Time is an illusion, lunchtime doubly so…

In the dim and distant past, time was, to humankind, a thing and not much more. There was light-time, then there was dark-time, then there was another lot of light-time; during the day we could hunt, fight, eat and try to stay alive, and during the night we could sleep and have sex. However, we also realised that there were some parts of the year with short days and colder night, and others that were warmer, brighter and better for hunting. Being the bright sort, we humans realised that the amount of time it spent in winter, spring, summer and autumn (fall is the WRONG WORD) was about the same each time around, and thought that rather than just waiting for it to warm up every time we could count how long it took for one cycle (or year) so that we could work out when it was going to get warm next year. This enabled us to plan our hunting and farming patterns, and it became recognised that some knowledge of how the year worked was advantageous to a tribe. Eventually, this got so important that people started building monuments to the annual seasonal progression, hence such weird and staggeringly impressive prehistoric engineering achievements as Stonehenge.

However, this basic understanding of the year and the seasons was only one step on the journey, and as we moved from a hunter-gatherer paradigm to more of a civilised existence, we realised the benefits that a complete calendar could offer us, and thus began our still-continuing test to quantify time. Nowadays our understanding of time extends to clocks accurate to the degree of nanoseconds, and an understanding of relativity, but for a long time our greatest quest into the realm of bringing organised time into our lives was the creation of the concept of the wee.

Having seven days of the week is, to begin with, a strange idea; seven is an awkward prime number, and it seems odd that we don’t pick number that is easier to divide and multiply by, like six, eight or even ten, as the basis for our temporal system. Six would seem to make the most sense; most of our months have around 30 days, or 5 six-day weeks, and 365 days a year is only one less than multiple of six, which could surely be some sort of religious symbolism (and there would be an exact multiple on leap years- even better). And it would mean a shorter week, and more time spent on the weekend, which would be really great. But no, we’re stuck with seven, and it’s all the bloody moon’s fault.

Y’see, the sun’s daily cycle is useful for measuring short-term time (night and day), and the earth’s rotation around it provides the crucial yearly change of season. However, the moon’s cycle is 28 days long (fourteen to wax, fourteen to wane, regular as clockwork), providing a nice intermediary time unit with which to divide up the year into a more manageable number of pieces than 365. Thus, we began dividing the year up into ‘moons’ and using them as a convenient reference that we could refer to every night. However, even a moon cycle is a bit long for day-to-day scheduling, and it proved advantageous for our distant ancestors to split it up even further. Unfortunately, 28 is an awkward number to divide into pieces, and its only factors are 1, 2, 4, 7 and 14. An increment of 1 or 2 days is simply too small to be useful, and a 4 day ‘week’ isn’t much better. A 14 day week would hardly be an improvement on 28 for scheduling purposes, so seven is the only number of a practical size for the length of the week. The fact that months are now mostly 30 or 31 days rather than 28 to try and fit the awkward fact that there are 12.36 moon cycles in a year, hasn’t changed matters, so we’re stuck with an awkward 7 day cycle.

However, this wasn’t the end of the issue for the historic time-definers (for want of a better word); there’s not much advantage in defining a seven day week if you can’t then define which day of said week you want the crops to be planted on. Therefore, different days of the week needed names for identification purposes, and since astronomy had already provided our daily, weekly and yearly time structures it made sense to look skyward once again when searching for suitable names. At this time, centuries before the invention of the telescope, we only knew of seven planets, those celestial bodies that could be seen with the naked eye; the sun, the moon (yeah, their definition of ‘planet’ was a bit iffy), Mercury, Venus, Mars, Jupiter and Saturn. It might seem to make sense, with seven planets and seven days of the week, to just name the days after the planets in a random order, but humankind never does things so simply, and the process of picking which day got named after which planet was a complicated one.

