Is Physics the Right Path for Me?

[Nano-Passion]

I hope you haven't gone over to the dark side. It's okay to realize that not everything should be visualized, but there also a danger in not visualizing enough. It can be kind of a subtle thing to know when to draw the line.

Part of the reason why it can be easier to do physics without conceptualizing too much is just an artifact of our educational system. It undervalues these things.

It would indeed have been easier for me if I had not swam against the stream and come up with my own visual explanations of things. But if I had done that, I would not have the deep understanding that I do now.

There are so many topics I can think of that were incomprehensible until I developed a way to visualize them, at which point, everything became trivial and obvious.

Another point to realize is that intuition is more fundamental than visualization. Intuition is the most important thing in math, I think, and probably physics, too.

I got the intuition part down, for the most part at least. But what I was trying to convey is that I got caught in a rut trying too hard to visualize everything by itself, I found out the hard way that variable manipulation is essential tool. If you have three variables to solve for you can sit there all day imagining pictures in your head but it won't help till you start writing down some mathematics to solidify the concepts.

The problem isn't visualization for me either, as my diagrams tend to be pretty accurate. It's really just making the correct inferences and when to use shortcuts that is my problem. It seems no matter how many problems I do, the professor will put questions on the exam that I wouldn't even know how to attempt.

If I am struggling with introductory stuff (mechanics), how would I expect to do well in upper year classes? I'm sure the majority of the students taking those classes found mechanics to be a joke and breezed through it.

At this point, I'm just lost and don't really know what to do. Doing extra problems didn't help me at all for the second test, so I don't know how to go about this course anymore.

If someone thought it was a joke and breezed through it then its a product of their past experiences and knowledge. You can develop the same thing, I don't see why not. You just need a conscious effort in bettering yourself, learn from your mistakes. And if you can figure out how to get better at physics then you will get better! The hardest part is figuring out how to get better; different people need different things. Sometimes it just clicks one day, sometimes it will take much longer. But one thing is for certain, if you keep at it, you will get better. Its often hard to learn how to get better. The reason is because most will focus on learning the material. But learning how to learn is not something that is talked about everyday. It is one of the reasons that research isn't easy, your required to adapt to change. Give up now and there will be no change.

You haven't helped us pinpoint your problem, it would be better if you can try to narrow down what you have trouble with in physics. Physics often needs a certain mindset, a scheme. If you are having trouble with elastic potential energy then it would be very useful to know something such as:

An object set in motion in an elastic system is at its highest velocity when elastic PE is 0. That is, when a spring is at its non-compressed height.

This is stated rather indirectly when they say E = K + U is constant.

Edit: I've gotten better at physics since the beginning of the semester by keeping a conscious effort. People don't wake up one day solving every problem flawlessly; especially not with a beginner physics course because it is a bit different then what most are used to. At the moment I haven't mastered the elastic potential energy concepts, if I can't do one of the problems then I know that my knowledge needs to be improved. And I'm working at it. Point is, you need to do the same thing too, it comes with hardsmart work and effort.

 

[twofish-quant]

Just as a point of reference, I have a Ph.D. in astrophysics. What's your background?

You can view equipotential surfaces if you want to, but I really don't know how you can claim that imagining a visual picture adds to your understanding.

I'm a very visual person. The way that I'd visualize that equation is by imaging two lines. One with kinetic energy and one with potential energy.

It becomes really useful because then you get "deep insight" into what is going on. For example, one thing about that situation is that if you imagine lines rather than equations, it becomes obvious that there is no such thing as "escape velocity". As you get further away from the object, the potential energy always increases so that the lines will always cross. Now if the potential energy is -1/r, then it will flatten out, the lines won't always cross, and it's possible for an object to escape.

Now I ask you what happens if the object is non-spherical, and if you visualize the situation, you figure out that it doesn't matter.

This comes in really useful when you are dealing with weird situations. For example suppose I'm orbiting three non-spherical object that is collapsing into a black hole with objects that are moving near the speed of light. Before I even try to reduce that into equations (and sometimes you *can't* reduce it to equations), the first thing I do is to draw some diagrams. Often it's only *after* I draw the pictures that I start writing the equations.

