Gold number 0, 3D rendering of number zero made of gold with reflection isolated on white background.
The number zero, the number we use when we talk about emptiness or nothingness. Do you know who introduced the idea of the number zero or why we use a number with no meaning?
a matter of mind
The number zero has been used for a long time, even though it's a meaningless number, and it's used in all cultures. When we want to refer to the absence or lack of something, we use the symbol for zero. Words like "empty" or "nothing" are difficult to imagine, and that makes them complex for our minds.
Our mind is capable of imagining an object in which there is nothing inside, an empty object inside, an object with zero products inside. But it is very difficult for us to think in the sense of "empty" or "lack of something" in a broader, absolute sense.
Maths
In the case of mathematics, we do understand its meaning and the importance it has when making calculations and using numbers.
Zero: from non-existence to its widespread use
Greece and Rome
Today, we use zero in many operations and even use it as a synonym for "nothing," but we must remember that zero hasn't existed forever. For example, the ancient Romans or Greeks didn't use zero. They were very advanced in mathematics and astrology, calculating volumes or even predicting the exact location of stars, but they did all of this without zeros. If such important calculations could be performed without using this symbol, why was it introduced later, and who introduced it?
The zero has Indian roots, and from there, it became used worldwide
If we want to know where this symbol that represents nothing comes from, we must go to India. We must look specifically at Buddhist and Jain philosophy. Although they did not call it "zero", they did use a word to designate that state of "nothing", "empty", "absence"... but which in Sanskrit was known as suyna y kha.
The mathematical sages of India used the word Sunya to refer to what we now know as "zero." But let's not think that this usage spread from philosophy to mathematics in a matter of days. In fact, the use of the word Sunya began in a discipline we haven't yet discussed: grammar, between the 5th and 2nd centuries BC. It was then that Panini and Pingala, grammarians of that time, used a symbol very similar to the zero we know today, although it wasn't a zero as a number, but as a letter. And they used it when referring to something that didn't appear.
India and China
It is not known exactly when it was first introduced because historical documents are missing and it is not clear. In addition, the Indian culture was found between different cultures such as the Chinese, Greek civilization and the peoples of Mesopotamia. That is to say, an important cultural mix and that also covers some 400 years of documentary doubts that do not make the clear beginning of the use of zero entirely clear.
For example, in China they used base 10, in which a zero appeared, but in this case it did not have that meaning of emptiness or nothing. Even so, they used calculation tables made up of several columns and the column that was empty was the zero column.
india and greece
Cultural exchange between India and Greece was the order of the day. Beyond the empire of Alexander the Great, right on the border between India and Greece, Indo-Greek kingdoms grew, that is, kingdoms where both Greeks and Indians lived side by side. Two different cultures coexisting in a single place. This led to a cultural fusion between the two cultures in all areas. Furthermore, we are talking about two cultures that dominated trade and were great thinkers.
In this case, the Greeks provided the Indians with astronomical treatises that featured a symbol similar to zero, a symbol the Indians had learned from the peoples of Mesopotamia. This symbol served at the time as a placeholder for numbers.
culture fusion
We can find, for example, the use of zero as a placeholder in the astronomical treatise Yavanajataka, from the third century AD. The name of the treatise itself once again teaches us about the fusion of cultures. Why? It's an Indian document in which the word "yavana" means "Ionic," which, in turn, means "Greek."
The mathematical zero
So far, we've seen that the symbol zero was used as a grammatical symbol to indicate emptiness or absence of something, but not as a number, as we know it. When did this leap from grammar to numerology occur?
The first treatise in which we can find zero used as a number is the Brahma-sphuta-siddhanta treatise. This is a treatise on algebra written by the mathematician Brahmagupta in 628 AD. It is the first place where zero is used as a number and where it is explained how this symbol is used to perform calculations with it. In this treatise, zero takes on a completely algebraic meaning.
Even so, the zero of that time was not like it is today. For example, according to Brahmagupta's treatise, if you divided a number by zero, the result was a number, a very large value, but of an indeterminate quantity. Therefore, it was a number, with an associated value.
from east to west
Again the ideas and wisdom of some peoples are transferred to others. In this case the word sunya is changed to sifr but it also serves to designate emptiness or absence, zero. In this case we must travel to the city of Baghdad, in the middle of the IX century AD. Khawarizmi Persian, better known to the medievals as Algorismus, he wrote the treatise On Indian Calculation based on Indian astronomical treatises. And it was precisely he who translated the word sunya by sifr. A different word for the same meaning.
And Leonardo Fibonacci, son of a Pisan customs officer, was the one who truly spread these calculation techniques that came from the East because he traveled constantly. In fact, it was this Italian who introduced the zero sign to Europe. In 1192, he wrote Liber Abaci, in which he explains that nine numbers were used, as well as a special symbol. The translation of the word sifr from Arabic to Latin, sephirum, introduced two concepts to Europe: zero and digit.
Zero in modern times
As we've seen, zero hasn't always been an easy symbol to define. It hasn't even always been used as a number, but was initially used as a letter. And not only mathematicians but also philosophers and astrologers have excelled in the study of this symbol.
Even so, it could be said that its use as such, as a number and as we know it today, didn't arrive until 1657, with the help of John Wallis. He was the first to use this number with a real (present) value of zero, meaning that if it was added to any other number, it didn't change its value; it remained zero and contributed nothing to the other value. This concept, which we now consider so normal and which we use routinely, was very difficult at that time; it wasn't fully understood.
A simple definition gave meaning to the number zero
It was a year later that the philosopher and mathematician George Boole gave some meaning to this number by saying that a set of objects has two limits: an upper limit known as the Universe, and a lower limit called nothing. And it is with the lower limit, nothing, that the number zero is associated. This definition made it much easier to understand why adding a digit to zero caused that digit to remain unchanged. It was at that moment that people also realized the relationship it had with the zero in Indian treatises. The truth of Indian philosophy, which until then had been so difficult to interpret or understand.
Furthermore, following set theory, great mathematicians such as Zermelo, Cantor and Von Neumann later continued to study the value of zero in these sets and even what was known as the set without elements.
zero today
Currently, do we really know what the zero value means? Well, the answer, even if it seems like a lie to us, is that not at all. We will have understood it according to the model we choose. We can perfectly understand the value of zero in the field of set theory, in the mathematical field. What's more, we use it regularly and we do it without doubting this digit. However, in the philosophical field we have been left behind. In this regard, there is still a debate about the value of “nothing”.