A low-key True Lab Story, in honor of the previous post on knowing more about your experiment than anybody else.
One of the first times I had to run my grad school experiment all by myself, I had trouble getting the discharge in the metastable atom source to light. I went through all the usual steps, but nothing worked. Happily, the student who had built the experiment was still around, and working on writing up his thesis, so I went over to his office and told him what the problem was. He said “I’ll take a look,” and we headed over to the lab.
Before we even got into the room, he started walking faster, and once we got inside marched directly the the cryopump (the same one from an earlier story), and re-set it. “The cryopump was off,” he said. “That’ll fix it.”
“How did you know that?” I asked. He looked baffled. “Couldn’t you hear it?” he said. I had no idea what he was talking about.
Fast-foward a few years, to a time when I was working on writing up my own thesis, and some post-docs were running the experiment without me…
One morning, one of them came into my office and said, “The discharge won’t light.”
“I’ll take a look,” I said, and we headed for the lab. And from the hall outside the door, I could hear it– the regular ka-chunk-ka-chunk of the cryopump wasn’t there. All the other lab sounds were there– the rattilng mechanical pump, the high-pitched wine of the turbo pumps, the hum of the air handling, the rushing of the cooling water– but no cryopump.
I opened the door, walked directly the the cryopump controller and re-set it. “The cryopump was off,” I said, “That’ll fix it.”
“How did you know that?” they asked. I was genuinely baffled for a second. “Couldn’t you hear it?” I asked.
And then, enlightenment dawned, and I realized it was time for me to graduate…
I try to teach this principle all the time to my students:
The mark of a truly educated mind is when, in evaluating a situation, the person can spot when something is missing.
Any idiot can evaluate something that’s present. Noticing something that’s absent, that puts you in a whole ‘nother league.
The Case of the Dog in the Night.
At the risk of thwarting future moments of self-discovery, have you considered putting up a sign in the lab?
“If the discharge fails to light, reset the cryopump.”
I’ll be damned. I didn’t even realize it, but after four hours of laptop fan whirring during data anaylsis, the excessive quietness is really quite surprising!
It’s like the anti-particle of a DING, you’re done.
I used to do that in a machine shop. Noisy place but, when the noise is wrong, it’s wrong.
I’m getting to this stage with mass spectrometers. I get the feeling something’s wrong, then it dawns a few minutes later that the autosampler beep’s not come yet, or the source isn’t making the right sort of ringing sound (they’re noisy things, and the sources on most resonate a lot when they’re at operating temperature for some reason).