20130429

Obedience


George MacDonald, fantasy writer par excellence


I said: “Let me walk in the fields.”
He said: “No, walk in the town.”
I said: “There are no flowers there.”
He said: “No flowers, but a crown.”

I said: “But the skies are black;
There is nothing but noise and din.”
And He wept as He sent me back –
“There is more,” He said; “there is sin.”

I said: “But the air is thick,
And fogs are veiling the sun.”
He answered: “Yet souls are sick,
And souls in the dark undone!”

I said: “I shall miss the light,
And friends will miss me, they say.”
He answered: “Choose tonight
If I am to miss you or they.”

I pleaded for time to be given.
He said: “Is it hard to decide?
It will not seem so hard in heaven
To have followed the steps of your Guide.”

I cast one look at the fields,
Then set my face to the town;
He said, “My child, do you yield?
Will you leave the flowers for the crown?”

Then into His hand went mine;
And into my heart came He;
And I walk in a light divine,
The path I had feared to see.

Obedience - George MacDonald

Such gut-wrenching poignant truth in economy of words! How I wish I could encapsulate what I want to convey in a similar manner rather than blather on and on...  (I come from a church background where multiplicity of words is almost a dogma.)

I suppose I was led to MacDonald by Lewis, possibly in his reference:

Turning to the bookstall, I picked out an Everyman in a dirty jacket, Phantastes, a Faerie Romance, George MacDonald. Then the train came in. I can still remember the voice of the porter calling out the village names Saxon and sweet as a nut—‘Bookham, Effingham, Horsley train.’ That evening I began to read my new book.

The woodland journeyings in that story, the ghostly enemies, the ladies both good and evil, were close enough to my habitual imagery to lure me on without the perception of a change. It is as if I were carried sleeping across the frontier, or as if I had died in the old country and could never remember how I came alive in the new” (Lewis, Surprised by Joy).

Finding a paper copy of Phantastes took many years - now it is available for free download on the internet. Of his other fantasy stories I suppose I love At the back of the North Wind the best as discussed elsewhere.

Macdonald was not accepted by the Christian status-quo in his time - this alone has tended to attract him to me. Some paint him with the heresy of universalism but this in-depth treatment seems to say otherwise. MacDonald is said to have burst into tears when the concept of predestination was first explained to him. Interestingly I, too, recoiled from the idea as explained to me by someone at college who took a hard, Calvinistic line.

Lewis regarded MacDonald as his mentor as is evident in his The great divorce.  In his preface to "George MacDonald. An Anthology" he says "I have never concealed the fact that I regarded him as my master; indeed I fancy I have never written a book in which I did not quote from him."  And of Phantastes he writes “After this I read Macdonald’s Phantastes over my tea, which I have read many times and which I really believe fills for me the place of a devotional book. It tuned me up to a higher pitch and delighted me.

I could go on and bore you with my favourite passages from MacDonald's writings. Maybe another time...

20130416

Euler



Euler, mathematician par excellence

In spite of what people say, I am not a mathematician. This is evident in that I can't play a decent game of chess. I enjoyed and excelled at O and A level maths but became unstuck at college level with divs and curls and wot-not.  And so I cannot eulogise over Euler as befits him.  A statement attributed to Pierre-Simon Laplace, another master in mathematics, expresses Euler's influence on mathematics: "Read Euler, read Euler, he is the master of us all."

But I do remember my fascination on meeting Euler's famous formula for the first time in PSS days

e^{ix} = \cos x + i\sin x \

which brought together so many threads in the A level maths syllabus - convergent series, imaginary numbers, trigonometry, logarithms and exponentials - just as the diverse characters are in the last chapter of a crime novel.  Substituting  pi for x we have the identity shown in the bottom right of yesterday's Google doodle:


20130414

Second use of new bike

Distance 35.2 miles
Maximum speed 29 mph
Average 10.9 mph
Route - not very interesting*, but some nice daffodils
Weather - supposedly high 15'C but windy so felt like zero
Highlight - hot bath on return home
Pictures - none
Track - HTC gave up half way, new battery is ordered

* Dunlavin / Baltinglass

20130413

Spinc and Glenealo Valley


Spinc from Upper Lake

Today I hiked the Spinc and Glenealo Valley trial (White Route) barefoot - with a group of youngsters (not barefoot) I had difficulty keeping up with. Scary signs of age.

