I Didn't Learn Anything from My Physics Education

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I earned a B.S. in Physics. I don't think that I learned much of anything. The professors fed me a bunch of supposed facts, but no one ever explained why they were true, so I had to take it on faith. I think that a person needs to understand why something is true in order to claim knowledge of it; otherwise, the learning is actually just memorization. Perhaps it would have been impractical, but I think the curriculum would have been far more meaningful if the professors or at least the textbooks had explained the early physics experiments and then narrated a line of logic leading from those experiments to the laws and theories we have now. Without a line of reasoning, I have no way to determine whether or not something makes sense, and any work I do based on that information (homework or experiments) is subject to corresponding errors, particularly, errors that are difficult to detect: errors in fundamental theory.

After university, I bought a lot of physics books, thinking I would find these sorts of explanations. I was wrong. It's often just the author throwing equations at the reader with no background. Seeing how many concepts I had to take for granted to graduate, I now find it impossible to read beyond the first few pages of many such books because I don't fully understand the meaning of fundamental things such as atoms. All I know about atomic theory is that Democritus proposed that all matter is only physically reducible so far before it loses its essential physical characteristics, and scientists for generations after him ran with this idea. To me, it sounds like it's just something everyone simply accepts uncritically; we can't see atoms but supposedly somebody somehow detected something that lends credence to their existence. But I don't know what that evidence is. I could dig it up (I know it will be difficult to find), but, until I do, I can't legitimately accept atomic theory, and I think that it is completely unnacceptable for a physics education to leave out discussions of evidence supporting such crucial theoretical elements.

The absolute worst thing about physics is that it is drowning in metaphors. The metaphors barely make any sense to me; I don't know the experimental and theoretical history, so I don't have a good sense of why the metaphor is an apt explanation of the phenomenon or why it was even chosen. To me, it seems like layering metaphor on top of hypotheses, experiments, and results just makes science more complicated by adding an unnecessary layer of abstraction between the natural world and the study of the same.

I once read a book in which the authors lamented the state of undergraduate education in the U.S. They thought that students weren't actually learning how to think, but were instead merely being trained to be competent technicians of one sort or another. This opened my eyes up to the problem with physics education: it isn't really meant to help students understand physics, it is meant to shape them into people who can do physics, hence the pages and pages of computations we were given, the unexplained jargon we were expected to parrot.

Did you not take experimental physics classes where you performed the basic conceptual experiments as a way of solidifying your understanding of the topics and topic progression? My school had a great physics department with excellent hands-on learning experiences, so I was able to conceptualize what we were being taught. That said, I've always had a talent for being able to wrap my head around theories (as long as I have the foundational math skills and other background knowledge), so I could be oversimplifying it. I'm sorry if that's the case.

I'm the other way around-- I can't just plug and play. I'm actually mediocre at best at that part of things. I'm better at qualitative concepts. I can explain nebular theory in quite a bit of detail, but I can't calculate the mass of the protostar nearly as easily.

What was your focus? Or was it a general physics degree?

One thing to keep in mind with theories building on each other is that often they're just backed up by patched together supporting evidence and not necessarily clear and solid "proof" in one all-encompassing experiment. So you have to kind of poke around to pick up the pieces until you get to a place where there is enough evidence for you to give credence to the theory.

J.J. Thomson's experiments showed that there were EM fields around atoms made up of negatively charged particles, now called electrons. So he's a good one to read about.
A good PDF of a slide show explaining experimental evidence for atomic theory:
http://iweb.tntech.edu/jkim/courses/CHE ... 20FW-2.pdf

Hope that those help out some!

It's hard to believe!

Where did you study?

The sort of questions you say they don't cover are part of most 101 lecture series.

The evidence for atoms, methods of detection, analysis, etc. is easy to find and understand. Just look for it.

^ This.

I found university physics very intuitive and there was a good mix of theory and experimentation along with historical details and the inferences and deductions made from the data at the time.
Maybe the OP didn't attend a very good university, or maybe the focus has changed since my days away from understanding and more towards pumping out technicians? Though I can't understand how anyone could be a good physicist without the associated insight and intuition based upon their studies.

I would have earned a physics degree instead of one in engineering were it not for the toss of a coin -- they both seemed so fascinating!

I think the OP means things like how did Schrodinger come up with his famous equation.

I think part of the problem is that undergrad physics is like a pre-med degree, so that you don't get learn things in a natural way until grad school (I didn't go, so I'm guessing, tho).

I.e. I read somewhere that Schrodinger was looking at Hamiltonian formulations of geometric vs. wave-based(?) optics and noticed how easy it would be to make an analogy with "matter waves." The problem is that (I, least) was never fully taught the so-called canonical method/theory (Hamiltonian stuff), so understanding that isn't possible without knowing more.

And, I think for me, at least, it would've confusing to learn that without knowing what the Schrodinger equation is good for and how to use it first, so I can kind of see why they do it the way they do. Also, the workload where I went was ridiculous and can't imagine more stuff being crammed in. (I remember grad students telling me the workload in grad school is a lot more reasonable.)

[edited due to writing after being up all night and consequent brain scamblage.]

I think you are supplying a more understandable message for the one that is there.



