Babylon's Horizon

Updated: 25th July 2020 19:01 (UTC)

This article builds on the discussion found in Timed Events it is best to consider that article first

Did the walls of Babylon create a horizon?

Babylon is situated in a wide valley, from a high tower in Babylon it would be possible to see for many miles (Check out this site). It's been surmised that the astronomical observations were made within the city walls from a high tower or the walls themselves. The walls were reported to be very high, some say as much as 97 metres high (320'), which is hard to believe. If the observations were made from this kind of height, then the horizon would be a long way off without any obstruction. This is probably the assumption of modern day scholars studying astronomical diaries.

What difference does it make if the horizon is higher?

For the purpose of this website, if there was just a small difference in the height of the horizon that would make some of the observations in 568 BC impossible. The observations affected the most are the "one god seen with the other". It would also affect all the "sunset to moonset" times on the tablet. Not just this tablet, it could affect most of the timed events on astronomical diaries.

Is there evidence of a higher horizon in Babylon?

The article Timed Events demonstrates how many of these times are not accurate. No amount of adjusting the horizon up or down produces consistent results for the events they are meant to be measuring. It's almost as if they were timing something else.

The timed rising of Jupiter to sunrise in 379 BC is of interest (-378 Obv 7). The diary gives a time of 11.5° which equates to 46 minutes. That is the exact time between Jupiter rising above the horizon to when the Sun rose, and yet 48 hours earlier presumably the same observer with the same timer was 56% out with the time between sunrise to moonset! How can one measurement be so precise and yet another time be incorrect?

Consider, the measurement of time between Jupiter rising and the Sun rising (in 379 BC) is not affected by the height of the horizon. The reason for this is because they are both rising over the same horizon. Whereas the time measurement that is out by 56% is between two opposite horizons (east and west).

Another consideration is that acronychal risings are said to be calculated once the rising planets are seen for the first time. This calculation is made backwards to when they think the planet would have been at the true horizon (Source). It makes you wonder how the time between Jupiter and the Sun rising was observed, if the acronychal rising of a planet was difficult to observe on the day it occurred. Could it be that the Babylonians knew that the wall created a higher horizon? Maybe acronychal risings were calculated back to when it would have been visible if they had observed it from the city wall. Did they also know that it didn't affect the time between the two rising bodies of Jupiter and the Sun in 379 BC.

The Twilight Zone

If the observations were made from behind the walls in Babylon in a position where the walls created a higher horizon, this creates a couple of possibilities

Firstly, could this fortuitously put the observer in the optimum situation to view the moon. How so? If you want to observe Venus during the day, it is easier if you completely block out the Sun with something like a building. The high walls in Babylon would be perfect way to block the Sun for the observer. Maybe from this vantage point early sightings of the new Moon were possible.

Secondly, if there was a higher horizon (higher than 0°) how would this affect the timed events? As mentioned above if you consider the very varied accuracy of the timed events it is difficult to determine what is being timed . Due to the amount of inaccurate times VAT 4956.com experimented with the times using different horizon heights. The results are reproduced below. The purpose of the experiment was to see if the times could be related to another event.

How did the experiment work?

The events are identified on the tablet by the NA symbol, which is translated as one of the Lunar Six intervals (Sachs & Hunger, 1988), either "sunset to moonset" or "moonset to sunrise" depending on what time of the day it is interpreted to be measuring. Only times identified by the NA symbol will be considered.

Assumptions: Timed events made in the evening were triggered by the Sun setting and the events measured in the morning ended when the Moon set. This was based on the Sun being the god of the Day and the Moon being the god of the night.

The horizons: The west horizon was set at 3° 30' above the true horizon. The east horizon was set at 2° 30' above the true horizon. These heights were arrived at by raising them by 30' at a time.

This experiment tried to simulate the perceived beginning and end of twilight either after the Sun set (Beginning or end of the month) or before the Moon set in the morning (around the middle of the month) This was carried out using the method below

  • When the setting Sun reached the 3° 30' horizon in the west the position of the Sun was recorded after the amount of minutes in the tablet had passed. This would be the distance in degrees the Sun was below the horizon (the height of the horizon was added to this amount).
  • For the early morning times when the setting Moon reached the 2° 30' horizon the position of the Sun was recorded after the amount of minutes were subtracted. This would record the position of the Sun below the horizon prior to the Moon setting (the height of the horizon was added to this amount).

The calculated result represented the amount of degrees the Sun was below the horizon created by the walls.

