The Point of Physics Homework Exercises

[Lunar_Lander]

At my University, we get (in Experimental Physics) weekly homework which consists of three exercises with 3, 3 and 4 points (thus giving a total of 10 points for each sheet). Now I have received the sheet for the next week, on which the third task is "Oil Drop in an electric field". The first half of the task is to determine the number of elementary charges on the oil drop according to the numbers given in the task. The second part asks:

b) Who was the first to determine the elementary charge in this way?

After reading that, I was concerned. I was concerned that students would get two points by writing "Robert A. Millikan" on the sheet. In the last semester, in Experimental Physics 1, there never had been a question like that. Everything was for calculation and the only questions which required to evaluate something were based on the calculation results of the other partial tasks.

Did you experienced something like this? What did you think about this? In my opinion, the tasks are to train the usage of the laws and principles given in the lecture.

 

[fasterthanjoao]

Did you experienced something like this? What did you think about this? In my opinion, the tasks are to train the usage of the laws and principles given in the lecture.

I think it's very important that one is aware of the history of physics too. Whether or not that should be part of a question sheet is another matter, do the question sheets count for credit? In any case, I don't really see anything to be concerned about? If you're worried about getting problems to solve, there are plenty of textbooks out there begging to be bought.

expanding on the topic:
I'm a big fan of essays. I think essay assignments are horribly under-used in physics (at least at the UK institutions I've had experience with), an essay is the great way to force someone to research for themselves and the perfect way to address background learning such as this.

 

[Klockan3]

I'm a big fan of essays. I think essay assignments are horribly under-used in physics (at least at the UK institutions I've had experience with), an essay is the great way to force someone to research for themselves and the perfect way to address background learning such as this.

I think that essays really have no room within formal physics education. Sure it is important to be able to know how to write essays but that is something you can learn elsewhere, and any subject related knowledge gained from it is too specific to make it a good way to learn before grad school.

 

[dacruick]

I think that essays really have no room within formal physics education. Sure it is important to be able to know how to write essays but that is something you can learn elsewhere, and any subject related knowledge gained from it is too specific to make it a good way to learn before grad school.

I disagree. I don't necessarily think that essays per se should be a part of a physics education, but they do force you to understand what you are writing about thoroughly. No matter what job you have, you need to be able to convey your thoughts well on paper. Maybe report writing would be a better idea. I also find that when explaining things, and when going through your knowledge in depth, you get a stronger grasp of the concepts, and even sometimes make connections to other concepts. Essays promote deep thinking, and maybe that's what this professor is trying to get at.

 

[Klockan3]

Essays promote deep thinking, and maybe that's what this professor is trying to get at.

But as I said the knowledge gained is way too focused to be of much use. Also it do not promote deep thinking in my opinion, it promotes copy pasting with small modifications. Those who would think deeply about it already do think deeply about what they do so there isn't much gain.

But I am against graded assignments in general before grad school, so it might have something to do with that.

 

[Lunar_Lander]

I concur that the history of Physics is very important, however, in all the lectures we had so far (Experimental Physics 1/2, Physicist's Math 2/3, Theoretical Physics 1), history only did have a small space. More important were the ways how to get to the laws which are required to solve problems. The homework also asked for calculations of problems, which were sometimes more "advanced" than in the lecture (or to say it better: The context was more advanced, i.e. in an exercise about momentum they described a context of nuclear beam scattering).

 

[fasterthanjoao]

But as I said the knowledge gained is way too focused to be of much use.

As with almost the entirety of a physics degree, the knowledge you learn isn't the important part. Being able to do maths and solve problems is all well and good, but if you're incapable of researching and writing then you'll never survive in the workplace. In my experience, these writing and reporting skills are almost exclusively limited to the few 'standard' lab experiments, where for research the student needs only consult a single, basic undergraduate text.

Also it do not promote deep thinking in my opinion, it promotes copy pasting with small modifications.

If you want to plagiarise instead of putting proper effort in, that's a personal issue.

Those who would think deeply about it already do think deeply about what they do so there isn't much gain.

How come this doesn't apply to education in general, then? Surely there is no need for lectures?

