Home-made UAVs

A UAV is an unmanned aerial vehicle. In the old days, a home-made unmanned aerial vehicle would be called a model airplane, or perhaps an RC (radio-controlled) plane. But the fancy-pants term UAV is well earned these days because of the amazing things amateur enthusiasts can do with them. It’s remarkably close to what much more expensive military UAVs can do.

For example, I read a fascinating article in Make magazine about the GPS-driven autopilot you can put into your kit. Sadly, the article is not online, but the article’s author Chris Anderson (who happens to be editor in chief at Wired magazine), runs a whole web site called DIY Drones. They’ll help you get started, and when you’re ready they’ll sell you an miniature open source inertial navigation unit that costs less than $100. That’s something that couldn’t be had for less than a hundred times that cost only a few years ago. By the time you’re done, you’ll have a device that can go spy on your neighbors. I won’t dwell on the point, but you can easily imagine many more mischievous uses for a cheap easily built spy plane.

If you make them small and nimble enough, you can fly indoors. Here’s a simple blimp that can pilot itself around your building, but the engineers at MIT have made something much niftier: precision-controlled helicopters. This video is especially impressive.

Here’s a Popular Mechanics article from last year about MIT’s indoor flight lab: Crash-Proof UAVs Fly Blind at MIT’s RAVEN Aerospace Controls Lab. I wish I had this stuff back when I was in grad school!

Fundraising for autism research

Every year in October Wendy and I do our best to get you to pay good money to send us around a horse track. The part about the money is serious. It’s hard for you to earn it and we accept it with respect. The horse track, on the other hand, is a MacGuffin. It’s not really the point, but it focuses the action into a story. You pay, we walk. But what about the money? We give it, by way of Autism Speaks, to medical researchers who are trying to turn autism from a voracious family-devouring monster into a historical curiosity.

jay

There are a lot of charities competing for your money. Let me tell you why mine is the most important: my son Jay is autistic, and dealing with autism sucks rocks. That’s the most accurate statement of my situation… I chose this malady because it chose me. This gives me great sympathy for others in my predicament.

I realize that, by itself, my personal connection may not convince you to give, so I ask you to consider this. Autism rates continue their mysterious climb, and now parent-reported rates of autism are greater than one percent (1 in 91). If you don’t already know a child with autism, you will. Unless you can do something to stop it.

You can.

Donate to Autism Speaks by supporting Jay’s Team (http://bit.ly/give4jay).

Many of you already have, and I thank you for that. As usual, I conclude this note with Wendy’s annual message.

Continue reading “Fundraising for autism research”

The talking piano

Fourier analysis tells us that you can do a darn good job modeling any periodic waveform by adding together a series of sine waves. The image below was lifted from the Wikipedia article on the Gibbs phenomenon, in which the goal is to assemble a square wave.

synthesis_square

On Jim Bumgardner’s KrazyDad blog I came across this talking piano. It’s from a German-language documentary, but the modeled words are in English. What’s going on? In a process similar to Fourier analysis, you can play lots of piano notes that together add up to a pretty good approximation of someone talking. Spoken words have lots of structure, and musical notes are building blocks of acoustic structure. With the help of a computer and many-fingered robotic pianist, you can make a piano talk.

It’s an uncanny sound. I think it’s just begging to appear in a haunted house movie.

Slow eyes and the Great Defrosting

Seeing is believing, but sometimes just seeing is not enough. A snapshot of a sick glacier with a sad caption doesn’t really compel. The hour hand advances and the water slowly rises, but busy people can be forgiven for shrugging and moving on. James Balog is a photographer, in the seeing business as you might say, and he realized that if he couldn’t make glaciers jump into your lap, no one would ever believe. I saw his TED talk on extreme ice loss and came away impressed.

The Extreme Ice Survey is basically the world’s largest time-lapse photography experiment. Only when you put on the slow eyes of time lapse do you see the glaciers staggering and collapsing like expiring dinosaurs. Here’s a video of a shrinking Icelandic glacier.

http://vimeo.com/moogaloop.swf?clip_id=5415263&server=vimeo.com&show_title=0&show_byline=0&show_portrait=0&color=&fullscreen=1

Also be sure and watch this Greenland glacier calving a massive iceberg.

It took years for scientists in the 1800s to become convinced that glaciers were actually moving rivers of ice. Let’s hope these videos help people understand more quickly what’s happening now.

Larval Debridement Therapy

If you’re looking for new ideas for medical therapies, it’s generally a bad idea to seek inspiration in the therapeutic practices of eighteenth century medicine. Bleeding was prescribed for almost any ailment (including bleeding-induced weakness), and compounds laced with mercury were commonly used in diuretics and antisyphilitics. And how about the practice of placing maggots in festering wounds? Surprisingly, this last techique is seeing a revival.

In the blog Bitesize Bio I came across a press release (PDF) from Monarch Labs on their Larval Debridement Therapy, also known as maggot therapy. To their credit, Monarch doesn’t shrink from using the word “maggot”. No hiding behind fancy latinate euphemisms for them… they spell it right out for you on their home page.

Medical Maggots™ are used to clean (“debride”) and manage wounds in a procedure known as “maggot therapy.” Sometimes wound debridement using maggots is also called “maggot debridement therapy,” “MDT,” “larva therapy,” “larval therapy,” “larva debridement therapy,” or “biodebridement.”

