Sign - AbsoluteAstronomy.com

A sign is something that implies a connection between itself and its object. A natural sign bears a causal relation to its object—for instance, thunder

Thunder

Thunder is the sound made by lightning. Depending on the nature of the lightning and distance of the listener, thunder can range from a sharp, loud crack to a long, low rumble . The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within...

is a sign of storm. A conventional sign signifies by agreement, as a full stop

Full stop

A full stop is the punctuation mark commonly placed at the end of sentences. In American English, the term used for this punctuation is period. In the 21st century, it is often also called a dot by young people...

signifies the end of a sentence. (This is in contrast to a symbol

Symbol

A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...

which stands for another thing, as a flag

Flag

A flag is a piece of fabric with a distinctive design that is usually rectangular and used as a symbol, as a signaling device, or decoration. The term flag is also used to refer to the graphic design employed by a flag, or to its depiction in another medium.The first flags were used to assist...

may be a symbol of a nation).

The way a sign signifies is called semiosis

Semiosis

Semiosis is any form of activity, conduct, or process that involves signs, including the production of meaning. Briefly – semiosis is sign process...

which is a topic of semiotics

Semiotics

Semiotics, also called semiotic studies or semiology, is the study of signs and sign processes , indication, designation, likeness, analogy, metaphor, symbolism, signification, and communication...

and philosophy of language

Philosophy of language

Philosophy of language is the reasoned inquiry into the nature, origins, and usage of language. As a topic, the philosophy of language for analytic philosophers is concerned with four central problems: the nature of meaning, language use, language cognition, and the relationship between language...

.

How a sign is perceived depends upon what is intended or expressed in the semiotic relationship of:

Signification
Significance (i.e. meaning
Meaning (semiotics)
In semiotics, the meaning of a sign is its place in a sign relation, in other words, the set of roles that it occupies within a given sign relation. This statement holds whether sign is taken to mean a sign type or a sign token...

)
Importance

Thus, for example, people may speak of the significance of events, the signification of characters, the meaning of sentences, or the import of a communication. Different ways of relating signs to their objects are called modes of signification.

Uses of conventional signs are varied. Usually the goal is to elicit a response or simply inform. That can be achieved by marking something, displaying a message (i.e. a notice

Notice

Notice is the legal concept in which a party is made aware of a legal process affecting their rights, obligations or duties. There are several types of notice: public notice , actual notice, constructive notice, and implied notice....

), drawing attention or presenting evidence of an underlying cause (for instance, medical symptom

Symptom

A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s signify a disease), performing a bodily gesture

Gesture

A gesture is a form of non-verbal communication in which visible bodily actions communicate particular messages, either in place of speech or together and in parallel with spoken words. Gestures include movement of the hands, face, or other parts of the body...

, etc.

Nature

Semiotics

Semiotics, also called semiotic studies or semiology, is the study of signs and sign processes , indication, designation, likeness, analogy, metaphor, symbolism, signification, and communication...

, epistemology, logic, and philosophy of language

Philosophy of language

are concerned about the nature of signs, what they are and how they signify. The nature of signs and symbols and significations, their definition, elements, and types, is mainly established by Aristotle

Aristotle

Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...

, Augustine

Augustine of Hippo

Augustine of Hippo , also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius . He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province...

, and Aquinas. According to these classic sources, significance is a relationship between two sorts of things: signs and the kinds of things they signify (intend, express or mean), where one term necessarily causes something else to come to the mind. Distinguishing natural signs and conventional signs, the traditional theory of signs sets the following threefold partition of things:

There are things that are just things, not any sign at all;
There are things that are also signs of other things (as natural signs of the physical world and mental signs of the mind);
There are things that are always signs, as languages (natural and artificial) and other cultural nonverbal symbols, as documents, money, ceremonies, and rites.

Thus there are things which may act as signs without any respect to the human agent (the things of the external world, all sorts of indications, evidences, symptoms, and physical signals), there are signs which are always signs (the entities of the mind as ideas and images, thoughts and feelings, constructs and intentions); and there are signs that have to get their signification (as linguistic entities and cultural symbols). So, while natural signs serve as the source of signification, the human mind is the agency through which signs signify naturally occurring things, such as objects, states, qualities, quantities, events, processes, or relationships. Human language

Language

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

and discourse

Discourse

Discourse generally refers to "written or spoken communication". The following are three more specific definitions:...

, communication

Communication

Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

, philosophy

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, science

Science

Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

, logic

Logic

In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...

, mathematics

Mathematics

Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, poetry

Poetry

Poetry is a form of literary art in which language is used for its aesthetic and evocative qualities in addition to, or in lieu of, its apparent meaning...

, theology

Theology

Theology is the systematic and rational study of religion and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary.-Definition:Augustine of Hippo...

, and religion

Religion

Religion is a collection of cultural systems, belief systems, and worldviews that establishes symbols that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions and sacred histories that are intended to give meaning to life or to...

are only some of fields of human study and activity where grasping the nature of signs and symbols and patterns of signification may have a decisive value.

Types

A sign can denote any of the following:

Sign, in astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

: often used to mean the Sun sign
Sign or signing, in communication: communicating via hand gestures, such as in sign language
Sign language
A sign language is a language which, instead of acoustically conveyed sound patterns, uses visually transmitted sign patterns to convey meaning—simultaneously combining hand shapes, orientation and movement of the hands, arms or body, and facial expressions to fluidly express a speaker's...

