# Time - What does it means according to physics and philosophy, and its characteristics

###### Time and other conceptions

We explain what time is, the different meanings it has according to physics and philosophy and what its characteristics are.

## What is time?

Time is, in a general sense, a physical magnitude that is used to measure the duration, simultaneity and separation of facts and events. This makes it possible to order events in a sequence, from which the notions of past, future and present emerge.

The term “time” comes from the Latin tempus, which means “extent” or “measure”. Time is thought of as the duration of the states of things that are subject to change.

Whether from philosophy, physics, quantum mechanics or the theory of relativity, it is problematic to find a single answer about what time is (its ontological condition), how we know it (its knowability) and what are its properties and its relation to space.

On the other hand, time is a unit of measurement of daily use. The development of the life of human beings is mediated by the transition between one moment and another of their daily, historical and social life.

## Time in physics

From physics it is possible to define time as the separation of events that are subjected to change. It is also understood as a flow of events.

In this way, events are organized in sequences that determine their belonging to past, present and future time.

The International System of Units determined the second (S) as the basic unit of time. This determination constitutes the common point between the different conceptions of time:

• Classical mechanics: Consider time as an absolute magnitude , identical for all observers. From it follows the classification into (1) past events, (2) the present as an observation point of view, and (3) future events.
• Relativistic mechanics: For relativistic mechanics, time is relative. This means that the time values can vary depending on who the observer is, the reference system used and the point where they are. It may happen that for two observers, two events A and B occur simultaneously or one before the other, depending on their position and their reference system.

## Time in philosophy

Time is one of the central axes of philosophy. From Antiquity to the present day, different philosophers and thinkers wondered about the nature of time, if it is something real, if it is measurable, if we can know it or even if we can talk about time, whether it exists or not.

Philosophical investigations regarding time usually address their object of study in relation to space. Among their points of discussion, we can distinguish the following issues:

• The ontological autonomy of time with respect to the mind.
• The possibility that time exists independently of space .
• The difficulty in explaining time linearly.
• The existence of dimensions of time other than the present (past and future).
• The change of state of a given object in space-time.

Among the different responses to these concerns, it is worth noting the canonical ideas of some historical philosophers.

• Aristotle: It relates time to movement , just like in physics. It defines time as that measure of movement in relation to what preceded and what happened.
• Saint Augustine: It relates time with the soul. This is because the past is something that no longer exists, the future something that will come and the present slips away, becoming a memory, which, being part of memory, is located in the soul.
• Immanuel Kant: It relates time to sensitivity. In the Kantian system, space and time are forms of sensibility: we receive the information that objects give us as something spatiotemporal. Without being something in itself, time and space are only forms, channels, filters.

Currently there are different philosophical positions regarding time. Contemporary thinkers such as Martin Heidegger, Edmund Husserl, Henri Bergson, Giles Deleuze, Jacques Derrida or Jean-Luc Marion wrote numerous works that approach the issue from a philosophical position.

## Time and other conceptions

Science and philosophy are the disciplines that worked the most at the time, but also other branches of science meditate on the issue. Theology, politics or sociology approach time from their particular approach.

Finally, we can mention another meaning of time, which refers to atmospheric weather: the state of the atmosphere at a given time and place.

The weather depends on factors such as atmospheric pressure, temperature, cloudiness, wind and humidity, among others.