Faster Cars and Smellier Air

Josh has a new article up about “spacediving”. The enormous speeds we ordinarily associate with atmospheric re-entry result from de-orbiting. If you just go straight up and straight down, re-entry speeds are reduced to the point where spacediving ceases to be impossible and becomes merely gonzo-stupid.

Proceeding from this premise, the beryllium heat shield on Alan Shepherd’s Freedom 7 Mercury Spaceship must have been fairly over-designed. Freedom 7’s non-orbital, ballistic trajectory reached a top altitude of 187 kilometers (116.5 miles). If you dropped an anvil from this height through a vacuum, it would hit the ground at about 1,755 meters per second (5,758 feet per second.) Of course, in Earth’s atmosphere the anvil would reach terminal velocity before achieving this speed.

15 minutes and 22 seconds after blast-off, Freedom 7 splashed down 486 kilometers (302 miles) from its launch pad. That corresponds to an average Eastward velocity in the same ballpack as our idealized anvil — about 527 meters per second (1,730 miles per second.)

Cringely has a surprising article this week about the use of giant kites to harvest electricity from the wind. The hardest part of flying a kite is launching it, and I’m a little hazy on how they plan to get these monsters off the ground, where the windspeed is modest. But the proponents think they can generate electricity for the game-changing price of 0.5 cents a kilowatt hour. Forget windmills, this price beats coal. Reportedly, the Google People are involved, which suggests this is science fiction rather than fantasy.

It’s gratifying to see somebody draft aerospace engineering to fight global warming. I’m reading an interesting book, Break Through: From the Death of Environmentalism to the Politics of Possibility, which suggests that efforts to reduce global poverty can also help combat global warming. The conventional wisdom says that economic progress will result in more industry and therefore more pollution. The authors of Break Through argue convincingly that nations must escape poverty before they feel secure enough to focus on environmental issues and expend the kind of resources necessary to really secure rain forests and reduce greenhouse gas emissions. The authors advocate a new Apollo project (again with the aerospace engineering!) to jumpstart large-scale clean technologies that we can share with them and, of course, use ourselves.

I’ll keep riding my bike to work, but this is good stuff.

I now commute by bicycle, partly because it’s fun, but primarily to limit my greenhouse gas emissions.

I’ve only recently started thinking about the fact that I always change out of lanes when I can’t keep pace with the prevailing speed of traffic. However, if I see a red light or a stopped car ahead, I typically have continued on in that lane with the understanding that I’m not reducing overall traffic throughput.

Unfortunately, this seems to preoccupy many automobile drivers behind me. They apparently cannot bear to be going any slower than physically possible. They will often elect to switch out of their lane (or switch partially out of their lane), speed up, pass me, switch back, and then slam their breaks on when they realize they are about to smash into the right side of a garbage truck.

I presume that they didn’t notice anything beyond my bicycle intruding on their fundamental human right to (briefly) change their position with respect to the positions of other objects at a large rate.

Aside from being dangerous, these irrational drivers are wasting fuel. So from now on, I resolve to switch out of my lane if I can’t keep pace with the car behind me, regardless of overall traffic throughput.

I am intrigued by all these little, split-second decisions our minds make, often without conscious direction. For example, I have gotten really good at catching fumbled objects. I marvel at it because I know how hard it would be to teach a computer the same trick.

Earlier this year, I read Jeff Hawkins’s interesting book On Intelligence. Hawkins believes that the ability to recognize patterns and sudden departures from them is central to intelligent action. He goes into great detail describing the sophistication of sensory perception. Hawkins further believes that our minds accomplish this through the application of an as-yet undiscovered, high-level, invariant mechanism.

What if Hawkins is right about the centrality of patterns, but not about the mechanism? What if intelligence is little more than the ruthless application of a zillion simple edge-detection and flood-fill algorithms?

Perhaps I will start treating Photoshop with a little more respect.

I was finally able to participate in Bike to Work Day this year.

There were a respectable number of bikes on the road, a few of which were operated by old folks who appeared to be in better shape than I am in.

As expected, there were also inconsiderate and clueless automobile drivers. And for some reason, Georgetown seems to be their Mecca. One behaved as though my bike and I were invisible, changing into my lane and forcing me to get out of the way to avoid an accident. On the way home, I was parked in the right lane at a stop light when a taxi cab driver behind me, in apparent frustration that I occupy volume, started honking.

But I received my free bagel and T-shirt. I self-actualated. It was a good time. Outpacing cars and trucks on a bicycle is always exhilirating.

So how many of us will be biking to work Monday?

If you look at commuting time, biking is by far my fastest route to work. The important factor isn’t the distance between my home and my office, but between my office and the gym. In my case, it’s about four city blocks. A little on the long side, but doable. I’d need to get better at getting ready quickly in a locker room environment, where I have to observe time-consuming protocols that aren’t necessary at home. It’s sort of like elevator-etiquette, but naked.

Since I’m currently commuting by subway and not by automobile, I suspect that the benefit to the environment of switching would be modest. I guess if enough riders made the change, it would relieve crowding and might make the subway more attractive (or less unattractive) to automobile commuters. Of course, extra trains and better schedule-keeping would accomplish that, too.

If nothing more, Bike to Work Day is valuable because it promotes dialogue, and reminds us that that we have alternatives.

I’m finally caught up on sleep from the Desktop Matters conference and subsequent hiking trip to Zion last weekend. Both were great!

