Happy Solstice

I’m a few days late, but Happy Solstice to you. Now the days will at last be getting longer again. Or at least, that’s what will be happening in South Africa, where so much of the world’s attention has been focused for the Great Big Soccer Thing. Those poor soccer players have been laboring away in the depths of the antipodean winter. Perhaps that’s why the South American teams are playing so well… being from the same latitudes, they don’t suffer any seasonal-displacement jet lag.

Okay, I know that winter in South Africa isn’t so bad, and I know that most of the world’s best soccer players have their day jobs in Europe, no matter where they were born, but still, I’ve often wondered if north-to-south induced season lag is as disorienting as east-to-west time zone lag. I suppose not, but the one time I was south of the equator, I saw an advertisement in Sydney for a “Spring Halloween Party” that threw me for a figurative loop (and an anti-sense loop at that). I knew about the Australian phenomenon of Santa on the beach, but somehow I find Halloween and springtime mentally immiscible.

Back in the northern hemisphere, here’s an APOD link to Sunrise Solstice at Stonehenge. (Only recently I was reminded by Dan to be attentive to and thankful for the ever-enjoyable APOD.) And I will close with a nice email message that I got from the Revels, a Boston-based performance troupe. I knew about the sun standing still, but I wasn’t aware that bonfire comes from bonefire.

The word solstice comes from the Latin solstitium; literally “sun stands still.” For approximately six days in June and again in December, the sun appears to rise and set at approximately the same point on the horizon. To a civilization that believed the earth to be the center of the universe, the heavens appeared to literally stand still.

This pause in the natural order of things is a prerequisite to the whole idea of celebration. The heart of a birthday celebration is a familiar sequence of events: a call for quiet, a cake, candles are blown out, a song is sung. Whatever activity is going on in the room is interrupted, this draws attention to the moment and the entire group becomes a witness to something of importance. Interestingly this can happen in a large restaurant filled with strangers or in a foreign country in an unfamiliar language without losing anything in clarity of purpose. This heightening of awareness used to be very apparent in ancient celebrations of the solstice. Midsummer was an occasion for great merriment and license with the sun at the height of his power. Fiery wheels were rolled down hills representing the sun beginning its descent. “Bonefires” or a ritual burning of clean bones invoked the flames of renewal and summer poles were erected to symbolize the fruitful union of earth and sky.

In times past, a closeness to nature was both necessary and desirable in order to maintain crops sufficient to keep the family alive; now we can theoretically buy anything, anytime and climate is a matter of raising or lowering a thermostat. Gradually however, the hidden costs and limitations of our relatively new found independence are creeping up on us and there are nagging reminders that we ignore the forces of nature at our peril. Paying attention would seem to be topical activity.

Light a candle, thank your lucky stars, and pay attention!

Left-to-Right Flipper Bridge

Time to revisit one of my favorite topics: crystal grain boundaries and the limits of annealing.

Of course you know what I’m really talking about is driving. Specifically: which side of the road do you drive on? Driving standards (any standards, really) make me think of polycrystalline solids, because they are assembled from an earlier chaotic and somewhat fluid state. First, people are driving all over the place, but if you and I live close to each other, then we’ll come to a social accommodation. Let’s agree to both stick to the right side of the road, and life will be much easier. Local conditions favor alignment of standards and these standards spread. But eventually you get two big pools of people, the left-drivers and the right-drivers, growing together, and they meet at a grain boundary. Despite the nuisance of life at the boundary, the standards have solidified, and it’s very difficult to change them. Behold, the grain boundaries of the driving world.

Sometimes, grains can realign in a process similar to annealing. The famous example of this in driving standards is Sweden: in 1967, they switched from left to right, bringing continental Europe under one standard. But this was just the last act in a long list of such changes. It works the other way too: Okinawa switched from right to left in 1978 and Samoa did the same thing only last year.

What happens at these grain boundaries? In a small economy without much traffic, it’s not a big deal. But it gets to be a problem as trade grows. One look at that map shows some long borders in places experiencing significant economic growth. This all brings me to Hong Kong and a report I saw on the Fast Company site: Ingenious Flipper Bridge Melds Left-Side Drivers With Right-Side Drivers. Why not just have the bridge do the flipping for you? Sadly, the bridge is notional. They didn’t win the design competition. But it’s still intriguing. And it turns out, such bridges really exist, as Wikipedia happily informs us. Here is a map of the Lotus Bridge in Macao. Trace the curves. That’s as easy as life at the crystalline grain boundary gets.

A flying Armadillo

In recent news under the heading “Private Enterprise Goes to Space”, most of the press coverage has gone to SpaceX’s launch of the Falcon 9 rocket. This is a genuinely big deal, and it deserves the glowing prose, but it overshadowed an impressive test by a smaller private launch company called Armadillo Aerospace.

Here’s a video of the test. You’ve seen dozens of rocket launches. No matter! Keep watching, because you’ve never seen a rocket land like this before.

Making that work is hard. I’d ask you to take my word for it, but since I’m no longer a practicing aerospace engineer, you’d have to take my word for it that it’s worth taking my word for it. I work in software now, and you can safely take my word for it that software is easier than launching rockets. But then again, I just realized that I can name three companies that are hard at work on commercial launch services, and in each case, the funding has come from software: Armadillo Aerospace (Jon Carmack’s Doom/Quake video game empire), SpaceX (Elon Musk’s PayPal), and BlueOrigin (largely funded by Amazon‘s Jeff Bezos).

The moral of the story appears to be that software may be easier than rocket science, but it also instills a powerful desire to make science fiction come true.

