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BEE 1992, MEE 2001, PhD in progress

Starting building Heathkits in early 70s. Consumer electronics tech through 80s. EE since then. Sold company in 00s. Teach EE classes on occasion now.


Aug
19
comment Integrating a Dirac delta function with the argument dependent of a parameter
Suppose that $x(t) = D$ once over the interval of integration. Now, suppose that $x(t) = D$ n times over the interval. But, now suppose that $x(t) = D$ over a continuous subset of the interval...
Aug
18
answered Integral ambiguity
Aug
17
comment Can we apply Quantum Superposition
"If the cat is dead or alive with 50% probability..." What is the operator corresponding to the, apparently, two-state observable with allowed states "Alive" and "Dead"?
Aug
16
answered Dot product of vector and its derivative with respect to time? How does $L \cdot\frac{dL}{dt} = \frac{1}{2}\frac{d(L^2)}{dt}$?
Aug
16
comment Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
@XiangruLian, updated.
Aug
16
revised Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
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Aug
16
comment Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
@XiangruLian, yes, I will update my answer later with a new graph.
Aug
16
comment Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
@XiangruLian, the ends of the rod are not inertial and, further, do not, in general, have the same momentarily co-moving reference frame.
Aug
16
comment Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
@XiangruLian, let's assume that the world lines of the ends of the rod are the two right-most lines in the spacetime diagram above. Then, the proper length is the spatial separation of the world lines when $t=0$ since the rod is momentarily at rest in this reference frame then.
Aug
15
answered Consider relativity. If a stick accelerates from a stationary state, how will it look like during the acceleration?
Aug
15
answered Measuring position and momentum at the same time?
Aug
14
comment A common definition of a scalar
@BenCrowell, I started to write a response but I just noticed that ACuriousMind has responded to your similar comment there with essentially what I was about to write.
Aug
14
comment How does electric field intensity look like along a wire which has one end connected to an AC source and the other one is left free?
Martin, be aware that if the length of the conductor is large enough, the charge distribution will vary along the length of the conductor, i.e., the voltage and current along the conductor will be a function of position. Essentially, you would have a 'long wire' antenna: northcountryradio.com/Articles/Long%20Wire%20Antenna.htm
Aug
14
comment How does electric field intensity look like along a wire which has one end connected to an AC source and the other one is left free?
@ACuriousMind, the AC source will alternately charge / discharge the conductor since there is an unavoidable capacitor formed by the conductor and, I presume, ground.
Aug
14
answered A common definition of a scalar
Aug
14
revised Why is the Schwarzschild radius the radius of an event horizon?
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Aug
14
comment Why is the Schwarzschild radius the radius of an event horizon?
@PML, I fixed a typo - I want to expand and clarify this answer a bit but I'm in the middle of grilling supper right now so allow for some time.
Aug
14
revised Why is the Schwarzschild radius the radius of an event horizon?
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Aug
13
revised Why is the Schwarzschild radius the radius of an event horizon?
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Aug
13
answered Why is the Schwarzschild radius the radius of an event horizon?