What do you do when, say, you want to visualize how an electron moves around a nucleus?

I think of a cloud.

How do you visualize chaotic motion, such as that of a double pendulum?

Imagine potential surfaces. Start at a initial condition. Tweak slightly. Watch things diverge.

Imagine a bowl of spaghetti.

Also what happens is that if you think of the thing in phase space, you'll find that the motions will happen on a torus. If it is a dissipative system, then the torus will shrink over time. There's a beautiful set of books by Ralph Abraham in the Visual Mathematics Library.

Therefore, the Earth bulges outward at the equator. Suppose the Earth is a giant slippery block of ice. If I were standing at the equator with no initial velocity, which way would I slide?

By symmetry you wouldn't go north or south. At that point it's a 1-d problem to see if you will slide left or right. If you start off with zero velocity the only force is straight down, and so you wouldn't move in any direction.

Now let's change the problem. I nudge you so that you are moving north. What happens next. The first thing that I'd do is to figure directions. Which direction would I slide?

I'm not saying that visualization is a bad thing, but sometimes it is unnecessary and misleading, and trying to visualize literally everything leads right into certain traps and pitfalls. Visualization is a qualitative thing, and physics aims to be as qualitative as possible.

Nope. It doesn't. I've found it better to try to avoid numbers and complex math as much as possible. Complex math can get you into a lot of trouble when you start focusing on the math and lose site of what is going on. This can have huge consequences.

 

[Woopy]

can all you Ph.D's be my personal tutors? Especially when i have to take my intro electromagnetism course for engineer majors

 

[twofish-quant]

Ever since my first midterm, I've been studying hard with a friend and drilling through very difficult problems almost everyday and throughout the weekends. I think this time, I did much worse.

First of all find how badly you really did. If you are hitting class average, I'd wouldn't panic.

One thing is that high school grading is very different from college grading. High schools like to give tests that demonstrate total mastery and so people usually get 90% on them. College tests are designed to be tough so it's not uncommon to be doing really well and getting 60%.

So the first thing to do is to figure out if it's just that college tests are different or do you really have a problem.

 

[Highway]

can all you Ph.D's be my personal tutors? Especially when i have to take my intro electromagnetism course for engineer majors

i struggled pretty hard with physics 1, but made it through physics 2 (e&m) the first try, with a B. you should be ok if you work hard and do lots of practice problems. . .

 

[-Dragoon-]

First of all find how badly you really did. If you are hitting class average, I'd wouldn't panic.

One thing is that high school grading is very different from college grading. High schools like to give tests that demonstrate total mastery and so people usually get 90% on them. College tests are designed to be tough so it's not uncommon to be doing really well and getting 60%.

So the first thing to do is to figure out if it's just that college tests are different or do you really have a problem.

Last time, I was 4% below the class average (1% above it before the curve).

I'm still kind of shocked at how fast paced university is. There doesn't seem to be any time to actually allow students to master concepts before moving on to more advanced ones. For example, when I spent a few days practicing dynamics problems and slowly mastering the concepts, I fell behind like two chapters (momentum and introduction to energy). It's as if my prof expects the entire class to understand an entire chapter in one day and to do every difficult problem he could give on that chapter.

 

[-Dragoon-]

Edit: I've gotten better at physics since the beginning of the semester by keeping a conscious effort. People don't wake up one day solving every problem flawlessly; especially not with a beginner physics course because it is a bit different then what most are used to. At the moment I haven't mastered the elastic potential energy concepts, if I can't do one of the problems then I know that my knowledge needs to be improved. And I'm working at it. Point is, you need to do the same thing too, it comes with hardsmart work and effort.

Thanks for the encouragement and advice, Nano-Passion.

You see, that is my problem. I can spend my day finishing 15-20 intermediate problems or 5 very difficult problems, but neither seems to do me any good. If I try to change my study habits to work "smarter" and not as hard, I feel like I am getting lazy and thus should deserve a bad grade if I don't work hard enough.

 

[atyy]

Does your physics course involve calculus?

Did your prof teach you that F=dp/dt (or F=ma in a non-calculus course) is meaningless on its own?

Do you know what a third law pair is?