And it was cold and very wet.  We walked through that white stuff in the picture.


20130412

Summer day


I found this poem whilst following a LinkedIn link and liked it...


The Summer Day

Who made the world?
Who made the swan, and the black bear?
Who made the grasshopper?
This grasshopper, I mean-
the one who has flung herself out of the grass,
the one who is eating sugar out of my hand,
who is moving her jaws back and forth instead of up and down-
who is gazing around with her enormous and complicated eyes.
Now she lifts her pale forearms and thoroughly washes her face.
Now she snaps her wings open, and floats away.
I don't know exactly what a prayer is.
I do know how to pay attention, how to fall down
into the grass, how to kneel down in the grass,
how to be idle and blessed, how to stroll through the fields,
which is what I have been doing all day.
Tell me, what else should I have done?
Doesn't everything die at last, and too soon?
Tell me, what is it you plan to do
with your one wild and precious life?


Running (barefoot) and hiking answers for me - at least when it is warm it does. But how can life be all holiday? For most of us it takes the major part of our lives working to pay the bills so that we can work.

"Don't aim at success--the more you aim at it and make it (your final) target, the more you are going to miss it. For true success, like happiness, cannot be pursued; it must ensue, and it only does so as the unintended side effect of one's personal dedication to a cause greater than oneself. Listen to what your conscience commands you to do and carry it out to the best of your knowledge." -- Viktor Frankl, Man's Search for Meaning.

20130410

Occam's razor


Eric Isaacson programmer par excellence

Occam's razor in the vernacular might be "Keep It Simple Stupid!".  William of Ockham was a 14th century logician and Franciscan friar. He wrote in latin but, roughly translated, Wikipedia has it as a principle of parsimony, economy, or succinctness used in logic and problem-solving.

I try to apply the principle in my work as an electronics design engineer. I often use Microchip PIC processors in my designs, mostly 8-bitters, and typically code in assembler. Recently I have tried my hand at 'C' (just the ANSI flavour) - apparently it is the "way to go" and, anyway, one's hand is forced by the need to use C-friendly libraries.  But I hate the verbosity and obfuscation of 'C'. What requires little thought and a few simple statements in assembler can consume hours of research and require far more typing in 'C'. In short it contravenes Occam's razor.

OK - I like the way 'C' encourages good structure and offers ready made functions to save one having to re-invent the wheel. But couldn't these good things have been provided in a simpler, more intuitive way? So I figured I would create a new language and call it 'Occam' - but I am too late - Occam already exists but is not at all the 8-bit job I was looking for.

'C' poses itself between low level (i.e. assembler) and high level languages. It's not that I have anything against high level languages - they have their place - just that I hate unnecessary verbosity, and not only in the field of programming.

Long ago in the heyday of MSDOS I purchased and used A86, an assembler for the PC. The author Eric rightly claims that A86 "is the finest assembler available, at any cost under any terms, for the Intel 86-family of microprocessors". No painful setup red-tape is required - you write your assembly statements, assemble and, hey presto you have an executable.  That's as good an example of Occam's razor as you'll get.


Shalom is often translated as 'peace' but means much more - well-being, completeness, wholeness, health, soundness, tranquility, prosperity, fullness, rest, harmony, the absence of agitation or discord. How is 'shalom' encoded in brain neuron-patterns?  Similarly, a high level programming language command like "draw a 3D cube with rendering" – who cares how it is encoded? Except that you do care at the hardware level I work at. I care about every bit and every micro-second and, for some applications, only assembler will fit the bill.

20130408

Analog


Robert A. Pease, analog designer par excellence

They say we live in a digital age. This age was dawning when I started in electronics and I had the privilege of being involved in some of the early work on digital TV and radio at Kingswood Warren.

