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Wednesday, March 28, 2007

Website Update- New Page: X-Plane as an Engineering Tool

At my job, just about every time we have visitors that have never been to our shop before, my boss has me give a short demonstration on how we use the X-Plane flight simulator, not just as a pilot training tool, but as an engineering tool, as well. Most of the people find it interesting, so I thought I'd adapt it to an article on this site. It's not very technical, so hopefully non-engineers will still find it interesting, and get a small taste of part of what is that us aerospace engineers do. The article is X-Plane as an Engineering Tool, and I've added an appropriate entry to the Aviation page.

Monday, March 19, 2007


BodyWorlds Whole Body PlastinateThis past weekend, my family and I went down to Dallas to see BodyWorlds, the traveling museum exhibit that shows preserved human bodies in various poses and various states of dissection. After reading PZ Myers' review on Pharyngula, I was a little worried that it was going to be too artsy. But I have to say, it was great. After reading a few reviews from other locations, it seems like certain locations may not get the full exhibit, either because the venue isn't large enough for all the exhibits, or political pressure keeps the museum from displaying all of the specimens, but it seemed like Dallas had quite a bit.

If you haven't heard of this exhibit, yet, like I said above, it's made up of many specimens of preserved humans. The preservation process is called plastination, which, to quote the Dallas Museum of Nature and Science, "Plastination, invented by German anatomist Dr. Gunther von Hagens in 1977, is a process whereby all bodily fluids and soluble fats are replaced with reactive plastics that harden after curing with light, heat or gas. All tissue structures are retained." To make things even more interesting, the bodies have been dissected in various ways to show off different aspects of human anatomy (and a handful of other animals, as well). For example, there are some specimens that show all of the muscles, others that show the circulatory system, others that show the nerves, and yet others that show different combinations of systems, so that you can see how it all works together. Yes, a few of the specimens may have been overly artistic, but those were the exception, and not the rule. Aside from the "whole body plastinates" in poses, there were several specimens of whole bodies that were sliced into ~1/4" sections. These were another, very interesting, and very informative way to show how the body fits together. On top of that, there were many, many more specimens that were of individual organs, or smaller groups of organs (such as the digestive system), also disected in various ways. These included not just healthy, but also abnormal and diseased tissues, so you could see what they looked like. It also showed how much variation there is from person to person.

One of the other complaints from Myers' review that had me a little worried was this, "I like my biology wet. It's supposed to be vital and dynamic and messy and complicated, but it all ties together into a lovely integrated whole. A collection of plastinated cadavers is precisely the opposite of what I enjoy about the science: it's dead and static and distressingly dry." So here's my response to that. In our trips to Guatemala (2005 & 2006), I've been lucky enough to help out in a few of the operations and get a peek inside of a living body. My wife's a nurse, so she's gotten to see much more than I have, and she had to go through all of those anatomy classes to get her degree. And both of us thoroughly enjoyed BodyWorlds. It gives you the type of overall view that you just can't get unless you actually perform your own dissection, and that's certainly not something that's going to be available to most people. The closest most of us will ever get to that is dissecting non-human animals, which although informative, just isn't the same as seeing the inside of your own species.

One more positive review is the fact that my 7 year old daughter was interested enough in the whole thing to spend an hour and a half looking at it, up until the time they closed the exhibit and kicked us out. She probably would have spent a little more time there if we'd had it.

I guess I ought to make note of the general mood. It was, after all, an exhibit full of dead people. The atmosphere was respectful, almost like a cemetary, with everybody talking in hushed tones. For the most part, I wasn't too bothered by it, since these were mostly adults who had lived (hopefully) full lives, and who had willed their bodies to this exhibit. There's still the sense that these were once living, feeling people who were now gone, but the presentation, and the knowledge that this was how these people wanted to be remembered, kept it from being sad. That is, all the exhibits except for the babies. I must admit, those were very moving. If you think that would bother you too much, the way the exhibit was laid out in Dallas, you could bypass that section if you wanted to. But even though it was sad, I think it was still worth seeing.

So, if you're reading this and planning on going to see BodyWorlds, my advice is to buy your tickets a few days in advance. The exhibit is so popular that the Dallas museum has expanded their hours to 9 am till 9 pm. And even at that, they're selling out. We waited until the night before to buy our tickets, and they were all sold out until the 7:15 pm entry time - 7:30 was the last slot they sold tickets for (and because they were running late, we didn't get in until 7:30 - so we ended up having to rush a bit at the end just to see everything). Buy your tickets well ahead of time so you can go in the morning and look at your own pace, and then have plenty of time to go look at the rest of the Museum of Nature and Science.

Thursday, March 15, 2007

CarterGyro Jump Takeoff Videos

CarterGyroJust a small entry for today, and I'm a few months late in getting to it, but I thought people might still find it interesting. I work for Carter Aviation Technologies, an aviation research and development company. One of our recent projects was heavily modifying an ultralight autogyro to retrofit it with some of our technologies, that we call the CarterGyro Demonstrator Trainer. To explain what we've done and how this benefits the aircraft, I'll just go ahead and quote our website.

