Library and links

Baren forum

An amazing group of very nice people engaged in all sorts of printing

Fibonacci numbers

The golden mean, the golden rectangle, Parthenon, Nautilus shell, sunflower seed heads....check it out

Astronomy picture of the day

Every day another magnificent photo about space or an event linked to space. This is a double rainbow over Waimauku.

Global warming

When I was working in South Nigeria, my boss, Nico van der Laan, told me that data obtained by the missionary indicated a drop in precipitation of 25% since WWII to 1970. Vast tracts of the Northern Sahara used to be lush and green, supporting elephants and lions long ago.

Much of the deforestation and desert creep happened well before mankind even imagined all kinds of CO₂ producing inventions. It probably had more to do with issues beyond our control like intensity, duration and frequency of sunspot activity over time. What did not help was mankind keeping goats and using farming methods not keeping pace with population growth.

The oil palm in this picture is barely 24 years old, yet it already shows four growth bursts indicating a return cycle of between four and six years. Ideally it ought to be more like sixteen years. If you can find a copy, I suggest reading Ritchie Calder's book 'Men Against the Desert'.

Art work of my sons

Flickr website pages of Social advances by my son, Pieter, who is deep into photography. He also posted some work of my other two sons, Marten and Robert. This photo is made by Pieter ten Broek.

Bumble bee

Another matter under investigation. For some funny reason everyone seems to know quite a bit about wasps or bees, but when it comes to bumble bees a mist descends and answers become questions. Meanwhile some answers from this interesting web site.