## Chicago – Sunday, 07/26/2009

We had a tough time getting up Sunday morning, being exhausted from walking many, many miles on concrete and asphalt the day before. I think by 8:00am we managed to be out of bed. The first order of business was breakfast, but this time I chose the Blueberry Hill Cafe (in historic LaGrange, IL), having been discovered by my keenly observant mother a few weeks earlier. You see, Mom, my sister Sarah, and my nephew Alec were visiting me in early July. Sarah and I wanted breakfast at IHOP. On the way, Mom spotted the Blueberry Hill Cafe with a decidedly subordinate comment like “Oh, that looks like a nice place to eat” as we drove past it. After we failed to locate a local IHOP, Mom asserted the Blueberry Hill Cafe again, knowing from her long experience that it’s better to eat at a local (vs. large chain) restaurant when traveling. I couldn’t agree with her more.

Sharing in Mom’s wisdom, I took Dad to the Blueberry Hill Cafe.  He loved the restaurant on the way in, but got an omelette he didn’t like, spoiling his impression.  We made it to the train station and headed for the Museum of Science & Industry.  On the basis of the transit map alone, we decided the shortest way to the museum was to take the green line towards Cottage Grove all the way to the end.

Exiting the train station and finding ourselves in the projects, I realized there’s a lot more to getting around a city than train stops and street names. You’d think I would have remembered this lesson from when I lived in the D.C. suburbs, but apparently not. We made a hair-raising 2 mile walk through this war zone, replete with gold-toothed thugs wearing wife-beaters and pants sagging down to their knees. We got more than a few hostile stares from street goons, but managed to avoid any tolls or beatings. Both of us were sweating bullets. Dilapidated and crumbling structures with barred doors and broken windows boxed us in at every turn, while chain link fences with barbed wire rounded out the scenery.

Emerging suddenly from the projects was the University of Chicago, which was at once both a visual and psychological safe-haven, but the damage was done to any desires I might have about a postdoc there.  It’s too close to the projects (literally, one street away).  Although the campus was lush and green and seemed safe, one needs only to stray down a wrong street or two to find oneself in trouble. Finding ourselves out of the danger area, our heart and perspiration rates returned to normal. My brain emerged from fight-or-flight mode, and its cognitive abilities were freed up enough for me to generate a good idea: Mark regions of high crime rate on maps, especially tourist maps. Somebody should do this. Maybe they already have.

A quick walk past UChicago and Hyde Park, we arrived at the Museum of Science and Industry, the largest science museum in the western hemisphere. Flashing our CityPass booklets again, we skipped lines and made it into the exhibit halls. Confronting us head-on was a Foucalt pendulum, and I couldn’t help but think of the Coriolis effect and noninertial reference frames.

Focault Pendulum

I surprised Dad by telling him I could calculate the length of the pendulum by just measuring the period of its swing (the period is the time for the pendulum to make one full swing back and forth). Indeed, the period of a simple pendulum is given by $T=2\pi\sqrt{\frac{L}{g}}$ where $L$ is the length of the pendulum and $g$ is the magnitude of the gravitational acceleration at the pendulum’s location. Solving this equation for $L$ we get $L=\frac{gT^2}{4\pi^2}$. I measured the period $T$ of the pendulum over several swings and averaged my result, getting $T=8.9\pm 0.1\textrm{~s}.$ Taking $g=9.81\textrm{~m/s}^2$ we get $L=19.7\pm 0.2\textrm{~m}.$ Thus the length of the pendulum shown in the picture is 64 feet 7 inches, with an uncertainty of about 7 inches. Thus just by measuring the period alone, I am able to calculate how long the wire is that connects the pendulum to the ceiling, several stories above. Even though this is freshman physics, I still think it’s pretty cool.

Our first major exhibit was the Henry Crown Space Center, where was saw the original Apollo 8 space capsule and the Apollo 11 training mock-up. Next were the giant LEGO models of Adam Reed Tucker and the Navy, Auto, and Ships exhibits. Passing by a whispering gallery, I mentioned the reflection property of an ellipse. But the real gem of our trip was the U-505 submarine. This is the german U-boat captured by the United States on June 4, 1944. We only toured a few compartments of the U-boat, but it was enough to give you a palpable feel for life in those conditions. The tour was timed and had visual and audio cues, which I thought might be hokey at first but were pretty effective. Das Boot was on my mind during the tour. If you haven’t seen it, you should rent it. English subtitles will get you through this compelling movie.

Exiting the U-boat, I saw some of the original German Enigma machines and told Dad a little about Alan Turing and the contributions made by mathematicians that helped end World War II, since this was largely neglected from the exhibit. I guess math isn’t sexy enough for museums, even a science one. After briefly seeing a few more exhibits, like the Genetics Lab, Chick Hatchery, and Earth Revealed, we focused our attention on the Transportation Gallery, which has a replica of the 1903 Wright Flyer. But the gallery has even more more important originals, such as one of the only two remaining German Stukas in existence, a Spitfire, the Piccard Gondala, and a Boeing 727, whereupon Dad couldn’t help but reciprocate by lecturing me about jet engines and telling me all about the instrument panels in the flight deck.

Transportation Gallery

After finishing our visit to the museum, we opted to take the #10 bus for the trip back to the loop, avoiding our harrowing experience earlier, which no doubt would be worse as dusk was coming on fast. Despite having to stand on the bus on account of crowdedness, it was well worth it in terms of personal safety.

Having had such a good experience the night before at Elephant & Castle, we decided not to risk anything new and repeated ourselves. We weren’t disappointed. Dinner conversation centered on organized religion again, and whether or not faith is a virtue (no need to say which way I argued that point). We left downtown around 6:30pm. Making it back to my car, I drove Dad through Westmont, IL and then on to Argonne National Laboratory, my reason for being in Chicago this summer. At 9:00pm we were back near the hotel, and Dad, with his characteristic generosity, insisted on filling my car up with gas despite having paid for almost everything so far the entire trip. Against my protestations to the contrary, he still filled it up. As the Borg say, resistance is futile.

Finally, I had the impulse to drive down the famous Lake Shore Drive at night, a scenic drive splitting Lake Michigan and the Chicago skyline. So we did.  The city was gorgeous at night time.  The trip up Lake Shore Drive was so nice, I surprised Dad by doing it twice. We made it home by around midnight again, and stayed up an hour or so talking, before fading to sleep.