## Archive

### What is new ?

2016-03-10

Category: Mathematics

In this new version of my article Spherical design with METAPOST(external link) I replaced several calculations by concepts and added in the astronomical application section the handling of orthogonal projections of orbits in space.

2015-10-06

Category: General

The Content Management System was upgraded to version 1.12.1 Rontiki.

2015-05-15

Category: Mathematics

Vor 80 Jahren hat Piet Hein die Soma Würfel erfunden -- in dem Artikel werden sie mit einigen METAPOST Zeichnungen beschrieben.

2015-03-04

Category: Mathematics

All articles have been updated and make use of the option *colorlinks* of the *hyperref* package. Apart from some fixes to typos no textual changes have been applied.

2015-01-06

Category: Mathematics

Réédition du d'Orsay de l'année scolaire 1969/70.

2014-10-31

Category: Mathematics

The hull speed of a displacement boat is the maximal attainable
speed and is determined by the wave system generated by the displacement.
It is proportional to the square root of the length of the waterline:
*v = R * √L* where *L* designates the length of the waterline
This article explains the formula and the factor *R*.

2014-09-01

Category: Website

The Content Management System has been upgraded to CMS 1.11.11 *San Cristobal* on September 1, 2014.

2014-03-20

Category: Mathematics

All articles have been reworked due to changes in macros (March 20-24).

2014-02-18

Category: Website

The Content Management System has been upgraded to CMS 1.11.10 *Pinzon* on February 18, 2014.

2013-10-29

Category: Mathematics

Qt5 has moved several classes to a new module *QtWidgets*.

2013-09-15

Category: Mathematics

Plane curves of 2. order (conic sections) treated by their invariants.

2013-07-06

Category: Website

The Content Management System has been upgraded to CMS 1.11.7 (Genovesa) on July 6, 2013.

2013-04-20

Category: Sailing

Am Samstag, 20.04.2013, war Ansegeln im Bezirk Unterhavel und ich habe die Segelsaison mit *Aries* auf einem Segeltörn begonnen.

2013-04-17

Category: Sailing

*Aries* has been slipped into Havel last Saturday by my fellow sailors and I attached shrouds and halyards to the mast and brought the sails on board on Tuesday, see *Aries* preparation

2013-03-06

Category: Website

The upgrade to CMSms 1.11.4 end of last year was not completely clean: there were remnants of previous upgrades somewhere in the file system or the database (or both - I couldn't find out), so I made a fresh clean install (Feb 21) and moved the information from the old to the new database (Feb 22-28).

2013-02-24

Category: Sailing

Since November 10, 2012 through February 22, 2013 I closely followed the *Vendée Globe* race. Here are the final results.

2013-02-20

Category: Sailing

Erste Vorbereitungen zur neuen Segelsaison beginnen.

2012-12-30

Category: Website

The Content Management System has been upgraded to CMS 1.11.4

2012-09-08

Category: Sailing

On the page Sailing you find an article on the drawing of the Conger mould by METAPOST.

2012-04-13

Category: Website

*nunavut* is now operated under Windows 7 Home Premium.

2012-01-11

Category: Mathematics

Notes on .

2011-12-23

Category: Website

My Linux Server *inuksuk* has been *squeeze*d

2011-11-29

Category: Mathematics

Im Abschnitt ist zu dem Lehrgang über Kurven zweiter Ordnung das *Lösungsheft* erschienen.

In section the solution booklet for the course on plane curves of second order is published.

2011-07-19

Category: Mathematics

New article on dedicated to *Thomas*.

2011-06-02

Category: Sailing

Migration of Albums to Galleries - completed Dec 13, 2011. Several flash videos added.

2011-05-25

Category: Website

I added some tricks of the trade in

odds and ends.

2011-05-02

Category: Mathematics

I completed the drawing of the modular fundamental domain with METAPOST. The also contains the previous version drawn with Xy.

2011-01-30

Category: Mathematics

A short on local *L*-functions, functional equations and the ε-factors occuring in these functional equations.

Dedicated to my sister.

2010-12-19

Category: Mathematics

Command line C and GUI C++ program for *Julian* day numbers with documentation resp.

2010-11-16

Category: Website

2010-10-05

Category: Mathematics

Artikel über für die Wurzeln kubischer und biquadratischer Polynome.

2010-09-28

Category: Mathematics

elucidates the cube group and accounts for recent results on the minimum number of necessary turns to fix the cube.

2010-05-05

Category: Mathematics

A new article on the visualisation of the orbits of the *inner planets*: Mercury, Venus, Earth and Mars has been added. The drawing of the orbits is done with a METAPOST program, the calculation of the *true anomaly* for the positions of the planets with a C program.

2010-03-30

Category: Mathematics

Plane curves of 2. order (conic sections) treated by their invariants.

2010-03-01

Category: Sailing

Flash video of May 2009 trips to and round *Lindwerder* added.

2010-02-25

Category: Mathematics

Minor change to the programming notes using the *sudoku* environment.

2010-02-24

Category: Website

Almost all content of my domain has been moved under the regime of the content management system.