Instant

{{Short description|Shortest interval in time}} In physics and the philosophy of science, '''instant''' refers to an infinitesimal interval in time, whose passage is instantaneous. In ordinary speech, an '''instant''' has been defined as "a point or very short space of time," a notion deriving from its etymological source, the Latin verb ''instare'', from ''in-'' + ''stare'' ('to stand'), meaning 'to stand upon or near.'<ref>''Webster's New World College Dictionary'', 4th ed. (1999), p. 740.</ref>

The continuous nature of time and its infinite divisibility was addressed by Aristotle in his ''Physics'', where he wrote on Zeno's paradoxes. The philosopher and mathematician Bertrand Russell was still seeking to define the exact nature of an instant thousands of years later.<ref>{{citation |chapter-url=https://books.google.com/books?id=29E9AAAAIAAJ&pg=PA129 |title=The structure of time |author=W. Newton-Smith |chapter=The Russellian construction of instants |page=129 |publisher=Routledge |year=1984 |isbn=978-0-7102-0389-2}}</ref>

{{As of|2020|October}}, the smallest time interval certified in regulated measurements is on the order of 397 zeptoseconds (397 × 10<sup>−21</sup> seconds).<ref>{{cite web|url=https://www.sciencedaily.com/releases/2020/10/201016090209.htm|title=Zeptoseconds: New state record in short time measurement|last=|first=|date=2020-10-16|website=|publisher=Science Daily|access-date=2010-05-12}}</ref>

==In correspondence== In correspondence, particularly before the twentieth century, instant (usually abbreviated to inst.) can be used to indicate "of the current month". For example, "the 11th inst." means the 11th day of the current month.<ref>{{cite web |url = https://www.oxfordreference.com/display/10.1093/oi/authority.20110803100005710 |publisher = Oxford University Press | website = oxfordreference.com | title = instant | access-date = 2024-07-05 }}</ref><ref>{{Cite book |last=Chambers |first=Alfred B. |url=https://www.gutenberg.org/cache/epub/56911/ |title=The New Century Standard Letter-Writer |publisher=Laird & Lee |year=1900 |location=Chicago |pages=258 |language=en-US}}</ref> Its use is consistent with the Latin ''proximo'' (prox.) for the following month, and ''ultimo'' (ult.) for the month just past.<ref>{{Cite book |last=Crowther |first=Mary Owens |url=https://www.gutenberg.org/cache/epub/22222/pg22222-images.html |title=How to Write Letters |publisher=Garden City Publishing Co. |year=1922 |location=New York |pages=41 |language=en-US}}</ref>

==See also== {{Wikt}} * Infinitesimal * Planck time * Present

==References== {{reflist}}

Category:Time