S. J. Farthing

www.farthing.me.uk

Miscellaneous

This page consists of various ramblings and partly-formed (or even ill-formed) ideas.

Introduction

In developing a web site there are ideas which don't really belong anywhere. This page is a collection of topics which are not sufficiently extensive or well developed to justify a page of their own, but some of these topics will eventually be promoted to such a page.

Some of the pages on this site have grown from small ideas in just this way, and similarly some small pages I once had on a personal web site have increased so much that they have broken away and become a whole independent web site. Indeed most of my web sites have grown in this 'organic' way.

Under construction

Opinion

When we read a review of a film or CD we want to know about the thing being reviewed. We are not seeking to learn about the person giving the review, i.e. to learn about what his tastes are. However, people have different opinions so you need to know something about the reviewer. A person cannot review anything without disclosing something about himself, and there is nothing wrong with that.


Writing the words that no-one will hear

Like Father McKenzie in Eleanor Rigby, that is pretty much what I'm doing now. I am well aware that this site does not get many visits, and of those even fewer will reach this page. Its a bit like practicing a musical instrument.

Anyway, this text is a resource which will endure until such time as it gets seen, either here or re-used elsewhere.

Still, there is a difference between writing something privately, and writing something which is publically visible. The fact that somebody CAN or MIGHT see it affects the writing.

Some concepts are difficult to explain. When you think in mathematical concepts and symbols you can find it difficult to explain some things to people who do not have the same background, or whose knowledge and experience you do not know. Once the task has been accomplished once, it becomes easier to do.

Strangely, I have found that when I have expressed things in these pages I have found that others in society have expressed similar views publically. I don't claim to have influenced them, it is probably a case of people independently coming to the same conclusions as me from the same evidence which is around us all.


Chauvinism

Feminists are not the only people to dislike chauvinists, though it is true that chauvinists are usually male. There is something about men which makes them (us) want to control things, and control other people. MAN the MANager and the MANipulator. (MANgler?).

In the workplace some supervisors love to be in charge of people and seek such a position regardless of its higher pay (which is unfortunately usually available). Sometimes or often they go beyond the requirements of their job and mis-use their position of authority in order to achieve personal gratification.

There is a term "control freak" which was once a form of slang from the hippy era, but is now being used in literature and the media. It depicts those people who get a "buzz" out of controlling people. Certain professions attract such people, very notably the police, but also schoolteachers to a lesser extent.

I personally, when a young adult contemplating ethics, decided I preferred to be a liberal, that is, to control my own life only, and not presume to dictate to others except in so far as their actions directly affected me.

There was an adverse consequence of this in one of my jobs. Some young people were fooling around in the absence of the boss, and it was interfering with my concentration on my work. Even though the boss had hinted that he would like me to act in a mentoring and minor supervisory role to the young people, when I protested to the boss it was seen as an unwelcome complaint.

Matriarchy

Having criticised some of the less desirable qualities of men, I now turn to women.

Women have different ideas from men about what constitutes correct conduct in society. Furthermore, with the rise of feminism, women are gradually infiltrating into ever greater positions of power and influence in society. In particular they are often in the role of receptionists acting as a kind of gatekeeper to the services principally offered by professional men. However they are also sometimes in positions of direct power themselves such as school teachers and police officers and politicians, with a large amount of personal discretion, and able to enforce their female-oriented view of society in tangible and practical ways which do more than simply expressing their views.

One of the manifestations of womens influence in society is that courtesy is more important than honesty.

Chivalry

Most men have a concept of fair play and decency which we call chivalry, and even men at the low end of society have it, perhaps in their own way more than others. Of course it is now accepted that the ancient concept of chivalry, attributed to the medieval knights, was not what we now mean by chivalry. The modern day version of chivalry nevertheless exists, but seems mainly to be a male characteristic which is often lacking in women.

The Nanny State

We often hear people use this term. It refers to the interference of the state in people's lives aiming to provide an excessive protection to us all, but in so doing reduces freedom. I believe it is related to the rise in the influence of women in our society, as described above.

Actually, being over-protective of people can cause harm. Human beings need some challenge and excitement for their psychological well-being. There are people who would like to see us all living in little compartments watching television like battery chickens. They are treating their fellow human beings the same way they treat their animals. Now I know the meaning of the expression 'you are what you eat'.

