Ada Lovelace: Visionary

Cover of Issue 20 of CS4FN, celebrating Ada Lovelace

By Paul Curzon, Queen Mary University of London

It is 1843, Queen Victoria is on the British throne. The industrial revolution has transformed the country. Steam, cogs and iron rule. The first computers won’t be successfully built for a hundred years. Through the noise and grime one woman sees the future. A digital future that is only just being realised.

Ada Lovelace is often said to be the first programmer. She wrote programs for a designed, but yet to be built, computer called the Analytical Engine. She was something much more important than a programmer, though. She was the first truly visionary person to see the real potential of computers. She saw they would one day be creative.

Charles Babbage had come up with the idea of the Analytical Engine – how to make a machine that could do calculations so we wouldn’t need to do it by hand. It would be another century before his ideas could be realised and the first computer was actually built. As he tried to get the money and build the computer, he needed someone to help write the programs to control it – the instructions that would tell it how to do calculations. That’s where Ada came in. They worked together to try and realise their joint dream, jointly working out how to program.

Ada also wrote “The Analytical Engine has no pretensions to originate anything.” So how does that fit with her belief that computers could be creative? Read on and see if you can unscramble the paradox.

Ada was a mathematician with a creative flair and while Charles had come up with the innovative idea of the Analytical Engine itself, he didn’t see beyond his original idea of the computer as a calculator, she saw that they could do much more than that.

The key innovation behind her idea was that the numbers could stand for more than just quantities in calculations. They could represent anything – music for example. Today when we talk of things being digital – digital music, digital cameras, digital television, all we really mean is that a song, a picture, a film can all be stored as long strings of numbers. All we need is to agree a code of what the numbers mean – a note, a colour, a line. Once that is decided we can write computer programs to manipulate them, to store them, to transmit them over networks. Out of that idea comes the whole of our digital world.

Ada saw even further though. She combined maths with a creative flair and so she realised that not only could they store and play music they could also potentially create it – they could be composers. She foresaw the whole idea of machines being creative. She wasn’t just the first programmer, she was the first truly creative programmer.

This article was originally published at the CS4FN website, along with lots of other articles about Ada Lovelace. We also have a special Ada Lovelace-themed issue of the CS4FN magazine which you can download as a PDF (click picture below).

See also: The very first computers and Ada Lovelace Day (2nd Tuesday of October). Help yourself to our Women in Computing posters PDF (or sign up to get FREE copies posted to your school (UK-based only, please).

 

The very first computers

A head with numbers circling round and the globe in the middleVictorian engineer Charles Babbage designed, though never built the first mechanical computer. The first computers had actually existed for a long time before he had his idea, though. The British superiority at sea and ultimately the Empire was already dependent on them. They were used to calculate books of numbers that British sailors relied on to navigate the globe. The original meaning of the word computer was actually a person who did these calculations. The first computers were humans.

Babbage became interested in the idea of creating a mechanical computer in part because of computing work he did himself, calculating accurate versions of numbers needed for a special book: ‘The Nautical Almanac’. It was a book of astronomical tables, the result of an idea of Astronomer Royal, Nevil Maskelyne. It was the earliest way ships had to reliably work out their longitudinal (i.e., east-west) position at sea. Without them, to cross the Atlantic, you just set off and kept going until you hit land, just as Columbus did. The Nautical Almanac gave a way to work out how far west you were all the time.

Maskelyne’s idea was based on the fact that the angle from the moon’ to a person on the Earth and back to a star was the same at the same time wherever that person was looking from (as long as they could see both the star and moon at once). This angle was called the lunar distance.

The lunar distance could be used to work out where you were because as time passed its value changed but in a predictable way based on Newton’s Laws of motion applied to the planets. For a given place, Greenwich say, you could calculate what that lunar distance would be for different stars at any time in the future. This is essentially what the Almanac recorded.

Now the time changes as you move East or West: Dawn gradually arrives later the further west you go, for example, as the Earth rotates the sun comes into view at different times round the planet). That is why we have different time zones. The time in the USA is hours behind that in Britain which itself is behind that in China. Now suppose you know your local time, which you can check regularly from the position of the sun or moon, and you know the lunar distance. You can look up in the Almanac the time in Greenwich that the lunar distance occurs and that gives you the current time in Greenwich. The greater the difference that time is to your local time, the further West (or East) you are. It is because Greenwich was used as the fixed point for working the lunar distances out, that we now use Greenwich Mean Time as UK time. The time in Greenwich was the one that mattered!

This was all wonderful. Sailors just had to take astronomical readings, do some fairly simple calculations and a look up in the Almanac to work out where they were. However, there was a big snag. it relied on all those numbers in the tables having been accurately calculated in advance. That took some serious computing power. Maskelyne therefore employed teams of human ‘computers’ across the country, paying them to do the calculations for him. These men and women were the first industrial computers.

Before pocket calculators were invented in the 1970s the easiest way to do calculations whether big multiplication, division, powers or square roots was to use logarithms. The logarithm of a number is just the number of times you can divide it by 10 before you get to 1. Complicated calculations can be turned in to simple ones using logarithms. Therefore the equivalent of the pocket calculator was a book containing a table of logarithms. Log tables were the basis of all other calculations including maritime ones. Babbage himself became a human computer, doing calculations for the Nautical Almanac. He calculated the most accurate book of log tables then available for the British Admiralty.

The mechanical computer came about because Babbage was also interested in finding the most profitable ways to mechanise work in factories. He realised a machine could do more than weave cloth but might also do calculations. More to the point such a machine would be able to do them with a guaranteed accuracy, unlike people. He therefore spent his life designing and then trying to build such a machine. It was a revolutionary idea and while his design worked, the level of precision engineering needed was beyond what could be done. It was another hundred years before the first electronic computer was invented – again to replace human computers working in the national interest…but this time at Bletchley Park doing the calculations needed to crack the German military codes and so win the World War II.

