The
Lowest Limit of the Moon Visibility Criteria with Particular Reference to the
Month of Ramadhan
Published in Jurnal Akademi Sains Islam Malaysia (ASASI)
Kesturi Jilid 6 bil.2 Julai-Dis. 1996
Azlan Bin M. Hashim azhashim@yahoo.com
1. INTRODUCTION
The modern solar calendar which is the most commonly used calendar nowadays
is a clear example of the widespread Western influence. Presently, most people
have worked within the conceptual framework of this solar calendar and there
are many Muslims accustomed to its precise and seemingly predictive nature.
Unfortunately, Muslims today also have the tendency to improperly ‘place’
physical scientific facts above Religious Truth (For a more comprehensive
explanation on the concept of ‘relational place’ see "Prolegomena to the
Metaphysics of Islam" by Prof. Syed Muhammad Naquib Al-Attas, ISTAC 1995).
The sighting of the new Moon had been a controversy because Muslims who lost
their lead in astronomical science had followed the precise mathematical
calculations of the position of the Moon rather than a decree in the relevant
Hadith. Eventually new criteria have been independently adopted by various
Muslim nations to determine the beginning of Ramadhan and a number of
‘Islamic calendars’ have been tabulated having similar characteristics to the
solar calendar which does not fit in an Islamic world-view. The global Islamic
calendaring system must be formulated using conceptual schemes within the
Islamic world-view coherent with The Quran and Hadith [ref. 2]. This short
paper contains an outline the basic precepts for determining the most important
month in the Islamic calendar that is the Ramadhan.
2. SIGHTING THE CRESCENT
Every year
Muslims are especially reminded of the Lunar cycle with the arrival of the
Blessed month of Ramadhan when every able adult Muslim must perform the ibadah
of fasting which is the Third Pillar of Islam. The Prophet(SAW)had,decreed
"The month of Ramadhan may consist of 29 days. Do not Fast till you see
the new Moon, and do not break Fast till you see it (again); but if the weather
is cloudy 'calculate' about it."
This Hadith and its variations in Kitab Al-Sawm of Sahih Muslim has been transmitted by Ibn Umar, Ubaidullah , Abdullah B. Umar, Sa'ad B. Ubaida and Abu Huraira. From this Hadith the attempt of the physical sighting of the new crescent with the unaided eye for the month of Ramadhan is clear and must be practiced by the relevant authorities. The sole use of pure Mathematical calculations to determine the exact day of the beginning of this blessed month is not proper even though it may be based on very accurate Astronomical data because the standard measurement of time has to be made with reference to a physical event. So, fundamentally time cannot be just mathematically calculated but must be standardized by sensing a periodic process that is changing. In fact, the present measurement of time refers to an average fictitious movement of the sun and it is corrected every year with respect to the actual motion of the earth around the sun. God had said in the Holy Quran surah II verse 189:
"They ask thee The New Moons Say: They are signs to mark fixed periods of Time In (the affairs of) men and for Pilgrimage."
Therefore the simple phase of the Moon which may be observed almost anywhere on
earth must be used for the standardization of the Islamic Lunar month.
However, this does not mean that Astronomical calculations cannot be used at
all. It is our opinion that The Prophet (SAW) had given allowances to
‘empower’ with the best of our astronomical knowledge and experience to
determine the new month when the weather is cloudy (refer to The Hadith above).
Past great Muslim astronomers had embarked on research into determining the
visibility of the new Moon and they had made careful observations to improve on
their calculations. Recently Dr. M. Ilyas (1984, 1996,1997) has made some
contributions in this field of study on the visibility criteria of the new Moon
but unfortunately we believe that many Muslim nations are still using wrong
criteria to determine the beginning of Ramadhan. Thus, this paper will
present the proof of a limit for the determining criterion of the
beginning of the Islamic lunar month based on the available data collected by
Mohammad Ilyas (1984) and the Hadith and Sunnah of The Prophet (SAW).
This limit is not a further scientific elaboration of the Moon visibility
criterion but it is formulated from a deductive reasoning based on an
interpretation of the Hadith and Sunnah of The Holy Prophet (SAW)
using Astronomical data and calculations of the apparent position of the Moon
in the sky.
3. RUQYAH & HISAB
The equatorial regions are well known for frequently having heavily clouded skies. Since the new crescent Moon is not bright, even a light haze will obscure its sighting. Obviously the sighting of a cloud covered new Moon (which is common in this region) will be totally blocked. Therefore, observing the new Moon is very difficult in this part of the world. To overcome this difficulty the 'ulama's in this region had decided on a method of using both calculation and observation (Hisab and Ru’yah) to determine the new Moon, which we agree in principle, but we also believe that the present Ru’yah & Hisab method applied needs to be proven. It is our contention to amend the current Ru’yah & Hisab procedure due to reasons explained below.
