domain, so the issue is not ownership. The issue is that the Rorschach inkblot test requires that the images be novel to the subject, so would Wikipedia be doing harm by potentially depriving those in need of psychological help a potential treatment tool. The conversation on the talk page has gotten quite long so I’ve only skimmed most of it, but it’s interesting to look through – both for the debate on this particular issue and for the view of how it is determined what to include or not. Is the choice of whether to include the images on Wikipedia the same as the choice of whether to include them in a scholarly text which the public might also access (but presumably less conveniently). Is the fact that there are many experts who deny the validity of the test and feel it is not a legitimate psychological tool?
With regards to the blots, they are currently shown at the bottom of the page. It sounds like there has also been discussion of whether they ought to be hidden behind a link with a disclaimer that allows people to choose whether they wish to see them or not.
Roving Mars
I have been doing a lot of reading about robots this summer in preparation for a couple of classes I am teaching in the fall. The most recent selection I finished off, which I don’t intend to use in any course but thought might be good for background, was Roving Mars by Steve Squyers, the principle scientist for the current Mars rover missions with Spirit and Opportunity. I thought this might be a slightly dry but informative read. In fact, the book was quite engaging.
While there is a ton of detail about the rovers and what they do, the real story is about how Steve and his team went from a couple of people designing a camera to sent up to Mars to designing and constructing an entire Mars expedition including a lander, rover and suite of scientific equipment. There are many, many. many failures along the way, and a lot of uncertainty, up until days before the launch, as to whether the rovers will even be judged stable enough to send into space. Knowing how well, and how flexibly, the rovers have performed, it was fascinating to read about all of the uncertainty and fears about whether they would succeed at even their most basic tasks. In the end, Squyers credits the exceptional successes to exactly the conservative, meticulous engineering that made them second guess the rovers so much during the construction and testing process.
Having the story start back long before the design of the rover, we get to see the decision making that led to sending a robotic vehicle to explore Mars, as well as the other projects that were considered. There is a fair bit of the academic/grant-system politicing included in the book too, with a fair bit of discussion of how teams were recruited and the strategy of what to include in your proposal or not in tell the best story. It is a fun inside look at how much these considerations effect what proposals actually win – and at how much the scientists were able to still keep their eyes on the scientific objectives of the mission even in the midst of that.
Maybe my favorite part of the story was the account of how two rovers were sent to Mars instead of just one. I had always assumed that this was part of the plan from the beginning – part of the initial proposal. But reading the book, the proposal from Squyers’ team that was initially accepted was to send a single rover. It was only in further review of the proposal that NASA asked whether two rovers could be built instead of just one. Squyers says that as soon as this was asked, it was clear to him that a two-rover plan was necessary. It would allow some redundancy both in terms of getting the rover safely down to the surface in functioning order, but also in terms of the odds of hitting a location on the planet that would be interesting to explore. He also notes that had the original proposal included two rovers, the cost estimate would have been so high that the proposal would have been dismissed out of hand. The suggestion had to come from NASA. It was also interesting that having two rovers to construct actually sped up the testing process. The team was on an extremely compressed timeline for construction and testing, and by having two rovers they could be running two tests at once, and even swap parts between the two as necessary to keep things running quickly.
I am a huge Spirit and Opportunity fan so I was pretty sure I would find something to enjoy in this book, but I think that it would be interesting to pretty much anybody who was interested in the modern process of science or curious about space exploration. The passion that everybody involved had for trying to answer the question of whether there was life on Mars is infectious. While the book does not try to address the question of whether we are spending too much, or too little, on space exploration, it is an excellent case for the central role of robotics in the current and probably upcoming generations of missions.
ISS Sightings
I somehow hadn’t realized that the International Space Station was visible from Earth, but it is, particularly if you are at an angle to catch the sun’s reflection of its solar panels. NASA has a tool to help you figure out when the ISS or the shuttle will be overhead wherever you are – use the “Sighting Opportunities” pull-down menu on the left-hand side to select exactly the town you are in for a list of times and how long it will be visible over the next couple of weeks.