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Florence Nightingale: rebel with a cause

a glowing lantern

Florence Nightingale, the most famous female Victorian after Queen Victoria, is known for her commitment to nursing, especially in the Crimean War. She rebelled against convention to become a nurse at a time when nursing was seen as a lowly job, not suitable for ‘ladies’. She broke convention in another less well-known, but much more significant way too. She was a mathematician – the first woman to be elected a member of the Royal Statistical Society. She also pioneered the use of pictures to present the statistical data that she collected about causes of war deaths and issues of sanitation and health. What she did was an early version of the current Big Data revolution in computer science.

Soldiers were dying in vast numbers in the field hospital she worked in, not directly from their original wounds but from the poor conditions. But how do you persuade people of something that (at least then) is so unintuitive? Even she originally got the cause of the deaths wrong, thinking they were due to poor nutrition, rather than the hospital conditions as her statistics later showed. Politicians, the people with power to take action, were incapable of understanding statistical reports full of numbers then (and probably now). She needed a way to present the information so that the facts would jump out to anyone. Only then could she turn her numbers into life-saving action. Her solution was to use pictures, often presenting her statistics as books of pie charts and circular histograms.

Whilst she didn’t invent them, Florence Nightingale certainly was responsible for demonstrating how effective they could be in promoting change, and so subsequently popularising their use. She undoubtedly saved more lives with her statistics than from her solitary rounds at night by lamplight.

Big Data is now a big thing. It is the idea that if you collect lots of data about something (which computers now make easy) then you (and computers themselves) can look for patterns and so gain knowledge and, for people, ultimately wisdom from it. Florence Nightingale certainly did that. Data visualisation is now an important area of computer science. As computers allow us to collect and store ever more data, it becomes harder and harder for people to make any sense of it all – to pick out the important nuggets of information that matter. Raw numbers are little use if you can’t actually turn them into knowledge, or better still wisdom. Machine Learning programs can number crunch the data and make decisions from it, but its hard to know where the decisions came from. That often matters if we are to be persuaded. For humans the right kind of picture for the right kind of data can do just that as Florence Nightingale showed.

‘The Lady of the Lamp’: more than a nurse, but also a remarkable statistician and pioneer of a field of computer science…a Lady who made a difference by rebelling with a cause.

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Who invented Morse code?

by Paul Curzon, Queen Mary University of London

Morse code tapper: www.istock.com 877875

Who invented Morse code? Silly question, surely! Samuel Morse, of course. He is one of the most celebrated inventors on the planet as a result. Morse code helped revolutionise global communications. It was part of the reason the telegraph made fast, world-wide communication a practical reality. Morse did invent a code to use for the telegraph, but not Morse code. His code was, by comparison, a poor, inflexible solution. He was a great businessman, focussed on making his dream a reality, but perhaps not so good at computational thinking! The code that bears his name was largely invented by his partner Alfred Vail.

Samuel Morse was originally a painter. However, his life changed when his wife died suddenly. He was away doing a portrait commission at the time. On hearing of his wife’s illness he rushed home, but the message, delivered by a horse rider had taken too long to reach him and she died and was buried before he got there. He dedicated his life to giving the world a better way of communicating as a result. Several different people were working on the idea of a way to send messages by electricity over wires, but no one had really come up with a usable, practical system. The physics had largely been sorted, but the engineering was still lacking.

Morse came up with a basic version of an electrical telegraph system and he demonstrated it. Alfred Vail saw the demonstration and persuaded Morse to take him on as a partner. His father built a famous ironworks, and so he had worked as a machinist. He improved Morse’s system enormously including making the tapping machine used to send messages.

He wasn’t just good at engineering though. He was good at computational thinking, so he also worked on the code used for sending messages. Having a machine that can send taps down a wire is no use unless you can also invent a simple, easy to use algorithm that turns words into those taps, and back again once it arrives. Morse came up with a code based on words not letters. It was a variation of the system already used by semaphore operators. It involved a code book: essentially a list of words. Each word in the book was given a number. A second code turned numbers in to taps – in to dots and dashes. The trouble with this system is it is not very general. If the word you want to send isn’t in the code book you are stuffed! To cover every possibility it has to be the size of a dictionary, with every word numbered. But that would make it very slow to use. Vail came up with a version where the dots and dashes represented letters instead of numbers, allowing any message to be sent letter by letter.

He also realised that some letters are more common than others. He therefore included the results of what we now call “frequency analysis” to make the system faster, working out the order of letters based on how common they are. He found a simple way to do it. He went to his local newspaper offices! To print a page of text, printing presses used metal letters called movable type. Each page was built up out of the individual metal letters slotted in to place. Vail realised that the more common a letter was, the more often it appeared on any page, and the more metal versions the newspaper office would therefore need if they wasn’t to keep running out of the right letters before the page was done. He therefore counted how many of each “movable type” letter the newspaper printers had in their trays. He gave the letters that were most common the shortest codes. So E, for example, is just a single dot as it is the most common letter in American English. T, which is also common, is a single dash. It is this kind of attention to detail that made Morse code so successful. Vail was really good at computational thinking!

Morse and Vail worked really well as a team, though Morse then took all the credit because the original idea to solve the problem had been his, and their agreement meant the main rights were with Morse. They almost certainly worked together to some extent on everything to do with the telegraph. It is the small details that meant their version of the telegraph was the one that took over the world though and that was largely down to Vail. Morse maybe the famous one but the invention of the telegraph needed them both working together.

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