Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Electron band structure in germanium, my ass (2001)

pages.cs.wisc.edu

Post reply on HN
Print view View original

151–160 of 429 posts

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

#151

Post by realo »

Isamu wrote: post #124
orlp wrote: post #99

Earlier quoted context omitted.

What I don't understand is why it took you 8 weeks to distinguish a timer from a transistor. That doesn't make your professor's reaction alright, I just find it puzzling.

Same package. 555 is typically a DIP-8, transistor packages are available in the same. So you would have to examine the cryptic markings and compare them with the other students, and that’s only if you suspected some fuckup on the part of the knowledgeable people.

ALWAYS suspect some fuckup on the part of the knowledgeable people... especially them!

Trust, but verify.

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

#152

Post by don-code »

potato3732842 wrote: post #142
don-code wrote: post #87

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…

>I chose to take a horrible but passing grade in the lab, finished the class with a C- (which was unusual for me), and went on to pretend that the whole thing never happened. This sentence could have also ended "my gpa dipped below the threshold for some bullshit mark it up to mark it down exercise masquerading as a scholarship and I had to re-take the class for a better grade anyway"

Indeed it could have. I was on a fairly prestigious scholarship; luckily, my marks were good enough that this was a low-risk decision.

That said...

I graduated with a 3.2 GPA, after being the stereotypical "gifted" student up through high school. A 3.2 is, apparently, still decent. However, I did feel a bit of a twinge seeing my peers walk at graduation with with cords, bents, and other regalia, where I just had my standard-issue black robe.

It had less to do with my grade in this particular class, and more to do with the fact that I had a part-time engineering job - 10-20 hours a week - and was making money. When you've spent a couple of years being broke, having an extra few hundred dollars per month was a big deal. Enough so that I didn't really care about putting the extra effort in for A's - that extra time was time better spent working. B's were fine if I could afford to take my girlfriend out to dinner every month.

In the years since then, it seems like this was a good decision. That job became full-time after college, and I stayed there six years. At the end of six years, nobody really cared about my college GPA. At the end of nine years (when I next looked for a job), I didn't even bother listing it on my resume.

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

#153

Post by im3w1l »

tomxor wrote: post #61
veggieroll wrote: post #53

Earlier quoted context omitted.

I can totally relate. I had the same experience in grade school science class, where the teacher assigned an experiment with a suggested solution and an invitation to come up with your own method. I was the only person in class that chose to do my own method. And, it didn't work because I didn't account for an environmental difference between my house and the school classroom. And, he gave me a failing grade. It real…

The irony is that you learned something. Failure is a very useful learning opportunity in understanding what affects the success of an experiment, so long as you analyse it and demonstrate that, which arguably is where you should have been encouraged and graded. Compared to accidentally succeeding while following a standard procedure. I write learning software, and this is an interesting pedagogical weakness we've be…

Yes he learned to avoid physics. Good job teacher!

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

#154

Post by poincaredisk »

NikolaNovak wrote: post #120
Sesse__ wrote: post #102

Earlier quoted context omitted.

My physics professor told us once about a lab he had to do when he was a student himself, about measuring the adiabatic gas constant of air. The workload at that point was immense, so lots of students would just write a report and give the textbook answer—and be marked wrong. It turned out the TA had sabotaged the experiment by putting alcohol in the bottom of the (dark glass) measurement bottle, so the measurement w…

That would be a very valuable lab, IF students hadn't been explicitly trained in opposite behaviour for a decade by then. I lived a very similar experience: My 4th year computer science professor in software engineering assigned us a four-phase programming assignment for the semester. My teammate and I spent several sleepless days on the first assignment, and felt some of the requirements were contradictory. Finally…

>That would be a very valuable lab, IF students hadn't been explicitly trained in opposite behaviour for a decade by then.

I teach students sometimes. I briefly considered whenever I should give them such important lesson. Very briefly: my job is to teach students my specialty, not give them life lessons. Why would I deal with potentially angry students for doing something that's not obvious I'm allowed to do? Hell, it's not even obvious it that would be a "good" (career advancing) lesson.