 

[fasterthanjoao]

I concur that the history of Physics is very important, however, in all the lectures we had so far (Experimental Physics 1/2, Physicist's Math 2/3, Theoretical Physics 1), history only did have a small space. More important were the ways how to get to the laws which are required to solve problems. The homework also asked for calculations of problems, which were sometimes more "advanced" than in the lecture (or to say it better: The context was more advanced, i.e. in an exercise about momentum they described a context of nuclear beam scattering).

So, essentially, the format for one class assignment is different to the rest? I don't see that as alarming, it's very common considering it's different people that write the different assignments. Consistency is another thing, and it is one that is extremely difficult to effectively maintain. If you're ever concerned about matters like this, raise them at the next staff-student committee meeting.

 

[twofish-quant]

I think that essays really have no room within formal physics education. Sure it is important to be able to know how to write essays but that is something you can learn elsewhere, and any subject related knowledge gained from it is too specific to make it a good way to learn before grad school.

I very strongly disagree. Part of the important thing about physics is to make contact with reality, and having students think through the experiments is a very, very important thing. Also you learn general things by learning specific things.

I'd phrase the question differently so that it's can be answered with an obvious cut and paste:

1) Come up with a way to measure the mass of the electron that is different from how Millkan did it?

2) How much would it cost to measure the mass of the electron today and how is that different from what milkan did?

3) What are the major errors in the Milkan experiment and how would you improve on them?

One other this. In any essay question, you should assume (and encourage) students to use google, so what you want is to ask the question in such a way that they can't immediately google the answer.

 

[twofish-quant]

Something else to ask that isn't obvious...

"Who was the *third* person to determine the mass of the electron?"

 

[twofish-quant]

If you want to plagiarise instead of putting proper effort in, that's a personal issue.

Also, it's not hard to ask a question in a way that plagiarism is pretty obvious.

Interview a family member and tell them how the mass of electron impacted their lives.

Find a news article that was written in the last month, and explain to me the relationship between that article and the mass of the electron.

Take a shoebox and create a diorama about the electron mass experiment.

The reason that plagiarism becomes an issue is that questions that are hard to plagiarize are hard to grade, so there is an issue of the institutional lack of effort of the instructor as much as the lack of effort of the student.

Also one problem is that we live in a world of google in which one important skill is to work with other people. Homework assignments should be set up to *encourage* people to use google and collaborate rather than discourage it.

 

[Klockan3]

As with almost the entirety of a physics degree, the knowledge you learn isn't the important part. Being able to do maths and solve problems is all well and good, but if you're incapable of researching and writing then you'll never survive in the workplace. In my experience, these writing and reporting skills are almost exclusively limited to the few 'standard' lab experiments, where for research the student needs only consult a single, basic undergraduate text.

Everyone have done extensive studies on writing and doing reports already by the time they hit college, there is no need to do the same thing over and over... The degree is there to teach them what they need to know to be a physicist/mathematician, not what they should already know being citizens of a proper democracy.

Then in grad school you learn the proper procedure for how research should be presented and how papers should be published and that is not something any amount of courses in undergrad can teach you.

If you want to plagiarise instead of putting proper effort in, that's a personal issue.

It isn't about me, it is about people in general. When I say "copy paste" I do not mean exactly copying but instead copying methods and concepts instead of learning the things themselves. When I do hand-ins I don't ask for help nor do I look for similar examples, I see that as cheating myself. Instead I generally read about the subject till I can do it without any other help than a pen and paper, then I start with it using just that.

How come this doesn't apply to education in general, then? Surely there is no need for lectures?

Um, are you serious? Teacher lead lectures will always be important since it is dynamic in that you got direct contact with the teacher so you can ask questions while a books information is static. There is no way to substitute the human connection, just knowing that it is a live person standing there talking makes a huge difference compared to a recording or a book.

Undergraduate assignments on the other hand are just there to try to force you to read things on your own, there are plenty of substitutes for that.

Homework assignments should be set up to *encourage* people to use google and collaborate rather than discourage it.

Which is why I strongly prefer tests with extensive aids rather than homework. Then there is nothing prohibiting them from working together learning the material but each one of them got to make sure to learn it. Why is that so important? Because you really can't look up everything or ask someone about every problem later and it is impossible to gain knowledge of higher subjects without a solid foundation.

You don't need to know is every detail, but you really should know every concept by heart.
Btw, I agree that things like encouraging google is good, I am just against reports since it leads to very fragmented learning by the students unless you force each individual to do his own work on his own subject forcing each person to actually learn about what he is doing.

