Folha: ‘Does our mind have a horror of zero?
Reproduction of Marcelo Viana’s column in Folha de S. Paulo.
In my generation, we often heard at school that “according to Aristotle, nature has a horror of vacuum”. In fact, the Greek philosopher never said that: it was a simplistic re-reading of his thoughts, perpetrated by medieval scholastic thinkers, and used by them to “explain” natural phenomena such as the behavior of liquids in containers. When scientific explanations of these phenomena – for example, the discovery of atmospheric pressure – were found, the ridicule of the idea of “vacuum horror” also splashed on the reputation of Aristotle, who had nothing to do with it.
What Aristotle (384 BC – 322 BC) actually said was that empty space does not exist, nor can it exist, “because every place is a place for something”. The irony is that modern-day physics is right. Quantum mechanics, for example, states that the most perfect vacuum is filled with subatomic particles that appear and disappear without ceasing. It’s likely that space itself is a result of this frenetic subatomic bubbling, without which it would have no meaning.
Aristotle believed that “nothing results from nothing”, but St. Augustine (354 – 430), one of Christianity’s greatest philosophers, pointed out that God created everything from the primordial vacuum. For him, the void is what preceded Creation and is therefore alien to God’s work. Thus, through different paths, Augustine ended up agreeing with Aristotle that the void does not exist.
However, the human brain is capable of conceiving of emptiness, absence, nothingness. How do we do this, neurologically speaking? The young neuroscientist Benjy Barnett, from the University of London, asks. It’s a challenging question, he acknowledges, but “fortunately, there are other, more tangible types of absence that help us deal with the nebulous issue of ‘nothingness’ in the brain”. And he reveals: “that’s why I spent most of my PhD thesis studying how our mind understands the number zero”.
The fact is that, many centuries after we “officially” accepted zero as a number, we still treat it in a unique way. Experiments with babies suggest that this may be because our mental perception of zero is essentially different from the way we understand other numbers. In one experiment, the researcher shows a doll and then hides it with a screen. Then the screen is removed and there are now three dolls: the baby stares longingly, puzzled. But if the experiment is carried out starting with no dolls, the babies show no interest in the “magical” appearance of the toys.
Children in kindergarten already understand to some extent the relationship between zero and nothing, but they still resist accepting zero as a number: when asked, they usually reply that the smallest number is one. Some of these issues can persist into adulthood: a good example is the perennial “controversy” over whether zero is even or odd (it is even), which signals a difficulty in treating zero like any other number.