once the moon revolve around the earth in a specific orbit and constant speed then why muslims try to find it?

Question

lunar calender has twelve months, which are of 29 or 30 days. once the moon revolve with the same speed and same orbit around the earth, why muslims see it to determine start of a month. when orbit and speed of moon is constant why lunar month can be of 29 or 39 days. why days of months are not fixed?

Answer 1

The moon doesn't revolve at a constant speed as the orbit is elliptical, and as Kepler's Second Law states, orbiting bodies sweep out equal areas in equal time, i,e, the moon moves faster when nearer to earth (at perigee) and moves slower when further away from earth (at apogee).

I think what you mean is "The moon's orbit has been extensively studied and its position and phases are able to be precisely calculated. and accurately predicted so why do (some) Muslims insist on seeing the New Moon with their own eyes as regards when a month starts?"

Orbital speeds, whether of the earth around the sun or the moon around the earth, are not a reliable basis for the measurement of time. The idea of how long does it take to complete one orbit and get back to the same point where you started (1 year) is much more useful, though still slightly variable (the second has been defined by an Atomic Clock (Caesium 131) since 1967 and the year is a fixed number (of such seconds, and occasionally leap seconds are then added to it).

The reason why we have 12 months in the year and not 13 (there are between 12 and 13 lunar months in a year) is the same reason that we have 12 hours in the night: the 12 signs of the Zodiac. which are a handy way if sudividing a circle of 360 degrees (The Baylonians and their sexagesimal base-60 number system gave us that) into equal parts.

Mariners at night in ancient times needed to know what time it was to assist their sailing to where they were heading and the 12 subdivisions of the night arose from that very practical need. It seemed logical to extend this to the day as well, which is why we have a 24-hour clock.

The same 12 zodiacal signs also help tell what month of the year we are in. This became important as regards when to plant crops and when to expect flooding of the Nile, once the majority of humanity stopped being nomadic, and developed agriculture. Again the sub-structure of the clock and calendar driven by a very practical need.

MATHEMATICS IS NEAT AND TIDY BUT REALITY USUALLY IS NOT

It would be unreasonable to expect the Sun and the Moon to have years and months that are exact multiples of days or human divisions of time. So whatever system is employed will not be mathematically neat. And there will be consequences to that.

The Chinese New Year and the Jewish New Year have start dates that can vary from year to year. It doesn't seem to bother them. The Babylonians opted for a 360-day year of 12 30-day months and every 5 or 6 years had to add on an extra 30-day month, so there was a somewhat closer correspondence between the calendar and the seasons.

There was something militarily precise about the Roman Empire, with its straight roads and rectilinear designs, which has conditioned our thinking so that we expect the year and the month to start at exactly the same time. I suggest this is cultural and that other cultures do not share that expectation, Islam among them.

Interestingly the French Republican calendar, introduced as part of the world's first metric system, allowed for the start date of each of the 12 newly-named 30-day months to vary by 2-3 days and for the extra 5 or 6 days to be inserted inbetween them, by decree.

And even the Romans made a couple of changes to what was supposedly fixed, Augustus Caesar decided that if Julius Caesar could have a month named after him, then so could he, and that as Sextus, the month after July (Quintus) only had 30 days, he decreed that thereinafter it should be called August and should have 31 days and he lopped a day off February (which was 29 or 30 in a leap year) to make up for it.

The Roman year, which used to start on March 1st i.e. near the Spring Equinox was also arbitrarily altered so that it started on January 1st, just after the winter solstice and there was a year with onlty ten months in it, at the transition point. So nothing is actually quite so fixed as we are taught to think it is!

THE ISLAMIC CALENDAR

The Islamic calendar is a lunar calendar, and months begin when the first crescent of a new moon is sighted. Since the Islamic lunar calendar year is 11 to 12 days shorter than the solar year, the holy momth of Ramadan migrates throughout the seasons. The estimated start and end dates for Ramadan are as follows:

1426 AH – First day: October 4, 2005; last day: November 2, 2005
1427 AH – First day: September 24, 2006; last day: October 23, 2006
1428 AH – First day: September 13, 2007; last day: October 12, 2007
1429 AH – First day: September 2, 2008; last day: October 1, 2008

Most Muslims insist on the local physical sighting of the moon to mark the beginning of Ramadan, but some insist on using the calculated time of the new moon or the Saudi Arabian declaration to determine the start of the month.

As a result, Ramadan dates vary in different countries, but usually only by a day or two.

At the termination of the great month of Ramadan, Eid ul-Fitr is celebrated. Muslims come out and rejoice with a sense of accomplishment for coming closer to Allah. It is a time for Muslim families and friends to worship and celebrate together.

DATE ANNIVERSARIES OF EVENTS OF HUNDREDS OF YEARS AGO ARE NOT WHAT THEY CLAIM TO BE

It seems that in many cultures important festivities do not HAVE to be celebrated on the date anniversary each year. Diwali, the Hindu celebration is a "movable feast" and its date can vary, from year to year, like Ramadan in Islam and Passover in Judaism do. And indeed, so does Easter in our culture! So these other cultures really aren't any different from us. We all have movable feasts,

The idea of a date anniversary is in any case dubious given the change-over from the Julian to the Gregorian calendar e.g. in England in 1752, the changeover year, September 2nd was immediately followed by September 14th and 11 days were trimmed from the calendar, making it a 355-day year (it was a leap year). so what does "a birthday" or a "wedding anniversary" mean in that context?

Similarly, the Russian "October Revolution" of 1917 was in fact in November as they were still using the Julian Calendar at that time.

i.e. it is in fact arbitrary when the anniversary is declared to fall and we should not allow our own cultural prejudices to cause us to condemn other cultures who do it a different way, It is always decided by decree, in any culture,

And as explained above, some Muslims do use the astronomical calculation of when a New Moon falls as the basis of their saying when the new month will start, So what you say in your question isn't universally true. Muslim practice is not consistent, and you can't make the generalisation "why do "Muslims" insist on seeing the New Moon?" as some do and some don't.

The category "Muslims" is not one homogenous whole, in other words. It contains a range of practices and beliefs, as does the category "Jews" and the category "Christians",

Answer 2

becasue a lunar month and a yearly month are different. The lunar callender doesnt mesure the length of time the earth takes to go around the sun.

lunar calender = moon going around earth
yearly calender = earth going around the sun

Answer 3

lunar calendar predates Islam, it was used in ancient Mesopotamia and Egypt at the dawn of civilization. it is easy to use because of it's relatively short duration. solar calendar requires better measurements and was probably introduced by the Celts in Europe (Stonehenge could be a site where the state of the sun was measured). Muslims copied the old Jewish calendar, that was a lunar calendar, and still use this calendar. the Romans used the solar calendar, and we still use the roman calendar (as can be deduced from the names of the months, which are roman gods and emperors)

Answer 4

I dont get your question , only you r last I can answer : the number of sdays in a month are not fixed simple because the moon doesnt evolve in a multiple of days around the earth.