The delicate balance of explanations

Yesterday I talked about (and linked to) Vi Hart’s masterful explanation of logarithms. By coincidence, today I found myself in a deep discussion about visual explanations with someone who creates them for a living (she builds interactive graphical explanations of financial trends for a major newspaper).

We ended up talking about the delicate balance of explanations. If you focus only on making things accessible, you run the risk of oversimplifying. People who watch your explanation may feel good about themselves, but they haven’t really learned something in a useful way. By “useful” I mean understanding something well enough to apply that understanding in new and different situations.

On the other hand, if you try too hard to be comprehensive, you might end up drowning your viewers in detail. When people are subjected to information overload, they are likely to walk away before having learned anything really useful.

And so, as with any narrative art, teaching with visual explanations is a process of opening doors for people at just the right rate, so that viewers can have the pleasure of truly absorbing something new, and then building on what they have just learned, in a series of satisfying steps.

It is an art at which Vi Hart excels, which is why I study her videos with such fervor and delight. Every time I watch the “Logarithms” video I learn something new about how to teach.

1 + 1 + 1

I have been spending the last few days simply in awe of this video:

How I Feel About Logarithms

Vi has done something here that I’ve never seen anyone do before: She has made logarithms completely clear and fun and accessible to everyone — not just to people who are already into math.

Why should you care? Well, the pitch and volume of every sound you have ever heard, the color and intensity of everything you have ever seen, how things feel when you touch them, and just about every other sensation by which your brain receives the world — all of it is on a logarithmic scale.

Considering that your entire experience of reality is best measured by logarithms, really understanding them is quite a big deal.

And Vi has singlehandedly, through this one lovely video, done away with all the formulaic misinformation and useless crap that so many people “learned” in school. In their place she has given us a perfectly intuitive and elegant explanation that is as easy as 1 + 1 + 1.


This evening I was fortunate enough to attend one of those little parties where a number of the guests (as well as the host) were highly talented musicians. At some point in the evening the party drifted away from the food and toward the piano room, where people took turns performing.

A number of instruments were heard from, including clarinet and ukelele, in addition to our host’s magnificent grand piano. But what really struck me was not the variety of instruments, but rather the variety of musical genres, and the unique way that each genre communicated.

The choice of music was highly eclectic. There were folk songs in abundance, from Bob Dylan to Oscar Brand to that old standby Anonymous, for obscure ditties whose origins have been lost in antiquity. There was Dave Brubeck and Cab Callaway, and various selections from the Great American Song Book.

But one work in particular was quite different — a piano piece by Brahms. This was from another world entirely. Whereas the songs required you to focus on their lyrics, to be present in a very worldly way, the Brahms took us all to a place beyond mere thought, beyond language, a place of pure emotion — a sublime region of the human soul for which there simply are no words.

I am left marveling at the sheer range of all the wondrous things we call music.

Turks and Indians

A colleague told me today that he relies on Amazon’s Mechanical Turk for his academic user interface research.

For those of you who don’t know, this is a facility that allows people to sign up anonymously to take simple tests on-line. They get paid small amounts for taking these tests. In the words of Wikipedia, it is:

“…a crowdsourcing Internet marketplace that enables individuals or businesses (known as Requesters) to co-ordinate the use of human intelligence to perform tasks that computers are currently unable to do.”

The term “Mechanical Turk” was inspired by Wolfgang von Kempelen’s famous 18th century chess playing robot, known as “The Turk”, which turned out to be a hoax — there was actually a chess-playing human cleverly hidden inside the robot’s housing.


If you’re doing market research, or trying to understand whether a new kind of software interface is better than the old one, Mechanical Turk can be an effective way to get lots of people to try things out for you, at modest cost.

During my colleague’s description of the process, he mentioned that the great majority of the people who answer these questions are located in India.

Which is when the following thought occurred to me: As computer interface design studies come to rely ever more on Mechanical Turk, perhaps the interfaces we use will become increasingly optimized for use by people in India.

I’m not entirely sure whether this is a good thing or a bad thing.

Seven of nine

As many have pointed out, Star Wars and Star Trek represent opposite ends of an American pop-cultural dialectic. Whereas Star Wars is serious, Star Trek is jokey. Whereas Star Wars is fundamentally religious, Star Trek is decidedly secular. One could create a long list of such oppositions.

But only this week did it occur to me that these differences are embedded in the very names of the characters. Here are a few names from each, together with notes on likely influences or meanings:


Star Wars:



Luke Skywalker

One who strolls among the stars


Lei + Geia (Hawaiian princess as earth goddess)

Han Solo

Exotic loner


Yoga + Buddha


Star Trek:




“The real McCoy” — an honest guy


A guy from Scotland


A guy from Russia


A gal from Africa


An guy from Outer Space


As you can see, Star Wars names are all about exotic mysticism, whereas Star Trek names are about a bunch of regular folks hanging out and getting along, despite their ethnic diversity.

On the other hand, the original meaning of “Kirk” is “Church”, so I could be wrong about all this. Besides, it’s not as though the same person will ever direct a movie in each of these fictional worlds. One human being could never be permitted to have that much power.

In any case, if there were another Star Wars movie, it would be seven of nine, which everyone knows is part of the Star Trek universe.

