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Electron band structure in germanium, my ass (2001)

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341–350 of 429 posts

Re: Electron band structure in germanium, my ass (2001)

#341
I felt that, I felt that deeply

One of the most devious analytic chemistry labs I had was the one where the spectroscope was ancient, its tray was less transparent and more milky white, and the fluid to analyze was some sort of expired flavored water. The attempt vs result chart looked exactly like that figure.

A really eye-opening experience in many ways.

Re: Electron band structure in germanium, my ass (2001)

#342

Earlier quoted context omitted.

Make marks on the thermometer at 0 and 100 degrees C, then project light from a candle to a wall to see these marks with say 5x magnification. Now project marks from the 128 mark ruler to the same wall and align marks from both, then place marks on the thermometer with 5x better accuracy.

A candle is an exceptionally unstable light source. The flame continually moves location as it burns. Any air currents in the room will disturb it and cause flame shadows to be cast. Adding magnification will just make this all worse.

These problems are easy to solve in practice: just put the candle into a lantern.

Try it: it's easy. Use a flashlight from your phone instead of a candle, then project light to a wall, then put your palm in the front of the light.

Re: Electron band structure in germanium, my ass (2001)

#344

Earlier quoted context omitted.

This is, more or less, exactly what happened when I took Electronics I in college. The course was structured in such a way that you could not move on to the next lab assignment until you completed the one before it. You could complete the lab assignments at your own pace. If you failed the lab, you failed the class, regardless of your grade. The second or third lab had us characterize the response of a transistor in…

That's a tragic story. However, I'm surprised that the transistor was supposed to come in a DIP package. Usually through-hole discrete transistors come in a three-lead package like TO-92. Of course, that would not have helped you since yours looked like every other student's except the for the markings.

There can be 2 or more transistors in a dip-8, but I think the point is more that the wrong dip-8 was given, not which specific dip-8.

I change details when I tell stories, both to prevent eyes glazing, and because the details don't matter that much. If I told this story to a neighbor it wouldn't involve the words "dip-8", 555, or "transistor".

For instance I had a professor that just did not like me. I did all the work, the papers, but the second paper assigned was about bioethics and at the time there was a lot of negative press about that subject and I went really deep into a subject I had never heard of before. Well the prof was a bioethicist, and on some bioethics committee, and did not like my prose. I barely passed that class that semester. I think they knew they couldn't fail me because, as I said, I did the work; but they certainly made me not want to continue college, that's for sure.

Re: Electron band structure in germanium, my ass (2001)

#345

Earlier quoted context omitted.

That's a tragic story. However, I'm surprised that the transistor was supposed to come in a DIP package. Usually through-hole discrete transistors come in a three-lead package like TO-92. Of course, that would not have helped you since yours looked like every other student's except the for the markings.

There can be 2 or more transistors in a dip-8, but I think the point is more that the wrong dip-8 was given, not which specific dip-8. I change details when I tell stories, both to prevent eyes glazing, and because the details don't matter that much. If I told this story to a neighbor it wouldn't involve the words "dip-8", 555, or "transistor". For instance I had a professor that just did not like me. I did all the w…

Never seen any DIP-8 transistors. Usually the discrete arrays like the CA30xx are DIP-14. Personally I'd read the label on the chip.

Re: Electron band structure in germanium, my ass (2001)

#346

Earlier quoted context omitted.

The 2023 education and general fund budget for Penn State allocated 5.7% to equipment and maintenance and repairs of approx $2.5 billion in use. I assume that would include thing other than just lab equipment. Overwhelmingly, most education fund use goes to salary, benefits and student aid (~$2 billion, 81%). Interestingly the amount of money raised by tuition and fees almost exactly matches the amount spent on salar…

Wow, you went down the rabbit-hole, much appreciated! Do I understand correctly, that your analysis boils down to the money is indeed being pocketed rather than used for equipment or improving anything at all at the university?

> money is indeed being pocketed

No. What amount (if any) is being pocketed is not apparent from such data. Perhaps contrary to your expectation, it's basically impossible to pocket money allocated for salaries (people would complain they don't get what they're owed). It's much easier to pocket equipment. In any case, the referenced data is quite independent of that.

Instead, it shows that the universities do not allocate money on equipment (because that's what grants are for). Of course, spending grant money on lab equipment for undergrads directly competes with equipment for research, which puts a group at a competitive disadvantage in their field of research.

Re: Electron band structure in germanium, my ass (2001)

#347
post #27

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 stopw…

I remember in chemistry class in high school (in Sweden), where we'd do lab work in pairs often. I'd pair up with the other actually smart and interested guy in class and we'd divide the work between us: One of us would start doing the theoretical work, calculating what numbers we should be getting, and the other would do the experiment. Then we'd adjust all our findings to be within what was theoretically reasonable.

We got good grades.

Is it like 5 people doing real science and everybody copying their homework? I mean, we've got technology to prove that a lot of natural science must be right in some way, so somebody is doing real discovery and real experiments. Right?

Re: Electron band structure in germanium, my ass (2001)

#349

Earlier quoted context omitted.

This is, more or less, exactly what happened when I took Electronics I in college. The course was structured in such a way that you could not move on to the next lab assignment until you completed the one before it. You could complete the lab assignments at your own pace. If you failed the lab, you failed the class, regardless of your grade. The second or third lab had us characterize the response of a transistor in…

That is enraging. I've seen similar things happen too and it blows my mind how ridiculous some of these teachers can be. I don't know if it's dehumanization of their students in their minds or an utter unwillingness to devote 30 seconds of directed attention to understanding the situation and making a reasonable judgment, but whatever the cause it is prolific. The only thing worse is when one of them will add somethi…

Aggression, Social Stress, and the Immune System – Takahashi, Flanigan, McEwen & Russo, 2018

https://www.frontiersin.org/journals/behavioral-neuroscience...

“Aggression has an adaptive significance for most animal species and is critical for acquiring and protecting territory, food, reproductive mates, and offspring. In animals with hierarchical societies, aggressive behavior is thought to help individuals gain and maintain higher social status (Box 2). It has been shown that aggressive behavior, especially the experience of winning, has rewarding properties in animals and repeated aggressive experience may lead to compulsive, pathological aggression that is highly reinforcing (Fish et al., 2002; Falkner et al., 2016; Golden et al., 2016, 2017).”

Re: Electron band structure in germanium, my ass (2001)

#350
post #27

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 stopw…

This is the complete opposite of my experience.

You always got partial credit even if you made a mistake as long as the following results were achieved using the correct method and with the correct calculations despite one of the inputs being wrong due to a previous error.

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