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Warum Mathematiker Selbstmord begehen..

Wir haben uns alle schon gefragt, warum Mathematiker Selbstmord begehen. Aber wie sollten sie das nicht tun, wenn sie mit derartigen Grausamkeiten konfrontiert werden?

Easter and Ramadan

It’s interesting to notice, that christians would have the same problems in finding easter. I just read an article about easter calculation and at some point i thought i know the whole problem of having to supply dates for events based on natural (mostly lunar) calendar in a world dominated by a rather artificial calendar.

The FAQ Site explains the date-choosing for easter like this:

The calculation of Easter is complicated because it is linked to (an inaccurate version of) the Hebrew calendar.

Jesus was crucified immediately before the Jewish Passover, which is a celebration of the Exodus from Egypt under Moses. Celebration of Passover started on the 15th day of the (spring) month of Nisan. Jewish months start when the moon is new, therefore the 15th day of the month must be immediately after a full moon.

It was therefore decided to make Easter Sunday the first Sunday after the first full moon after vernal equinox. Or more precisely: Easter Sunday is the first Sunday after the “official” full moon on or after the “official” vernal equinox.

The official vernal equinox is always 21 March.

The official full moon may differ from the real full moon by one or two days.

(Note, however, that historically, some countries have used the real (astronomical) full moon instead of the official one when calculating Easter. This was the case, for example, of the German Protestant states, which used the astronomical full moon in the years 1700-1776. A similar practice was used in Sweden in the years 1740-1844 and in Denmark in the 1700s.)

For muslims, the same applies when searching for a date for Ramadan beginning and end. Many muslims would never dream of calculating these dates based on an “official” full moon¹. Others think it’s high time to adopt a practical solution that would enable one to plan his vacation times.. Some predominantly muslim countries already adopted the calculated calendar, while others are rather flexible in their official vacations.

via

1. actually they would have to be based on the newmoon rather than the full moon..[↩]

Lazy and Impractical Mathematicians

Tagesschau.de ran a piece about a mathematical solution to the question if a person waiting for a bus should keep waiting or walk the distance to the next bus stop. The authors of the paper called “Walk versus Wait: The Lazy Mathematician Wins” came to the obvious conclusion that it is – in most cases – more practical to wait for the next bus, that is if one is not able to walk the whole distance up to the destination in a shorter time than would the bus need to arrive and then drive the whole distance.

The authors Justin G. Chen, Scott D. Kominers and Robert W. Sinnott argue that if you’re lucky and you reach the next bus stop before the next bus arrives, you would still not have saved any time, since the bus would’ve arrived at that time anyway, even if you boarded it at the first stop. Moreover if you didn’t arrive on time, you would miss the next bus! Either way, unless you wanted to walk the whole distance to your destination it’s much easier and cheaper (from an energetic point of view) to wait for the next bus.

The only problem with the paper is its very shallow analysis of the problem at hand. There are some things the authors should have better considered before coming to that rather rash conclusion:

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