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

#155

Post by ahartmetz »

jerf wrote: 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…

When I did the mandatory lab exercises in physics, there was a more benign variant of that problem: the conventional value had to fall inside the error interval. However, it was allowed to add additional errors with a good explanation (...some creativity). I really didn't like to increase the estimated errors to make the result work, and I think the (unimportant) grades were reduced for doing it.

I remember being really consistent with the stopwatch in one exercise, so sadly the spread of measurements (implying a natural uncertainty) was small. That was bad!

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

#156

Post by emmelaich »

BeetleB wrote: post #85

Oh, BTW, the whole "Friction is directly proportional to the normal force": My Ass! I could never reproduce it well in the lab, because it's really not true. Take a heavy cube the shape of a book. Orient it so that the spine is on the floor. It's a lot more friction to move it in one direction than in the transverse direction. Yet the normal force is the same. Any kid knows this, and I feel dumb it never occurred to…

Yep, cars can accelerate at over 1g.

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

#157

Post by alterom »

ninetyninenine wrote: post #69
npongratz wrote: post #50

Earlier quoted context omitted.

> From grade school on, you are graded on whether or not the grading authority likes the results you got. I took an exam in a high school science class where I answered a question with the textbook's definition exactly as presented in the textbook, complete with the page number the definition was found on. I knew a bit about the topic, so I then cited outside scientific sources that explained why the definition was i…

> he was angry, he marked it wrong. That’s grounds for termination to me. Seriously. I would put this man out of a job and endanger the livelihood of him and his family for this kind of shit.

>That’s grounds for termination to me. Seriously. I would put this man out of a job and endanger the livelihood of him and his family for this kind of shit.

Agreeing with you as a former instructor (who left academia for greener fields after completing the PhD).

I've had people cry on me in office hours because they come out with — quite literally — PTSD from instructors like the one we're discussing.

It's nothing short of psychological abuse of children, and it leaves lifelong damage.

It's worse than no instruction at all. I've had to have college kids unlearn things before I could teach them.

We've got to draw a line somewhere. I draw the line at actively traumatizing children.

That person should not be allowed to teach, period. We'd do both their students as well as themselves a huge favor by removing them from teaching.

By all indications, they'd be a happier person doing something else, where they wouldn't be driven "mad" by seeing that they've done a good job — which, for a teacher, means their students being proficient in the subject they teach.

-----

TL;DR: this teacher was driven "mad" by seeing that he's done a good job, and one of his students was really good in the subject.

Spare them from this pain.

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

#158

Post by emmelaich »

russdill wrote: post #10
Y_Y wrote: post #7

A thing of beauty is a joy forever - John Keats Honestly, physics is so full of pretension and hero worship. Even among seasoned lecturers there's a tendency to mythologise the progress of the art by making it sound like all the great results we rely on were birthed fully-formed by the giants who kindly lend us their divine shoulders. Ironically there's a kind of Gell-Mann amnesia here, working scientists know that m…

There's a single instance in Einstein's notebooks where he attempts to use numerical methods to come up with a result. He manually graphs some result of the cosmological constant and then integrates it by counting the squares under the curve.

An esteemed emeritus professor of engineering I know used to cut out the graph and weigh it on a sensitive scale to integrate. It was not an uncommon technique.

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

#159

Post by euroderf »

Natsu wrote: post #141
don-code wrote: post #87

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…

It's funny, because while that's a terrible educational experience, you actually learned some important lessons despite them. I remember the first time I found out that the software documentation I had been relying upon was simply and utterly wrong. It was so freeing to start looking at how things actually behaved instead of believing the utterly false documentation because the world finally made sense again.

Proving the truism that incorrect documentation is worse than no documentation.

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

#160

Post by tomxor »

im3w1l wrote: post #153
tomxor wrote: post #61

Earlier quoted context omitted.

The irony is that you learned something. Failure is a very useful learning opportunity in understanding what affects the success of an experiment, so long as you analyse it and demonstrate that, which arguably is where you should have been encouraged and graded. Compared to accidentally succeeding while following a standard procedure. I write learning software, and this is an interesting pedagogical weakness we've be…

Yes he learned to avoid physics. Good job teacher!

Well, yes unfortunately, but the takeaway should be scepticism of the validity of learning institutions, something most of us aren't prepared to even consider at a younger age.
Post reply on HN