As my retirement as a teacher approached in the summer
of 2000, I started thinking about what I should do in my so-called third
life to avoid falling into the famous hole. I had heard that you shouldn't
start something completely new, like learning Chinese. You don't get very
far and frustration is the result. Instead, you should work on something
you know and want to deepen your knowledge. As a mathematics teacher, I
also thought of recreational mathematics. In 1970, I had brought a booklet
on entertainment mathematics by Martin Gardner from the USA. Later I bought
more books (in German) by Gardner on special offer - because they were
out of stock. The bookseller warned me: "Make no mistake, this is heavy
stuff". I found a lot of interesting material - assuming only school mathematics
- for further study. I tried out some topics in project weeks in school.
Accidentally internet also came to our house at the end of the 1990s. This was due to the universities, which thus got in touch with their students. We got ISDN with one connection for telephoning and one for internet access. At first, I didn't find anything on the net that particularly interested me. Only after months I did come across, among other things, Lee Stemkoski's Mathematrix site, which is still available today (URL below). There they were, all the topics by Gardner that I had already dealt with. I decided to make a site like that too. I was surprised that Stemkoski only gave one link. I didn't want to be that elitist.
Since English was the language of the Internet more than it is today, it probably had to be translated into English. Unfortunately, as a pupil of the mathematics/science grammar school, I had to deselect English in the primaries and stick to Latin. But I had nice people who supported me in my English. Despite all that, native speakers later let me know, that was German English. Around 2010, I stopped translating, better that way.
The page about Flexagons looked like this.
In 1989 and 1990, I made twelve pages in German and English. I kept the header of the flexagon page for all further web pages. This was recommended to me because of recognition. At that time, a homepage had an index page with a heading and a table of contents and contained a description.
I chose the title "Mathematische Basteleien", although I was advised to keep it shorter.
The description was "Topics include Flexagon, Soma Cube, Pentominos, Cube-it, Rubik's Cube, Froebel's Star, Tangram, House of Santa Claus, Chronogram, Numeric Palindromes". Later I added "English/German".
I soon deleted the family tree page. I realised that one should be cautious with private data on the internet.
"Description of my 12 websites" was elaborate and dispensable.
To contact me, I gave my email address. It was accessible via an animated send me email. That was funny, but was soon plainly replaced by the address jkoeller@.... .
Now it was time to put the homepage on the Internet and make it accessible to others.
Without thinking about data protection, I registered the homepage with Denic (URL below) with my name, place of residence, telephone number and email address.
The first provider of my homepage was the Bertelsmann subsidiary Lycos with the URL http://members.tripod.de/jkoeller. The homepage was free because of advertising. When pants appeared, I preferred to pay for my hobby and switched to Netbeat. My children gave me the domain as a present, a year later I paid for it myself. From then on, the URL was www.mathematische-basteleien.de.
The homepage should also be found. At that time it had to be registered with search engines like Yahoo!, Fireball, Lycos, Netscape. In July 1999 my homepage became better known, when it appeared in the Open Directory or DMOZ (URL below).
This page is also available in German.
© 2021 Jürgen Köller