Electron band structure in germanium, my ass (2001)

One of my Core Memories when it comes to science, science education, and education in general was in my high school physics class, where we had to do an experiment to determine the gravitational acceleration of Earth. This was done via the following mechanism: Roll a ball off of a standard classroom table. Use a 1990s wristwatch's stopwatch mechanism to start the clock when the ball rolls of the table. Stop the stopwatch when the ball hits the floor.

Anyone who has ever had a wristwatch of similar tech should know how hard it is to get anything like precision out of those things. It's a millimeter sized button with a millimeter depth of press and could easily need half a second of jabbing at it to get it to trigger. It's for measuring your mile times in minutes, not fractions of a second fall times.

Naturally, our data was total, utter crap. Any sensible analysis would have error bars that, if you treat the problem linearly, would have put 0 and negative numbers within our error bars. I dutifully crunched the numbers and determined that the gravitational constant was something like 6.8m/s^2 and turned it in.

Naturally, I got a failing grade, because that's not particularly close, and no matter how many times you are solemnly assured otherwise, you are never graded on whether you did your best and honestly report what you observe. From grade school on, you are graded on whether or not the grading authority likes the results you got. You might hope that there comes some point in your career where that stops being the case, but as near as I can tell, it literally never does. Right on up to professorships, this is how science really works.

The lesson is taught early and often. It often sort of baffles me when other people are baffled at how often this happens in science, because it more-or-less always happens. Science proceeds despite this, not because of it.

(But jerf, my teacher... Yes, you had a wonderful teacher who didn't only give you an A for the equivalent but called you out in class for your honesty and I dunno, flunked everyone who claimed they got the supposed "correct" answer to three significant digits because that was impossible. There are a few shining lights in the field and I would never dream of denying that. Now tell me how that idealism worked for you going forward the next several years.)

At my high school, somehow physics was the dumb jock science course. I think it was because the head football coach taught physics for decades before retiring my sophomore year. Anyway, as a kid who was doing well in school and was headed for college, it was a natural decision for me to not bother taking physics and study for the AP test on my own. But one day a kid showed up in one of my classes with a hall pass for me to go to the physics classroom. The new teacher needed my help.

She had planned on teaching a lab on gravity and acceleration that day, but she was having trouble getting the right experimental results. Now, this story is not going to reflect well on her, so I want to say up front that she was already taking physics education at my high school to unprecedented heights by 1) trying out the lab on her own before trying to teach it, and 2) actually giving a shit about the results. I doubt the coach who had previously taught physics ever bothered to do any of the experiments himself, and I'm guessing everyone who ever turned in a lab report to him got an A regardless of the contents.

So there I am, a future physics major walking into a physics classroom for the first time in my academic career. I'm nervous because I have a reputation as a smart kid, and specifically as a smart science and math kid, but I was better with math and theory than with machines and measurements. I'm excited about getting to look smart in front of the other kids, but I'm also sweating bullets that there might be something about the equipment that I might not be able to figure out. So I ask her to show me what the experiment is and how she's doing it.

The experimental setup is a small but heavy piece of metal attached to a long, thin strip of the kind of paper used for carbon copies. (Or carbonless copies maybe. You know the paper where you write on one sheet, and there's a pressure-sensitive sheet underneath that creates a copy? It was a long strip of that pressure-sensitive paper.) The final piece of the experimental setup was a loud clacking thing that the strip of paper fed through. When it was turned on, a little hammer inside it slammed down every 1/4 of a second. The idea was, as the paper traveled through, the hammer left a mark every 1/4 of a second, and you could measure how far the paper traveled in each interval between the hammer strikes. Much more precise than a stopwatch!

You have already figured out how the experiment works. You hold the clacker at a fixed height against the wall or some other high fixed point, thread the weight end of the paper through it, turn the clacker on, drop the weight, and the clacker leaves marks on the paper that let you calculate g.

The teacher understood this, to an extent. But she decided that it would be less of a logistical hassle if the students did the experiment at their lab tables, by holding the clacker on the table and pulling the weight horizontally across the table with their hand. She tried this quite a few times herself, plotted the numbers, and could not get the plot to look like a parabola like in the textbook. I explained to her, "We're measuring gravity, so gravity has to do the work. If we move it with our hands, we're just measuring our hands. If gravity moves it, we'll measure gravity." We tried it, it worked, and she sent me back to whatever class I had been in when she sent for me.