There have been cases of people suffering bad accidents when abroad, because they have become so accustomed to being protected in Britain that they did not recognise the need for caution in another less safe environment.

I would not too much mind a society where certain things are disapproved of socially. The problem now is getting more serious. In 1997, the modern man Tony Blair, recently appointed prime minister, and his government introduced the law of Harassment. Originally intended to prosecute serious persistent harassment of people and particularly 'stalking'. However the law was so broadly applicable that the threshold for comitting the crime of harassment is now very low and we have a situation where discourtesy is a crime.

See also my page on Justice.

I believe that this has come about because of the rise of women in society. It is interesting to observe that Tony Blair's wife is a lawyer and is likely to have influenced her husband in this.

Ad Hoc Measures

My comments here are particularly motivated by laws. In the UK there have recently been made a number of special laws which apply only to very specific things. One of the most prominent is that crimes which are racially motivated carry a higher sentence than other crimes. The problem with singling out special cases is that some equally important cases are left out. Quite often the thing is already illegal and so no special arrangements should apply to foreseeable special cases.

Other such ad hoc laws are extra severe penalties for illegal acts associated with animal rights. The theft of mobile phones is taken to require a more severe penalty than other thefts, even over similar little goodies carried around like MP3 players and cameras. Also on the subject of mobile phones, driving while handling a mobile phone is a new offence but there already are laws about careless driving, and needing to be in proper control of the vehicle. There are other actions which are equally distracting. On thing I have found to be especially so is smoking, and especially rolling a cigarette. Then there is fooling around with car radios or tape players.

The anti-virus measures available for PCs are nearly always based on ad hoc principles. Each an every virus has to be separately identitified and dealt with, rather than using a general policy of good practice.


Ivory Towers

You know you're in trouble once an organization sets up barriers around itself, making it difficult to contact them. It manifests in security systems, secure fences, CCTV cameras, but also in telephones which are not answered for a long time. The typical telephone defence is a high tariff number which when you ring gives rise to a menu and queueing system, and all this takes place after your billing for the call has started.

It happens with almost all large organizations whether large companies or government departments. If the person you require is not available they will not give you a direct number but will promise to ring you back. That is always a bad sign. There is a well-known expression used in show business "don't ring me, I'll ring you." Widely recognised now as a polite way of saying "go away".

Sometimes they really mean to ring back, and will perhaps try once, but if they don't get you right away that will be the end of it. The reality is, that they are at work, supposed to be there all day, but actually never available (they say). They expect a private individual to be at their beck and call waiting endlessly for their whim.

If you get the call back it is difficult to be prepared with right attitude, presence of mind, and documents to hand.

I wonder how much of this is a kind of power game. One-upmanship. Are they really not at their desk as they say. If so, why does it happen so often?

The technology of telephones has helped people set themselves apart. In particular it has helped people make themselves unavailable. The conceal their numbers. They hide behind receptionists and telephone menu and queueing systems.


The Obvious

One of my least favourite expressions is "I would have thought that was obvious" when given in reply to a question. Beware of the obvious, it is not always true. People using this expression are those who have jumped to conclusions, and not considered that there might be other possibilities. Sometimes asking a question likely to give this answer is taken to be a sign of stupidity, (and don't people love to establish their superior intelligence at every opportunity). On the contrary, asking such questions is a sign of caution, and seeking certainty.


Steps to Success

If you look at the life of a successful man, you will probably observe that they seemed to make amazingly intelligent and informed decisions every step of the way. You might wonder how anyone could be so intelligent, well informed and skillful. However, what you do not see is all the people who may have made very similar decisions, but did not achieve the success. It reminds me of television coverage of the Grand National, (a long horse race over obstacles where many horses fail to even finish). At the end of the race they might interview the winning jockey, and show a replay to illustrate how the jockey did all the right things. Of course the jockey will say that he won because of his tactics. In fact it probably depends on a great deal of luck.

There is something similar in evolution and natural selection. We are looking at the process from the viewpoint of the end result, the finishing post. It seems incredible that those species which have made it to the present day were lucky enough to get everything right over millions of years, and so to survive. However we do not see the millions of other species which got something wrong along the way and never made it.

