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 reason is their interpretation of the Quran, which has wording that implies that the full moon must be physically seen prior to starting celebrations.

The US Muslims decided this year to start Ramadan based on computer predictions, but that's considered to be unacceptable by the traditionalists.

Answer 2

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 3

becasue a lunar month and a each year month are diverse. The lunar callender doesnt mesure the size of time the earth takes to bypass around the sunlight. lunar calender = moon going around earth each year calender = earth going around the sunlight

Answer 4

It is out of respect for Allah. It is arrogance to predict the works of God, no matter how predictable they may be. This does create some practical problems, especially when planning for the Eids, but this is the cost of devotion.