The basis of this amendment is from the Hadith and Sunnah of The Prophet(SAW). The Holy Prophet(SAW) had emphasized that the Lunar month can be 29 days. The Prophet(SAW) even physically unfolded his hands thrice and folding a thumb at the third time gesturing 29 in a most profound manner. On another occasion (not related to Ramadhan) when The Holy Prophet(SAW) took an oath not to go to his wives for a month. Aishah and many other people counted that The Prophet(SAW) returned after 29 days and when asked The Holy Prophet gestured with his hands and said "The month may also consist of 29 days." Zuhri, Jabir, Umm Salama and many others had narrated this Hadith and its variations
Therefore, The Prophet(SAW) had decreed to attempt observation of the new Moon on the night after the 29th day of the month and when the crescent is sighted by the naked eye the new month begins. If the Moon is not sighted (on a clear night) the month is considered as 30 days and the next month commences on the day after When the weather is cloudy the length of the month should be calculated based on past observations. This is the author’s interpretation made with the aid of astronomical data. Even though this Sunnah will be subjected to various interpretations its basis is absolutely correct and its fundamental principles will never be invalidated.
Owing to the meteorological constraints (explained above) at the equatorial region, some basic precepts in applying Astronomical data and calculations to guide the observation of the new crescent will be forwarded. It is not proper to use the Astronomical data to calculate for the day of the beginning of Ramadhan because most of the time it is not feasible to confirm the calculated visibility of the Moon owing to the frequent clouded skies at the equatorial regions. Also more significantly, the observation of the new Moon of Ramadhan must be physically attempted because it is a decree of The Holy Prophet (SAW). Therefore for regions with frequent cloudy weather we consider a more appropriate Astronomical criterion called ‘the night of sighting criterion’ of the new Moon which is not the same as the new Moon visibility criterion.
4. THE NIGHT OF SIGHTING CONDITION
As stated in the
last section, the 'night of sighting criterion' should not be
regarded the same as the Moon visibility criterion. The reason being not
only a matter of definition but due to the period of the Moon to complete its
orbit around the earth with respect to the Sun has been measured to
be slightly more than 29 and half days (29.530589 days) which is
known as the Synodic month. So, the visibility criterion cannot
be used to strictly determine the
night of sighting because if the Moon is just sighted at a
very close margin to its visibility limit then on the night
after 29 days when the sighting of the Moon is attempted again, the
apparent position of the Moon will definitely fall below
visibility because it is short of about another half a day to
complete its period. The attempted observation on the night after 29 days is
clearly stated in The Hadith, therefore Moon visibility is not a
necessary condition for the night of attempted sighting.
Since The Prophet (SAW) had decreed to attempt sighting the Moon on the night after the 29th day of the month, the night of attempted sighting of the new Moon has been standardized on this night and the general apparent position of the Moon in the sky at sunset on every 29th day after the Moon was first sighted should correctly determine the night of sighting condition. So, although by this definition the night of sighting is dependent on the visibility criterion, these two criteria are not the same (explained above).
To determine the night of sighting condition, all the Moon visibility criteria (known to us) utilized in the past, including those used by other civilizations which adopted the Lunar calendar had been compiled by Mohammad Ilyas (1984) (see table I), to be used in an initial analysis for any common characteristic. These criteria range from the earliest known records of Lunar sighting through the Islamic period until the recent development made by Ilyas in the last decade where this compilation is obtained [ref. 3]. The table also shows the various types of measurement angles used to determine visibility. Whatever the basis used in the angular measurement of these visibility criteria, they all had an important characteristic in common that is for all region within the tropics their occurrence are all when the Moon's age is noticeably more than half a day at sunset.
Letting MV be Moon's age during sunset at first sighting and SL be the difference in Sunset times during the month and EM is the time difference between the next conjunction and simultaneous Sunset-Moon set at a location of the same latitude. From table 1,
All MV > 0.53 + SL + EM (1)
Therefore the Moon's age at sunset after 29 days MS is
MS = 29 + MV > 29.53 + SL + EM (2)
where 29 is the Day of sighting and 29.53 is an approximate synodic month period. Since MS is greater than the period of the Synodic month inclusive of all the correction terms, the Moon is above the horizon at sunset (because the total accumulative age of the Moon is greater than its period of revolution with respect to the sun). The simple and incomplete explanation in the bracket is made for easier comprehension. Therefore when the new crescent is sighted, on the night after the 29th day of the month (night of attempted sighting) the Moon will be at a position above the horizon at sunset (or Moon set is after sunset).