Born Into Prosperity

We like to think that in modern times there is equality of opportunity for rich and poor. Many great people of the past were certainly talented, I do not deny it, but many of them were able to achieve greatness because they were born into prosperity to some extent. This is true of Newton and Darwin for example. It is true of many philosophers, for example Descartes who had a good education which was no doubt costly.

Richard Branson, multi-millionaire founder of Virgin is portrayed as a self-made man who started with nothing and built a great business empire, but nevertheless was born into a prosperous family. His father was a judge. Even if such people never call upon their parents for funding, there is still that assurance that they would provide a safety net, and so can take risks which others could not take.

Policies

You can make mistakes, but making a mistake of policy is the worst. A mistake of policy results in making individual mistakes over and over. On the other hand, getting a good policy produces the reverse effect.


Gambling

I am not against gambling, but I will only gamble if I feel the odds are in my favour. That is the crucial difference between the casino customer and the proprietor. They both gamble, but the casino can expect to consistently make money.

There are myths about the Law of Averages. The past history of a random event does not affect the future. For example people might believe that if Red on roulette has come up many times recently, there is a greater chance that Black will occur next. Not so! However, what the Law of Averages does predict is that if you make a lot of small bets, everything is likely to even itself out, but because casinos, bookmakers etc have a slight advantage with the odds, the punter will be almost certain to lose. Betting twice for alternative outcomes on the same event is a bad idea for similar reasons. It is not unusual for people to back two horses in the same race. Buying more than one lottery ticket is even more common. The picture is much clearer if you were to bet simultaneously on Red and Black at roulette.

One appeal of the football pools and lotteries, is the very large odds. For a small stake there is a chance of a very large prize. How stupid it is therefore to enter into syndicates, where the stake money is pooled and any wins are shared. The effect is simply to reduce the odds of the bet. It would be more sensible to bet on something with lower odds in the first place, for example betting on a horse.

The National Lottery

For a large part of my life gambling was frowned upon by the state. It was heavily regulated almost to the point of prohibition. Then the government decided to introduce the National Lottery. Gambling was suddenly socially acceptable. Those hitherto serious and respected organizations, the Post Office and the BBC got involved, no doubt getting some revenue from their participation, and all their principles went out of the window.

Decisions in everyday live

We all have to make judgements in everyday live, which inevitably involves taking chances. If you make a decision which turns out to be wrong, it does not necessarily mean you did the wrong thing. If the decision was made with the best possible judgement based on what was known at the time, then it was the right thing to do.


Coincidences

It is not legitimate to wait until something happens and then remark on how unlikely it was. For example if you spin a coin and get H, T, H, T, H, T you might say afterwards that the chance of that happening were one in 2 x 2 x 2 x 2 x 2 x 2, i.e. one in 64, BUT you would have said the same if it had been T, H, T, H, T, H, or if it had been all heads, or all tails or perhaps H, H, H, T, T, T, etc.

The chances of it being ONE of these possibilities might only be only about one in four, depending on what you regard as sufficiently remarkable.

Derren Brown presented an astonishing television programme where the programme showed a woman being guided by Derren to back a succession of horses, putting the winnings of each bet onto the next. She won every bet.

The trick is, that unknown to the woman and the viewer of the programme so far, he had taken a large team of people, and followed the same procedure with each. Each was given a different horse in the same races covering all possibilities, so it was certain that somebody would win all their bets. (This was revealed later in the programme).

That is a good example of waiting until after something has happened before declaring it to be remarkable!

Some Real Coincidences

The following story was told on a television programme. If true, it is a remarkable coincidence.

A man had a day off work for some reason and was walking past a phone box which was ringing. He answered it and was astonished to find it was from his workplace and wanting to speak to HIM. The secretary had wanted to ring him, but by mistake had dialled the man's personnel number, and got through to the phone box he was just passing!

The moon is exactly the same visual size in the sky as the sun. When there is a total eclipse of the sun, it exactly covers the sun. The moon is 1/400 the diameter of the sun, but is also 1/400 the distance away.

The 3 4 5 triangle

345 triangle

A triangle with sides 3, 4, and 5 units in length forms a perfect right-angled triangle. (The ancient Egyptians used it to measure right angles).

You might say that it follows from Pythagoras' Theorem, because
32 + 42 = 52
However that is not enough to explain why it works with three consecutive small integers.


Clocks

Written 26th October 2008, just after the switch back to GMT. The time when, in Britain, we all put our clocks back one hour for the winter. (Spring forward, fall back).