 

[Woopy]

Last time, I was 4% below the class average (1% above it before the curve).

I'm still kind of shocked at how fast paced university is. There doesn't seem to be any time to actually allow students to master concepts before moving on to more advanced ones. For example, when I spent a few days practicing dynamics problems and slowly mastering the concepts, I fell behind like two chapters (momentum and introduction to energy). It's as if my prof expects the entire class to understand an entire chapter in one day and to do every difficult problem he could give on that chapter.

I totally feel you on this, I don't even have the chance to go into the professors office hours to clarify my conceptual issues before we are onto the next chapter, and then I fall behind even more. It really sucks

 

[homeomorphic]

The problem isn't visualization for me either, as my diagrams tend to be pretty accurate. It's really just making the correct inferences and when to use shortcuts that is my problem. It seems no matter how many problems I do, the professor will put questions on the exam that I wouldn't even know how to attempt.

It's not 100% clear that visualization isn't your problem, since it may be that there are gaps in your understanding, and, as I have said, that is where visualization can play a big role. You said it was physical intuition and so on.

If I am struggling with introductory stuff (mechanics), how would I expect to do well in upper year classes? I'm sure the majority of the students taking those classes found mechanics to be a joke and breezed through it.

Well, if it's any consolation, I got two Cs and one A in math before I switched my major to math. In upper division math, I got mostly straight A's. Gpa was above 3.9 in the last two years of my undergrad, although my overall gpa was around 3.4 (tells you how much I improved, even though the courses were supposedly more difficult). If you are happier in another major, there's no shame in that, though. Maybe not everyone will be able to make a big come-backs like I did. Figuring out better study habits can make a huge difference, though.

At this point, I'm just lost and don't really know what to do. Doing extra problems didn't help me at all for the second test, so I don't know how to go about this course anymore.

There are two possibilities, if more practice isn't working. The first is that you need to spend more time thinking about the concepts and making sure you know why everything works. The second is that maybe you need better problem-solving skills. My technique was to try to be able to derive all the results myself, and run through everything (summarize) that had been covered in the class up to that point in my head, each day. Mental rehearsal. That way, I had everything at my fingertips. I didn't have to stop and think about anything because I knew all the concepts covered in the class and could call anyone of them to mind instantly.

There are a lot of books about problem-solving, for example, The Art and Craft of Problem Solving, by Paul Zeitz, or How to Solve it by Polya. These are about math, but I think the ideas will transfer to physics. The Zeitz book might be relevant to test-taking situations, since Zeitz has a lot of experience with math competitions, in which you have to do things on the spot, like a test.

 

[twofish-quant]

Last time, I was 4% below the class average (1% above it before the curve).

I'd be a little nervous, but I wouldn't be panicking.

It's a good idea to study with a study group. It's sometimes not obvious whether you are really in trouble or if you aren't, and being in a group with other students helps.

I'm still kind of shocked at how fast paced university is. There doesn't seem to be any time to actually allow students to master concepts before moving on to more advanced ones.

Yup. It's the firehose philosophy of physics. They aim a firehose at you and see what you can absorb.

The educational philosophy in college is very different from high school. In high school, there are a list of concepts and you are expected to master one before going to the next. In college, they just dunk you in the water to see what sticks. The reason they do that is to give you preparation for the "real world."

I think the big problem is just getting used to that.

It's as if my prof expects the entire class to understand an entire chapter in one day and to do every difficult problem he could give on that chapter.

No. In college courses, most professors don't expect you to be able to master everything. Part of the goal of the course is to get you to push yourself harder. If you understand 100% of everything, then you are done. So the goal is to present material fast enough so that you understand 50% of what is going on so that you push yourself to try to understand 60%.

You know that rabbit at the greyhound track that goes out so that the dogs chase the rabbit. You are the dog.

You see, that is my problem. I can spend my day finishing 15-20 intermediate problems or 5 very difficult problems, but neither seems to do me any good. If I try to change my study habits to work "smarter" and not as hard, I feel like I am getting lazy and thus should deserve a bad grade if I don't work hard enough.