Anythingabove -7° 30' was considered a fail. The results are reproduce below:

No.YearMdDate°MinsStartEndHorizonTotal
VAT4956 - Data for year 588 BC
1-587Obv 4114BC588-05-16NA41603:53-13°52'16.8" 02°30'00.0"-16°22'16.8"Twilight Start to Moonset
2-5882262392
3-587Obv 1231BC588-06-30NA208018:45-11°08'58.8" 03°30'00.0"-14°38'58.8"Sunset to Twilight End
4-587Obv 17315BC588-07-15NA7.53003:55-11°07'32.8" 02°30'00.0"-13°37'32.8"Twilight Start to Moonset
5-587Rev 5111BC587-02-22NA14.55817:30-08°47'58.2" 03°30'00.0"-12°17'58.2"Sunset to Twilight End
6-587Rev 81115BC587-03-08NA72805:48-09°38'33.1" 02°30'00.0"-12°08'33.1"Twilight Start to Moonset
6-587Rev 81115BC587-03-08NA176805:48-18°04'37.3" 02°30'00.0"-20°34'37.3"Twilight Start to Moonset
7-587Rev 12121BC587-03-24NA2510017:51-17°53'06.1" 03°30'00.0"-21°23'06.1"Sunset to Twilight End
8-588Rev 161212BC587-04-05NA1.5604:44-14°57'21.7" 02°30'00.0"-17°27'21.7"Twilight Start to Moonset
VAT4956 - Data for year 568 BC
1-568Obv 4114BC568-05-06NA41604:51-04°58'46.4" 02°30'00.0"-07°28'46.4"Twilight Start to Moonset
2-567226BC568-06-172392
3-567Obv 1231BC568-06-20NA208018:42-11°12'01.4" 03°30'00.0"-14°42'01.4"Sunset to Twilight End
4-567Obv 17315BC568-07-05NA7.53004:29-04°20'32.5" 02°30'00.0"-06°50'32.5"Twilight Start to Moonset
5-567Rev 5111BC567-02-12NA14.55817:21-08°26'16.8" 03°30'00.0"-11°56'16.8"Sunset to Twilight End
6-567Rev 81115BC567-02-27NA72807:22+07°40'38.6" 02°30'00.0"+05°10'38.6"Twilight Start to Moonset
6-568Rev 81115BC567-02-27NA176806:42-00°34'32.0" 02°30'00.0"-03°04'32.0"Twilight Start to Moonset
7-567Rev 12121BC567-03-14NA2510017:44-17°45'09.2" 03°30'00.0"-21°15'09.2"Sunset to Twilight End
8-568Rev 161212BC567-03-26NA1.5605:42-05°48'45.7" 02°30'00.0"-08°18'45.7"Twilight Start to Moonset
Data for other diaries
9-463Obv 2527BC464-09-04NA145618:09-08°22'42.8" 03°30'00.0" -11°52'42.8"Sunset to Twilight End
10-463Obv 561BC464-09-08NA187218:05-11°39'01.3" 03°30'00.0"-15°09'01.3"Sunset to End of Twilight
11-463Obv 8614BC464-09-21GE63.514
12-453UE 4111BC453-02-12NA145617:22-08°03'27.5" 03°30'00.0"-11°33'27.5"Sunset to Twilight end - Dense clouds
13-418BObv 281BC419-10-19NA208017:12-13°35'37.5"-03°30'00.0"-17°05'37.5"Sunset to End of Twilight
14-384Obv 8915BC385-12-15GE611.546
15-382Obv 8215BC383-05-31NA52004:29-04°53'53.2"-03°30'00.0"-08°23'53.2"Twilight Start to Moonset
16-382Obv 16314BC383-06-29SU3.6615
17-382Obv 16315BC383-06-29ME1.336
18-382Obv 18327BC383-07-12KUR16.3366
19-382Rev 91112BC382-02-19SU520
20-381Obv 111BC382-04-07NA24.339818:00-17°07'14.4"03°30'00.0"-20°37'14.4"Sunset to Twilight end
21-381Obv 7112BC382-04-19SU4.3318
22-381Obv 21214BC382-05-20NA62404:28-06°34'26.1"02°30'00.0"-09°04'26.1"Twilight Start to Moonset
23-381Rev 561BC382-09-01NA13.665518:12-08°03'39.5"03°30'00.0"-11°33'39.5"Sunset to Twilight - Mi[st]
24-381Rev 11616BC382-09-16GE6624
25-380BObv 21014BC381-12-31NA31207:02-01°49'48.7"02°30'00.0"-04°29'48.7"Twilight Start to Moonset
26-380BObv 81027BC380-01-13KUR12.6651
27-380BRev 61213BC380-02-27NA1.5606:11-06°35'01.7"02°30'00.0"-09°05'01.7"Twilight Start to Moonset
28-380BRev 71215BC380-02-28GE616.566
29-379Rev 21113BC379-02-16SU9.6639
30-378Obv 381BC379-10-27NA14.55817:02-08°42'27.9"03°30'00.0"-12°12'27.9"Sunset to Twilight End
31-378Obv 6814BC379-11-09ME9.538
32-378Obv 6814BC379-11-10NA4.51805:57-06°39'41.3"02°30'00.0"-09°09'41.3"Twilight Start to Moonset
33-378Obv 7816BC379-11-12NA-SU11.546
34-375AObv 1714BC376-10-07[GE6]5.6623
35-375BObv 51012BC375-01-03SU16.3366
36-375BObv 1015BC375-02-05GE611.1645
37-375BObv 12111BC375-01-20NA156017:01-08°21'47.0"03°30'00.0"-11°51'47.0"Sunset to Twilight End