What a lot of nonesense is talked about this. Everybody has a view on it. The most absurd idea is that somehow putting the clocks back is responsible for the shortening of the day length. Some people would like to see BST all the year round. The effect of BST is that any particular clock time, e.g 8am occurs at an earlier part of the day. Well if people want their working day or the school day to start an hour earlier, why not just change the start time from 9am to 8am and leave the clocks alone.

There is a breed of people who just like to get up early and they want to force us all to do the same. Personally I prefer GMT. It is "God's time" and the time which correctly matches the movement of the sun through the day as has been established since hours and minutes were invented.

Around 2006 there was a vote in parliament promoted largely by Tory MP Tim Yeo. The aim was to leave the clocks one hour forward all the time, indeed they may have been seeking to put them forward two hours in summer. (It is interesting to note that these movements all seem to originate in London and the eastern parts of Britain. The sun rises earlier there. The claim was that it was better for environmental reasons. Apparently a study by Cambridge University had done research to say that putting the clocks forward would save energy. I believe the exact opposite is the case.

The study was by Elizabeth Garnsey, Stephen Benjamin and Mauricio Carcano of the Centre for Technology Management, Department of Engineering and Judge Business School, University of Cambridge. I can't find any details of this study despite a thorough search on the web. It probably did exist, but was clearly not a major work.

It appears that they looked at electricity only. They compared national usage for two consecutive weeks, one before clocks were put forward, and one after, and again for two more consecutive weeks around the time the clocks were put back.

It should be noted that you would expect lower power consumption during the summer period, regardless of the setting of clocks.

I prefer to use logical reasoning. The great consumption of energy in buildings is heating, and not lighting. The temperature of a building (residence or workplace) lags some hours behind the outdoor temperature and the heat from the sun, so we find that the mornings are cold for some time, and then the evenings stay warm long after the sun has set. In winter we have to apply a large burst of energy in the morning to warm our buildings before the sun has had chance to warm us. Starting the day an hour earlier means we must start heating our buildings an hour earlier too. Conversely at the end of the day the building has warmed up, but in the case of the workplace people will go home and leave the warmth in the building to go to waste.

In summer the problem is one of cooling. Here our homes can still be uncomfortably warm at the time we want to sleep, and this too is worse if we are doing everything an hour early. Traditionally this has been an issue of comfort rather than energy use, but now that air conditioning is becoming common it means a further use of energy to cool the bedroom for the night.

Finally, the setting of clocks has the full force of law behind it. It is not just an informal agreement with our employers, or even just part of our contract of employment. Failure to observe putting clocks forward and back can result in a breach of the law, and yes, even the criminal law. For example, licensing hours, and the obligation for children to attend school.

Midnight and Noon

It seems particularly unfortunate that we use, for example, 12:30pm to mean 12:30 in the afternoon. From 1am we are counting the hours from midnight. 11:59am is 11 hours and 59 minutes after midnight, just before noon. Two minutes later at 12:01 we suddenly switch to pm. And what is 12am and 12pm. Actually as far as I know they are undefined and should not be used. The correct terms are noon and midnight.

These things have come about for historical reasons. We are saying "It's 12:30, and by the way, it's afternoon". Digital clocks present a problem because they have to display 12pm and 12am. There is no other way. 12pm has to mean noon, because once the moment of noon has arrived it will truly be afternoon a fraction of a second later.

Fortunately the 24 hour clock system is more sensible.

And there's something else. I have noticed in the late night weather forecast on the radio, i.e. those presented just after midnight, they talk about 'yesterday' and 'later today' as if we were now in a new day. It is confusing and there's no easy answer to it, but I have noticed that the problem is acknowledged by the BBC and they will somtimes refer to the days by their name to clarify what they mean by today and tomorrow.


A Moment of Silence

There are times when the effectiveness of a speech, a statement, or a musical performance has its impact on the listener a second or two after its completion. A moment of silence is justified in such cases. For example at the end of a drama with a stunning conclusion; after a profound statement, perhaps in a political interview; after a musical performance.

It is unfortunate when such things are followed by other material immediately afterwards. It happens in discussions, when other participants wish to jump in with their own material after a speaker, or when the interviewer does the same. It happens at the end of television programmes when the programme is immediately followed by an advert or trailer. I have also seen it happen after a stunning conclusion to a musical performance when an over-eager disk jockey has immediately played some recorded music.