Peter O’Toole

“He looked like a beautiful, emaciated secretary bird … his voice had a crack like a whip … most important of all you couldn’t take your eyes off him … acting is usually regarded as a craft and I claim it to be nothing more except in the hands of the odd few men and women who, once or twice in a lifetime, elevate it into something odd and mystical and deeply disturbing. I believe Peter O’Toole to have this strange quality.”

— Richard Burton

Hunger Games, the reality show

I always thought the premise of “The Hunger Games” was a bit ridiculous. After all, what kind of society would allow a government to send its children to fight to the death? But after seeing the second film, I finally realized what Suzanne Collins has been up to.

In the real world, children are indeed sent by their government to fight to the death. In fact this is absolutely standard, and has been so for centuries. Here in the United States, you are eligible for this honor when you are seventeen — the same age as Katniss Everdeen in the second Hunger Games novel/movie.

This isn’t something that we or any nation does maliciously, but I think there may be unconscious forces at work. Sending our children to die (as opposed to, say, sending ourselves) is a sign that our love for our country comes even before our love for our children. It is the ultimate expression of nationalism, the secular equivalent of Abraham’s willingness to sacrifice his son.

When you see it that way, it is not surprising that this particular expression of nationalism has been a property of many cultures down through the centuries. And it is one of those human practices that, like religion, is powerfully resistant to censure.

After all, a nation that sanctions such a policy is not going to take kindly to criticism. “Support our troops” is such a sacred creed that even to question putting teenagers into mortal danger can be seen as disrespectful to our brave soldiers.

I am amazed that it took me so long to understand the nature of this near universal practice, and that it required the tag team of Suzanne Collins and Hollywood to get me there.

Robotic furniture movers

As Richard’s comment from yesterday confirms, there would be a real use for furniture that can rearrange itself.

Alas, the economics just don’t add up. The cost of equipping each table and chair with the appropriate motors, electric power, control electronics and wireless communication would be prohibitive. Decent office furniture is already too expensive. Robotic furniture would be far more expensive.

But there is another way.

Rearranging your furniture overnight does not require real-time performance. It just requires that the job get done over the course of hours — say, between the hours of 2am and 6am. Which means that your various pieces of furniture don’t need to move at once. They just need to end up in their proper places by the end of the night.

If the tables and chairs are built with a few design constraints — such as being easy to roll and having legs that can be readily gripped by a low-to-the-ground robot (say, four to six inches off the ground) — then all the work could be done by a single robotic furniture mover.

This would, in a sense, be a cousin to the Roomba, but rather than pick up dust, it would move around tables and chairs.

Given the advanced state of today’s computer vision and path planning algorithms, I don’t really see any engineering impediments. During the day the robot would park itself in an out-of-the-way corner and recharge. After everyone is gone for the night, it would get to work.

Going on-line to schedule a conference room or classroom would be pretty much the same as it is now, except that you could also specify the kind of furniture arrangement you’d like for that day’s workshop, lecture or discussion group.

What could be easier? 🙂

Robotic furniture

I’m involved with MAGNET, a wonderful new interdisciplinary facility shared by various schools at NYU and NYU/Poly. As you can see if you visit the web site, there are many great spaces for students to discuss ideas, form study groups, collaborate on group projects, or just work by themselves.

One issue is that at certain times, particularly toward the end of the semester, things can get a little chaotic. The moveable furniture which contributes to the flexibility and reconfigurability of the space can end up in all sorts of odd and inconvenient places.

All too often, somebody needs to come in and put the furniture back into a workable arrangement, so that the space can continue to work for its many simultaneous uses — lectures, workshops, research projects and both individual and group study.

I realize that there is currently no cost-effective way to do this, but wouldn’t it be great if we just had robotic furniture? During the day the tables and chairs would compliantly move wherever you put them, but at night they would magically rearrange themselves back to a fresh state, ready to be put to optimal use by the next day’s eager young minds.

And wouldn’t it be nice, for once, to walk into a shared use classroom and find the chairs all arranged for that morning’s lecture, or moved discreetly to the side in preparation for the following day’s roundtable workshop?

Besides, it would be really cool to have robotic furniture. 🙂

Windsor, Crockett and Joe

Three brilliant creators from very different eras drew on the same wellspring of inspiration. From the time I was a child, their collective ideas have influenced my own work. Now, in a search for a kind of graceful simplicity, I find myself drawn to those ideas with fresh enthusiasm.

The creators I speak of are Windsor McCay, Crockett Johnson and Joe Harris.

In 1914 McCay picked up his pencil and draw a picture of a dinosaur, who then came to life. Gertie was, in my view, the first truly successful animated character. The minimalism of her appearance was very much part of her charm.


Forty four years later, Crockett Johnson wrote and illustrated a little children’s book called Harold and the Purple Crayon. The idea was delightful in its simplicity: Any time Harold wanted something, he could just pick up his purple crayon and draw it. But it went deeper than that. In a sense, Harold was the creator of his entire world.


About a decade after that, Joe Harris created an animated show for television called “Tennessee Tuxedo and his Tales”. It features a scientist named Phineas J. Whoopee, who drew on his three dimensional blackboard (or “3DBB” as he called it) to create all sorts of wondrous explanations that magically began to move.

As a child I loved all three of these things. Looking back at them now, I realize how much they have in common. No flash and dazzle, fancy special effects, or high polygon count. Just the simple power of drawing something and seeing it come to life.

What could be lovelier?