To enable jump takeoffs, the aircraft has been modified with the Carter propeller & the two-setting Carter prop pitch control mechanism, the Carter designed mechanical pre-rotator, and the Carter rotor with automatic mechanical pitch control. For improved safety on landing, the aircraft now has the Carter smart strut on a Carter designed main gear, and a slightly modified commercially available nose gear with more stroke and a larger tire than the original nose gear.

In the current configuration, the CGD/T will fly straight and level as slow as around 20 mph airspeed, can perform zero-roll landings, and can jump over 150 feet straight into the air.

Anyway, what's so cool that I wanted to link to were the videos on the website. Follow the link above to watch them. They're pretty damn cool, and show just what an autogyro is capable of performance-wise. Keep in mind that this is an autogyro, not a helicopter. The rotor is only directly driven by the engine while on the ground when the tires can take care of the torque, and is disengaged before the aircraft lifts off the ground - you don't need any anti-torque devices like tail rotors that way. The aircraft can jump about 150' straight up just from that energy stored in the rotor.

Friday, March 9, 2007

More on Origin of Species

This is a follow-up to a previous entry. However, both of thses entries have been supplanted by a newer post, which combines the two, with a little editing, and a paragraph's worth of new content.

Cover of Origin of SpeciesWell, I finally finished reading Origin of Species (actually, I finished it a couple weeks ago, and I'm just now getting a chance to write about it). My impressions that I wrote about in a previous entry haven't really changed, but there were two other things that struck me that I wanted to write about.

First, and maybe this is just my fault for my own ignorance, but it's changed my perception of Darwin (kind of like as an aviation buff, I always get upset when people think of the Wright brothers as just tinkerers, and don't give them their proper due as engineers). The story you're always presented with about Darwin is this naturalist who went on a voyage on the Beagle to observe plants and animals, had an epiphany at the Galapagos islands, and came up with this theory of evolution. While this is true to a certain extent, and Darwin was a very keen observer, Origin of Species had more than just his observations from the Beagle and some interesting ideas to explain it. Let me give a couple examples. In one of the chapters on geographical distribution, Darwin discusses how certain plants might spread from one pond to the other. In addition to trying to think up plausible means, he then goes on to test how plausible they might be. Consider this passage, discussing the possibility of seeds sticking to water fowl and being transported from pond to pond in that way:

I do not believe that botanists are aware how charged the mud of ponds is with seeds: I have tried several little experiments, but will here give only the most striking case: I took in February three table-spoonfuls of mud from three different points, beneath water, on the edge of a little pond; this mud when dry weighed only 6 3/4 ounces; I kept it covered up in my study for six months, pulling up and counting each plant as it grew; the plants were of many kinds, and were altogether 537 in number; and yet the viscid mud was all contained in a breakfast cup!

Later in the same chapter, Darwin discusses inhabitants of oceanic islands, and the problem of how certain animals could have come to live on them. I'll just let Darwin speak for himself on this one:

Almost all oceanic islands, even the most isolated and smallest, are inhabited by land-shells, generally by endemic species, but sometimes by species found elsewhere. Dr. Aug. A. Gould has given several interesting cases in regard to the land-shells of the islands of the Pacific. Now it is notorious that land-shells are very easily killed by salt; their eggs, at least such as I have tried, sink in sea-water and are killed by it. Yet there must be, on my view, some unknown, but highly efficient means for their transportal. Would the just-hatched young occasionally crawl on and adhere to the feet of birds roosting on the ground, and thus get transported? It occurred to me that land-shells, when hybernating and having a membranous diaphragm over the mouth of the shell, might be floated in chinks of drifted timber across moderately wide arms of the sea. And I found that several species did in this state withstand uninjured an immersion in sea-water during seven days: one of these shells was the Helix pomatia, and after it had again hybernated I put it in sea-water for twenty days, and it perfectly recovered. As this species has a thick calcareous operculum, I removed it, and when it had formed a new membranous one, I immersed it for fourteen days in sea-water, and it recovered and crawled away: but more experiments are wanted on this head.

It's this practical approach from Darwin that impressed me. He didn't just sit around trying to come up with just-so stories - when he came to a question, he'd go and get his hands dirty doing real experiments.

The other thing I wanted to discuss from Origin of Species is how it made me appreciate how much we know now. Let me explain this a bit - right now, there's a lot we don't know about a lot of things in the universe, and it kind of fills you with a longing to know the answers, even though you know you won't survive long enough to learn them. Like life on other planets - I would love to travel to other solar systems and see how complex life has developed on them, what strategies and structures have evolved in an environment completely isolated from our own, but I know that that's something I'll never know. Now, consider Darwin's condition in relation to his theory, having the limited evidence that he did. In the final chapter of Origin, Darwin wrote, "Numerous existing doubtful forms could be named which are probably varieties; but who will pretend that in future ages so many fossil links will be discovered, that naturalists will be able to decide, on the common view, whether or not these doubtful forms are varieties?" We are those "future ages!" Granted, our knowledge of the fossil record is still far from perfect, but we've discovered so many things since Darwin's time. For example, we now have a pretty good idea how whales evolved, how the first tetrapods went from water to land, how birds evolved from dinosaurs, and so many other things that Darwin could only dream of. So, while I'll still long to know the things I can't, I can at least be grateful for the things we know now, that were the longings of people in the past.

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