1) Come up with a way to measure the mass of the electron that is different from how Millkan did it?

2) How much would it cost to measure the mass of the electron today and how is that different from what milkan did?

3) What are the major errors in the Milkan experiment and how would you improve on them?

These subjects are perfect examples of something were a handful of students would think it through and the rest would just follow their lead. I am sorry but I have not seen any evidence that most undergrads can handle doing creative work, mostly it seems like the complete opposite and even grad students have large problems with that.

This is for undergraduates by the way as I said, for grad students I agree that assignments (especially creative ones) is a good thing.

I think that college should never value hard work in itself, it should only value actual knowledge. Giving value to hard work is just a substitute where you think that the students somehow will learn better from working harder. But making them work to learn is what you want to do, not making them work just to pass the class.

Cramming the night before a test means that they at least remembered it for a day, passing a hand in don't mean anything at all. And the highly motivated students will learn what they need almost no matter how you examinate them, what matters is what happens to the rest of the class.

You could argue that it is a good way to motivate some, I can't really argue with that. It is probably good advertising to some even though I personally hate just about all of those arbitrary assignments and is a strong reason why I went with the subject. Also since I am very colored by that on the subject I guess that it is likely that they are good to most and I just refuse to see it.

 

[D H]

I side with twofish-quant. One of my jobs is interviewing job candidates. We hire aerospace engineerings, physicists, astronomers, and mathematicians. Over the last ten years the quality of the engineering graduates has increased considerably. The same cannot be said for math and science grads.

The reason is simple: Engineering schools have placed an increased emphasis on teamwork and communications skills over the last decade. This has not detracted one iota from technical skills. To the contrary, this has improved the technical skills of the top graduates (our target new hires). Science and math education have lagged in comparison.

 

[twofish-quant]

The reason is simple: Engineering schools have placed an increased emphasis on teamwork and communications skills over the last decade. This has not detracted one iota from technical skills. To the contrary, this has improved the technical skills of the top graduates (our target new hires). Science and math education have lagged in comparison.

This really depends on the school. At the school that I was an undergraduate at, the physics curriculum very much encouraged people to work with each other on the problem sets. You made sure that the students learned the material on the tests.

Also I strongly do think that most lectures are useless (which is why my alma mater has gotten rid of them in teaching physics). In a typical 200 person lecture hall, you are just not going to stop the teacher to ask a question, and just because you are physically in the same room as someone doesn't mean that there is any human interaction. You can get this sort of dynamic with a 20 person class, or better yet a 5 person class, but those aren't "lectures."

 

[Klockan3]

Also I strongly do think that most lectures are useless (which is why my alma mater has gotten rid of them in teaching physics). In a typical 200 person lecture hall, you are just not going to stop the teacher to ask a question, and just because you are physically in the same room as someone doesn't mean that there is any human interaction. You can get this sort of dynamic with a 20 person class, or better yet a 5 person class, but those aren't "lectures."

That is funny since I went through my whole undergrad without doing anything outside of lectures except some minutes of reviewing before each quiz and a few hours before each exam, we barely had homework and you could get the highest grade without it so I never bothered with it. Without the lectures I would have been toast, I stopped buying the books since I realized that I don't read them anyway, most books are frustrating to read.

And you can get that dynamic in 100 person classrooms, I talked a lot with my professors in those classes too. But yet again maybe it is just me and none else feels like this. Also it is very dependent on the lecturer, a good lecturer will activate the class.

*NOTE* I know that you can't go on like that forever, I am just saying that at least for me lectures worked like a charm *END NOTE*

The reason is simple: Engineering schools have placed an increased emphasis on teamwork and communications skills over the last decade. This has not detracted one iota from technical skills. To the contrary, this has improved the technical skills of the top graduates (our target new hires). Science and math education have lagged in comparison.

Again, I am not talking about post grad education nor am I talking about engineers. Saying that it have a positive development for engineer grad students means basically nothing for science undergrads.

 

[fasterthanjoao]

Everyone have done extensive studies on writing and doing reports already by the time they hit college, there is no need to do the same thing over and over...