38-375BRev 21113BC375-02-02SU6.526
39-375BRev 31115BC375-02-03GE63.3314
40-375CRev 312.21BC375-03-20NA145617:49-08°33'53.5"03°30'00.0"-12°03'53.5"Sunset to Twilight End
41-372A. Col i, 8113BC373-04-09ME1352
42-372A. Col i, 9113BC373-04-10SU728
43-372A. Col i, 9114BC373-04-10GE63.3313
44-372A. Col i, 9114BC373-04-11NA2.831105:18-05°35'05.3"02°30'00.0"-08°05'05.3"Twilight Start to Moonset
45-372C. Obv 531BC373-05-25NA197618:29-10°58'57.5"03°30'00.0"-14°28'57.5"Sunset to Twilight End
46-372C. Rev 8427BC373-07-21KUR2392
47-372C. Rev 1151BC373-07-23NA124818:43-05°48'11.6"03°30'00.0"-09°18'11.6"Sunset to Twilight End
48-372A. Col iii, 6615BC373-09-05ME520
49-372A. Col iii, 6615BC373-09-06[NA]1664
50-372D. Obv 2727BC373-10-18KUR11.546
51-372D. Obv 7815BC373-11-04[…]18.574
52-372E. Rev 1111BC372-01-17NA166416:59-09°11'32.0"03°30'00.0"-12°41'32.0"Sunset to Twilight End
53-372E. Rev 51114BC372-01-30ME14
54-370Obv 651BC371-08-01NA14.55818:39-07°49'28.2"03°30'00.0"-11°29'28.2"Sunset to Twilight End
55-370Rev 581BC371-10-28NA13.55417:02-08°05'31.5"03°30'00.0"-11°35'31.5"Sunset to Twilight End
56-368Obv 7213BC369-05-23ME2080
57-368Obv 7213BC369-05-24NA11.1645Dated correctly?
58-368Rev 941BC369-07-10NA14.55818:46-07°26'32.6"03°30'00.0"-10°56'32.6"Sunset to Twilight End
59-366Col. i 9113BC367-05-03SU936
60-366Col. i 10114BC367-05-04NA[4]1604:47[-09°06'39.2"]02°30'00.0"[-11°36'39.2"]Twilight start to Moonset - See notes
61-366Col. i 11115BC367-05-04ME520
62-366Col. i 18127BC367-05-17KUR1144
63-366Col. i 2321BC367-05-19NA145618:25 -07°31'24.9"03°30'00.0"-11°01'24.9"Sunset to Twilight End
64-366Col ii 1131BC367-06-18NA156018:42-07°47'32.9"03°30'00.0"-11°17'32.9"Sunset to Twilight End
65-366Col. Iii, 1427BC367-08-14KUR17.3369
66-366Col. Iii, 751BC367-08-17NA197618:27-11°41'31.6"03°30'00.0"-15°11'31.6"Sunset to Twilight End
67-366Col. Iii, 3461BC367-09-15NA145617:55-08°36'31.0"03°30'00.0"-12°06'31.0"Sunset to Twilight End
68-366Col. iv, 2171BC367-10-15NA197617:16 -12°44'50.4"03°30'00.0"-16°14'50.4"Sunset to Twilight End
69-346Obv 191BC347-12-02NA208016:38-12°23'25.8"03°30'00.0"-15°53'25.8"Sunset to Twilight End
70-346Obv 8913BC347-12-15SU5.6623
71-346Obv 8914BC347-12-15GE6312
72-346Obv 8914BC347-12-16NA114406:35-05°21'46.0"02°30'00.0"-07°51'46.0"Twilight start to Moonset
73-346Obv 15101BC346-01-01NA520broken? - 2nd day
74-346Rev 16121BC346-03-01NA22.59017:36 -15°34'18.1"03°30'00.0"-19°04'18.1"Sunset to Twilight
75-346Rev 3411BC346-03-30NA176817:54-10°48'54.8"03°30'00.0"-14°18'54.8"Sunset to Twilight

Conclusion

The results demonstrate that there is a correlation between the times and the position of the Sun below the horizon. The position of the Sun in the middle of the month could be due to the bright full moon affecting the observation. The times highlighted in amber that are greater than -18° below the horizon could have been affected by light reflecting off the moon after it had dipped below the horizon.

Whilst the results don't necessarily prove that the Babylonians were timing the length of twilight or that the walls created a higher horizon, it does show that the timed events in the year 588 BC are consistent with all the other astronomical diaries (with one exception) and that 568 BC is not consistent with all the other diaries

Notes

Line 60 - The tablet reads "20 NINDA na" NINDA is the same as LIMMU which means 4 (erbet) if it was 4 na this equates to 16 minutes which is consistent with the other results. Otherwise it could read 24 which makes the error greater

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