If you spend your day jogging, you may not immediately notice any improvement but it helps. Part of the reason it doesn't feel like you are improving is that they move the target. Once you figure out how to do something, then they will move the target so that you get to study something harder, and you never catch the rabbit.

What will help you is that at the end of the class you will be know something that you didn't know when you started the class.

Now as far as the original question "should you do physics?" One thing that you have to understand is that the feeling that you have of not understanding and not knowing what is going is something that is going to be a constant for the rest of your life if you choose physics as a career. At some point, the teachers will stop giving your problems, and the problems that you get will be given by "the real world" and you'll always be working at just your limit which means that you will be spending most of your time in confusion.

What will determine whether you will thrive or not in physics is whether you can get used to the feeling of not knowing and not understanding, and a lot of what gets taught in freshman physics is less the equations than how to deal with the feeling of being overwhelmed.

 

[AlephZero]

The educational philosophy in college is very different from high school. In high school, there are a list of concepts and you are expected to master one before going to the next. In college, they just dunk you in the water to see what sticks. The reason they do that is to give you preparation for the "real world."

I think the big problem is just getting used to that.

A nice analogy to all this is being in a group of people who are being chased by a lion. It doesn't matter that neither you nor anybody else can run faster than the lion. You just have to run faster than the other people.

 

[Harrisonized]

If I am struggling with introductory stuff (mechanics), how would I expect to do well in upper year classes? I'm sure the majority of the students taking those classes found mechanics to be a joke and breezed through it.

I hated intro mechanics. It was boring stuff, especially since my professor was kind of nuts. You can't really do much with intro mechanics, and the theory is very limited in the intro course.

For the record, just because you're not doing well in mechanics doesn't mean that you'll do poorly in further subjects. Physics is a broad subject. You don't have to be good at one topic to be good at another. It really depends on your interests.

For example, you don't have to be good at geometry to master calculus, even though geometry is usually presented before calculus.

Last time, I was 4% below the class average (1% above it before the curve).

That's not terrible. That means that you're ahead of just less than half your class.

I'm still kind of shocked at how fast paced university is. There doesn't seem to be any time to actually allow students to master concepts before moving on to more advanced ones. For example, when I spent a few days practicing dynamics problems and slowly mastering the concepts, I fell behind like two chapters (momentum and introduction to energy). It's as if my prof expects the entire class to understand an entire chapter in one day and to do every difficult problem he could give on that chapter.

The point of an intro class isn't to let you master something. Anyone can master anything given an infinite amount of time. The point of an intro class is to -introduce- you to basic physics so that you can master it in the future when you actually need it.

For example, you don't master sight-reading a piece of sheet music before beginning to play on an instrument. You learn how as you go along.

If I try to change my study habits to work "smarter" and not as hard, I feel like I am getting lazy and thus should deserve a bad grade if I don't work hard enough.

If you feel like you understood the material, there's no reason to feel like you're lazy. If you're washing your hands and after one minute, you have already washed off all the dirt and used soap to kill the germs, you don't have to feel lazy because you didn't wash for five minutes straight.

Just as a point of reference, I have a Ph.D. in astrophysics.

So what? You're still just another person who is on the internet who is replying to a thread.

I'm a very visual person.

And I'm not.

I think of a cloud.

That's how it is in most chemistry textbooks. However, if you work the equations, you'll find that there's no definite border like a cloud implies. If you imagine a cloud with borders, you're somewhat cheating yourself.

There's a beautiful set of books by Ralph Abraham in the Visual Mathematics Library.

I know that there are people who sit down and think of how to visualize everything. However, the advice I was trying to give was to move on if the visualization of something isn't immediately obvious (or if its so obvious that it's unnecessary), because it's really pointless to try and visualize everything in intro mechanics.

By symmetry you wouldn't go north or south. At that point it's a 1-d problem to see if you will slide left or right. If you start off with zero velocity the only force is straight down, and so you wouldn't move in any direction.

Now let's change the problem. I nudge you so that you are moving north. What happens next. The first thing that I'd do is to figure directions. Which direction would I slide?

The center of mass in a system of bodies acts as though the mass moving is concentrated at that point. If you were at rest and you nudged me, you'd have to slide in the opposite direction as I'm moving. (You said you pushed me north, so you'd have to be moving south) The center of mass of you and me will fall into the Earth as though there were a hole in the earth.

