There is no real difference between analogue and digital is a philosophical article.
The words analogue and digital have been in the lips of many Kenyans since the 2012/2013 political campaigns and the current Digital Migration programme. The comedian Smart Joker has also helped familiarize the words to many and that’s why a close friend wanted to know the exact difference between the two concepts not only as concerns digital tv broadcast but also as basic fundamental concepts as used in technology and as a matter of tangible reality.
As I was explaining to him, based on my understanding, I realized that probably, philosophically, there isn’t any difference between analogue and digital ideologies as such. This is why.
Analogue is best understood as a set of continuous data. That is, a member of this set (element) that must appear between any two initial elements of the set, has an infinite possible points/positions to take in the space between the initial two elements. For example, if the set of data is defined as height of students in class A, and two students selected at random have heights 1.23 meters and 1.52 meters respectively, a third students whose height fall between 1.23 meters and 1.52 meters can measure anything from 1.23…. (where the dots represent infinite decimal places) and 1.51….
In the number line, analogue data takes the form of rational numbers.
Digital data on the other hand can be said to be that data represented by discrete data set. This is the type of data set that is described by whole or natural numbers technically known as Integers. From the class example, the number of students in the class can only take the values of a positive Integer thereby making the outcome of counting the number of students in the class be a discrete data or digital data.
The concept of analogue and digital have been exemplified further by analogies of flowing water vs discreteness of water drops from a tap. In flowing water analogy e.g. from a shower, one sees no discontinuity of the flow whereas the water drops analogy implies that each drop of water can be treated as a single discrete entity. But as we know, whether the water flows or drops the constitution of water boils down to a single water molecule that cannot be destructed; if destructed you end up with totally different things other than water, that is an oxygen atom and at best a hydrogen molecule if not two hydrogen atoms. In this regard it is better to understand water, in its basic form, as discrete water molecules that can only be represented by an Integer when reporting the number of molecules of water in the ocean, in a glass or in a rain drop.
What the above paragraph is trying to explain is that analogue data is in away “big data” composed of digital components. In reality it has been documented that the world as we know it, including energy, consist of discrete components like quarks or quanta. Collection of these point particles to the millions and gazillions in complex physical or chemical reactions give rise to reality in analogue forms.
In the world of ICT, digital data is represented by the absence or presence of a signal represented in 0s and 1s. When a particular circuit in a computer has 5 or 3.5 milivolts (+ or – a few microvolts) for instance, the circuit can made to understand that it has registered a presence of signal thereby a value of 1. If the voltage is anything less than the predetermined voltage point, e.g. 1.78 milivolts, the circuit registers an absence of signal thereby a value of 0. As you can see, the voltage input to the circuit can be analogue but the output data from the circuit is digital whose collection can be analogue or digital depending on a number of factors and circumstances.
A track carrying cargo in bulk from Mombasa to Busia can be thought of as an analogue mode of transport. The cargo can be smartphones in boxes or bottles of cokes in crates. The track will take about ten days to reach Busia due to restricted speed. The speed restriction come about by technology and economic considerations. The bulkiness of the cargo and restrictions in speed makes this mode of transport be considered as an analogue mode of transport. What if someone was to “shoot” the smartphones from Mombasa to Busia at the speed of a bullet making a single phone to travel at 1,500Km/hr instead of 60Km/hr for the bulk transport mode? This bullet mode of transport could be considered a digital mode of transport. But unless the person could shoot not less than a 1,000 bullets simultaneously, then the analogue mode of transport remains superior in this case. Digital mode of transport (or transmission of information) only makes practical and economic sense at speeds close to the speed of light.
An image created by use of pencil on paper is analogue. The reason is that the creator arranges millions of atoms per inch of paper instead of arranging individual carbon atoms one at a time. An image created by a computer printer that works on the principle of spraying a limited number of molecules of ink per inch calculated based on dots per inch can however be considered as a digitally created image.
In essence analogue means manipulating a unit composed of a collection of millions to the gazillions of digital entities whereas digital means manipulating the individual digital entities themselves. In TV broadcast, analogue means transmitting the image as a whole unit but digital broadcast means breaking down the image into digital components that can be translated into 1s and 0s, transmitting the digitized 1s and 0s of the image either one after the other or simultaneously depending on bandwidth considerations; to be reconstructed later into original image at the destination.
At the end of the day, the information transmitted originally consisted of digital entities.