A polyhedron in the time: Easter and Science

3 may 2011

Easter and Science

Last Sunday 17 of April, Christian people celebrated Palm Sunday of the Holy week. Each year, every Christian branch (Catholics, Anglicans, Methodists, Orthodoxies, etc.) celebrate the Holy week and Easter week. There are no exact dates for these days but depend of every year.

In Sheffield, England, the government usually put a metal cross in front of the government building. The metal is a symbol of the city because they used to fabricate cutlery and other metal stuff since ancient times.

In December, they put a Christmas tree in the same place. We thought that the government usually put symbols for every epoch of the year.

However, after Palm Sunday mass, all the Christian churches of the city join together in a ceremony around the metal cross.

For the foreigners, this custom is totally new because we are used to see ceremonies for only one particular branch of the Christians and not an only one for everybody. It is really nice to see the people of different religions sharing good thoughts and beautiful songs in an only one ceremony. I remember see dances from Nigerian people dressed in white and songs from Polish people. This should be the behavior of all religions around the world.

But let us go to science now and how it is related to these celebrations.

Occidental Christian churches follow the Gregorian calendar for their celebrations. Actually most of the people in the world follow it as well. E.g. you and me and this computer and the www world! But Orthodox Church follows the Julian calendar.

The Julian calendar was invented by Julius Caesar in 46 BC. In this calendar, we have 3 consecutive years of 365 days and a leap year of 366 days and so on. However, there was a mistake in the calculus until XVI century. And the Julian calendar did not fit with the astronomical events. The mistake was about 10 days.

The pope Gregorio XIII corrected the problem, proposing the Gregorian Calendar that substituted the old Julian calendar in 1582. This new calendar was adopted in 1583 in the New Spain (today

Mexico

) and in 1782 in

England

The Easter Sunday is the Sunday following the ‘paschal new moon’ that differs from true new moon by 2 days. This paschal new moon is related with astronomical tables elaborated during the Julian calendar. Its calculus is complex and only few times is related with a true astronomical phenomenon.

In XIX century, the German mathematician Carl Friedrich Gauss proposed and algorithm for calculating the Easter Sundays based in divisions and residuals. Other algorithms have appeared in the scientific journal Nature and in specialized books. Even today, some priests and mathematicians and every people interested in the calculus propose new algorithms!