Recent content by Sylvia Else

OK, I can follow that, thanks. He starts discussing eigenfunctions and eigentvalues a bit later. Perhaps readers are meant to take it on trust until then. Sylvia.

I'm, slowly, working through "Quantum Physics" by Stephen Gasiorowicz, second edition. On page 49, he gives the equation i\hbar\frac{\partial ψ(x, t)}{\partial t} = -\frac{\hbar^{2}}{2m}\frac{\partial ^{2}ψ(x, t)}{\partial x^2} He then makes the identification (h/i)(\partial/\partial x) =...

The simple view is the electrons depart from the top plate, pass through the battery, and arrive at the bottom plate. Thus the battery itself neither gains nor loses electrons. Its function is to provide the force that moves the electrons. The battery is analagous to a water pump - it makes the...

I would expect the relay coil to be energised in both cases, as soon as the power is applied. Note, BTW, that you need a diode across the relay coil in real circuits, or you'll quite likely destroy the transistor when you try to turn the coil current off.

Those circuits don't really convey anything - they're just using the transistor as a diode, and the only difference between the configurations is the order of the battery and the load - which is irrelevant. For this to make any sense, you'll have to provide details of the base driving.

The circuit simulator may be giving you an unrealistic zero source-impedance power source, which can mask some circuit errors. You really need to provide more detail of the circuit - and in particular show how you're driving the base.

No doubt we will. But is it actually any better than the old design, or is it just different? Whatever happened to the engineering adage "If it ain't broke, don't fix it"? Designers seem to mistake change for progess. In some areas (such as supermarket self-checkout systems) one can at least...

Change for the sake of change.

Since Einstein, if not before, the contraction has not regarded as being a physical effect on the object, but rather the result of a coordinate transformation between the object and the observer. It's a special case of applying the Lorentz transform to the situation being examined. The Lorentz...

i8uncertainty, EPR style experiments with angles of 30 and 60 degrees certainly show the non-locaility result, with 30 degrees producing a 1 in 4 difference, and 60 degrees producing a 3 in 4 difference. But do an EPR style experiment with 45 degrees and 90 degrees, and you get a 2 in 4...

The interpretation of these erasure experiments bothers me. The ones I've looked at all have a similar characteristic, which is that the interference patterns that 'result' from the erasure are not directly detectable, but instead have to be found by dividing photons into two sets, which produce...

I obviously cannot speak for your specific air conditioner, but they don't all require large starting currents. Indeed, when I did some specific tests on a Daikin model that I have, I found that its startup requirements were very benign. It is one of the "inverter" type, which I think are...

As far as the environmental impact is concerned, the effect of solar panels is far from clear. If one assumes a typical grid generating mix of coal or nuclear, combined cycle natural gas, single cycle natural gas, which covers the base load, medium load, and peak load, with each type being...

Julie might be disappointed as to the savings. Assuming reasonably constant daylight during the day, the solar panels will produce a reasonably constant output, but the dollhouses demand will vary considerably. If the solar panels are small, then it's possible their entire output will always be...