Notice: This is the official website of the All Empires History Community (Reg. 10 Feb 2002)

  FAQ FAQ  Forum Search   Register Register  Login Login

Time measurement origin

 Post Reply Post Reply
Author
Melqart View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 02-May-2006
Location: France
Online Status: Offline
Posts: 0
  Quote Melqart Quote  Post ReplyReply Direct Link To This Post Topic: Time measurement origin
    Posted: 02-May-2006 at 05:20

Hello,

Does anybody know where does our universal time scales (hour, minute, second) come from ? I have been told that they came from the Babylonians but I dont understand why we decided to divide the day in 24 hours and the hour in 60 minutes and so on ? Does any one have any idea ?

Thanks

Back to Top
Leonardo View Drop Down
General
General
Avatar

Joined: 13-Jan-2006
Location: Italy
Online Status: Offline
Posts: 778
  Quote Leonardo Quote  Post ReplyReply Direct Link To This Post Posted: 02-May-2006 at 08:00
Originally posted by Melqart

Hello,

Does anybody know where does our universal time scales (hour, minute, second) come from ? I have been told that they came from the Babylonians but I dont understand why we decided to divide the day in 24 hours and the hour in 60 minutes and so on ? Does any one have any idea ?

Thanks

 

The usage to devide the day in 24 hours derives from ancient Egyptians and the usage of a sexagesimal unit for minutes and seconds derive from ancient Babylonians.

Back to Top
Melqart View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 02-May-2006
Location: France
Online Status: Offline
Posts: 0
  Quote Melqart Quote  Post ReplyReply Direct Link To This Post Posted: 02-May-2006 at 18:18
Thanks for your answer. Do you know why did they chose to devide the day in 24 hours ? and why use a sexadesimal unit ?
Back to Top
Leonardo View Drop Down
General
General
Avatar

Joined: 13-Jan-2006
Location: Italy
Online Status: Offline
Posts: 778
  Quote Leonardo Quote  Post ReplyReply Direct Link To This Post Posted: 03-May-2006 at 15:30

About the 24 hours in a day a possible reconstruction of its introduction by ancient Egyptians is the following.

Ancient Egyptians used to devide the ecliptic constellations in 36 "decans" of equal lenght (360:36= 10). During a night at the average latitude of Egypt rise and fall (theoretically) 18 decans (each corresponds to 40 minutes of sidereal time), but due to dusk and twilight only 12 were taken into account when reckoning time at night. So they used to devide the night in 12 equal parts. Symmetrically they extended this subdivision of time also to the daylight and so we have 12 + 12 = 24 hours in a day.

About the usage of a sexagesimal unit by the ancient Babylonians I have read about two (at leat) possible explanations: a astronomical one and  a mathematical one. The first considers an approximation of the measure of the year as 360 days and 360 = 60 x 6. The second considers the number 60 as a "good" number because it is neither too big nor too little and it has a high set of divisors: 2, 3, 4, 5, 6, 10, 12, 15, 20, 30.

Nota bene: these are only possible but not sure explanations and they are disputed by some historians of astronomy.

Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.56a [Free Express Edition]
Copyright ©2001-2009 Web Wiz

This page was generated in 0.109 seconds.