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Present (time)
Encyclopedia
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
that is associated with the events perceived
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...
directly and in the first time, not as a recollection (perceived more than once) or a speculation (predicted, hypothesis, uncertain). It is a period of time between the past and the future, and can vary in meaning from being an instant to a day or longer. In radiocarbon dating
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...
, the "present" is defined as AD 1950.
It is sometimes represented as a hyperplane
Hyperplane
A hyperplane is a concept in geometry. It is a generalization of the plane into a different number of dimensions.A hyperplane of an n-dimensional space is a flat subset with dimension n − 1...
in space-time, typically called "now", although modern physics demonstrates that such a hyperplane can not be defined uniquely for observers in relative motion. The present may also be viewed as a duration (see specious present
Specious present
The specious present is the time duration wherein one's perceptions are considered to be in the present. Time perception studies the sense of time, which differs from other senses since time cannot be directly perceived but must be reconstructed by the brain....
).
Society and religion
Contemporary history
Contemporary history
Contemporary history describes the period timeframe that is without any intervening time closely connected to the present and is a certain perspective of modern history. The term "contemporary history" has been in use at least by the early 19th century. In the widest context of this use,...
describes the historical timeframe that is immediately relevant to the present time and is a certain perspective of modern history
Modern history
Modern history, or the modern era, describes the historical timeline after the Middle Ages. Modern history can be further broken down into the early modern period and the late modern period after the French Revolution and the Industrial Revolution...
.
General overview
The present is contrasted with the pastPast
Most generally, the past is a term used to indicate the totality of events which occurred before a given point in time. The past is contrasted with and defined by the present and the future. The concept of the past is derived from the linear fashion in which human observers experience time, and is...
and the future
Future
The future is the indefinite time period after the present. Its arrival is considered inevitable due to the existence of time and the laws of physics. Due to the nature of the reality and the unavoidability of the future, everything that currently exists and will exist is temporary and will come...
. Modern physics
Modern physics
The term modern physics refers to the post-Newtonian conception of physics. The term implies that classical descriptions of phenomena are lacking, and that an accurate, "modern", description of reality requires theories to incorporate elements of quantum mechanics or Einsteinian relativity, or both...
has not yet been able to explain the perceived aspect of 'the present' as 'eliminator of possibilities' that transfers future into past. A complicating factor is that whilst a given observer would describe 'the present' as a spatial structure with a zero-length time lapse, other observers would associate both time and space to this structure and therefore disagree on what constitutes 'the present'.
The direct experience of the present for each human is that it is what is here, now. Direct experience is of course subjective by definition yet, in this case, this same direct experience is true for all humans. For all of us, 'here' means 'where I am' and 'now' means 'when I am'. Thus, the common repeatable experience is that the present is inextricably linked to oneself.
In the time aspect, the conventional concept of 'now' is that it is some tiny point on a continuous timeline which separates past from future. It is not clear, however, that there is a universal timeline or whether, as relativity seems to indicate, the timeline is inextricably linked to the observer. Thus, is 'now' for me the same time as 'now' for you on a universal timeline, assuming a universal timeline exists? Adding to the confusion, in the physics view, there is no demonstrable reason why time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
should move in any one particular direction.
Adding substance to the supposition that the timeline view of 'now' may not hold the full picture, the qualities of 'now' or the 'present' in the human direct experience are very different from the qualities of past and future available through memory or anticipation. In the human direct experience, 'now' has a certain aliveness, reality and immediacy not present in our concepts of past and future. Indeed, any experience is always happening 'now', even a re-living of some past event. Thus, there is a deep philosophical case for saying that the present moment is all there ever is, from moment to moment.
When comparing time in places separated by great distances, the notion of present becomes more subjective. For example, we visually perceive star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s to be where they were when the light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
now reaching our eyes was emitted, because even though light travels at approximately 300000000 m/s
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
, it takes many years to reach us from distant sources. Thus, light travel time must be taken into account in such time comparisons.
When used in the term "Before Present
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
" (BP), as used in expressing ages or dates determined by radiocarbon dating
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...
, "Present" is defined as AD 1950.
The present in Buddhism
BuddhismBuddhism
Buddhism is a religion and philosophy encompassing a variety of traditions, beliefs and practices, largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha . The Buddha lived and taught in the northeastern Indian subcontinent some time between the 6th and 4th...
and many of its associated paradigm
Paradigm
The word paradigm has been used in science to describe distinct concepts. It comes from Greek "παράδειγμα" , "pattern, example, sample" from the verb "παραδείκνυμι" , "exhibit, represent, expose" and that from "παρά" , "beside, beyond" + "δείκνυμι" , "to show, to point out".The original Greek...
s emphasize the importance of living in the present moment — being fully aware of what is happening, and not dwelling on the past
Past
Most generally, the past is a term used to indicate the totality of events which occurred before a given point in time. The past is contrasted with and defined by the present and the future. The concept of the past is derived from the linear fashion in which human observers experience time, and is...
or worrying about the future
Future
The future is the indefinite time period after the present. Its arrival is considered inevitable due to the existence of time and the laws of physics. Due to the nature of the reality and the unavoidability of the future, everything that currently exists and will exist is temporary and will come...