For people prone to slow-healing or non-healing wounds and ulcers, maggots can be a godsend. The real problem is convincing doctors to use them. If you believe the press release, “about 600,000 diabetics get foot ulcers every year nationwide, and traditional medical practices can cost up to $8,000 to treat such wounds,” whereas “… a single course of maggot therapy costs about $100.” What’s more, antibiotics can lose efficacy over time. Green bottle fly larvae, on the other hand, are in no danger of losing their appetite for gleaming pearls of necrotic flesh. Om nom nom.

Welcome to the new frontier of medical science: how’s about a nice whipworm smoothie to go with your maggoty salve? It’s only a matter of time before we rediscover the charms of iatrogenic bloodletting.

For the record, I advise that you not do a Google image search for the words “larval debridement.”

Local Twitter trends with Trendsmap

What are people talking about? That used to be a speculative question, but since the advent of blogs and now Twitter, it’s become a more tractable problem. You don’t have the time to read and distill a million Twitter messages, but your computer does. Algorithmically it’s getting to be pretty straightforward.

Trendsmap caught my eye tonight, partly because of two weather related events dominating local weather in two different parts of the world. Trendsmap uses Twitter to show you what the buzz is both globally and locally, and the design is so attractive that you can easily waste a lot of time on it.

Okay, here’s your quiz. What are people talking about in the greater Atlanta metropolitan area these days?

georgia-flood

That one didn’t surprise me, since I had been following that story on the news. But I didn’t know about the dust storms in Australia.

australia-dust

Crikey! It’s pretty apparent that dust is not only dominating local brainwaves, but that the massive storm has an end-of-the-world feel to it. Watch this video from Broken Hill, New South Wales and see if you can see why.

Train wrecks and momentum in the movies

When it comes to big things, it’s hard to get momentum right. We don’t have much experience with truly massive things moving quickly and unpredictably. Airplanes, trucks, and trains in normal circumstances aren’t surprising. But here’s a video of a train wreck during a tornado (nobody gets hurt). Watch through to the end to see Old Man Momentum get his due.

In old movies, they had to substitute small models for the real thing, so the physics were all wrong. Watch this video of the steamboat in the African Queen going over a waterfall. It’s clear the boat in the waterfall is about two feet long. With computer simulations and graphics, they can do much better these days. Here’s a clip from The Incredibles that involves a van speeding through traffic. Since they aren’t using a mechanical model, they can get the physics right, or close enough for a cartoon fantasy world.

Möbius music

Hofstadter’s Gödel, Escher, Bach is one of my all-time favorite books. As the name implies, there are many references to Bach’s music, particularly his fugues and canons. When I was reading the book back in high school, it was hard to track down and listen to all the music that came up in the book, let alone their musical scores. The world is different now, though. Take Bach’s Crab Canon, for example. Now you can find sites aplenty that describe it, show you the music, and play it. It’s called a crab because it is played against itself forward and backwards simultaneously. Don’t believe me? Look at this MIDI roll visualization (it looks like a crab!), and then listen to the audio file played backwards. You can’t do that to too many pieces of music and still have something worth hearing.

But wait! Why not look at how Bach’s canons resemble functions, and our friend the crab is g(t) = f(18-t). And if you print the piece out on a Möbius strip, you and a friend can play it together, assuming you’re on the same differentiable manifold (ha ha! you knew that). But don’t take my word for it. Watch the video.

Curiously, when it comes to Möbius music, Bach is not the only game in town. I was thoroughly charmed by this video of Vi Hart playing her comparatively recent composition, the Harry Potter Septet on a Möbiola. I like how the variable crank speed is part of the performance.

PLEASE NOTE: I don’t know if it’s really called Möbiola, but that’s what I would call it if I were king.

The electrification of motoring

The Economist gives a surprisingly upbeat assessment of the future of electric cars in this week’s article The electrification of motoring. I hope they’re right. It seems clear enough that if the battery cost comes down, then a lot can be simplified out of a car. This is looking pretty far down the road, but consider this scenario. If you put the motor into the wheel itself (something that is possible with an electric motor), then you can remove the engine under the hood, the transmission, the drive shaft, the gas tank, and the emissions controls, muffler, and exhaust. Not only does that free up a lot of space, but, as the article points out, it changes the car so drastically that the competitive advantage of existing car companies is much diminished. As a result, we’re likely to see some new players in the automobile industry.

Michelin has already built such an in-wheel motor, dubbed the Active Wheel. It may be a while before it goes mainstream, but it already works in the lab. Check it out.

The warehouse is the robot

Everybody likes humanoid robots (especially the Japanese, for some reason), but even nontechnical folks these days realize they’re not useful for much more than entertainment. Too tippy, too breaky, too expensive. Instead, we’re accustomed to things like robot arms bolted onto the factory floor. Much simpler. Simpler still is the Roomba, the ultimate in workaday non-tippy robots. Boring, but useful.

We’re so used to seeing robots as individuals that it’s hard to visualize the next leap: swarms of robots acting as a single entity. Kiva Systems (which I learned about from the ever interesting BotJunkie) has developed a warehouse robotics system that orchestrates the entire warehouse floor. In effect, the building is the robot. And it appears to be a genuine breakthrough.

I’m mesmerized by these images of little orange worker-blobs doing logistical origami. They’re like the fingertips of an enormous unseen brain. It reminds me once again of the ascendancy of software in all things. The warehouse effectively becomes a large physical version of computer memory. You’re seeing what amount to memory management algorithms in fully embodied glory: adaptive caching, clustering, batching.

The interviews with the smiling human workers are almost poignant. They’re talking about what an improvement this system is. Makes their job so much easier. Reduces it to almost robotic simplicity. I bet your job gets even easier when version 2 comes out.

If you’re as interested as I am in this stuff, you’ll want to watch this demo and read this article.