Segway lessons

From playing with robots we tried an actual application of robotics. We had the Segways 101 course at the St. Louis Science Center.

The lesson itself was fun, with an entertaining video of people falling off Segways. They also had a little obstacle course to let you try doing all of the things the video told you not to do (but most of it was for the more advanced class).

Afterward, we discussed the fact that this too was robotics and a pretty advanced application at that. We did not talk much about how the Segways were supposed to revolutionize urban transportation but students did recognize the fact that aesthetics were a major impediment to their broader adoption.

The price was a bit steep however, and I’m a little conflicted about if it was worth it.

Lego Mindstorms

I’ve been curious about the Lego Mindstorms robotic systems for a while now, and I had my first chance to try them at the St. Louis Science Center.

The kits come with a micro-controller, a few motors and some sensors. While there are quite a number of ways of assembling these to make robots, the ones at the science center were pre-built except that you could just plug in a bulldozer or sweeper attachment (and a head which was purely decorative). This limited the degrees of freedom to three, which made it easier to program something useful in the hour we had with the robots.

The programming is very basic. There are two sets of instructions, one to control the movement of the robot in general, and one to control its response when the sensor detected a change in the environment. The objective of the science center’s game was to clear off a set of objects from a white rectangle within five minutes.

You could tell the robot to move forward, back or rotate while it’s on the board and to activate its sweeper or shovel. So a full program could have just five elements; general: lower shovel –> move forward –> rotate; sensor: move backward –> rotate. With these strict limitations, the programming interface is also very simple; you plug in blocks with each instruction in the series for either the general movement or the sensor reaction. With all this simplification, I’m not sure just how much the students learned about programming from our short session.

The full kit from Lego offers more freedom to design robots and thus more flexibility with the programming interface so with a little thought it could be easily integrated into the curriculum. At about $300 each the system is a bit pricy, we’d probably need to get one kit for each small group of 3-4 kids. They would probably be worth it however if we used them more than just once.

I’ve been playing with the Basic Stamp micro-controller for a while, and while it offers almost infinite flexibility, making it more useful for practical applications, it does not provide the immediate gratification of the robots, and the ease of assembly to make it the better tool for introducing robotics to middle schoolers. I still, however, tend to favor practical applications, so perhaps I can persuade a student to do an advanced project to build an automatic window for the greenhouse.

The session at the Science Center was worthwhile. All of the students seemed to enjoy it. It provided a nice integration of the mechanics and electronics we’ve been learning about all year, and a glimpse of where technology is taking us in the future.

Anheuser-Busch and the industrial revolution

Fermentation vats.

Why take a group of middle schoolers on a tour of the Anheuser-Busch factory? After all, no one will be trying any samples and the main point of the museum and the tour itself is to make people feel good about the company and buy more of its products. Which would be beer.

Rail track leading into the brewery.

The answer is that the history of the company ties directly into the history of the industrial revolution in the U.S.. Its large scale industrial process was made possible by the serendipitous German immigration into St. Louis in the late 1800’s. Just then the expansion of grain farming in the mid-west and the railroads could supply the raw materials for beer on a massive scale. New assembly lines and automation could efficiently process these inputs, resulting in large scale production. Successes bred new inventions, with the company retaining the services of Rudolph Diesel to introduce his engine to the U.S..

Assembly line producing hundreds of bottles a minute with only five workers.

The survival of the company during prohibition (1920-1933) was another point of interest. Anheuser-Busch survived by diversifying from its core business, making non-alcoholic drinks and selling baker’s yeast among other things. At the end of prohibition, Anheuser-Busch was the only large brewer left in the city St. Louis.

Barley.

We also saw a bit of chemistry during the tour. The breakdown of complex starches into sugars as part of the fermentation process is a basic example of organic chemistry in action (polymers –> monomers). Light beer, for example, is kept in the tanks longer so that more of the starches are broken down into simple sugars. There were even a couple of big models of barley grains and hops buds showing their parts, that tie in to our life-science lessons next year.

First encounter with the barrage of advertising.

Even the surfeit of advertising could be used to advantage; the first thing inside the door of the museum is a television playing Anheuser-Busch’s most successful commercials. We’ve been discussing propaganda all year, so the students were somewhat inoculated to the barrage of feel-good messages, and we specifically discussed this in our post-tour group meeting.

Our tour guides were great. Informative, friendly and willing to answer questions, I particularly appreciated that they joined us in our group discussion after the tour and answered the questions that came up as best they could.

This tour exceeded my expectations.

Scrap metal playground

The St. Louis City Museum is an excellent place for the kinestetic. They assembled scrap metal from all around the city, including coils of metal, wire fencing, steel-plate slides and airplane fuselages, and gave it to artists to produce an exceptional, innovative playground.

Wire tubes extended across the air, two-three-four stories high, barely wide enough to crawl through. If you’re claustrophobic and afraid of heights you would think it would be a nightmare, but the wire mesh is sturdy enough that you feel secure, while being open enough to so you don’t feel closed in.

There’s other stuff inside the museum, the staff says it’s always under construction, including a warehouse of gargoyles and building facing saved from demolition, however it’s the outside that’s most remarkable.

Glassworks

Molten glass, upwards of 2000 degrees, cools slowly, quickly, slow enough to pull, twist, fast enough to feel the brittleness between metal tweezers in seconds. Runny to viscous as it cools. Change of state — freezing — feel it in the glass.

Tweezers and jacks keep hot glass at a distance. Third class levers require balance and firmness to control their mechanical advantage.

Glass, silica, SiO2. Quartz crystals, ordered array of molecules. Glass, no organization, amorphous.

