The digital revolution finds its roots in the invention of the microprocessor in the '70s of the last century.
The idea behind microprocessors is very simple and not new at all: to associate a symbolic value with a signal. It had already been done manually for centuries with smoke signals or lanterns. More recently with the electrical impulses on the telegraph lines. The microprocessor makes it possible to automate the on-off process and, above all, to execute it with a frequency that is unthinkable for a human being. In less than 50 years we have gone from about 750,000 states per second of the first microprocessors to several billions today. And the newly made quantum microprocessors available on the market demonstrate the possibility of increasing these numbers by several orders of magnitude.
If each state of presence or absence of signal is associated respectively with the value "1" or the value "0", a sequence of them can be interpreted as a natural number in binary representation. Mathematical theory ensures that all representation systems of natural numbers in different bases are equivalent to each other. Therefore it is possible to associate the sequences of states of a microprocessor with decimal or hexadecimal numbers, which humans use to order lists since the dawn of history. The letters of the alphabet or a palette of colors are just two of the infinite examples. Taking advantage of this principle, it becomes possible to represent texts or images by means of standard codes and appropriate interfaces between human beings and microprocessors.
However, the power of this method does not stop there. Once again the mathematical theory from the seventeenth century tells us that any continuous geometric entity can be accurately approximated at will through lists of values. This system of approximation by tessellation can be applied almost everywhere and it is the principle that allows us to use the "digital representation" to describe the world through computers. It might be useful to remind that "digital" is a derivative of the English word "digit", that means "number". In turn, "digit" derives from the Latin word "digitus", or "finger".
Its application in the field of image representation is a good example of the nature and the power of the digital technique. A screen is nothing but a finite matrix of points. Each point can be identified by an index number and therefore the screen can be traced back to a list. Moreover, a color list can be associated with each point. In modern monitors it is common to have 4-million-dot matrixes, with each dot able to reproduce millions of colors. The combination of these two lists allows us to produce approximations of images by tessellation, which are indistinguishable from the original by the human eye. This fidelity is obtained at the price of being able to generate a sequence of about 1 billion "1" or "0" per second. A task safely within the reach of today's commercial microprocessors.
A fundamental corollary of the above train of thoughts is that our ability to manipulate energy to generate semantic value in an ubiquitous way is the breakthrough element introduced by digital representation technologies. Probably Michelangelo, if he lived in our days, would not say that he saw an angel in the stone and he sculpted until he was able to free him, but in energy and that he coded rather than using a chisel. Another great figure in human history, the aforementioned Albert Einstein, explained with his famous equation E = mc2 that mass and energy are simply two different states of the matter. Since that holds true, Michelangelo today might choose to shape the image of the David in this mind as a statue made of marble or as an hologram made of energy indifferently. Both would be material constructs.
The previous statement leads to a revealing linguistic problem. It is immediate to describe the hologram as a digital material construct, but which adjective to use for its marble counterpart? Before the spread of digital representation techniques, there was not a litmus test that showed that "matter" and "mass" are not the same concept. In common practice they were often confused and the language did not develop to differentiate the two situations adequately. "Tangible" is the adjective most often used to describe a material object in a mass state, but, again, this is an element that creates confusion in speeches, when digital comes into play. The intangibility of the digital is what pushes the common sense to classify it instinctively as immaterial, but it is a categorization that simply loses its meaning in this wider reality.
Pending the maturation of our culture, a word that can be used provisionally is "objectual". It was invented at the beginning of the twentieth century in the context of the Cubist formal research and then taken up by Futurists and Dadaists. The term for Picasso and the Cubists places the emphasis on the semantic value that a material construct assumes in a given context by virtue of its having form as an object. Although it is not a conceptually completely satisfactory solution, it has the advantage of offering a clear differentiation with respect to a digital material construct that assumes value only as a representation process.