More African animals

Here are some more pictures of my recent trip to South Africa (click to zoom):


Giraffe (photo: Anthony Dekker)


Impala (photo: Anthony Dekker)


Pin-tailed whydah (photo: Anthony Dekker)


Wildebeest – also known as gnu (photo: Anthony Dekker)


Little egret (photo: Anthony Dekker)


Warthog with babies (photo: Anthony Dekker)


The Sci-Bono Discovery Centre, Johannesburg


Interior, Sci-Bono Discovery Centre (photo: Nick Gray)

On my recent South African trip, I visited the Sci-Bono Discovery Centre in Johannesburg. This science museum is a little like Questacon in Canberra. Sci-Bono’s strengths are the large number of well-built interactive exhibits and the large number of helpful staff. Exhibits concentrate mostly on physics and technology. All ages from toddlers to adults are catered for.


Interactive electrolysis exhibit (photo: Anthony Dekker)

The Sci-Bono Discovery Centre is not free, but is value for money. I enjoyed it, and Tripadvisor gives it 4.5 stars. Sci-Bono is active on Facebook and Twitter.


Atlas Cheetah E aircraft on display (photo: Alan Wilson)


African animals

Here are some pictures of my recent trip to South Africa (click to zoom):


Burchell’s zebra (photo: Anthony Dekker)


Lion (photo: Anthony Dekker)


White rhinoceros (photo: Anthony Dekker)


Southern masked weaver (photo: Anthony Dekker)


African elephant (photo: Anthony Dekker)


Goliath heron – world’s largest heron (photo: Anthony Dekker)


Happy Christmas to all my readers!

The Christmas fresco above, by Giotto, shows the Star of Bethlehem as a comet (top centre). It is likely that this fresco depicts Halley’s Comet, which Giotto saw in 1301, about two years before he began the series of frescos of which this is part. This work by Giotto was celebrated in the name of the Giotto spacecraft, which observed the comet in 1986.

Let me take this opportunity to wish all my readers a very happy Christmas (and apologies for duplicating a previous post).


A sample of elements

  • Helium (He, element 2) – used in balloons, because it is lighter than air
  • Carbon (C, element 6) – one of the key elements in living things
  • Nitrogen (N, element 7) – makes up 78% of the atmosphere
  • Oxygen (O, element 8) – makes up 21% of the atmosphere
  • Aluminium (Al, element 13) – a light metal used to make saucepans and aeroplanes
  • Silicon (Si, element 14) – used to make electronics
  • Phosphorus (P, element 15) – used in elemental form on the side of matchboxes
  • Sulfur (S, element 16) – a widely used element which occurs naturally in elemental form
  • Titanium (Ti, element 22) – a light, strong metal
  • Iron (Fe, element 26) – the most widely used metal (mixed with other elements it becomes steel)
  • Copper (Cu, element 29) – a metal that has been used for about 10,000 years, named after the island of Cyprus
  • Zinc (Zn, element 30) – used in batteries and to prevent corrosion
  • Silver (Ag, element 47) – widely used in jewellery since ancient times (the symbol is from the Latin argentum)
  • Tin (Sn, element 50) – about 5,000 years ago, tin (Latin stannum) was mixed with copper to produce bronze
  • Iodine (I, element 53) – dissolved in alcohol, it is used as a disinfectant
  • Gold (Au, element 79) – widely used in jewellery since ancient times (the symbol is from the Latin aurum)

For more on the elements, see the fantastic book The Elements by Theodore Gray of periodictable.com, which I have previously reviewed.