Some thoughts:

• With the new Apps Framework, progress on the Binding JSR, and some great RAD tools, desktop Java has become a serious contender. If they can nail the deployment problem, look out!
• The real night sky makes the city sky seem like one viewed from some other planet.
• When clinging for dear life to a chain along a steep, narrow ridge, gloves are helpful.

I’ve started a new science webcomic called Sandals. I will try to post new installments 4 to 5 times a month.

There is an article in this month’s AAA World about environmentally-conscious tourism.

AAA World, for all of you living in countries where the predominant form of transportation is hansom cab or catenary, is the “official publication of the Metro Washington and Virginia Regions” of the American Automobile Association. It periodically enlightens us with profound pieces like AAA’s Best-Kept Secret: We Sell Insurance and West Virginia: They’ve Paid Us to Tell You to Visit. We throw out the magazine upon receiving it.

Ordinarily, I would let this go. I’m sure the author had good intentions. I have on occasion offered energy-saving tips on my own website. But Shani assures me that targeted diatribes are exactly the kind of thing people want to read in the blogs, so here goes.

The article begins

TREE-HUGGERS aren’t the only ones trying to tread lightly on the environment while traveling these days.

Impressively, the author has already alienated her entire target audience. She goes on to suggest

Choose an environmentally conscious airline (ask about policies)

Hello? Transcontinental Monopoly Airlines? Does your company have environmentally conscious policies? They do? Great!

Don’t buy souvenirs made from endangered species

Thank you for heroicly exposing the heretofore unknown, hidden environmental cost of souvenirs made from endangered species.

Here are some of my own Earth-friendly travel tips for my fellow auto club members:

1. Don’t travel in the first place, or if you must:
2. Stop driving everywhere and try walking for a change.

Happy New Year.

I fondly remember puzzles from classic interactive fiction that involve revisiting places after long periods of time. In Quendor, it seems, objects can remain intact and undisturbed for tens or even hundreds of years.

And on Earth. too. In the Spring of last year, a careless realtor presumably left the mug depicted here on a window sill near the intersection of Rhodes Street and Wilson Boulevard. I took this picture today.

It might be fun to conduct an open-ended scavenger hunt, with some items to be collected in the future.

My XSLT-based blog software, by the way, did not successfully weather the change of year (Y2k+6 problem?), lending support to the adage that If it isn’t tested, it doesn’t work.

I have posted an update. [Note: this blog has since been moved to WordPress]

Shani and I are back from a great trip to Utah! We visited her dad at Bryce Canyon and have many, many pictures to organize.

At Zion we saw this funny sign.

The apparent instruction here is “Don’t feed the miniature deer”, or perhaps more specificly “Don’t feed the miniature deer Oreos”.

The “current” issue of Scientific American has a terrific series of articles on the future of our planet and the challenges our population faces.

(I anticipate that most of it will be available free online here during September. Despite the reversal of a nutty price hike, unfiltered electronic access to the magazine remains more expensive than print susbcriptions.)

The editors, following the lead of their friends at the National Geographic Society, and no doubt acquiesing to the repeated pleas for “less speculative cosmology” that I scrawl on my subscription renewal cards, have put together some very interesting and at times surprisingly upbeat analyses. Many of the pieces question the conventional wisdom that the interests of business and ecology inherently conflict.

1.1 billion people get by (or fail to get by) on less than one dollar a day. In an recap of his recent book, Jeffrey Sachs asserts that an additional $80 billion annular investment could ultimately eliminate that level of extreme poverty. Certainly this is audacious, and has generated rancorous argument (if you like that sort of thing, see the Washington Post Book World’s nasty review, a review of that review in a blog I follow, and the author’s response.)

What’s clear to me is that we have to do more, because the magnitude of this human suffering is outrageous and unacceptable. I hope we can avoid globalizing the traditional Left/Right arguments. We need to find areas of consensus and act, quickly. As governments and as individuals.

Like any endeavor, some things we try won’t work. But others will. Asia has already begun to turn things around.

Now that Discovery is happily back safe and sound, it’s hard not to be dissapointed about another ginormous chunk of foam detaching from its external fuel tank after everyone worked so hard to prevent it.

There were some successes here. Notably, the repair process worked well. The centerpiece of this success was Canadarm, the newly-extended remote manipulator arm contributed by our friends to the north.

I agree with astronaut Scott J. Horowitz and others that the design of the shuttle is simply too complicated. If you amortize the total cost of the program, each launch burns about a billion dollars, and human resources account for much of it.

There is really no effective way to test the shuttle. Other manned rocket systems are launched dozens of times without people in them before they are considered safe. Only the pieces of the shuttle can be tested. As Richard Feynman pointed out in the Challenger investigation chapter of his excellent book, when you assemble 100 components that each are 99% reliable, you should expect the resulting machine to be less than 36.6% (0.99 ^ 100) reliable. The only ways around this problem are to use fewer components, or to rigorously test the finished assembly.

When considered against the initial goal of routine access to space, one has to conclude that the space shuttle program has not been a success. In the near future, a return to more conventional rocket technology is appropriate. However, we can’t drop the ball developing the promising scramjet technology. If we ever have spaceships like the kind they have in Firefly, they’re going to use scramjets. We should take all the money we save by scrapping the next generation space shuttle and invest heavily in non-military scramjet research. And, of course, continue the highly successful unmanned exploration programs to Mars and the outer solar system.