# Tag Info

20

In case anyone is curious, Wikipedia provided no help. The articles on the hour and the minute have no in-line citations in their relevant sections, and I don't think they'll lead anywhere interesting. Fortunately (believe it or not), there are other sources online besides Wikipedia. So I'll go to those. From this site: The Babylonians (about 300-100 B.C....

15

First of all, whether the earth is rotating or everything else is rotating around it, is completely irrelevant for the question. This is just the matter of point of view. As seen from the earth, the fixed stars rotate with period day+night. On this background, the Sun describes a circle slowly with period "one year". When one looks closely, one sees that ...

14

It comes from the ancient Babylonian numeration system which had base 60. (The reason for the choice of such a base is simplicity of calculation: 60 is divisible by 2,3,4,5,6,10,12,15,20,30. Much more convenient than base 10, whose only justification is the number of fingers on both hands). It was used mainly in astronomy (ancient people had little need in ...

10

The French Revolution introduced a decimal clock, where the day was divided into 10 "hours" each, these hours into 100 minutes, and these minutes into 100 seconds. The clock looked like this: https://en.wikipedia.org/wiki/Decimal_time#/media/File:Clock-french-republic.jpg

6

The ancients distinguished two separate motions of the sun. On the one hand, the sun and all the stars seem to rotate around the Earth from East to West once every day. This was explained by the daily rotation of the sphere of the fixed stars. At the same time, the sun, moon and planets move in the opposite direction, along the ecliptic, around the Earth, ...

5

French Revolutionary time had ten hours to the day, 100 minutes to the hour, and 100 secnds to the minute. That same article describes a couple of other instances of decimal time.

4

The first written account of the phenomenon might be due to Eratosthenes (276-195 BC), the head of Alexandrian Museum and contemporary of Archimedes, with whom he corresponded. Eratosthenes is credited with proposing to use longitude and latitude to specify locations on Earth, an idea developed further by Hipparchus (190-120 BC), "the father of astronomy", ...

4

This is an interesting question because the answer depends on how you actually conceptualise time. In the ancient world, the usual system of time keeping involved “seasonal hours”. This means that the time from sunrise to sunset is divided into 12 equal “hours of the day” and the time from sunset to sunrise is divided into 12 equal “hours of the night”. The ...

4

The use of a base 60 number system in Babylon is mentioned at http://www.storyofmathematics.com/sumerian.html where it says, "Sumerian and Babylonian mathematics was based on a sexegesimal, or base 60, numeric system, which could be counted physically using the twelve knuckles on one hand, the five fingers on the other hand." (That presumably was supposed to ...

4

Right after your quote Wikipedia has "In 1267, the medieval scientist Roger Bacon, writing in Latin, defined the division of time between full moons as a number of hours, minutes, seconds, thirds, and fourths (horae, minuta, secunda, tertia, and quarta) after noon on specified calendar dates". This use was retained in astronomy but not colloquially, ...

3

This is an immediate logical consequence of sphericity of the Earth. Greek tradition credits sphericity to Pythagoras, but modern historians even doubt that he ever existed. So the question has no exact answer. Those Greek writers on astronomy and geography whose work survived take this fact as evident. Chinese mathematicians who thought that the Earth is ...

3

Electricity has nothing to do with the question. Clocks which could count minutes and seconds were purely mechanical and precise mechanical clocks (which could count seconds reliably) were invented in 18th century. Until 1970s most wristwatches were mechanical. They are available nowadays as well but good ones are expensive. People did not count minutes and ...

2

Because the various "calendar modifications" in Western Europe during the ages were driven by political and religious "interests" and not by scientific ones. European calendar is basically due to Ancient Rome; see Roman calendar : The Roman calendar changed its form several times between the founding of Rome and the fall of the Roman ...

2

The estimate of the length of the tropical year and the synodic month by Meton, Hipparchus and others has no bearing on the system of four-year Olympiads. The use of a 365-day year with a leap day every four years was introduced by Julius Caesar in the first century BC. A similar calendar had previously been decreed in Egypt in 238 BC, but never actually ...

2

It is unknown why the 4 year period, a.k.a. the olympiad, was chosen. Most of the writings concerning the origins of the games come from 2nd century AD historians, nine centuries after the fact, and are largely mythological. According to one of them, Pausanias, "dactyl" Herakles and his four brothers, Paeonaeus, Epimedes, Iasius and Idas, raced at Olympia to ...

2

I was trying to figure out how people came to know about time then I realized that people started keeping track of time to know about sunset and sunrise. People first kept track of time to know about the seasons, not sunrise and sunset. Knowing when to plant and when to harvest was a critical step in humanity's neolithic advancement. This knowledge was ...

2

By looking at stars position with respect to the point of intersection of the ecliptic and equator (this is a position of the Sun at the equinox). Or which is the same at the position of this point among the stars. This position varies slowly (this is called precession of the equinox), and it was discovered by Hipparchus. Hipparchus work did not survive and ...

2

Indian and Chinese calendars are astronomical, in that for instance dates are based on the exact moment of astronomical events. So wheter for instance a new Moon falls one second before or after midnight (in the Chinese case) or one seconde before or after sunrise (in the Indian case), can change the date of the start of a lunar month. That's why ...

2

The Jantar Mantar monument in Jaipur was built on the orders of the Rajput king Sawai Jai Singh II, and completed in 1734. Aside from the sundial it has an observatory with various other instruments for astronomical observations with the naked eye. Apparently the zīj at the time, Indian/Islamic version of ephemerides, were not very accurate, and the king ...

2

Oxford English Dictionary third, adj. (and adv.) and n. Definition B.7.a. The third of the subdivisions of any standard measure or dimension which is successively subdivided in a constant ratio; the subdivision next below seconds: see prime n.2 2 ... with some quotes 1595 J. Davis Seamans Secrets i. sig. B4, Euery degree..doth containe 60 minutes, ...

1

Weizsäcker did not change his mind and continued to develop "temporal logic" until 1990-s (e.g. in Zeit und Wissen, 1992). It is central to his general idea of the relationship between logic and physics inspired by Kant's idea that time is a precondition of experience of events/phenomena. Weizsäcker's views were quite distinct from then (and even now) common ...

1

How did people count seconds before clocks were invented? In general, they didn't, because there was no need to to so. The need for accuracy to the level of a second or less is a very recent need. Before the invention of trains and telegraphs, there was no need for even hour level accuracy, let alone minute or second level accuracy. Whether the roads were ...

1

Hipparchus, who lived in the 2nd century BCE, calculated the length of the synodic lunar month as 29.53059 days, and that of the tropical year as 365.24667 days (though he expressed both values not in decimal notation but in sexagesimal notation). These values were adopted by Ptolemy and became “common knowledge” among people who were interested in astronomy,...

1

EDITED. To add some more information to fdb's answer. They divided the day+night period into 10 hours, so their hour was more than 2 of our hours. They also introduced decimal units for angles (which is closely related to time). 100 decimal degrees in the right angle, so all circumference makes 400 degrees. Every decimal degree is divided in 100 decimal ...

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