.
Gang signal
Gang signal
A gang signal is a visual or verbal way gang members identify their affiliation. This can take many forms including slogans, tattoos or hand signs...
Sign, in Tracking (hunting)
Tracking (hunting)
Tracking in hunting and ecology is the science and art of observing animal tracks and other signs, with the goal of gaining understanding of the landscape and the animal being tracked...

: also known as Spoor (animal)
Spoor (animal)
Spoor is any sign of a creature. Spoor includes track, trail and droppings. Spoor is useful for discovering or surveying what types of animals live in an area, or in animal tracking.Generally droppings can be referred to as scat....

; trace evidence left on the ground after passage.
A signboard.
A sign, in common use, is an indication
Indication
Indication can refer to:* A synonym for Sign.* Human interface Highlighting the single object pointed to as a cursor is moved, without any other user action such as clicking, is indication....

that a previously observed event is about to occur again
Sign, in divination
Divination
Divination is the attempt to gain insight into a question or situation by way of an occultic standardized process or ritual...

and religion: an omen
Omen
An omen is a phenomenon that is believed to foretell the future, often signifying the advent of change...

, an event or occurrence believed to foretell the future
Sign, in ontology
Ontology
Ontology is the philosophical study of the nature of being, existence or reality as such, as well as the basic categories of being and their relations...

and spirituality
Spirituality
Spirituality can refer to an ultimate or an alleged immaterial reality; an inner path enabling a person to discover the essence of his/her being; or the “deepest values and meanings by which people live.” Spiritual practices, including meditation, prayer and contemplation, are intended to develop...

: a coincidence
Coincidence
A coincidence is an event notable for its occurring in conjunction with other conditions, e.g. another event. As such, a coincidence occurs when something uncanny, accidental and unexpected happens under conditions named, but not under a defined relationship...

; see synchronicity
Synchronicity
Synchronicity is the experience of two or more events that are apparently causally unrelated or unlikely to occur together by chance and that are observed to occur together in a meaningful manner...
Sign (linguistics)
Sign (linguistics)
There are many models of the linguistic sign . A classic model is the one by the Swiss linguist Ferdinand de Saussure. According to him, language is made up of signs and every sign has two sides : the signifier , the "shape" of a word, its phonic component, i.e...

: a combination of a concept and a sound-image described by Ferdinand de Saussure
In mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

, the sign of a number
Sign (mathematics)
In mathematics, the word sign refers to the property of being positive or negative. Every nonzero real number is either positive or negative, and therefore has a sign. Zero itself is signless, although in some contexts it makes sense to consider a signed zero...

tells whether it is positive or negative. Also, the sign of a permutation tells whether it is the product of an even or odd number of transpositions.
Signedness
Signedness
In computing, signedness is a property of data types representing numbers in computer programs. A numeric variable is signed if it can represent both positive and negative numbers, and unsigned if it can only represent non-negative numbers .As signed numbers can represent negative numbers, they...

, in computing, is the property that a representation of a number has one bit, the sign bit, which denotes whether the number is non-negative or negative. A number is called signed if it contains a sign bit, otherwise unsigned. See also signed number representation
Sign, in biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

: an indication of some living thing's presence
Medical sign
Medical sign
A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....

, in medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

: objective evidence of the presence of a disease or disorder, as opposed to a symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

, which is subjective
Sign (semiotics)
Sign (semiotics)
A sign is understood as a discrete unit of meaning in semiotics. It is defined as "something that stands for something, to someone in some capacity" It includes words, images, gestures, scents, tastes, textures, sounds – essentially all of the ways in which information can be...

: the basic unit of meaning
Information sign
Information sign
An information sign is a very legibly printed and very noticeable placard that informs people of the purpose of an object, or gives them instruction on the use of something. An example is a traffic sign such as a stop sign....

: a notice that instructs, advises, informs or warns people
People
People is a plurality of human beings or other beings possessing enough qualities constituting personhood. It has two usages:* as the plural of person or a group of people People is a plurality of human beings or other beings possessing enough qualities constituting personhood. It has two usages:*...
Traffic sign
Traffic sign
Traffic signs or road signs are signs erected at the side of roads to provide information to road users. With traffic volumes increasing over the last eight decades, many countries have adopted pictorial signs or otherwise simplified and standardized their signs to facilitate international travel...

: a sign that instructs drivers; see also stop sign
Stop sign
A Stop sign is a traffic sign to notify drivers that they must stop before proceeding.-Specifications:The Vienna Convention on Road Signs and Signals proposed standard stop sign diameters of 0.6, 0.9 or 1.2 metres. UK and New Zealand stop signs are 750, 900 or 1200 mm, according to sign...

, speed limit
Speed limit
Road speed limits are used in most countries to regulate the speed of road vehicles. Speed limits may define maximum , minimum or no speed limit and are normally indicated using a traffic sign...

sign, cross walk sign
Sign, in a writing system
Writing system
A writing system is a symbolic system used to represent elements or statements expressible in language.-General properties:Writing systems are distinguished from other possible symbolic communication systems in that the reader must usually understand something of the associated spoken language to...

: a basic unit. Similar terms which are more specific are character, letter or grapheme
Commercial signage, including flashing sign
Flashing sign
A flashing sign is a sign that contains a sequential flashing light source where the period of time of illumination is equal to the period of non-illumination, and is used solely to attract attention in a non-informative way....

s, such as on a retail store, factory, or theatre
Signature
Signature
A signature is a handwritten depiction of someone's name, nickname, or even a simple "X" that a person writes on documents as a proof of identity and intent. The writer of a signature is a signatory. Similar to a handwritten signature, a signature work describes the work as readily identifying...

, in history: a handwritten depiction observed on a document to show authorship and will

Nature

Types

See also