Recent content by wizzart

Thanks CWaters. Looks like the explanation I had thought of was pretty close :) Any other references or notes?

I'm writing a lab for high school students on the emission/absorption spectrum of table salt as part of a larger project to introduce them to quantum mechanics. I'm aware that there are many such lab instructions already, but that's not the point. While doing some tests and writing the lab...

Think I figured it out. For instance, in the case of the solenoid: if instead of reversing the current or rotating the solenoid 180 deg. I stand on my head and look at the magnetic field, I should still see the same field... If this is correct, I apologize for the forum pollution.

Time for me to feel stupid again: In Griffiths' introduction to electro dynamics examples 5.8 and 5.9 the magnetic fields of plane currents and solenoids are discussed. In both, certain components of the magnetic fields are said to be zero based on symmetry and current reversal arguments. I'm...

The electric field will also push electrons in part C of your structure, resulting in a pile up off charge (measurable as a voltage). Charge being pushed in part C just can't go anywhere. Moreover, don't think of the current as just a fast train of electrons: the electrons might not be moving...

Dude, I'll make it a lil worse...I'm one subject away from my bachelors degree :P Did research on noise in Quantum Dots and all that. The mechanics course was 5 years ago, and back then I didn't really get the whole orbit stuff (and the big point in the course was relativity, so I got away with...

The way you define your system only affects your bookkeeping, not the outcome. Proper system boundaries allow you to get the answers to the questions your asking, in other words gives you information that is useful. As for you title: work = energy Energy is the ability to do work. Doing work...

Dang, it's right here in my 1st year Relativity book...need to critically review some of the old stuff I guess. As for stationarity: stationary to me means nothing changes. For the orbiting object everything changes constantly, without drag the orbit itself (circle or ellipse) doesn't change...

hm...sounds plausible too :biggrin: Well, quasi-stationary then...slowly spiralling down to earth.

Geez it's been ages since I last was here. Anyway, I was thinking a little on the subject below and remembered this place. It's probably ridiculously trivial, but still I wonder: A satellite stays in orbit around the Earth because it's falling at the same pace as the Earth's surface curves...

thanks all...je comprend :) Like I said, just something I thought up while in the middle of stressful exam preps...just couldn't find where I was going wrong. Turns out I mixed measurement and expectation value, to put it in a short way.

ah yes, I see the confusion. Sorry, the vectors I mentioned need to be transposed...But still, where does my reasoning go wrong?

Spin 1/2 particles 'live' in a 2D Hilbert space, which is spanned by two basisvectors, which I can choose to be the eigenspinor of Sz. I can label these vectors as (1,0) and (0,1), corresponding to spin up or down in the z direction...Right? (like for instance Griffiths page 156)

I'm studying for a QM course test, and I was just doing a little thinking about the pauli matrices in a distracted moment. I came up with something, that to my knowledge isn't right, but I can't figure out where my argument goes 'boink'. The case is this: Imagine I have an electron polarised...

:cry: stupid me...ow well, still, if there weren't sinusoids, my post would be true ;), except when n is also a changing variable...Don't think it should be, but if you say so.