Should English spelling be reformed?

Did you catch much of the Spelling Bee last week? It finished up last Friday. The winner, Anamika Veeramani, knew how to spell nahcolite and stromur. Do you? Yes, you caught me: the correct spelling for a rheometer that measures arterial blood flow is actually stromuhr. Well done.

English spelling is full of oddities and inconsistencies. Humorists and reformers alike love to string together non-rhyming orthographic siblings like “The Tough Coughs As He Ploughs the Dough“.

Tough Coughs book

The humorist pauses for the laugh, but your true reformer plows (ploughs?) ahead with serious mean (I mean mien). Joe Little, my buddy from high school, is a true reformer. He puts his money where his mouth is too. Not only is he the director of the reform-oriented American Literacy Council, he actually traveled to Washington DC for the recent Spelling Bee so that he could protest its very existence. Not that he has anything against clever kids like Anamika Veeramani. It’s just that he thinks that, as his sign says: “English Spelling Spells Trouble”. Listen to what he has to say in this sympathetic USA Today video. By the way, that’s Joe in the bee costume.


Where do you come down? Are you convinced? Should English spelling really be reformed? The ever-informative Language Log has a good discussion about the relationship between spelling vs. rate of learning. But it all seems to be fairly equivocal. On the face of it, English spelling IS nutty. But who gets to reform it? And what gets left behind?

As I see it, the simplification of Chinese characters is a good historical lesson to learn from. In the name of stamping out illiteracy, Chairman Mao pushed through a set of drastically simplified characters. It’s easy to see the motivation, but the old characters didn’t go away, and as a result, some 2000 new (simple) characters have been added to the traditional set of around 50,000 characters. Is Chinese better off or not? The debate rages on.

Finally, now that you’re wound up about spelling, would you risk a wound to your pride by attempting the Spelling Bee’s sample test? If you take it, let us know how you did.

The Doppelgänger Distance

In the latest American Scientist, I came across a book review of Paul Davies’ new book The Eerie Silence. It’s another take on the old Fermi Paradox that bedevils the SETI crowd. Very briefly, it goes like this: if aliens exist, where are they? It sounds flip, but the more you pick at it, the more you realize it’s a significant puzzle. Shouldn’t we at least be able to detect other civilizations, since they’ve had ten billion years or so to get busy? You’d have to guess that we’re arriving late to the party. Only… where is everybody?

In this context, Davies touches on the concept of the Great Filter (which I’ve discussed before). The idea here is that, gosh darn it, intelligent life IS rare. And why? Here’s a quote from the review:

… given that we don’t see any evidence that other intelligent creatures have taken over big chunks of the cosmos, some Great Filter must be operating to prevent life from evolving to the point of colonizing our galaxy. […] Perhaps we’ve already made it through the Great Filter and will go on to colonize the visible universe ourselves. But it may be the case that civilizations as advanced as ours typically go on to destroy themselves before they reach the star-hopping phase, and that we have a Great Filter in our future.

This is why I’m interested in the the Doppelgänger Distance. It’s the distance from earth at which, given our current technology, we could hear the noise made by an exact copy of the current earth, assuming this noise was arriving right now (i.e. don’t worry about the time of transit). The Doppelgänger Distance could grow with either the sensitivity of our ears or the noise of our voices. Assume the listener knows where to listen, but the speaker is making no special attempt to be heard.

As the Doppelgänger Distance gets larger, we can feel better and better about having passed through the Great Filter. This is because, even if we are eventually so foolish as to do ourselves in, at least we will have rocked the neighborhood (which neighborhood being our Twin-o-Sphere, or the spherical volume for which the the Doppelgänger Distance is the radius). Someone clever in the vicinity will have heard us. And more importantly, we will have heard them. So: if we don’t hear anybody at all, then maybe we’re the first. Which would place the Great Filter behind us (in all likelihood).

If we make it this far and then wipe ourselves out, that would totally suck.

Robot helicopter’s impossible tricks

“Controls” is the branch of engineering that deals with the regulation of moving things. Thermostats and cruise control are the obvious examples, but control systems show up all over the place: temperature control, power control, attitude control… anything that, if left untended, is likely to become a puddle, a crater, or a ball of flame. Behind each one of those regulatory control systems is some code, probably written by a grad student, that spells out how the system should behave.

I was once a controls grad student, and one of the things we learned is that, once you’ve figured out how to control something, it’s not very hard, mathematically speaking, to control it amazingly well. Crank up the gain high enough, and you can make a tractor tap dance or a jet skywrite in cursive. In theory. The situation is similar to the old Archimedes quote “Give me a lever long enough and I can move the world.” It’s a nice line, but I checked the catalog, and they’re currently back-ordered on those super long space levers.

From a practical point of view, to do amazing things with control design, you need fast, accurate sensors with very clean signals and fast, accurate actuators with very clean response. This makes for a system that is heavy, hot, power-hungry, and very very expensive. Or rather, it always did until now. Everything is getting so much smallerer and betterer that old-timers like me can scarcely believe what’s possible. This is the best time ever to go to engineering school. Look at what you can build. Behold the insane quadrotor built by a group (of grad students!) at Penn.

Pardon my French, but that’s some crazy shit right there. Every working controls engineer in the world is wishing they were starting grad school right now.

The tactical value of these systems is obvious. Imagine snooping spy-bats that can perch on walls and quietly eavesdrop before flitting away into the night. Here’s a nice piece on perching planes at Stanford.

Prepare to see an unparalleled rush of innovation in micro-aircraft.