Generalisation

For me, recognising fundamental principles which apply to multiple situations is important and comes within the scope of philosophy. Children begin by learning individual facts and as their intellects develop they begin to recognise common principles. When a more general piece of information is known, it applies to large range of things and so is more important and powerful. It is strange that people may be criticised for speaking too generally. We must distinguish between useless generalisations which do not address the question being asked, and on the other hand, general truths which answer the question being asked, but whose scope is also more widely applicable.


Analogies

Analogies are interesting because they recognise common principles between things which are apparently quite different. An analogy illustrates a general principle, and at the same time serves as an example of that principle. By drawing an analogy between two quite different things we force the reader to recognise a fundamental principle, which might otherwise be difficult to describe.


Context

When naming or labelling things it is very valuable to recognise the context in order to give the most meaningful name. If something has already been classified into a particular category, it is not necessary to repeat that in the name.

This issue seems to arise a lot in computer work of various kinds. One example is when files are being classified by placing them in sub directories. Another is in the choice of identifiers for use in programming.


Classification

There are often times when classification systems permit items to be classified in more than one category. For example in classifying songs, you might have categories including Male Vocal, and Christmas Songs, then wish to classify Bing Crosby's White Christmas. This could go in either category.

One answer might be to put the entry in both categories. However there may be good reasons not to do this. One is when amendments are made it would be necessary to locate multiple instances.

A good way of dealing with the problem is to prioritise the categories, so that for example the Christmas category might be deemed to prevail over the Male Vocal category, so that any Christmas songs would then be categorised as such.


Defaults

First, there is some misunderstanding of the word Default. That is because it is often used euphemistically for non-payment of something like a loan. As such it can be thought by some to be a 'bad thing'. However, the word simply means to 'do nothing' and sometimes that can be a good thing.

In the context I mean, it is a fallback state of what happens if you do nothing. The default state.

I once used a most excellent version of the Basic programming language as implemented by Hewlett Packard. It had the great feature that almost all statements and expressions had implied default values. If you left something out, a default value was used, but you were also free to specify something in which case your choice would prevail. For example if you said 'print' it would print to the screen. Or you could say where you wanted it to be printed.

Many products can be expected to have a standard normal version which should be assumed unless specified otherwise. I find it quite annoying when shopping for example to be asked to specify which variety of a product I want when it is clear that there is a normal version and a variant. Because we have self service shops everywhere it usually happens with anything you have to ask for over the counter. Tobacco products, or perhaps pharmaceuticals.

Another example is when people give out a web site on radio or TV, i.e. in spoken form. The use the term 'forward slash' for example bbc.co.uk/radio4 is read as bbc dot co dot uk 'forward slash' radio4. Well is it ever anything else. Can't we just all assume that when people say 'slash' they mean '/'. It is only in rare and exceptional cases that backslash '\' is ever used. As far as I know it is never used in web addresses, and is only commonly used in DOS.


Meltdown

I refer to those situations where some process begins, and the longer it continues, the stronger it gets. A good example is when one end of a heavy chain falls through a hole in the floor of a helicopter. The more length of chain which is hanging out, the greater the force pulling the rest out. It can happen with financial problems where people's financial difficulties give rise to ever greater costs. For example, the need to buy on credit; bank charges for unauthorised overdrafts; bailiffs who sell goods at below their value and charge a fee to the debtor.

Of course there is a literal case of meltdown which should not go unmentioned, though I say something about it on my environmental pages. That is that as ice over the arctic melts, the earth's surface absorbs more heat and so caused further melting.

The term 'meltdown' is taken from the nuclear power industry.

Meltdown arises when we have 'positive feedback' that is that when something increases, the forces causing that increase become greater.

Log-jams and Gridlock

These are not really the same as meltdown but are the consequence of it, and a terminal one at that.


Queues

Long queues are not processed any faster than short ones.

Got it?

It applies to physical queues where people are actually standing in line, but also applies to queueing systems for telephones or awaiting the handling of correspondence. Sooner or later the processing will have to keep up with the new people coming to the back of the queue, otherwise the queue will keep growing. Assuming that the processing will eventially keep pace with new arrivals the queue might as well be short. Waiting in a queue is just a waste of time.

