IEEE Consultants' Network of Long Island

The Unsolvable Problem - John Dunn, Consultant, Ambertec, P.E., P.C.

Some problems have no solution, absolutely no solution at all. The following is my dilettante's look at one such problem.

In music, in a tempered chromatic scale of Do-Do#-Re-Re#-Mi-Fa-Fa#-Sol-Sol#-La-La#-Ti-Do, there are twelve intervals between all of the notes including the sharps and flats and this can be called a twelve-tone scale. (For the sake of this discussion, we can let Do-sharp equal Re-flat etc.)

We start at some particular frequency as the "root" note which we call "Do" and then each note going up the scale has a frequency of the note just below itself multiplied by the twelfth root of two which is an irrational number, but is approximately 1.059463.

The Design Review - John Dunn, Consultant, Ambertec, P.E., P.C.

Every circuit design has some chance of benefitting from having a critical eye cast upon it by someone other than its creator. You think you know your work, you've put your heart and soul into it and so you have all kinds of confidence, but darned if there isn't that little blind spot somewhere that prevents you from noticing something.

A professor I once had put it quite nicely: "Familiarity breeds the illusion of comprehension."

Thus there was this particular project that I brought into a design review, hoping to get a careful and thoughtful evaluation of my work. The profundity of the review commentary was astonishing:

            "Well, you know you have to keep all of the critical leads as short as possible, be sure that

            you've bypassed your rail voltages properly, make sure that all of the parts tolerances are

            reasonable and you also have to make sure nothing will overheat." 

The Shock Box - John Dunn, Consultant, Ambertec, P.E., P.C.

In the year 1924, when my mother was seventeen, she was stricken with polio which paralyzed her entire right side.

She was taken care of as well as anyone could have been at the time. Treatment consisted of receiving electrical muscle stimulation from an induction coil that was mounted on a wooden box. The stimulator's coil was mounted to the box on top of a painted wooden panel. In the center of the coil, there was a sliding brass plunger which was used to control the energy delivered to the patient during each treatment.    

 

Distance To The Horizon - John Dunn, Consultant, Ambertec, P.E., P.C.

The earth has a circumference of approximately 25000 miles and you're going to put up a structure of some particular height, perhaps an antenna. How far will it be from the top of that structure along the earth's surface to the horizon?

The calculation, or perhaps more properly, the estimation is as follows: 

 

While it's true that the algebra would be simpler using the arc cosine instead of the arc tangent, I wrote the code for this in GWBASIC and I only had the ATN function available to me, at least so far as I know.

 

The Dynamite - John Dunn, Consultant, Ambertec, P.E., P.C.

My boss had built his home at the very top of a multi-hundred foot hill in New Hampshire and true to that state's reputation, the hill was largely made of granite. He decided one day to add an extension and to do that, he had to extend the foundation. He got an architect's instructions about how to proceed.

The project involved removing of a lot of granite from right outside the kitchen door. I had volunteered to assist in the process which consisted of drilling a set of properly spaced two-inch diameter holes into the granite, loading each hole with a stick of a dynamite into which a blasting cap had been inserted, wiring the caps in a series circuit and setting them all off with a shot of 120 VAC line voltage.

Slosh - John Dunn, Consultant, Ambertec, P.E., P.C.

On a couple of different occasions, I needed to move a plastic tray of roughly 12 by 18 inches, filled with a couple of inches of water, from one part of the building to the other. At first, I tried to simply carry the thing, but it was too much of a challenge not to spill it. Slosh, slosh, round and about, oh boy!

So the next time, I thought I'd smarten up. I got this really slick rolling cart with great big smooth-riding wheels. That card would glide across a tile floor like Michelle Kwan on ice.

I put the filled tray on the cart and started off down the hall, but it wasn't long before the water started to really swing around in there, slosh, slosh, round and about, good grief!!

Corner Reflectors and Bonner - John Dunn, Consultant, Ambertec, P.E., P.C.

"As I went to Bonner, I met a pig without a wig, upon my word and honour." - Mother Goose rhyme

Upon my own word and honor, I once met an engineer, a living and breathing, bipedal, mammalian being, seemingly well educated in the sciences, who insisted that the entire Apollo space program was a fake and that nobody had ever actually landed on the moon. 

I told him how when Armstrong and Aldrin were at Tranquility Base, they installed a set of corner reflectors that are still there and which are still operational. NASA and other groups send pulsed laser beams to the reflectors which bounce the beams right back from whence they came. Measurements of the round trip transit times tell how far away the reflectors are and thus how far away the moon is.

He'd never even heard of corner reflectors, much to my further astonishment, so let's take a look at that.

Insects and Yellow Light - John Dunn, Consultant, Ambertec, P.E., P.C.

Some years ago, I was listening to "Crockett's Victory Garden" and the man spoke of reducing a white fly infestation on a caller's plant. He said to take a yellow Prestone anti-freeze container, cover it all over with a thin layer of petroleum jelly and set that container down next to the infested plant. The theory was that the white flies would be attracted to the yellow plastic and get stuck in the petroleum jelly coating.

Then, the next thing I notice is that so-called "bug lights" for use outdoors emit yellow light which is not supposed to attract insects to one's front door.

Can somebody tell me what's going on here? Are some insects able to see yellow and others not? Is there a significant spectral difference between the transmitted yellow light of the bulb versus the apparent yellow of the Prestone container's retransmission of incident white light or daylight?

The Violet Ray - John Dunn, Consultant, Ambertec, P.E., P.C.

There was a medical quackery perpetrator called The Master Electric Company Chicago whose goodies are discussed on line at http://www.radiolaguy.com/VioletRay.htm . Somebody once gave me one of those Master Violet Ray devices and I still have it:   

 

Capillary Pumping - Dick LaRosa

Figure that the solar heated evaporator surface is 10 cm (4 inches) above the sea surface. In the last post, a 0.1 mm (100 micro-meter) diameter capillary was found to lift seawater 29.1 cm. We only have to lift it 10 cm, so we have (19.1 cm)(1024 kg/m3)(9.8 m/s2) pressure available to overcome viscous friction. Poiseuille's formula tells us that the quantity of water pumped per second is proportional to the fourth power of the radius times the pressure difference divided by (viscosity)(length). Surface tension and viscosity of sea water are about the same as the respective values for fresh water. I used 1.0E(-6) m2/s for the kinematic viscosity. Multiply that by the density to get the viscosity used in the denominator of Poiseuille's formula. The result is that a single capillary tube transports 4.59E(-11) m3/s.