From DNA to Twitter: Data's digital journey to commodity

Which came first: information or the need to compute it?

The dangers of Darwin deniers

The scientific model begun by Darwin is about as irrefutable as such models get. Self-evidently before Darwin, evolution and its unstoppable ubiquitous force was not understood. After Darwin it was widely denied. That is why we see around us today: a large number of man-made institutions that were set in stone to last un-changed forever and that inevitably would become irrelevant, even dangerous, in a continuously evolving world.

Being unable to evolve they are powerless against challenge, ripe for disruption and schism and seek to prevent such by outlawing it, using terms such as following the party line, not rocking the boat, heresy and ineffability. It’s axiomatic that adherence to dogma is an admission of the inability to evolve.

As Nobel-winning physicist Richard Feynman said: “I would rather have questions that can’t be answered than answers that can’t be questioned.”

Whilst one can conceive of a message sent but not acted upon, it is evident that if there is no result it might as well not have been sent. If that is so then no information was conveyed by the message. In that sense we can define information as something that makes a difference to the recipient.

One can see also that repeating a message, or sending one whose contents are already known cannot make a further difference and such messages cannot contain information. They are said to be redundant. Most real messages contain a mixture of novelty and redundancy making techniques such as compression and error correction possible. We will come back to that.

If we want to see what information really is, we need to consider the destination. The destination must understand and verify the message whose contents must be novel or unpredictable. By verification is meant that the message probably is from the source purported to have sent it and that it has not been corrupted in transit. In some cases it is important that the message is only available to a designated recipient. This introduces concepts such as keys and encryption.

Speaking in tongues – and unlocking entropy

The basics of encryption can be found in the emergence of argot, language used by those forced to steal in order to eat, who found it better to communicate in a tongue that the authorities and those more privileged could not understand. One of the best known is Cockney rhyming slang: grasshopper rhymes with copper, so a grass is a police spy or informer. Much of Les Misérables is written in Parisian argot. Polari was an argot that evolved when homosexuality was illegal. A man was an omi, a corruption of homme, and a woman was a palone, from the Italian word for a straw mattress. Hence omipalone, if you can Adam an’ Eve it. Croianches-tu cela?

Keys and locks are possibly the oldest examples of man-made information technology. Locks originally used purely mechanical means to verify the identity of the key and by association the key holder. Typically a sliding bolt would be prevented from moving by a number of pins that were divided in two parts. Protrusions on the key would lift the pins, and only when the divisions of every pin were aligned with the surface of the bolt by the matching key could it move.

Clearly a lock is a classical true/false logical device. It cannot be partially unlocked. It implements what can now be identified as a mechanical AND gate whereby the bolt can or cannot move. Each pin could be divided at a number of places. That and the number of pins allowed the possible number of unique locks and keys to be determined.

Each of those could be allotted a different number. The lock is of further interest because it illustrates concepts such as entropy and irreversibility. The number of the key that opens the lock is a form of information. Suppose that 65,536 different keys are possible, then the key represents 16 bits. When the lock is opened by the correct key, the result is described by one bit, 0 = locked, 1 = open.

Information has been destroyed by the operation of the lock. Entropy has increased. Clearly the system is irreversible. If we only know that the lock is open, we cannot compute what the key was. Thus irreversibility is compatible with entropy only increasing and this requires time to have an unique direction. Opening your front door will never be the same.

Etymologically speaking, the use of the word “gate” in logic circuitry has been adopted because it is analogous to unlocking a physical gate with a key. The basic gates are the AND and the OR. Considering a two-input device, the output of the AND gate will be true if both inputs are true, and false if one, the other or both inputs are false.

One would read newspapers not to obtain objective information, but to find out how gullible the general public was. As Oscar Wilde put it: “We need journalists to keep us in touch with what the common people are thinking.”

The input combination causing a false output cannot be known from the output, so information is destroyed. Similarly with an OR gate, the output is true if one or the other or both inputs are true. The inverter is a logic element, but it not a gate because the input can be known from the output and it does not destroy information. The exclusive-OR gate is extremely useful in error correction because the output is true if one or the other but not both inputs is true. It therefore performs a parity function, which again we will come back to.

From woodcuts to photo-lithography

In addition to logical manipulations, there is the need to store and duplicate data. The first books were hand written and hand copied. Woodcuts evolved as an art form allowing pictures to be printed and it was a relatively small step to carve alphabetical characters into the wood so that text could be block printed. The big step was the adoption of movable type that began in China but the first use in Europe is usually attributed to Gutenberg in the mid fifteenth century. The printing revolution spread like wildfire and it took only 20 years for Caxton to begin printing in UK.

Whilst a lengthy printing process was not critical for books, technological developments reduced the time taken to get from manuscript to print and this made the newspaper possible and led to journalism. Whilst the spread of printing undoubtedly helped with the rise of literacy, the cost of printing equipment was such that it had to be centralised and inevitably this led to newspapers being used to protect the status quo or to promote the views of the proprietor rather than for educational purposes.

Newspaper barons were the first to create wealth from information technology and with it came corruption, seen in the unwavering support for fascism by a certain British paper prior to World War II and, more recently, in the use of voicemail tapping that led to the demise of The News of the World. With some exceptions, journalism became the art of writing what the target audience would find plausible, and to flatter their prejudices. One would read newspapers not to obtain objective information, but to find out how gullible the general public was. As Oscar Wilde put it: “We need journalists to keep us in touch with what the common people are thinking.”

In due course the production of newspapers would be computerised. Text would be manipulated by word processing and the printing plates would be made by Computer-to-Plate machines fed with the data. The process was known as photo-lithography, whereby light sensitive material could be selectively hardened to make a three dimensional structure that would serve as a printing plate.

There is a marvellous circularity there, because one day someone realised that photolithography could be used to make electronic components. The integrated circuit was born, which made it possible literally to print processing power and subsequently memory at low cost. The resultant revolution made the early spread of paper printing look pedestrian. Photolithography would also be the basis of optical discs that would lead to CD and CD-ROM.

Inevitably, when everyone had access to processing power there would be disruption. After all, why send the dog to a newsagent when news can be downloaded? Why believe a single account of the news when multiple accounts can be compared and eyewitness photographs can be seen? ®

Big Data and All That is John Watkinson's look at the technical history of computing and the impact on society of the IT revolution.