A Muslim Calculated the Length of the Year

Kids holding a cardboard paper

Knowing the exact length of the year is very important. With the knowledge, we are able to plan our activities with accuracy and precision from ceremonies to anniversaries to domestic and international events. Knowing the length of the year is among the first things children learn in school all over the world but
unfortunately, the source of this knowledge is never mentioned; not even a hint of its origin.

Popular belief says that anything that proves to be of benefit must have originated from the west and never from the east, but is this factual?

This wonderful piece of knowledge that has greatly influenced the way the world works was made known to the world by a Muslim named Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī (known popularly as al-Battani). Al-Battani was known in the west as Albategnius, Albategni or Albatenius.

The Muslim scientist calculated the length of the solar year to be 365 days, 5 hours, 46 minutes and 24 seconds which is just 2 minutes and 22 seconds different from values obtained by modern day scientists using modern day equipment.

The last time I checked, what we were taught in school did not include the hours, minutes or seconds which means the 365 days calculated by al-Battani sufficed and still suffices.

Western historians always attempt to deny the massive contributions of Muslim scientist and they have and are still doing so on this topic. They always try to ascribe this revelation to Hipparchus of Nicaea' whom they say made the revelation in the B.Cs that the length of the year was 1/300 of a day. Obviously, its very difficult making any sense from that statement. To save face, westerners try to make interpretations that Hipparchus himself never made. 

They say 1/300 of a day 'as asserted by Hipparchus' equals 365.25 days. The fallacy in this claim is proven by the fact that the decimal point notation was introduced into mathematics by another Muslim scientist, Sind bin Ali, in 864 C. E (9th Century), how then could a statement made in 2 B.C have an original place for a decimal point as seen in '365.25'?

Some others assert tha he set the length of the tropical year to ​365 1⁄4 − ​1⁄300 days. This another fallacy that will be detected by anyone who knows the history of science. The horizontal bar used to denote fractions or division was introduced to mathematics by another Muslim scientist, Abu Bakr Muhammad ibn Abdallah ibn Ayyash al-Hassar. He lived in Morocco in the 12th century. How could Hipparchus have given a figure containing the fraction notation in the BCs?

Westerners to this day have not been able to mention a single westerner or non-Muslim who gave a value for the length of the solar year to be '365 days, 5 hours, 46 minutes and 24 seconds' before Al Battani.

Al-Battani was born in Harran near Urfa which is now in Turkey in 858 C.E (9^th century) in the Islamic Golden Age era, his father was a known fashioner of scientific devices. He lived and worked in Raqqa, a city in Syria under the Caliphate. He is believed by some to have been of Turkish decent. His fields of expertise included mathematics, astronomy and geography.

Al-Battani corrected some of Ptolemy's results and compiled new tables of the Sun and Moon which were long accepted as the standard. Some of al-Battani’s measurements were even more accurate than the ones made by Copernicus many centuries later.

Al-Battani introduced the use of sines in calculations; this development is widely held as being independent of the influence of 5th century Indian astronomer Aryabhata.  He also calculated the values for the procession of the equinoxes (54.5" per year, or 1° in 66 years) and the obliquity of the ecliptic (23° 35'). He also discovered the reciprocal functions of secant and cosecant producing the first table of cosecants, which he referred to as a "table of shadows".

16^th century Polish scientist, Nicolaus Copernicus , quoted al-Battani the book that initiated the Copernican Revolution, the De Revolutionibus Orbium Coelestium, where al-Battani is mentioned at least 23 times. Al-Battānī was frequently quoted by Tycho Brahe, Riccioli, amongst others. German astronomer, Johannes Kepler and Italian polymath Galileo Galilei showed interest in al-Battani’s observations and his data continue to be used in geophysics to this day.

The fecund Abu Abdallah Muhammad ibn Jabir Al-Battani passed away in 929 C. E in Iraq at the age of 71.