Ancient Computers (2015)
ethw.org
ethw.org
> But why base-60, 360 degrees in a circle, 7 days in a week, etc.? All from Sumer around 2500 BC (Wilson), and inherited by the Babylonians.
> The Sumerians were great innovators in matters of time. It is to them, ultimately, that we owe not only the week but also the 60-minute hour. Such things came easily to people who based their maths not on a decimal system but on a sexagesimal one.
> Why were these clever chaps, who went for 60 because it is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30, fascinated by stubbornly indivisible seven? ...
> They worshiped seven gods whom they could see in the sky [using modern names they are: Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn]. Reverently, they named the days of their week for these seven heavenly bodies.
> The product of 12 and 30 is 360, the number of degrees in a circle; did the Sumerians define the 360 degree circle? Probably, because dividing the Zodiac into 360 degrees means Jupiter traverses 30 degrees in a year and Saturn 12 degrees; thereby coupling the periods of the gods Jupiter and Saturn.
> The Sun tracks through the Zodiac in one year. Jupiter would track 1/12 of the way in that time. Why not divide a year into 12ths, i.e., 12 months
I wonder, did Mayans and Aztecs also use this system? Or Chinese or sub-Sahara Africans?
1. The Romans used an 8 day "week", although it was a bit loose at best; and,
2. The Mayans used a pair of interlocking 13- and 20- day "weeks" (months?) that formed a 260-day ... thing.
A cursory search suggests that the Romans used 12 equihour subdivisions of the day (so: there were always 12 hours from sun up to sun down). It looks like the Chinese used ... 15? There's no evidence I can turn up in my (meager) literature at home that suggests the Mayans subdivided their day.
The Sumerians did not worship 7 gods seen in the sky, that claim is an anachronism. Among those listed, initially they worshiped only the Sun and the Moon.
Some time, probably during the 4th millennium BC, the Sumerian goddess Inanna has become associated with the Morning Star and the Evening Star, after the Sumerians have made the very important discovery that the Morning Star and the Evening Star are the same celestial body, which is now known as the planet Venus, by a transfer from Inanna to the goddess Ishtar in Babylon, then to Aphrodite in Greece, and finally to the goddess Venus in Rome. (There is an intriguing possibility that the association between Inanna and the planet Venus might have been caused by the sight of a great comet. When they are visible, the comets are seen in the same places as Venus, i.e. not far from the Sun. When the great comet became invisible, Venus could become visible in about the same place, and the Sumerians could have interpreted the facts as that they had seen Inanna going to war and then returning to her peaceful state, as in some of their myths. There are some poems and drawings that suggest the possibility of such an interpretation. The memory of such an impressive celestial event would explain the great awe of the Sumerians for Inanna and her star, now the planet Venus. Otherwise it would have been normal to consider the Sun and the Moon as much more important.)
Except for the Sumerians and those who have inherited their culture, there is no evidence of ancient people who were aware that the Morning Star and the Evening Star are the same body, even as late as in the first half of the first millennium BC, e.g. Homer and the other early Greek writers do not appear to be aware of this, even if they mention both the Morning Star and the Evening Star very frequently.
So the Sumerians knew only 3 celestial bodies associated with gods.
The 4 planets Mercury, Mars, Jupiter and Saturn have been discovered by the Babylonians, some time in the second millennium BC, and eventually they became associated with 4 of the Babylonian gods, e.g. the planet named now Jupiter was the planet of Marduk. The Greeks took the god-planet associations from the Babylonians, then the Romans from the Greeks.
There is no evidence that anyone had any knowledge about Mercury, Mars, Jupiter and Saturn before the Babylonians.
Obviously the earlier people must have noticed that there are some places in the sky where some times a bright star can be seen (i.e. usually Jupiter or Mars), but some times the star is in a different position or it is no longer seen anywhere close.
However, until the star observations began to be recorded, continuously for many years, like in Babylon, no earlier than the 2nd millennium BC, it was not possible to decide how many of these random star sightings correspond to the same wandering star, or to different stars that appear and disappear, and how many such mobile stars exist.
(I have a brunsviga and a sliderule or two, as well as some abacus)
> If you stare at an old mechanical calculator it just sits there. It does no computing and is, therefore, not a computer. When a person starts punching the keys and turning the crank the person-device computes and is a computer. So too, an abacus is just an assembly of beads and rods or lines and pebbles, and is not a computer. But when a person uses the abacus to perform calculations, then the person-abacus is a computer.