This is just embarrassingly incorrect. You're claiming that you had maxed out your ability in writing and reporting by the end of high school...? I've worked in many different industries and one of the most important things that they look for in new recruits is ability to convey information. This is why things like history and geography graduates are in-demand for HR/office work in large industries. Not to forget the importance of learning how to effectively gather information, too. Twofish is absolutely correct when saying that Google should be viewed as more of a tool than it currently is.

Um, are you serious? Teacher lead lectures will always be important since it is dynamic in that you got direct contact with the teacher so you can ask questions while a books information is static. There is no way to substitute the human connection, just knowing that it is a live person standing there talking makes a huge difference compared to a recording or a book.

You missed my point, but nevermind. In any case, though it isn't really relevant to this discussion, I disagree here. I never really enjoyed lectures, in undergrad or grad school. I have always preferred reading books and having the option of asking someone if I run into difficulty. Lectures are not personal, they're designed to cater for a big class - and this is the problem. I remember finding that, 20 minutes in, I would be lost and not able to properly follow the rest of the arguments made in the lecture - so for me, the remaining 40 minutes was a bust. The only time when I felt I had success in lectures was in my final year when there were only 5 students left in the class and the lecturer was able to take a much more individual approach.

You don't need to know is every detail, but you really should know every concept by heart.
Btw, I agree that things like encouraging google is good, I am just against reports since it leads to very fragmented learning by the students unless you force each individual to do his own work on his own subject forcing each person to actually learn about what he is doing.

You're missing the point. The idea behind setting reports and essays as assignments isn't so the student goes and learns about some arbitrary topic in great detail, it's to allow the development of their skills in planning, finding information, knowing which information is important and then being able to convey it effectively.

I agree with twofish.

 

[atyy]

Also I strongly do think that most lectures are useless (which is why my alma mater has gotten rid of them in teaching physics).

Oh, not because Walter Lewin retired? Seriously, MIT has no more physics lectures? In most universities, there are small group sessions that supplement the big lectures. Did MIT not have that, or did they decide it was more efficient to just have the small classes?

 

[Klockan3]

You're claiming that you had maxed out your ability in writing and reporting by the end of high school...?

No, my point is that if the students do not already have adequate skills within those fields after high school then they have wasted 12 years of their education since that is the prime focus of the sub college education. You are talking as if a few college credits would make all the difference but I don't see why they would, before college became mandatory for most positions people still did just fine on a high school degree.

If anything you should petition to change the sub college education to make it more meaningful if you think that what they do is worthless, not move the problem further down the education line.

 

[zpconn]

I think the Russian style of delivering mathematical lectures is much more effective than the American one. I have a Russian professor this semester who was an undergraduate at the IUM, and his principle--and this is also the principle of the IUM--is that lectures should be very interactive. The idea is that he tries to aid us in rediscovering the subject for ourselves, so a big part of anyone of his lectures will consist of the students and him going back and forth, discussing how to solve some classical problem of the subject. Of course, he's mastered the subject and we haven't, so generally the way it goes is we make a suggestion and he explains why it's wrong until we finally figure it out.

There are elements here and there of more traditional lectures where he talks for a bit without direct interaction with the students, but this is generally to cover material that, frankly, we would not be able to figure out on the spot even with his nudging. But these bits are scattered about and the spaces are filled in with the interactive segments of the type described above.

It works very well. Honestly, he's the best lecturer I've ever seen in my life. It doesn't hurt that he's also more or less a mathematical genius, which means he can respond immediately to any question.

It's worth pointing out that there are about 12 students in the class and the room is relatively small. Also, half the students are graduate students.

In general, during the "lectures" we all learn the big ideas and figure out the intuitive approaches to proving the classical theorems of the subject. He omits lots of details, and so do we. For instance, maybe an argument requires interchanging integral and summation. He will almost never justify it but tell us to read the justification in our book. Most teachers don't do this, but once you get used to it you realize it's a much more effective style. Arguments like those necessary to justify such things are precisely the arguments that don't go over very well in lectures because it's easy to miss details. So we all just read the justification in the book some time after class.

I think it takes a pretty special type of lecturer to be able to make this work, though. I've had professors attempt to do something like this in the past, and usually they aren't able to make it work, either because they haven't sufficiently mastered the subject and can't adequately respond to the many suggestions they'll get from students on the spot or because they don't have a strong enough persona to inspire people to risk embarrassing themselves.