Nothing, no-thing, or no thing is the complete absence of anything, as the opposite of something and an antithesis of everything. The concept of nothing has been a matter of philosophical debate since at least the 5th century BCE. Early Greek philosophers argued that it was impossible for nothing to "exist". The atomists allowed nothing but only in the spaces between the invisibly small atoms. For them, all space was filled with atoms. Aristotle took the view that there exists matter and there exists space, a receptacle into which matter objects can be placed. This became the paradigm for classical scientists of the modern age, like Isaac Newton. Nevertheless, some philosophers, like René Descartes, continued to argue against the existence of empty space until the scientific discovery of a physical vacuum.
Existentialists like Jean-Paul Sartre and Martin Heidegger (as interpreted by Sartre) have associated nothing with consciousness. Some writers have made connections between Heidegger's concept of nothing and the nirvana of Eastern religions.
Modern science does not equate vacuum with nothing. The vacuum in quantum field theory is filled with virtual particles. The quantum vacuum is often viewed as a modern version of an aether theory.
Contents
Philosophy
Western
Some would consider the study of "nothing" to be absurd. A typical response of this type is voiced by the Venetian Giacomo Casanova in conversation with his landlord, one Dr. Gozzi, who also happens to be a priest:
As everything, for him, was an article of faith, nothing, to his mind, was difficult to understand: the Great Flood had covered the entire world; before, men had the misfortune of living a thousand years; God conversed with them; Noah had taken one hundred years to build the ark; while the earth, suspended in air, stood firmly at the center of the universe that God had created out of nothingness. When I said to him, and proved to him, that the existence of nothingness was absurd, he cut me short, calling me silly.
"Nothingness" has been treated as a serious subject for a very long time. In philosophy, to avoid linguistic traps over the meaning of "nothing", a phrase such as not-being is often employed to make clear what is being discussed.
One of the earliest Western philosophers to consider nothing as a concept was Parmenides (5th century BCE), a Greek philosopher of the monist school. He argued that "nothing" cannot exist by the following line of reasoning: To speak of a thing, one has to speak of a thing that exists. If one can speak of a thing in the past, this thing must still exist (in some sense) now, and from this, he concluded that there is no such thing as change. As a corollary, there can be no such things as coming-into-being, passing-out-of-being, or not-being.
Other philosophers, for instance, Socrates and Plato largely agreed with Parmenides's reasoning on nothing. Aristotle differs with Parmenides's conception of nothing and says, "Although these opinions seem to follow logically in a dialectical discussion, yet to believe them seems next door to madness when one considers the facts."
In modern times, Albert Einstein's concept of spacetime has led many scientists, including Einstein himself, to adopt a position remarkably similar to Parmenides. On the death of his friend Michele Besso, Einstein consoled his widow with the words, "Now he has departed from this strange world a little ahead of me. That signifies nothing. For those of us that believe in physics, the distinction between past, present and future is only a stubbornly persistent illusion."
Eastern
The understanding of "nothing" varies widely between cultures, especially between Western and Eastern cultures and philosophical traditions. For instance, śūnyatā (emptiness), unlike "nothingness", is considered to be a state of mind in some forms of Buddhism (see nirvana, mu, and bodhi). Achieving "nothing" as a state of mind in this tradition allows one to be totally focused on a thought or activity at a level of intensity that they would not be able to achieve if they were consciously thinking. A classic example of this is an archer attempting to erase the mind and clear the thoughts to better focus on the shot. Some authors have pointed to similarities between the Buddhist conception of nothingness and the ideas of Martin Heidegger and existentialists like Sartre, although this connection has not been explicitly made by the philosophers themselves.
In some Eastern philosophies, the concept of "nothingness" is characterized by an egoless state of being in which one fully realizes one's own small part in the cosmos. The Kyoto School handles the concept of nothingness as well.
Laozi and Zhuangzi were both conscious that language is powerless in the face of the ultimate. In Taoist philosophy, however real this world is, its main characteristic is impermanence, whereas the Tao has a permanence that cannot be described, predetermined, or named. In this way the Tao is different from any thing that can be named. It is nonexistence, in other words, nothing.
Taoists also have the related concept of wu wei.
Science
Despite the proven existence of vacuum, scientists through the 17th to 19th centuries thought there must be a medium pervading all space that allowed the transmission of light or gravity. Thus, in this period, it was not accepted that complete nothing was possible. Theories describing such a medium are collectively known as aether theories, so named as an evocation of the aether, the classical element from Greek philosophy. In particular, the medium that is supposed to allow the transmission of light is called the luminiferous aether. This became the centre of attention after James Clerk Maxwell proposed that light was an electromagnetic wave in 1865.
Early aether theories include those of Robert Hooke (1665) and Christiaan Huygens (1690). Newton also had an aether theory, but to Newton, it was not the medium of transmission since he theorised light was composed of "corpuscles" which moved by simple mechanical motion. He needed the aether instead to explain refraction. Early theories generally proposed a mechanical medium of some sort, allowing the possibility of the same medium supporting both light and gravity. Proof that light has a wave nature, rather than Newton's corpuscles, was provided by Thomas Young in his 1803 interference experiment, seemingly confirming the need for an aether. The most well known attempt to detect the existence of the aether was the Michelson–Morley experiment conducted by Albert A. Michelson in 1881, later repeated with Edward W. Morley in 1887 with more precision. This failed to show the desired effect, but reluctant to abandon the aether theory, various attempts were made to modify it to account for the Michelson-Morley result. Finally, Albert Einstein, building on the work of Hendrik Lorentz, published his theory of special relativity in 1905 which dispenses entirely with the need for a luminiferous aether to explain the transmission of light.
Although a physical medium was no longer required, the concept of aether still did not entirely vanish. It remained necessary to assign properties to the vacuum for various purposes. In some respects vacuum and aether are treated as synonyms by science. In modern quantum field theory, a completely empty vacuum is not at zero-point energy, the lowest possible energy state. First proposed by Paul Dirac in 1927, the lowest energy state has constant random vacuum fluctuations which bring into existence short-lived virtual particles. This is somewhat reminiscent of early philosophical plenum ideas, and means that vacuum and nothing are certainly not synonyms.
Mathematics
A well-known usage of the term "nothing" in mathematics is the number 0, which is neither a positive number nor a negative number. It's sometimes included in the set of natural numbers, denoted by
N
{\displaystyle N}
, but it's always included in the set of real numbers, denoted by
R
{\displaystyle R}
. "Nothing" can also apply to empty sets, indicated by the symbol
∅
{\displaystyle \emptyset }
, whose size or cardinality is 0.