In around 1000 BC the Egyptians had decided to divide the daylight into twelve hours (because they knew how to pick a nice, easy-to-divide number), and the Babylonians then took this a stage further by dividing the entire day, including night-time, into 24 hours. The Babylonians were also great astronomers, and had thus discovered the seven visible planets- however, because they were a bit weird, they decided that each planet had its place in a hierarchy, and that this hierarchy was dictated by which planet took the longest to complete its cycle and return to the same point in the sky. This order was, for the record, Saturn (29 years), Jupiter (12 years), Mars (687 days), Sun (365 days), Venus (225 days), Mercury (88 days) and Moon (28 days). So, did they name the days after the planets in this order? Of course not, that would be far too simple; instead, they decided to start naming the hours of the day after the planets (I did say they were a bit weird) in that order, going back to Saturn when they got to the Moon.

However, 24 hours does not divide nicely by seven planets, so the planet after which the first hour of the day was named changed each day. So, the first hour of the first day of the week was named after Saturn, the first hour of the second day after the Sun, and so on. Since the list repeated itself each week, the Babylonians decided to name each day after the planet that the first hour of each day was named, so we got Saturnday, Sunday, Moonday, Marsday, Mercuryday, Jupiterday and Venusday.

Now, you may have noticed that these are not the days of the week we English speakers are exactly used to, and for that we can blame the Vikings. The planetary method for naming the days of the week was brought to Britain by the Romans, and when they left the Britons held on to the names. However, Britain then spent the next 7 centuries getting repeatedly invaded and conquered by various foreigners, and for most of that time it was the Germanic Vikings and Saxons who fought over the country. Both groups worshipped the same gods, those of Norse mythology (so Thor, Odin and so on), and one of the practices they introduced was to replace the names of four days of the week with those of four of their gods; Tyr’sday, Woden’sday (Woden was the Saxon word for Odin), Thor’sday and Frig’sday replaced Marsday, Mercuryday, Jupiterday and Venusday in England, and soon the fluctuating nature of language renamed the days of the week Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday and Friday.

However, the old planetary names remained in the romance languages (the Spanish translations of the days Tuesday to Friday are Mardi, Mercredi, Jeudi and Vendredi), with one small exception. When the Roman Empire went Christian in the fourth century, the ten commandments dictated they remember the Sabbath day; but, to avoid copying the Jews (whose Sabbath was on Saturday), they chose to make Sunday the Sabbath day. It is for this reason that Monday, the first day of the working week after one’s day of rest, became the start of the week, taking over from the Babylonian’s choice of Saturday, but close to Rome they went one stage further and renamed Sunday ‘Deus Dominici’, or Day Of The Lord. The practice didn’t catch on in Britain, thousands of miles from Rome, but the modern day Spanish, French and Italian words for Sunday are domingo, dimanche and domenica respectively, all of which are locally corrupted forms of ‘Deus Dominici’.

This is one of those posts that doesn’t have a natural conclusion, or even much of a point to it. But hey; I didn’t start writing this because I wanted to make a point, but more to share the kind of stuff I find slightly interesting. Sorry if you didn’t.

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What we know and what we understand are two very different things…

If the whole Y2K debacle over a decade ago taught us anything, it was that the vast majority of the population did not understand the little plastic boxes known as computers that were rapidly filling up their homes. Nothing especially wrong or unusual about this- there’s a lot of things that only a few nerds understand properly, an awful lot of other stuff in our life to understand, and in any case the personal computer had only just started to become commonplace. However, over 12 and a half years later, the general understanding of a lot of us does not appear to have increased to any significant degree, and we still remain largely ignorant of these little feats of electronic witchcraft. Oh sure, we can work and operate them (most of us anyway), and we know roughly what they do, but as to exactly how they operate, precisely how they carry out their tasks? Sorry, not a clue.

This is largely understandable, particularly given the value of ‘understand’ that is applicable in computer-based situations. Computers are a rare example of a complex system that an expert is genuinely capable of understanding, in minute detail, every single aspect of the system’s working, both what it does, why it is there, and why it is (or, in some cases, shouldn’t be) constructed to that particular specification. To understand a computer in its entirety, therefore, is an equally complex job, and this is one very good reason why computer nerds tend to be a quite solitary bunch, with quite few links to the rest of us and, indeed, the outside world at large.

