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

61–70 of 429 posts

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

#61

Post by tomxor »

veggieroll wrote: post #53
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…

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 become aware of when giving feedback (the asymmetry of learning opportunity in correct vs incorrect). It can be improved through overall design, and in a digital context there are also other opportunities.

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

#62

Post by shadowgovt »

This reminds me of how the Fahrenheit scale came about.

For all its flaws, Fahrenheit was based on some good ideas and firmly grounded in what you could easily measure in the 1720s. A brine solution and body heat are two things you can measure without risking burning or freezing the observer. Even the gradations were intentional: in the original scale, the reference temperatures mapped to 32 and 96, and since those are 64 units apart, you could mark the rest of the thermometer with a bit of string and some halving geometry. Marking a Celsius scale from 0 to 100 accurately? Hope you have a good pair of calipers to divide a range into five evenly-spaced divisions...

Nowadays, we have machines capable of doing proper calibration of such mundane temperature ranges to far higher accuracy than the needle or alcohol-mix can even show, but back then, when scientists had to craft their own thermometers? Ease of manufacture mattered a lot.

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

#63

Post by chrysander »

Very much my undergrad lab education experience...

I currently write my master's thesis in experimental quantum computing - the platform is similar to what Google published in December, just with less qubits. A lot of it just comes down to how much money the lab can spend to get the best equipment and how good your fabrication is.

You can have the best minds in experimental physics, but without the right equipment the grad students are just busy trying to make things work somehow and waste months if not years away.

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

#64

Post by wavemode »

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…

The worst is college science classes where sometimes the provided equipment and/or procedures aren't even correct, and the professor isn't around and you're dealing with a TA who is just as confused as you are.

So you debate with yourself between writing down the effect you got (and trusting that you will be rewarded for integrity and effort and rigor), or simply writing down what you know the effect was supposed to be.

Most people (smartly) do the latter.

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

#65

Post by matheusmoreira »

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…

https://v.cx/2010/04/feynman-brazil-education

> Then I held up the elementary physics textbook they were using.

> There are no experimental results mentioned anywhere in this book, except in one place where there is a ball, rolling down an inclined plane, in which it says how far the ball got after one second, two seconds, three seconds, and so on.

> The numbers have ‘errors’ in them – that is, if you look at them, you think you’re looking at experimental results, because the numbers are a little above, or a little below, the theoretical values. The book even talks about having to correct the experimental errors – very fine.

> The trouble is, when you calculate the value of the acceleration constant from these values, you get the right answer.

> But a ball rolling down an inclined plane, if it is actually done, has an inertia to get it to turn, and will, if you do the experiment, produce five-sevenths of the right answer, because of the extra energy needed to go into the rotation of the ball.

> Therefore this single example of experimental ‘results’ is obtained from a fake experiment.

> Nobody had rolled such a ball, or they would never have gotten those results!

Reading your post, I now realize education is dysfunctional in the entire world, not just in my country. Small comfort.

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

#66

Post by sdenton4 »

mystified5016 wrote: post #48
throwway120385 wrote: post #36

Earlier quoted context omitted.

That's an interesting way to measure the passage of time -- just use something that produces a "regular distance" and derive a way from kinematics to calculate the acceleration from the change in the distance.

The way boats historically measured speed was by dragging a rope behind them. The rope has knots tied with exact spacing. You drop one end of the rope in the water, and count how many knots pass you in a given time. That's then your speed in knots.

Using this method repeatedly to guess how far you've moved over the course of days is, historically, a fantastic way to crash into the side of France in the middle of the night.

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

#67

Post by lukan »

veggieroll wrote: post #53
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…

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…

We had the task of building a highly insulated small house. Big enough to hold a hot cup of tea (and meassure how good it holds its temperature inside).

Our design was very, very good in that regard. (I used insulation building material from the house my family build at that time) But granted, it was not so pretty.

But that was not a stated goal. But when it came to grades, suddenly design and subjective aesthetics mattered and a pretty house, but useless in terms of insulation won. And we did not failed, but got kind of a bad result and I stopped believing in that teachers fairness.

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

#68

Post by perlgeek »

madcaptenor wrote: post #51
roadbuster wrote: post #39

I read this in 1999 when entering university. It was so refreshing hearing a student provide a glimpse into the boots-on-the-ground reality of undergrad life at these world-renowned institution. The closing sentence is also prescient; the author pivoted to CS, ultimately completing his doctorate at the University of Wisconsin at Madison https://pages.cs.wisc.edu/~kovar/

LinkedIn has him as Staff Software Engineer at Google: https://www.linkedin.com/in/lucas-kovar-185a3531/

I'm pretty sure he's rolling in cash now :-)

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

#69

Post by ninetyninenine »

npongratz wrote: post #50
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…

> 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.

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

#70

Post by huijzer »

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…

> 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.

I think we should definitely not learn from this that science still works despite those things. Because then it's easy to just say it is what it is. I think it's much more helpful to be critical of the scientific process (scientific policies in particular) and see how it can be improved. As I said many times before here on Hacker News, basically nothing in science has changed since papers like Why Most Published Research Findings Are False by Ioannidis have come out. I think we as civilians should demand more from science than a bunch of false papers behind paywalls.

Post reply on HN