. This does not mean that they encourage hedonism
Hedonism
Hedonism is a school of thought which argues that pleasure is the only intrinsic good. In very simple terms, a hedonist strives to maximize net pleasure .-Etymology:The name derives from the Greek word for "delight" ....
, but merely that constant focus on one's current position in space and time (rather than future considerations, or past reminiscence) will aid one in relieving suffering. They teach that those who live in the present moment are the happiest. A number of meditative
Buddhist meditation
Buddhist meditation refers to the meditative practices associated with the religion and philosophy of Buddhism.Core meditation techniques have been preserved in ancient Buddhist texts and have proliferated and diversified through teacher-student transmissions. Buddhists pursue meditation as part of...
techniques aim to help the practiser live in the present moment.
Christianity and eternity
For some Christians GodGod
God is the English name given to a singular being in theistic and deistic religions who is either the sole deity in monotheism, or a single deity in polytheism....
is viewed as being outside of time and, from the divine perspective past, present and future are actualized in the now of eternity
Eternity
While in the popular mind, eternity often simply means existence for a limitless amount of time, many have used it to refer to a timeless existence altogether outside time. By contrast, infinite temporal existence is then called sempiternity. Something eternal exists outside time; by contrast,...
. This trans-temporal conception of God has been proposed as a solution to the problem of divine foreknowledge (i.e. how can God know what we will do in the future without us being determined to do it) since at least Boethius. Thomas Aquinas
Thomas Aquinas
Thomas Aquinas, O.P. , also Thomas of Aquin or Aquino, was an Italian Dominican priest of the Catholic Church, and an immensely influential philosopher and theologian in the tradition of scholasticism, known as Doctor Angelicus, Doctor Communis, or Doctor Universalis...
offers the metaphor of a watchman, representing God, standing on a height looking down on a valley to a road where past present and future, represented by the individuals and their actions strung out along its length, are all visible simultaneously to God. Therefore, God's knowledge is not tied to any particular date.
Philosophical problem
"The present" raises the difficult question: "How is it that all sentient beings experience now at the same time?" There is no logical reason why this should be the case and no easy answer to the question. For example, say somebody named John is experiencing a great deal of pain. John's friend Sarah takes pity on John because of John's situation. The problem is: is it logical for Sarah to feel bad for John at present, when there is no way to prove that both John and Sarah experience the same temporal existenceTemporal parts
Temporal parts is a concept used in contemporary metaphysics in the debate over the persistence of material objects. Objects typically have parts that exist in space—a human body, for example, has spatial parts like hands, feet, and legs. Some metaphysicians believe objects have temporal parts as...
? (See also Solipsism
Solipsism
Solipsism is the philosophical idea that only one's own mind is sure to exist. The term comes from Latin solus and ipse . Solipsism as an epistemological position holds that knowledge of anything outside one's own mind is unsure. The external world and other minds cannot be known, and might not...
and Philosophy of mind
Philosophy of mind
Philosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
.)
Special Relativity's "present"
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
's Special Theory of Relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
that there is no such thing as absolute simultaneity
Relativity of simultaneity
In physics, the relativity of simultaneity is the concept that simultaneity–whether two events occur at the same time–is not absolute, but depends on the observer's reference frame. According to the special theory of relativity, it is impossible to say in an absolute sense whether two events occur...
. When care is taken to operationalise
Operational definition
An operational definition defines something in terms of the specific process or set of validation tests used to determine its presence and quantity. That is, one defines something in terms of the operations that count as measuring it. The term was coined by Percy Williams Bridgman and is a part of...
"the present", it follows that the events that can be labeled as "simultaneous" with a given event, can not be in direct cause-effect relationship
Causality (physics)
Causality is the relationship between causes and effects. It is considered to be fundamental to all natural science, especially physics. Causality is also a topic studied from the perspectives of philosophy and statistics....
. Such collections of events are perceived differently by different observers. Instead, when focusing on "now" as the events perceived
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...
directly, not as a recollection or a speculation, for a given observer "now" takes the form of the observer's past light cone
Light cone
A light cone is the path that a flash of light, emanating from a single event and traveling in all directions, would take through spacetime...
. The light cone of a given event is objectively defined as the collection of events in causal relationship
Causality (physics)
Causality is the relationship between causes and effects. It is considered to be fundamental to all natural science, especially physics. Causality is also a topic studied from the perspectives of philosophy and statistics....
to that event, but each event has a different associated light cone. One has to conclude that in relativistic models of physics there is no place for "the present" as an absolute element of reality. Einstein phrased this as: "People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion".
Today vs. Now
"Today" signifies a "dayDay
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...
" in a 24-hour interval to signify one's stance within the plane of time, this is contrary to "now", because "now" has no definite measure for its own duration. On the graph of Space-Time, the present can appear to be infinitely small, or account for a large portion of a sequence.
See also
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Deixis In linguistics, deixis refers to the phenomenon wherein understanding the meaning of certain words and phrases in an utterance requires contextual information. Words are deictic if their semantic meaning is fixed but their denotational meaning varies depending on time and/or place... |