Furnaces blast hot, you can see the yellow-orange color, you can feel the hard infra-red light, thermal energy. IR – long wave – less energetic. When extra heat is needed, the blue/ultra-violet flame of propane (mixed with oxygen). UV – short wave – high energy – hard on the eyes though you can’t see it.

Combustion needs three things, heat, fuel and oxygen. Propane, C3H8, not methane, CH4 – the greater energy density. Propane, C3H8, not butane, C4H10 – is a gas not a liquid. To burn real hot needs extra oxygen.

Propane torch.

Conservation is a challenge. Furnaces –> heat –> lots of energy –> bad. Natural light, big doors, lots of windows. Recycle glass (at least the clear glass). No need for heat in the winter. Drink lots of water in the summer.

3rd Degree Glass Factory, make your own paperweights. About 12 minutes per person. Excellent way to spend a morning. Really cool faucets and water basins in the bathroom.

Lambert’s of Sikeston

Lambert’s Cafe is an interesting cultural icon. Seriously small-town and farm-country, the staff all wear red suspenders and bow ties. Seating in long wooden benches, and the drinks in enormous, reusable plastic cups. The cups really captures the ethos. Red, black and blue, they are cheap, thick walled and have see a lot of use, so much so that the logos and markings on many of them are coming off.

They also throw rolls to you from across the room. It’s their thing. It’s a lot of fun, although under and over throws can come as a bit of a surprise to the unsuspecting. Someone is always walking around with tins of sorghum mollasses and apple butter which are quite good.

At any rate, Lambert’s is located at a convenient half-way point between Memphis and St. Louis, so it makes for a reasonable break on the long drive.

[googleMap name=”Lambert’s Cafe” description=”Food stop” width=”400″ height=”350″ mapzoom=”6″ mousewheel=”false”]2305 E Malone Ave Sikeston, Missouri 63801[/googleMap]

Physics and history in Vicksburg, MS.

Salvage of the ironclad, USS Cairo, in Vicksburg National Military Park.
Salvage of the ironclad, USS Cairo, in Vicksburg National Military Park.

Four hours away, Vicksburg, MS. is just within reach for an immersion trip so, since we were in the area, I scoped it out for a future trip. Vicksburg was the final town to fall before the Union could control the Mississippi River and split the Confederacy into two, so it’s historically important. The Vicksburg National Military Park is chock full of monuments and markers that give a good idea about the chaos and carnage of the battle for the town, and even a chance to observe practical application of simple machines and steam engines.

Rifling in a cannon.

The park could complement Shiloh and Corinth quite nicely since Vicksburg’s importance was because of its control of transportation routes, just like with Corinth. It also has the salvage of the USS Cairo, an ironclad sunk during the Civil War. Much of he Hull is still missing so it’s a wonderful chance to see all the mechanisms and engines in a steam powered ship.

Watermill at Grand Gulf Military State Park.

What I found most interesting, however, were the old watermill and farming equipment at Grand Gulf Military Park, about 45 minutes south of Vicksburg. They seem almost in working order, and if you’ve been discussing simple machines, as we have, it’s a great opportunity to see how they were applied in real-life.

One-man submarine with bootlegger's still in background.

The watermill is quite picturesque, making it a great subject for sketching or drawing. I like to combine art and science in this way when possible. Grand Gulf also has a small, submarine used by bootleggers during prohibition which is quite the curious piece of engineering.

[googleMap name=”Grand Gulf Military State Park” description=”Watermill and camping” width=”400″ height=”300″ mapzoom=”8″ mousewheel=”false”]12006 Grand Gulf Rd, Port Gibson, MS[/googleMap]

Corinth Mississippi in the Civil War

Stream of American History at the Corinth Civil War Interpretive center.

The Memphis to Charleston line was the only railroad that linked the East Coast of the Confederacy to the fertile Mississippi River Valley. At a time when the fastest way to move troops, supplies and commerce was by river or rail, the Memphis and Charleston railroad was essential (this was well noted in Robert Black’s “The Railroads of the Confederacy”). Cutting the railroad was an important objective of the Union. Cutting it at Corinth Mississippi would also cut the Mobile and Ohio Railroad line which linked the north and south of the Confederacy. Thus the Battle of Shiloh, where the Union could disembark its armies using the Tennessee River, and soon after, the Battle of Corinth.

The Civil War Interpretive Center in Corinth (this is also a good reference) does a nice job of presenting the details of the battles for the town, and their video presentation, with different images projected on multiple screens in a circular room was quite good (though there was a lot of information and you did not know quite which screen to focus on, so some students had trouble keeping track of it all).

Standing waves: turbulence in the stream of American history.

The most interesting part of the center is the Stream of American History which is a wonderful place to learn about metaphors. The stream starts with a fountain that overflows through 13 notches cut in the rim of the basin into a shallow water course that gradually widens as more states are added to the U.S. In the first reach of the stream there are impediments in the paved stream bed that create turbulence, harbingers of the war to come (they create nice standing waves which is an additional point in their benefit).

The 13th Amendment.

When the stream gets to its main focus, the civil war, large granitic blocks, cut into prisms and labeled with the names of the battles, break the stream into two before it finally merges again as it reaches the reflecting pool.

I threw my students at the Stream without telling them what it was. The only hint I gave was that it was a “large metaphor”. There were enough clues that they could figure it out. They wandered around it individually, with their pencils and notepaper for 15 minutes (I required that they write down their interpretation, then we got them together to pool their thoughts.

The stream is a very nice puzzle, and the National Park Service has a good key (pdf). It was a good way to end our immersion trip, and it gave the students something to think about on the long drive home.

[googleMap name=”Corinth Civil War Interpretive Center” width=”400″ height=”350″ mapzoom=”4″ mousewheel=”false” directions_to=”false”]501 West Linden Street, Corinth, MS‎[/googleMap]