Math as Art
A Mathematician’s Lament was Slashdotted weeks ago, but I finally sat down and read my way through the whole thing. Lockhart, a math professor who returned to elementary and high school math education, writes about the fundamental flaws he sees in how we approach teaching math, particularly at the youngest levels. He opens with two stories that describe in his view what music and art education would be like if they were taught in the same way math is taught:
I was surprised to find myself in a regular school classroom— no easels, no tubes of paint.
“Oh we don’t actually apply paint until high school,” I was told by the students. “In seventh
grade we mostly study colors and applicators.” They showed me a worksheet. On one side were
swatches of color with blank spaces next to them. They were told to write in the names. “I like
painting,” one of them remarked, “they tell me what to do and I do it. It’s easy!”
After class I spoke with the teacher. “So your students don’t actually do any painting?” I
asked. “Well, next year they take Pre-Paint-by-Numbers. That prepares them for the main
Paint-by-Numbers sequence in high school. So they’ll get to use what they’ve learned here and
apply it to real-life painting situations— dipping the brush into paint, wiping it off, stuff like that.
Of course we track our students by ability. The really excellent painters— the ones who know
their colors and brushes backwards and forwards— they get to the actual painting a little sooner,
and some of them even take the Advanced Placement classes for college credit. But mostly
we’re just trying to give these kids a good foundation in what painting is all about, so when they
get out there in the real world and paint their kitchen they don’t make a total mess of it.”
The heart of the article is an argument for mathematics as an art, where creativity is central. Lockhart acknowledges that most people do not understand what mathematics really is – because they never get to really do mathematics in school. Math is taught as facts to be known rather than celebrating the ideas and insights that led to those facts being established. The drive to make math practical and relevant to our lives has taken out the part of math that is fun and interesting. I love the example that he gives of a good math question – one that asks you to think and have ideas:
Suppose I am given the sum and difference of two numbers. How
can I figure out what the numbers are themselves?
As he notes, if you know algebra you can apply it to this problem, but even if you do not know algebra you can think about it and come up with an answer and test it out. It is a puzzle that encourages creative thinking instead of applications of formulas to problems that follow a predictable template. Ultimately Lockhart doesn’t argue that we shouldn’t teach students to learn arithmetic and algebra, but that those things should come out of real, interesting problems that the students are trying to solve.
For me, I think about how different my introductory programming class would be if math was taught this way. I watch students struggle with how to solve a problem based on the things they know how to do, and a number of them want to be told what process to follow to come up with an answer – what similar problem that they have solved before can they slightly adjust to come up with an answer to this problem. Exploring ideas, some of which will fail, seems to be an unfamiliar process for a lot of them. Which is sad, because that is part of what is so fun about programming – you can have an idea and then test it out right there and see what happens. The whole process hinges on having learned at some point to think “what if I do this” and see where it takes you. If math was taught in school the way Lockhart describes, the transition to programming would simply be one of adding a bit of syntax so the computer can understand your ideas.
If you are all at all curious about the article but daunted by its length (it is very long), read the first section with the “dreams” and then just skim through the dialogs – they are a nice Socratic summation of Lockhard’s argument.
The Megastore killed the Traveliing Salesman
I spent a fair bit of time not only reading the content of this weblog post applying Traveling Salesman to the transportation of produce, but also the extensive comments. The idea is that one hears people say that locally grown produce has less of an environmental impact, but when you consider the transportation of food for all people, you probably ought to be minimizing the fuel spent across the entire community, which may not be the same as minimizing the fuel spent to get food to a single individual. Essentially – that distribution centers add fuel efficiency.