To have graduated with a Bachelor's in Physics and assert the first clause of that quotation is unimaginable to me.

To then assert "we can't see atoms" and then fault people for uncritically accepting recieved truths also seems utterly alien to the science programs I have participated in college/university. As someone with a lifelong interest in physics in particular and science in general, I have happened across many announcements that should give a physics student pause before writing such a statement.

What, for example, can be made of this image?


To then assert, from an internet enabled device of some kind, hat it would be difficult to find information about the evidence supporting atomic theory is really unbelievable. Mere seconds of Googling can bring you to something like this:
http://physics.stackexchange.com/questi ... mic-theory

And it's just one of millions of web pages that could help you in a quest to verify for yourself that atomic theory is grounded in reality.

But it's hard to believe that the introductory lectures did not go through Dalton, Thomson, Rutherford and Bohr. You can find tons of this on Youtube:
https://www.youtube.com/results?search_ ... Bbohr&sm=3
[youtube]https://www.youtube.com/watch?v=zRtRAeGuO7M[/youtube]

I would think most people interested in a B.S. degree in physics would already have had this in High School (they start on this in Middle School around here.)

I really do wonder what kind of college awarded this degree while imparting so little about the subject. The idea lies outside my experience of academic institutions.

http://en.wikipedia.org/wiki/History_of_physics

We can't see atoms with our bare eyes but we can see them with sufficient magnification.

http://www.extremetech.com/extreme/1637 ... ular-bonds

I don't know what that is.


It may be easy to find information about various parts of atomic theory, but I've found it difficult to find information about the most basic part: the existence of atoms. Without that, none of the rest is meaningful.

I looked at your link, and it confirmed my statement. I looked through the comments for information about the existence of atoms. Someone mentioned Brownian motion and posted the Wikipedia link. I followed the link. The article said that a paper Einstein wrote explaining Brownian motion proved the existence of atoms. So I followed the link to the paper. Nothing I could see in any of those pages actually said anything that would support the existence of atoms; from what I could gather, Einstein explained Brownian motion by attributing it to atoms. That requires that he presupposed the existence of atoms rather than proved that they exist. And going through all those links just to get those scraps of info? That's what I meant about the information being hard to find. If it's there, it's scattered. Perhaps I need to read Einstein's whole paper in order to understand. That too, would require more searching.

I also followed a link about JJ Thompson's experiment with cathode tubes. He, too, presupposed the existence of atoms and used them to explain his experimental results rather than providing any evidence that they exist:

Thomson believed that the corpuscles emerged from the molecules of gas around the cathode. He thus concluded that atoms were divisible, and that the corpuscles were their building blocks.



They only did so in an extremely cursory way.


I attended the University of California at Santa Cruz.

photos!

photos of atoms


http://www.extremetech.com/extreme/1637 ... ular-bonds

Are photos enough?

Ok. I've no way of knowing that those are pictures of atoms, though. I'd first have to have some idea of what atoms are like, then verify that description with the images. I would need to know what I assume those scientists know.

Do you really believe this? That you have to "know" that atoms exist before you can do any of the experiments that indicating the aspects of what does exist that we explain (very succesfully) with atomic theory?

That's a unique perspective, if true.

In a sense, you are right, atoms don't exist. We have experiments (Rutherford and many since) that prove that "Atoms" are mostly void. The little particles we thought of a the core "material" constituents of atoms turn out to be structured waveforms of energy... So in a sense you are correct, But your method prevents you from learning anything or using the information that is available.

It may be necessary for you to think this way. It may be an essential part of your philosophy of knowledge, but it goes off at a tangent from the scientific enterprise and it doesn't make sense to blame institutions that teach science for not going off on the same path.

Nice!

And there's always video, if you prefer
http://www.extremetech.com/extreme/1546 ... aced-atoms

But this will not satisfy Starkid. We need to rebuild the universe from first principles with precise knowledge of every action at the Planck scale and provide a logical proof that demonstrates certain knowledge of everything that we show in that process or it won't be "real knowledge." I don't think this is theoretically possible.

It's a single frame from a movie called A Boy & His Atom.


So, what do I win?

Last edited by Fnord on 23 Jan 2014, 4:59 pm, edited 1 time in total.

I'm not sure what you mean. My goal is to understand physics theory; in order to do that, I need to understand precisely what scientists are saying when they mention atoms. If somebody is basing an entire theory on the existence of something that is not obvious, then I need to at least know their reasoning for believing that it exists before the rest of the theory makes any sense. I don't have to believe it myself. On the other hand, if it's just an abstract model, I need to know what about the physical phenomenon motivated the selection of that particular model; otherwise, it's just an arbitrary choice in my eyes.

I can go through the motions of doing experiments without that understanding, but I wouldn't be able to interpret the results in a way that jibes with physics as it currently stands.


I didn't say that they don't exist.



I disagree with you. Digging into the precise meaning of theoretical elements can only help me learn more deeply. And I can't learn much if the basic explanatory systems seem like random constructs.

Ok, nevermind. I just read your latest post and see that you are making fun of me.

Last edited by starkid on 23 Jan 2014, 4:04 pm, edited 3 times in total.