The resulting "night of sighting criterion" is both simple and logically sound because certainly the Moon has to be in the night sky in order to be seen after sunset. Furthermore it is quite difficult to believe that the Prophet (SAW) had attempted to observe the Moon on the night after it has already set when obviously it cannot be seen. Islam being the only revealed religion[ref. 4 ] is perfect from the beginning. When the whole Quran was finally revealed God had declared the religion of Islam complete, thus Islam does not require any further period of time to mature. The Holy Prophet(SAW) as a model human being and the perfect interpreter of The Holy Quran cannot make a mistake which requires History to correct, especially in religious matters. Thus even after astronomical measurements had improved the Prophet (SAW) cannot be said to be mistaken or naïve by later astronomers of trying to observe the Moon when it is not in the sky. Therefore the night of sighting of the new crescent must be a night when the Moon is above the horizon at sunset in the night sky.
5. THE LOWEST LIMIT FOR THE NEW MOON SIGHTING
Based on the principle that The Holy Prophet cannot make a mistake in religious matters in the last section, the night of sighting condition is proved by deducing that Moon set after sunset is a necessary condition for the night after the 29th day of the month. Now we can use this general condition to calculate the lowest limit of the Moon’s position for its first sighting. This is done by using ‘the night of sighting’ condition as the fundamental axiom and deriving the limit from the lowest boundary for the night of sighting condition when the Moon sets simultaneously with the Sun. Letting LV be the (approximate) lowest limit for the Moon visibility criterion, then the left hand side of the inequality (1) in fact LV, i.e
LV = 0.53 + MV + SL + Em ~ 12hrs.+ SL + Em (3)
Therefore the inequality (1) is equivalent to
MV > LV (4)
Thus we conclude that it is not possible to see the Moon by the normal unaided eye (not subjected to extreme conditions) with certainty on the night when during sunset the Moon's age is less than an average of about 12 hours plus the time difference between sunset during the month and the difference in time between Moonset and sunset at conjunction. Incidentally, we also believe that the inequality (4) is the first inequality of this kind derived solely from the basis of the Hadith.
Although there may be several technologically sophisticated means of detecting the presence of the Moon in the sky, such modes of detection are not considered as direct visual sensing by the unaided eye and hence do not fulfilled the Syari’ah. Suppose there are a few individuals in Indonesia specially trained in ‘falak’ who will lock themselves up in darken rooms before observation. Suppose further that they will come out only after sunset and had claimed to be able to see the Moon far below this visibility limit. Again such claims should not have been allowed because their eyes are not under normal conditions and the validity of such practices are also questionable. Since most professional astronomers are not interested in new Moon observations some of the more reliable records are those made through amateur astronomy associations and a report (not official of course) of the youngest Moon ever observed reached very close to this visibility limit. Even this observation had been made through a 10 inch telescope at 60X magnification.
Therefore, after acknowledging that it is not possible to visually sight the new Moon by the naked eye with certainty below this lowest limit LV even under the clearest weather, the use any criteria below this limit such as the Sun-Moon conjunction (when the Moon's age is zero) and the Moon set after Sunset criterion to determine the beginning of Ramadhan must not be allowed because The Prophet had forbidden fasting on such doubtful day.
7. COMPARISON
The present generalized procedure of using Astronomical calculations and
sighting to
determine the beginning of Ramadhan is as follows:
1) Know the Moon visibility criterion.
2) Calculate the visibility criterion.
3) Confirm the calculation by observation.
The visibility criterion will be derived (by inductive reasoning) with uncertainty, complicated, and this method will be subjected to meteorological constraints.
Our recommended practice is as follows:
1) To Accept the night of Moon sighting criterion.
2) Calculate the night of sighting criterion.
3) Attempt to sight the New Moon.
The night of sighting criterion is simple logically sound and meteorological condition is not of primary importance.
8._SUMMARY
The following is a summary of our findings:
S1. Observation of the new Moon for the month of Ramadhan and Syawal by the naked eye must be attempted by the relevant authorities.
S2. Astronomical data and calculations can be used to determine the night of sighting of the new Moon especially in regions of the world where heavy clouded skies are frequent.
S3. The night of sighting condition is when Moon set is after sunset.
S4. The lowest limit for the new Moon sighting is the calculated apparent position of the Moon in the sky where after 29 days it sets simultaneously with the Sun.
Although the above recommendations in determining the beginning of Ramadhan was initially proven for regions with frequent cloudy weather, since all the criteria used was based on The Hadith and Sunnah of The Prophet. Therefore its applicability can be extended to all regions within the Tropics.
REFERENCES
2. Alparslan Acikgenc, Islamic Science: Towards a definition. Kuala Lumpur ISTAC,1996
3. Mohammad Ilyas, Islamic Calendar, Times and Qibla. Kuala Lumpur Berita 1984 pg 83
4. Syed Muhammad Naquib Al-Attas, Prolegomena to the Metaphysics of Islam Kuala Lumpur ISTAC 1995