The world we live in may be actually digital (quantum and all that) but for most purposes our senses interface with it, and electronic circuits emulate it, in an analog way. One notable exception - if you are young with good hearing and the night is quiet, you can just about make out the hiss caused by the random motion of air molecules hitting your ear drum. The ear is truly remarkable.

Electronics is increasingly digital. Just about any custom design I carry out will involve one or more micro-controllers.  A micro-controller is essentially a complete computer on a chip.  Some come as small as 1.3mm by 2.7mm and cost as little as $0.30. But at some stage most designs have to interface with humans or the world around us, and that generally means analog. Unless it is very high speed, designing digital is relatively easy - you just bolt functions together. Designing a good analog circuit is much more demanding.

Much honour is thus due to such gurus as Bob Pease and Jim Williams both, sadly, passed away.  Here's an example of Bob's writing style: I like the way he uses an ordinary phenomenon to explain a principle in electronics design.

I guess my inertial train controller was my first good analog design.  'Good' in that it was dead simple and very effective.



20130404

Clive Sinclair, slide rules and log tables




Clive Sinclair, entrepreneur par excellence


Long, long ago, when I was in the sixth form at PSS, calculators of the add / subtract / multiply / divide type were starting to become commonly available but were not allowed in school... Calculators, it seemed, were for the weak.

Instead we were taught long multiplication and division, and to use log tables in maths although in science we were allowed to use a slide rule. A slide rule works like log tables but is a whole lot easier to use.

If you know all about logs and slide rules, or if you are already bored out of your mind, then this is the place to stop reading.


If...


then, by definition,


Thus the exponent (aka index) x in the first equation is the logarithm to base n of y.  The clever bit comes as a result of the rules of indices, thus


Here I have changed the variable names (otherwise I would have run out at 'z'), and shown that when two numbers r and s are multiplied, their logarithms are added.

The same applies whatever the base n is.

So, back then, long, long ago, we had 4-figure log tables, or 5-figure if you were lucky (or had a lot of time on your hands). These were look-up tables for finding the logarithm of a number to 4 or 5 decimal places. The book would also contain tables for the inverse operation "anti-log" (which is one and the same as exponentiation) together with tables for finding the sine, tangent or cosine of an angle and their inverse operations, square and cube roots, and such-like.  A mathematician's ready reckoner. To multiply two numbers you first look up their logs, then add these together and look up the anti-log of the answer.

You show a book of log tables to today's youth and they won't believe that this is how we did multiplications and divisions.

The slide rule has logarithmic scales so that the logarithm of a number is translated into physical length - to multiple two number you simply move the sliding part (which also has a logarithmic scale for the second number) thus adding the distances and effectively adding the logarithms. The final value is read off using the first scale which thus takes the anti-log and gives the product.  Other scales are included for finding trigonometrical functions and squares or square roots.


You can get 3 figure accuracy from a slide rule if you are careful which was good enough for most undergraduate experimental work.




At college a friend purchased a Sinclair Scientific calculator - the first scientific calculator within reach of students. Although it only had 5 digit accuracy this machine was a wonder to behold. I bow to Clive Sinclair whose inventions have been truly prophetic even if they were not always wholly reliable.



Talking about Clive, the same friend owned a Micromatic - a matchbox sized radio - on which, during school lunch break, we used to listen to I'm sorry I'll read that again, a radio show which was a precursor to Monty Python.




When I started work at Kingswood Warren I was introduced to the HP35 which, apparently, was introduced in 1972 as the first ever scientific calculator but too expensive for the average student. It boasted a splendid bug in that it reckoned that exp(ln (2.02))=2.  This was corrected in the next model HP45.

These calculators had power-hungry red LED displays - liquid crystal had not been invented. Talking of LED's I remember a boy bringing an LED to school - it was the first I had ever seen and blew my mind: at last a source of light without (much) heat just like a glow-worm!

And talking about inventions - an interesting coincidence, for someone that works in electronics, is that the transistor was invented around the time or just before I was born.

So much has changed since then - the rest is history...