Deleuzean Potato

I got all this put together a couple of weeks ago, but I haven't posted photos yet. The first photo is my desk.



The apparatus itself is the smallish thing in the front. The stack of larger equipment in the back is used for creating the input signal and observing the output. The oscilloscope (top) is used to check the quality of the signal -- how much noise we're getting. It's a good way of checking all the connections, and visualizing the input and output. The amplifier is in the middle. It just takes an input signal, amplifies it, and sends it to the apparatus. The function generator is below that. It creates the original signal, and also accepts the output from the apparatus. The displays give us the magnitude of the output, and its phase relative to the input signal.

The other two photos are of the apparatus itself:





The coaxial cable on the right is the input from the amplifier; the smaller, blue cord coming out of the right is the pressure sensor, which sends the output signal to the amplifier and the scope. The clear tube is filled with distilled water (though there are some complications involved in that). The opaque white thing is a very small ball. Very much like a ball bearing, but it's plastic. Its presence affects the resonance frequencies of the chamber. It's also supposed to move when we turn the signal on, but there's too much friction (we think; more on this in another post).

I'm also realizing that very little of this probably makes any sense, as I haven't put all of this into any context. I'll do that in another post next week.

I finally got the soldering done. And it looks like it works. Exciting, and right as I was getting ready to leave for the day. So I was able to leave on a nice emotional high. Actual testing to begin tomorrow, and photos the apparatus.

Also, I added photos (see earlier posts, below) (also see my forthcoming discussion on the literary use of 'above' and 'below,' above). In honor of my adding photos (thanks, Google, for a not-completely-shitty method of uploading photos), I'm including one in this entry. This is a public phone in Bellavista, on our way back home from the Cerro San Cristobal adventure. This photo is for Steven.

By Friday afternoon, we had gotten all of the various parts of the apparatus together. All I had to do was to solder two more connections, then screw in the plug. This was a bit difficult. We have a connection to a BNC cable that screws into the rest of the apparatus. Two wires carry the elctrical connection between the BNC and the piezoelectric piece. I had to pass those two wires through the channel that the BNC plug screws into, then solder them onto the leads. Screwing it in was the problematic part. The two wires started wrapping around each other. Finally, one of them broke, severing the connection. By the end of the afternoon, I had disassembled everything. I'm going to start all over on Monday. But things should go faster this time around. That last bit of soldering will remain difficult.

Wednesday was nice. Joe and I left work early to goto Cerro Santa Lucia. In some ways this was better than Cerro San Cristobal had been. Because it was still the middle of the afternoon, we could actually see the city around us. I got some nice pictures of the view. Those will go up on Monday, after I do a few things with them (at work).

Yesterday was the first Independence Day I´ve spend not on US soil. To celebrate, we took off work a bit early, and met up with Christina, another American whom Matt, Carolyn and Nathan met in Valparaiso.

We all met at the Baquedano metro stop, and walked north into Bellavista. At the north end of Bellavista there is a "hill" called Cerro San Cristobal, which rises about 800 m above the rest of the city. It´s named for Saint Christopher, because of its use a point of reference (St Christopher is the patron saint of travellers). There is a ski lift-type trolley system that will take up to the top, but it doesn´t run on Mondays. So we just hiked up. At the top there is a 22 m tall statue of the Virgin Mary, and a church with an amphitheatre.

Photos to be added shortly.

Update: I wrote up a stub artible on Wikipedia about Cerro San Cristobal. I then added the link above.

Update 2: Photos

This is the Mapocho River, as seen from the Pio Nono bridge on the way into Bellavista. This photo is for Nora, to compare to the Los Angeles River.



This is the view from the top of Serro San Cristobal. These two photos are for Sam.

Nicolas gave me some papers to read to get up to speed on what's going on with my project. Earlier this week, he was asking me about my progess on those papers. I was mostly done with them, and had one question: Was there anything he had that I could teach myself fluid mechanics out of? The problem is that we don't have an introductory fluids class at UofC. The closest we come is Tom Witten's Structured Fluids class. That class doesn't really deal with the basic theory of fluids. And of course, all the papers I'm reading are assuming that basic theory. What we're working on doesn't address fluids directly, but the theory is helpful for understanding why we're studying what we're studying, and why things happen as they do. So I need to learn this fuild mechanics theory.

Nicolas was a bit surprised that we don't have a class on this at all at the undergraduate level. As I understand it, fuilds is a pretty standard part of most undergrad physics curricula. But not ours. He did say he had a book; he returned about an hour later, and handed me Landau and Lifshitz.