I think it is clear, and the comments point this out, that this is not really a condemnation of buying local produce. Fuel expenditures are not the only reason to do so. The distribution center model may be perfectly sustainable on a regional level but become more problematic on a national or international scale. I think the question the post is really wanting people who focus on buying locally, and specifically at farmer’s markets, to ask themselves is – are you doing this out of an intuitive sense that local means traveled less far means less environmental impact? And if so, you may want to think about whether you are following the best route to accomplish your goals. I believe that you can come back to saying you want to buy locally and support farmers markets – because you know the food is at least from this region and not the other side of the world, because you can have first hand knowledge of how your food is grown, because you may be able to buy varieties of food that would not ship as well under a distribution model, because it helps keep local farmers in business, etc. But I enjoy seeing this type of analytical approach applied to social behavior because of the deeper conversation that you see cropping up in the comments of the post about why this should or should not be done.
25 Years of Falling Blocks
I love the Google logo for the day – not just because it looks great, but because it kept me from missing Tetris’s 25th birthday. Like, well, everybody I remember losing hours and hours to playing Tetris.
I remember exactly where I first played it – in the summer of 1990 I was at the PA Governor’s School for the Sciences on the CMU campus, and Tetris was installed on the computers at the tiny computer cluster just down the hill from our dorm. It was an odd little computer cluster, shoehorned into a storefront space next to a laundromat across from various food vending trucks that never seemed to actually be open that summer. But we would go down there to work and end up playing “just one game” of Tetris that would turn into two, or three, or four – or as we got better that would go on for almost as long as endurance would allow. You got to develop a style – did you play it safe, laying down solid rows and clearing line at a time along the bottom? Or did you strategically form deeper holes that would let you plonk down the perfect piece and clear four rows at once? I think all of us had the experience of the cluster closing before our game had. At the time I was surprised they let us play on the cluster computers, but looking back I remember the many “No playing Netrek on cluster computers signs and remember that that was the era of schools suffering bandwidth issues because of MMORGs and other online games, and a few kids playing Tetris on localized machines on a summer evening was the least of their cluster abuse concerns. As an aside, I had no idea that Netrek was still up and running – nor at the time did I quite grasp what a technological innovation Netrek was. Modern WoW addicts and other online gamers owe a lot to that game.
Somehow after that summer, I ended up with a copy of Tetris on my Mac at home and I played it constantly. Even when I would grow bored, i could always sit down, weeks or a month later, and play a game and fall right back into the pattern. It was the first game that I would play to the point that I would go to sleep and dream the falling shapes and the patterns of rotation needed to play the perfect game. In college, the year I had to upgrade my computer past compatibility with my copy of Tetris was actually upsetting, and I think it is then that I ended up with a copy of Super Tetris 2, which spawned another “dreaming falling blocks” level addiction with the game.
It is the many, many variations of Tetris that keep coming out that convince me I am not the only one to have had that experience. I would be surprised if there was a platform that it was not ported to. You can access a version of it through emacs. You can play it online in a million places. You can play it in an unrealistically huge format. You can watch a Tetris game as recreated in stop motion by people in colored shirts (and how perverse that even in that format I have to grit my teeth at some of the stupid “moves” being made). You can decorate your house with Tetris furniture.
Excuse me now – I am off to put on my Tetris/Escher tshirt and play some Tetris.
Robots will kill them all!
Science fiction sometimes seems to simply pick between whether it is the robots or the aliens who are going to kill us all, so it is refreshing to see a headline warning us that the robots are killing the aliens. It is actually not a particularly fear-mongering story though. Instead, it is a nice article talking about how the fact that there is has been a complete lack of any organic found on Mars is in fact odd given the likelihood of transfer by asteroids or comets. This had let scientists to speculate that the perchlorates on Mars, when heated, are destroying any organic material that may be there to find. This suggests new ways of looking for organic materials in future rovers that will not result in destroying what is being looked for. There is an interesting mix here of wanting to collect data about Mars as a new environment, but also having to make some assumptions about Mars in order to plan out and revise the data collection procedures being used there.
Not nearly as cute as Aibo
I defy you to watch this video of a, sort of, robot dog and not be creeped out:
I have only heard of the uncanny valley being applied to people, but this has that same feel of being just natural enough as to be disturbing. In the first shot of the thing walking up the hill I wasn’t entirely convinced it wasn’t some poor real dog with a few artificial legs. It’s an impressive feat of engineering though – watch through to where it gets kicked while trying to walk on ice. The recovery it goes through to avoid falling is amazing.