One person who does not understand computers very well is me, despite the fact that I have been using them, in one form or another, for as long as I can comfortably remember. Over this summer, however, I had quite a lot of free time on my hands, and part of that time was spent finally relenting to the badgering of a friend and having a go with Linux (Ubuntu if you really want to know) for the first time. Since I like to do my background research before getting stuck into any project, this necessitated quite some research into the hows and whys of its installation, along with which came quite a lot of info as to the hows and practicalities of my computer generally. I thought, then, that I might spend the next couple of posts or so detailing some of what I learned, building up a picture of a computer’s functioning from the ground up, and starting with a bit of a history lesson…

‘Computer’ was originally a job title, the job itself being akin to accountancy without the imagination. A computer was a number-cruncher, a supposedly infallible data processing machine employed to perform a range of jobs ranging from astronomical prediction to calculating interest. The job was a fairly good one, anyone clever enough to land it probably doing well by the standards of his age, but the output wasn’t. The human brain is not built for infallibility and, not infrequently, would make mistakes. Most of these undoubtedly went unnoticed or at least rarely caused significant harm, but the system was nonetheless inefficient. Abacuses, log tables and slide rules all aided arithmetic manipulation to a great degree in their respective fields, but true infallibility was unachievable whilst still reliant on the human mind.

Enter Blaise Pascal, 17th century mathematician and pioneer of probability theory (among other things), who invented the mechanical calculator aged just 19, in 1642. His original design wasn’t much more than a counting machine, a sequence of cogs and wheels so constructed as to able to count and convert between units, tens, hundreds and so on (ie a turn of 4 spaces on the ‘units’ cog whilst a seven was already counted would bring up eleven), as well as being able to work with currency denominations and distances as well. However, it could also subtract, multiply and divide (with some difficulty), and moreover proved an important point- that a mechanical machine could cut out the human error factor and reduce any inaccuracy to one of simply entering the wrong number.

Pascal’s machine was both expensive and complicated, meaning only twenty were ever made, but his was the only working mechanical calculator of the 17th century. Several, of a range of designs, were built during the 18th century as show pieces, but by the 19th the release of Thomas de Colmar’s Arithmometer, after 30 years of development, signified the birth of an industry. It wasn’t a large one, since the machines were still expensive and only of limited use, but de Colmar’s machine was the simplest and most reliable model yet. Around 3,000 mechanical calculators, of various designs and manufacturers, were sold by 1890, but by then the field had been given an unexpected shuffling.

Just two years after de Colmar had first patented his pre-development Arithmometer, an Englishmen by the name of Charles Babbage showed an interesting-looking pile of brass to a few friends and associates- a small assembly of cogs and wheels that he said was merely a precursor to the design of a far larger machine: his difference engine. The mathematical workings of his design were based on Newton polynomials, a fiddly bit of maths that I won’t even pretend to understand, but that could be used to closely approximate logarithmic and trigonometric functions. However, what made the difference engine special was that the original setup of the device, the positions of the various columns and so forth, determined what function the machine performed. This was more than just a simple device for adding up, this was beginning to look like a programmable computer.

Babbage’s machine was not the all-conquering revolutionary design the hype about it might have you believe. Babbage was commissioned to build one by the British government for military purposes, but since Babbage was often brash, once claiming that he could not fathom the idiocy of the mind that would think up a question an MP had just asked him, and prized academia above fiscal matters & practicality, the idea fell through. After investing £17,000 in his machine before realising that he had switched to working on a new and improved design known as the analytical engine, they pulled the plug and the machine never got made. Neither did the analytical engine, which is a crying shame; this was the first true computer design, with two separate inputs for both data and the required program, which could be a lot more complicated than just adding or subtracting, and an integrated memory system. It could even print results on one of three printers, in what could be considered the first human interfacing system (akin to a modern-day monitor), and had ‘control flow systems’ incorporated to ensure the performing of programs occurred in the correct order. We may never know, since it has never been built, whether Babbage’s analytical engine would have worked, but a later model of his difference engine was built for the London Science Museum in 1991, yielding accurate results to 31 decimal places.

…and I appear to have run on a bit further than intended. No matter- my next post will continue this journey down the history of the computer, and we’ll see if I can get onto any actual explanation of how the things work.