Yet experience seems to show that somehow long queues are some sort of solution to the problem of high demand, as if somehow the number of people processed will increase when there is a long queue. Well if this is so, it is only because the person doing the processing might speed up when faced with a long queue. Another factor is that people might simply give up - either not join the queue, or drop out. And then there is what happens at the end of the day.


Backlogs

You would think that the best way to clear a backlog of work is the start with the oldest and work forwards from there. Not so! I like to think back to my work with paper tape in the computer industry as a metaphor. We would take a roll of vulnerable paper tape, perhaps 50 metres long. This was then read off the reel and allowed to simply pile up on the floor. Now if you tried to find the beginning of the tape at the bottom of the pile it would result in a terrible tangle. However it was simply necessary to take the end of the tape and start winding it back onto a reel. This could be done remarkably quickly and never caused any tangling whatever. The aparrently chaotic pile of tape would simply unfold itself in the reverse of its formation.

Similarly if you have a pile of papers which have accumulated it is better to deal with the ones at the top, i.e. the last ones to be placed on the pile. For one thing it saves the papers getting into a mess, but there is a more valuable advantage. Our memory of the oldest work will be the weakest, but memory probably falls away more rapidly in the first few hours or days. Anything older will be partly forgotten, but that memory is unlikely to fall any further. By dealing with the most recent work first we can at least have the benefit of a fresh memory of SOME of the work.


Packing

There are various issues aroung the question of putting objects in a box in the most efficient way, especially when the objects are of irregular sizes or shapes.

Sometimes it is easier to just put things in the box anyhow and shake it. For some reason everything seems to find its own best place.

Is caster sugar sweeter than ordinary granulated sugar? Assuming the grains are the same shape, and each sugar type has a constant grain size, then there should be exactly the same amount of wasted space in both, and they would therefore be of equal sweetness per spoonful. However if a substance consists of particles of different sizes it might be packed more densely. Consider a special case where there are just two particle sizes, one large and the other much smaller. The small particles will fill the gaps left between the large ones and the end result will be denser than either on its own. It seems to suggest that if the particles are of various sizes they will be packed more densely than when all are the same size.

There is a great problem of mathematics known as Kepler's sphere-packing problem, often also referred to as orange packing.

Sometimes hazlenuts are hollow. If a mixture of hollow and full ones are placed in a container and shaken gently the hollow ones find their way to the top. They act like a fluid.

Aquarium Filters

One of the first filters I ever came across was in chemistry at school using a filter paper in a funnel. The method of filtration aims to totally remove all particles from a liquid and can be used whether you want the solid material on its own, or the liquid without it.

When I first encountered a fish tank filter I thought it was an ill-concieved device, poor and ineffective. However I now see the principle is totally different, because the aim is different. Thoroughness is not so important. The thorough way to filter the water in a fish tank would be to remove all the water and pass it through a filter. A fish tank filter only takes some of the water at any one time, filters it, and then returns it to the tank so mixing it with the unfiltered water. In the short term it is useless, but in the long term it accomplishes a pretty good filtration where absolute 100% guaranteed filtering is not important. I suspect that engine oil filters work similarly.

It is interesting to look at these filters from the point of view of the water, and then from the point of view of the particles of dirt in the water. At the start of the process, i.e. suppose the filter has just been switched on with dirty water, when a small quantity of water has been cleaned it seems absurd to mix that clean water back with the dirty water again. However, from the point of view of the dirt, diluting the dirty water with a small amount of clean water will still leave dirty water and the filter will go on to do useful work, so seeing it this way it seems quite efficient.

Aquarium filters are a good example of what is called the exponential rate of decay. In this, the rate of fall of a quantity, at any moment, is directly proportional to its size. It is easy to see why this should be so in the case of an aquarium filter. There are a great many places in nature where this rate of fall occurs in nature. Another example is the decline in temperature of a hot object.

The same sort of principle applies to other things, such as clearing unwanted files from a PC to clear space. If there is no great problem in not being totally thorough, and a random, but sustained method will suffice.

However you would not wish to filter drinking water with such a method.


Numbers

We use the decimal number system. As we count, when we get to ten we begin to write the number in two digits, thus:

. . . 6, 7, 8, 9, 10, 11, etc.

It is tempting to think there is something really special about the number 10 to have this 'property'. However look at it another way:

* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * * * * - Did anything happen?

