Gabe
New member
- Joined
- Nov 17, 2007
- Messages
- 590
- MBTI Type
- ENTP
This is for anyone who has knowledge of electromagnetism and/or the university curriculum decision making process. I'd like only serious responses please, I am hoping to learn something here.
So, for those of you who have taken electromagnetism classes, you know the whole language, right. First you are taught the very basic process of electrostatics (charges, electric fields, definition of voltage). Then, one day, the teacher starts talking a whole different language. You learn about potential in a circuit, and about all the features in the artificial situations of idealized circuits. You learn that V=IR and kirchoffs rules.
Wait a minute though! What happened to the charges? What happened to the electric field. The mind checks for an understanding of mechanism, so you try to figure out what's actually happening with the charges in a circuit. I dare you to try it now. Try to explain some basic circuit phenomenon in terms of charges and electric fields.
If you've been taught electromagnetism the traditional way, you won't be able to do this. "how is there a potential difference in a wire across a circuit, when the source of the potential difference is all the way over there" "Does the electric field bend into the wire or something"?
The typical teacher responses to this are:
Robotically reemphasize that thier is a potential difference across the circuit.
Indroduce a vague (and false) principle of 'direct contact'
Say (falsely) that the electrons push each other along, like water in a pipe.
The truth is, in some very short time before the current flows, the electric from, say, a capacitor, pushes the charges around until they align in a 'steady state' distribution along the wire. Then there is actually an electric field in the wire and the current flows.
www4.ncsu.edu/~rwchabay/mi/circuit.pdf
So my real question is, why haven't physics professors changed thier way of teaching electromagnetism. The misconceptions the current method causes, and the lack of understanding it leaves students with is OBVIOUS.
So how do curriculum decisions get made, and what is preventing progress in curriculums in math and science departments?
So, for those of you who have taken electromagnetism classes, you know the whole language, right. First you are taught the very basic process of electrostatics (charges, electric fields, definition of voltage). Then, one day, the teacher starts talking a whole different language. You learn about potential in a circuit, and about all the features in the artificial situations of idealized circuits. You learn that V=IR and kirchoffs rules.
Wait a minute though! What happened to the charges? What happened to the electric field. The mind checks for an understanding of mechanism, so you try to figure out what's actually happening with the charges in a circuit. I dare you to try it now. Try to explain some basic circuit phenomenon in terms of charges and electric fields.
If you've been taught electromagnetism the traditional way, you won't be able to do this. "how is there a potential difference in a wire across a circuit, when the source of the potential difference is all the way over there" "Does the electric field bend into the wire or something"?
The typical teacher responses to this are:
Robotically reemphasize that thier is a potential difference across the circuit.
Indroduce a vague (and false) principle of 'direct contact'
Say (falsely) that the electrons push each other along, like water in a pipe.
The truth is, in some very short time before the current flows, the electric from, say, a capacitor, pushes the charges around until they align in a 'steady state' distribution along the wire. Then there is actually an electric field in the wire and the current flows.
www4.ncsu.edu/~rwchabay/mi/circuit.pdf
So my real question is, why haven't physics professors changed thier way of teaching electromagnetism. The misconceptions the current method causes, and the lack of understanding it leaves students with is OBVIOUS.
So how do curriculum decisions get made, and what is preventing progress in curriculums in math and science departments?