AB Engineering and Applied Physics
MSEE
Aerospace electronics career
Used to hike; classical music, esp. contemporary; Agatha Christie mysteries.
Abstract: The analysis of the two kinds of electric fields, namely the irrotational and non-conservative, is extended to electrodynamics, as exemplified by the high-frequency behavior of a parallel-plate capacitor and a radiating antenna. Since the concept of split electric fields still seems foreign in certain quarters I want to start back to square one for…
Main Point: The electric vector potential offers a means of determining the non-conservative component of mixed stationary or quasi-stationary electric field While many are familiar with the static magnetic vector potential ## \bf A = (\mu/4\pi) \int \bf j~ dv/s ## with ## \bf j ## = current (area) density within differential volume ## dv…
Introduction In a previous Insight, A New Interpretation of Dr. Walter Lewin’s Paradox, I introduced the fact that there are two kinds of E fields. One (Em) is generated whenever a source of emf is produced. The other (Es) is the electrostatic field. The Es field always terminates on free charges; the Em does not. …
Financial options (the right to purchase (“call“) or sell (“put“) stock (or other assets)) at a fixed price at a future date have been around for a long time. They are attractive for the option buyer since his/her total risk is the premium (price) paid for the option, as contrasted with futures contracts which are…
Much has lately been said regarding this paradox which first appeared in one of W. Lewin’s MIT lecture series on ##{YouTube}^{(1)}##. This lecture was recently critiqued by C. Mabilde in a second YouTube video and submitted as a post in a PF ##{thread}^{(2)}##. The latter cited the third source, that of K. T. McDonald of…
A long time ago I read a paper in the IEEEProceedings recounting the history of the superheterodyne receiver. Overall it was a very interesting and informative article, with one exception: in it the author remarked that the modulation (or mixing) principle was really nothing new, is already known to piano tuners who traditionally used a…
It is apparent that a subway tunnel could be built without the need for supplied energy like electricity, assuming zero friction everywhere. The tunnel would go underground, level off, and then climb back up, all just by exchanging potential and kinetic energy. However, the question arises: What should be the shape of the tunnel for…
A commonly used formula for mutual inductance M between two nearby coils L1 and L2 is M = k√(L1*L2). This formula however assumes equal percentage flux linkages between the two coils. This requirement is often omitted in several of the references I have looked at. That this requirement is not necessarily met can be…