The decimal number system is just a way of writing numbers down. It says nothing about the number itself. There is nothing special about the number ten, in fact it is a surprisingly uninteresting number, and rather a poor choice as the basis of our number notation system.

In computer work it is common to use different systems of notation such as binary and hexadecimal. Even some computer programmers think that these are somehow a different kind of number. They are not, they are just the ordinary numbers written differently. You can add binary numbers to decimal numbers and still get a number. You don't need to ask whether the answer is a binary or decimal number and you can choose to write it either way.

It is interesting that in weights and measures different numbers have been used, such as 12 inches to a foot, and 16 ounces to a pound. The set of weights used on traditional scales have the advantage that each is twice the weight of the its previous one, and the conseqence of this is that you only need one of each weight (and they stack nicely!). In grammes you usually have weights of 1, 2, 5, 10 etc, but you need to have two 2 gram weights. It's all pretty messy. Incidentally we get exactly the same range of values in currency too.

It is very natural when dividing things we naturally make use of halves and quarters. That may be how ounces came to be 1/16 of a pound.

On the subect of weights, the fact that there are 14lb to a stone is most unfortunate. We are still using stones, mainly to weigh people. In Britain the answer is to move gradually towards the use of the metric system. The Americans have used a simpler solution. They don't use stones, but express people's weights simply in tens and hundreds of pounds. It's a different approach to decimalisation and it shows that decimalisation is not the same thing as metrication.


Four By Four

Four wheel drive vehicles are often described as four by four or 4x4, but this is meaningless. There is no sense of multiplication of 4x4 in a four wheel drive vehicle. If there was, there would have to be 16 of something somewhere. Now if the term meant something like four wheels and four brake pads per wheel, then it would be OK. There would be 16 brake pads in total.

It would be tolerable if the expression remained colloqual, but we see cars described in catalogues as 4x4 and some even have a badge saying 4x4.


A difference between art and science

Science aims to be consistent and repeatable. If something is done more than once, we attempt to do it in exactly the same way. On the other hand, in art it is not necessary to be so consistent, and indeed positively desirable to change things a little each time. This applies for example to alternative versions of a painting such as Van Gogh's Sunflowers, and applies to music performances. It is often desirable to allow variations to intrude, whether they are intentional or not.


Mnemonics

Mnemonics are meant to help you remember something, but they seem to work with some sort of psychological trickery. Often the mnemonic is no easier to remember than the main fact.

I heard this one in a comedy programme:

Two point four centimetres laid in a row,
Make exactly an inch you know.

It is intentionally a parody of a mnemonic, but it reminds me of a real one which is nearly equally useless, intended to help remember the date Columbus discovered America:

In fourteen hundred and ninety two,
Columbus sailed the ocean blue.

I can testify to its ineffectiveness; I had to look up the date before I could remember the rhyme!


Heat Sink Compound

This is used when a semiconductor device is connected to a piece of metal, a heat sink, in order to assist cooling. Heat sink compound is added between the semiconductor and the heat sink. This technique has been used since the early days of transistors when it was applied to power transistors, but now it is also extensively used between the CPU of a PC and the heatsink. I have been in a position to see the work of others and sometimes noticed that the person who assembled the equipment had no understanding of the principles. The compound is there as an unfortunate necessity to fill any gaps between the two pieces of metal. It is not a perfect conductor of heat and will itself be an obstacle to heat flow and so should be as thin as possible. However in looking at its use in computers I have seen it applied much too thickly and also unevenly. It is another example of people with so-called qualifications failing to understand some basic principles of physics.

Handling Static Sensistive Devices

Comments here are only applicable to people in the electronics industry. I am fortunate that I had good teaching in the fundamental principles of static electricity as part of Physics at school. Things we normally regard as insulators of electricity, such as wood, and our own bodies, may be conductors of static electricity, because the voltages are so high and currents small.

The standard practice for handling static sensitive devices is to not touch the exposed conductive parts, for example when handling an integrated circuit, conventional practice is not to touch the pins. Strange then that such devices are often stored in a conductive foam to deliberately make electrical contact with all the pins. Our hand is conductive and rather similar to such a piece of conductive foam, and so it is perfectly safe to hold a static sensitive device firmly in our hand and the resulting contact with all the pins of the device will protect it rather than damage it.