Not really a recipe
I have been trying to get into the habit of taking a real lunch to work with me, and making up a batch of brown rice for the week that I can top with stuff seemed like a good idea – it would be filling and easy to throw together in the morning. Unfortunately, while I know brown rice is much better for me than white, I have not yet come around to liking the taste as much. So I decided I needed to make something aggressive enough to put on brown rice, while still being compatible with its flavor. I settled on making a spicy batch of vegetarian chili. Chili is fun, because I just go to the store and wander the aisles looking for stuff I want to throw in. Today, I ended up with:
- a large red onion and a couple of cloves of garlic, sauteed together in olive oil until well cooked,
- two huge carrots shredded finely, two green peppers, two “long hot peppers” (that is what the Giant Eagle called them – no idea what they actually were), and a cup of rehydrated TVP, all cooked in with the onion and garlic for about five minutes until softened,
- two cans of kidney beans, a can of black beans, and two large cans of crushed tomatoes, brought up to a simmer,
- a handful of oregano, basil, and chili powder, two handfuls of cumin, and about four chipotle peppers, after which the whole thing simmered through two periods of hockey.
The end result had a really nice texture (I chopped all my veggies very fine, and while I find TVP fairly flavorless I really like how it binds something like chili together) and a great flavor. It was also incredibly spicy; I have always associated chipotles with a smokey flavor, which the chili definitely has, and didn’t think about the added heat. I don’t mind, but this is definitely a chili to serve over something, not just to eat a bowl of plain. It also is an insanely huge batch of chili – I can never make a dish like this and not end up with enough for a week of meals and plenty to freeze. Fortunately, chili freezes wonderfully, and I am going to make up containers that I can thaw out and use to make up two or three lunches out of. Next time I would probably leave out the unknown hot peppers and remember to throw in shredded celery as well.
Yeah but assignment operators are cheap…
Coding Horror is often fun, and a good read, particularly for aspiring techies who want an inside glimpse of some of the details that would make up your life if you pursue that path. But when I read Jeff’s post on spaces versus tabs in code formatting I both cracked up and immediately thought of one of my Data Structures students who has to reformat any piece of code he is given before he starts working with it. With my students deep into their team projects, I wonder if they are running into the conflict that Jeff claims is inevitable:
The only programming project with no disagreement whatsoever on code formatting is the one you work on alone. Wherever there are two programmers working on the same project, there are invariably disagreements about how the code should be formatted. Sometimes serious disagreements. The more programmers you add, the more divisive those disagreements get. And handling those disagreements can be .. tricky.
He goes on to discuss the pitfall of team members taking it upon themselves to “fix” each other’s code – not just spacing, but even variable name conventions and the like. It may seem odd that such computationally trivial decisions (I mean, we all know the compiler doesn’t care…) could cause so much interpersonal strife on a team. But if you’ve ever really gotten into programming, the idea that someone else might be messing around with your code, after you get it how you like it….. well, it is probably at least a little agitating. And Jeff cites the classic “The Elements of Programming Style” to illustrate that these style principles actually do matter when it comes to code as a tool for comprehension and communication. Which is particularly key on a team project.
In their book called The Elements of Programming Style, Kernighan and Plauger also identify what we would call discourse rules. Our empirical results put teeth into these rules: It is not merely a matter of aesthetics that programs should be written in a particular style. Rather there is a psychological basis for writing programs in a conventional manner: programmers have strong expectations that other programmers will follow these discourse rules. If the rules are violated, then the utility afforded by the expectations that programmers have built up over time is effectively nullified.
I am now curious to see how my students navigate this problem – if they try to get consistency or not, and if the most obsessive person in the group just wins (I fear I have one group with people who don’t care that much and one group with people who do). And it makes me think about the style guidelines I set out for code in my introductory class, and that perhaps sharing some of this research would make it clearer why I have those standards.