If there is no friction, then the center of mass of you and me would oscillate back and forth within the Earth as though it were falling through the Earth and emerging out the other side.

If there is finite friction, then we'd eventually stop somewhere before colliding with each other on the other side.

Nope. It doesn't.

This somewhat amuses me. It's impossible to prove that visualization can never be confusing, yet you say it with such certainty.

I've found it better to try to avoid numbers and complex math as much as possible. Complex math can get you into a lot of trouble when you start focusing on the math and lose site of what is going on. This can have huge consequences.

Look. Everyone is different. The TS already said that visualization isn't his main problem. What are you trying to accomplish by reviving this subject? Convince me that my views are somehow "wrong"?

Just give the topic a rest. The thread is about the TS and his troubles with school. Just give him your advice, and don't go on tangents. I know it's somewhat hypocritical, but whatever.

On a side note, I never really understood why people make these kinds of topics. You can't solve a problem by just talking about it.

If the TS needs help with specific questions, then he should be asking about those questions, not about his performance in general. We don't know the TS specifically. We don't know his personality, his working style, what exactly he's having trouble with, etc. The best we can do is guess around generalizations and give the same advice as we give everyone else.

 

[homeomorphic]

That's how it is in most chemistry textbooks. However, if you work the equations, you'll find that there's no definite border like a cloud implies. If you imagine a cloud with borders, you're somewhat cheating yourself.

Why does a cloud imply a definite border? It's pretty easy to visualize things and see past these kinds of issues.

There's a beautiful set of books by Ralph Abraham in the Visual Mathematics Library.

I know that there are people who sit down and think of how to visualize everything. However, the advice I was trying to give was to move on if the visualization of something isn't immediately obvious (or if its so obvious that it's unnecessary), because it's really pointless to try and visualize everything in intro mechanics.

I don't think so. No one saying visualize every last thing. I think what I remember about intro to mechanics was mainly what I visualized or thought of in sort of a physical sense. There was a lot of geometric reasoning involved for me, and I got an A in the class. The main thing, though, is just that you ought to try to understand as much as you can, whether that involves visualization or not.

Actually, visualizations that aren't immediately obvious can be very useful. I have struggled with a lot of subjects that became easy once I was able to visualize them. This has happened many times. If the visualization had been immediately obvious to me, I wouldn't have had to do all that struggling.

This somewhat amuses me. It's impossible to prove that visualization can never be confusing, yet you say it with such certainty.

It's not that it can never be confusing. It's kind of like saying hammers can be bad tools. That is a problematic statement, for two reasons. First of all, hammers are good for certain purposes, and they are very good tools if used in the right context. Saying that they can be bad tools seems to suggest that there is something inherently wrong with them. Secondly, even if a hammer is the right tool, you can mess up. You could hit yourself in the thumb by mistake. That doesn't mean you shouldn't use the hammer or that the hammer is bad for pounding nails. It's your fault, if you mess up, not visualization's fault.

Look. Everyone is different.

Less so than you seem to assume. Just about anything improves with practice and visualization is no exception. If someone is bad at it, that shouldn't be seen as an inherent trait, but something that can be worked on. If you don't want to work on it, it's kind of like a basketball player saying, he can't dribble, but it doesn't matter because he can shoot so well. Okay, but you're not going to be as good of a player as you could have been. Why limit yourself?

The TS already said that visualization isn't his main problem.

But it could possibly play a role in the solution. Possibly.

Just give the topic a rest. The thread is about the TS and his troubles with school. Just give him your advice, and don't go on tangents.

People are reading this. Visualization cannot go undefended. Plus, it may be relevant.

On a side note, I never really understood why people make these kinds of topics. You can't solve a problem by just talking about it.

He has already tried working harder and that didn't work. Of course, it makes sense to think about what the best way of doing things is. It can make a huge difference. I was always "the smart kid" growing up, but when I was an undergrad I always felt that my learning strategies, rather than my intelligence alone was one of the key reasons why I was more successful than most of my classmates. I knew that the way I was tackling the material was likely to be radically different from what anyone else would have thought to do, and, furthermore, I also knew that what I was doing was fundamental to my success. So, it's a smart thing to try to ask people what strategies they used.

