The past is the portion of time that has already occurred;[1] it is the opposite of the future.
Contents |
Overview
The past is contrasted with the present. It is also regarded as the conglomerate of events that happened in a certain point in time, within the Space-time continuum. The aforementioned conception is closely related to Albert Einstein's relativity theory. The past is the object of such fields as history, archaeology, archaeoastronomy, chronology, geology, (historical geology), historical linguistics, law, paleontology, paleobotany, paleoethnobotany, palaeogeography, paleoclimatology, and cosmology.
Humans have recorded the past since ancient times, and to some extent, one of the defining characteristics of human beings is that they are able to record the past, recall it, remember it and confront it with the current state of affairs, thus enabling them to plan accordingly for the future, and to theorise about it as well.
Philosophy and science
According to presentism, the past does not strictly exist; however, the methods of all sciences study the world's past, through the process of evaluating evidence. Presentism is compatible with Galilean relativity, in which time is independent of space but is probably incompatible with Lorentzian/Einsteinian relativity in conjunction with certain other philosophical theses which many find uncontroversial.
A visualisation of the past light cone (at bottom), the present, and the future light cone in 2D space.In classical physics the past is just a half of the timeline. In special relativity the past is considered as absolute past or the past cone. In Earth's scale the difference between "classical" and "relativist" past is less than 0.05 s, so it can be neglected in most cases.
In the modern theory of relativity, the conceptual observer is at a geometric point in both space and time at the apex of the 'light cone' which observes events laid out in time as well as space. Different observers can disagree on whether two events at different locations occurred simultaneously depending if the observers are in relative motion (see relativity of simultaneity). This theory depends upon the idea of time as an extended thing and has been confirmed by experiment and has given rise to a philosophical viewpoint known as four dimensionalism. However, although the contents of an observation are time-extended, the conceptual observer, being a geometric point at the origin of the light cone, is not extended in time or space. This analysis contains a paradox in which the conceptual observer contains nothing, even though any real observer would need to be the extended contents of an observation to exist. This paradox is partially resolved in Relativity theory by defining a 'frame of reference' to encompass the measuring instruments used by an observer. This reduces the time separation between instruments to a set of constant intervals.[2]
For more details on axis of time, see Arrow of time.Quote
| “ | Those who cannot remember the past are condemned to repeat it. — George Santayana from The Life of Reason[3] | ” |
See also
| Look up past in Wiktionary, the free dictionary. |
References
- ^ Hegeler, E. C., & Carus, P. (1890). The Monist. La Salle, Ill. [etc.]: Published by Open Court for the Hegeler Institute. page 443.
- ^ Petkov 2005
- ^ 284 Santayana, George (1905). The Life of Reason: Reason in Common Sense. New York: Charles Scribner's Sons.
Categories: Time
|
Times Record News, TX
Connor (Matthew McConnaughey) is a player who should have treated his ex (Jennifer Garner) and all his past girlfriends better, otherwise he wouldn't be visited by his past , present and future flames in Ghosts of Girlfriends Past . ...
Ghosts of Girlfriends Past TheCelebrityCafe.com
Ghosts of girlfriends past The Age
The Lurking Ghosts of Rom-Coms Past Daily Nexus
Seattle Times - Journal Review
all 107 news articles
600px x 900px | 86.40kB
[source page]
Find More Pictures from Half Past Dead and read our reviews Michael Taliferro Ja Rule and Kurupt in Columbia s Half Past Dead 2002
Norman Rogers
Wed, 01 Jul 2009 12:06:24 GM
I can't get . past. the idea that he was "summoned" as if he were reporting for a useless round of waiting to be called for jury duty. Shouldn't a blogger be a bit more enthusiastic about being exposed to the opinions of a think tank? ...
Q. Also, because inflation has maintained a steady rate for the past 8 years, could this mean we could be headed towards a period of hyperinflation? And please no stupid answer like "George Bush" or "because the world hates us" real macroeconomic theories
Asked by kazmaniandevil05 - Tue Apr 22 07:09:38 2008 - - 2 Answers - 0 Comments
A. It's really quite simple. For the past several years, interest rates have been low, and money has flowed rather easily through the economy. Lower interest rates usually lead to greater spending, and this helps the economy. The downside of this is that lower interest rates drive investors away to other currencies where interest rates are higher. This increases exports and decreases imports, because the dollar buys fewer foreign goods, but domestic goods are priced at a discount versus foreign goods. This cycling helps with Balance of Trade, but it can develop into inflation, so interest rates tend to rise to combat this. This increase in interest rates caused turmoil in world markets, because it caused major adjustments for those who… [cont.]
Answered by Randall Parker, MBA - Tue Apr 22 07:33:39 2008
