Colours in national flags

The infographic above shows the most common colour in various national flags, excluding white and black. For example, red is the most common colour in the US flag. If there are two or more equally common colours (as in BE = Belgium or FR = France), the country is given partial credit for both. Similar colours are grouped using k-means clustering in R.

Overall, shades of red seem the most popular, followed by shades of blue. The set of flag image files I analysed wasn’t fantastic, however, and that may have skewed the results slightly.


Earthrise / Christmas


Earthrise, taken aboard Apollo 8 by Bill Anders on 24 December 1968 (NASA photo).

With Christmas coming up, it seems appropriate to post this iconic photograph, taken by Lunar Module Pilot Bill Anders on 24 December 1968, while orbiting the moon in Apollo 8. The team also did a live television broadcast, in which Anders read from Genesis:

For all the people on Earth the crew of Apollo 8 has a message we would like to send you: In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness.

Command Module Pilot Jim Lovell continued: “And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day. And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. And God called the firmament Heaven. And the evening and the morning were the second day.

Commander Frank Borman closed: “And God said, Let the waters under the heavens be gathered together unto one place, and let the dry land appear: and it was so. And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good. And from the crew of Apollo 8, we close with good night, good luck, a Merry Christmas, and God bless all of you – all of you on the good Earth.

And the same from me.


Lotus Blue: a book review


Lotus Blue by Cat Sparks (377 pages, published 2017)

I recently read, with great enjoyment, the hot new post-apocalyptic novel Lotus Blue by Cat Sparks. I’m a sucker for the genre, and this novel has shades of Dune, Mad Max, A Canticle for Leibowitz, and the works of Roger Zelazny – yet is not derivative. As a fan of the trans-Australia World Solar Challenge, I particularly liked the caravan of solar trucks on the cover. The cover also shows the falling satellite which marks the emergent threat to the world of the novel.

While opening with a solar-powered trading caravan, the novel has a few flashbacks to the three centuries of war that created the dystopian world of the story: “Mighty tankers were on the move, travelling in tight formation grids. Working together, not attacking each other. Not something you saw every day. Those mechabeasts had once roamed wild and free, following their own whims, their own flights of fancy. But something had changed. Something had gotten hold of their minds. Synchronous rhythm locked them into step. For Marianthe, the sight brought on a stream of flashbacks: glory days, when command and strategy spiked through her arteries like a virus. Like a drug. A platoon full of hearts beating in syncopation. You could feel your brother and sister soldiers, know they had your back, your breath, your sweat.” I’m trying to avoid spoilers, but of course that savage past collides with the protagonist’s present, and that’s where the adventure begins.

Some readers seem to have found the world, and the range of characters, somewhat confusing; I thought the level of complexity of the novel was just about perfect. I enjoyed both the characters and the world in which they were set. This book has had a fair bit of revision and polishing before hitting the shelves, and it shows (although a plethora of typos suggests some rather poor final editing). My only real complaint was that, although I liked Star, the 17-year-old protagonist, I would have liked to have seen more of her older sister Nene, the healer (why does Nene just vanish from the story?). With luck, this novel will have a sequel or two.

By the way, a blog post I read recently suggested that the protagonist of a young adult (YA) novel should:

  • Be aged between 15 to 18 years old (Star is 17)
  • Be autonomous from his or her parents (Star is an orphan)
  • Embark on a journey which has to do with coming of age or some sort of rite of passage (Yes, she does)
  • Learn something about who he or she is (Yes, in spades)
  • Have a ‘voice’ that readers can relate to (Yes again)

So OK, this is a YA novel, although it has not been specifically marketed as such. What that means is that it suits the age range from 14 up to and including adult (as opposed to, say, Great North Road, which is written for adults only). Having said that, for the benefit of parents of younger readers, I should point out that there is some bad language, but that the only mention of sexuality is 25 words on page 3: “Remy. Star should never have slept with him. He’d been hanging around her ever since, as if she would ever make the same mistake again.” And Star has quite a clear sense of what is, and is not, the right thing to do.

For me, this novel ended with a “Planet of the Apes” moment, since Cat Sparks has set part of the novel in the vicinity of her home town of Canberra, Australia. Calling one of the fortress cities “Nisn” was a clue I missed first time around – but I could hardly miss the reference to the Brindabella Range. I also finished this book with a strong sense of wanting to read more from this author. Lotus Blue was one of the best books I’ve read this year.


Lotus Blue by Cat Sparks: 4 stars


Looking back: 1982

In 1982 (35 years ago!) I finished my basic undergraduate degree, majoring in Mathematics and Computer Science (after sniffing around the job market, I continued my studies for an honours year). This was the year that the compact disc and the Commodore 64 computer came out:

Also that year, Stephen Cook won the Turing award for his work on computational complexity theory. The then Soviet Union landed two spacecraft in the hellish inferno that is Venus, and took photographs:

It was also a year of conflict – Argentina started a war with the UK over the Falklands Islands, and Israel invaded Lebanon. On a more positive note, there were several movies which became cult classics, such as Tron, E.T., and Conan the Barbarian. The superb science fiction movie Blade Runner stood out from the crowd (even with the flaws in the original cinema release):

In literature, Isabel Allende published her debut novel, as did Kazuo Ishiguro. In music, The Alan Parsons Project released their album Eye in the Sky and Australian band Icehouse (originally Flowers) released their classic single “Great Southern Land”:

Overall, it was a great year (apart from the wars).


Her pale fire she snatches from the sun

Shakespeare writes “the moon’s an arrant thief, and her pale fire she snatches from the sun” (Timon of Athens, Act 4, Scene 3). He is, of course correct. The moon merely reflects sunlight, and produces no light of its own. One way of telling this is that moonlight actually displays the same telltale absorption spectrum as sunlight:

Our eyes tend to perceive moonlight as “blueish” or “silvery,” but that is because of the way our eyes work at low light levels. Long-exposure photographs under moonlight, like this one, look much like daytime shots:

Anaxagoras (499–428 BC) seems to have been the first to discover that the moon shines only by reflected light:

Anaxagoras also explained that solar eclipses occur when the moon moves between the earth and the sun. Total solar eclipses are dark precisely because the moon produces no light of its own:


MODSIM Conference, Day 1

I am attending the MODSIM International Congress on Modelling and Simulation in Hobart, Tasmania. It promises to be another great event.

I spoke today on “Sampling bias and implicit knowledge in ecological niche modelling.” Out of the many interesting talks I listened to, one that stands out is “The Waroona fire: extreme fire behaviour and simulations with a coupled fire-atmosphere model” by Mika Peace. It introduced me to “pyrocumulonimbus clouds,” and some of the complex weather–fire interactions in severe bushfires. This is certainly a phenomenon that needs to be better understood.