If the TS needs help with specific questions, then he should be asking about those questions, not about his performance in general. We don't know the TS specifically. We don't know his personality, his working style, what exactly he's having trouble with, etc. The best we can do is guess around generalizations and give the same advice as we give everyone else.

I agree that we are limited in not having much information about him, and that the advice would have to be fairly generic, but that may be good enough to be worthwhile.

 

[twofish-quant]

So what? You're still just another person who is on the internet who is replying to a thread.

And I've someone that has done professional-level physics research who can provide some insights as to what is skills end up being useful in that research. One reason I'm interested in your background, is that I'm interested in comparing notes.

That's how it is in most chemistry textbooks. However, if you work the equations, you'll find that there's no definite border like a cloud implies. If you imagine a cloud with borders, you're somewhat cheating yourself.

So it's a fuzzy cloud.

I know that there are people who sit down and think of how to visualize everything. However, the advice I was trying to give was to move on if the visualization of something isn't immediately obvious (or if its so obvious that it's unnecessary), because it's really pointless to try and visualize everything in intro mechanics.

I don't think it's pointless. I *have* run into situations where it turns out that I can't visualize something and it was necessarily to avoid trying and then crunch the numbers (Clifford algebra and group theory proofs). However, the after crunching the numbers I was able to get a picture in my mind of what was going on..

Also, I think you are missing corolis forces...

Look. Everyone is different. The TS already said that visualization isn't his main problem. What are you trying to accomplish by reviving this subject? Convince me that my views are somehow "wrong"?

If you have done professional-level research, then I'm interested in why your views are what they are, because they seem bizarre. If you are an undergraduate sophomore, then yes, I am trying to convince you that your views on visualization are wrong and that you'll be shooting yourself in the foot if you go into graduate school with those views.

And if I can't convince you that you are wrong, I can convince other people not to agree with them.

On a side note, I never really understood why people make these kinds of topics. You can't solve a problem by just talking about it.

Yes you can.

We don't know the TS specifically. We don't know his personality, his working style, what exactly he's having trouble with, etc. The best we can do is guess around generalizations and give the same advice as we give everyone else.

Oh, I don't know anything about TS. I do know something about how physics works.

 

[twofish-quant]

One other piece of advice I'd like to give to the OP is to set realistic goals. You are in a marathon, and you need to pace yourself. If you are getting four points below class average, then a realistic goal would be to aim for getting four points above class average on the next test. The danger of setting goals that are totally impossible (like getting a perfect score) is that when it doesn't happen, you'll get depressed, and give up.

The other thing that you have to figure out is whether physics is for you. To quote Churchill, I have nothing to promise you but blood, sweat, and tears. Most people really shouldn't be physics majors. It's not a question of intelligence, but rather a question of goals. If your main goal is to live a life of contentment, then physics is not for you. I'm twice as old as you, and I'm working as hard (and messing up) as much as I did when I was a freshman, but the difference is that I've gotten used to it, and I'm an intellectual masochist.

So you really want to think about why you want to go into physics...

 

[Nano-Passion]

If I can't convince you that you are wrong, I can convince other people not to agree with them.

Quote of the year!

 

[Highway]

One other piece of advice I'd like to give to the OP is to set realistic goals. You are in a marathon, and you need to pace yourself. If you are getting four points below class average, then a realistic goal would be to aim for getting four points above class average on the next test. The danger of setting goals that are totally impossible (like getting a perfect score) is that when it doesn't happen, you'll get depressed, and give up.

The other thing that you have to figure out is whether physics is for you. To quote Churchill, I have nothing to promise you but blood, sweat, and tears. Most people really shouldn't be physics majors. It's not a question of intelligence, but rather a question of goals. If your main goal is to live a life of contentment, then physics is not for you. I'm twice as old as you, and I'm working as hard (and messing up) as much as I did when I was a freshman, but the difference is that I've gotten used to it, and I'm an intellectual masochist.

So you really want to think about why you want to go into physics...

amen.