The Sydney Observatory

Observatory exterior (photo by Greg O’Beirne, 2006)

An unusual free science museum in Sydney, Australia is the Sydney Observatory. This opened in 1858 as a working observatory. The time ball, which dropped each day to mark the exact time, is still operating at 1:00 PM each afternoon. The observatory now operates as a small museum, having been refurbished during 1997–2008. The telescopes can also be used on paid night tours.

The observatory is a stiff climb up Observatory Hill. The exhibits are limited in number, but include some excellent orreries. Unless you have some astronomical expertise, the paid guided tours will be helpful. My brief visit was an enjoyable one.

An orrery at Sydney Observatory (photo by Anthony Dekker)

Exploring the moral landscape with recursive partitioning

I’ve mentioned the World Values Survey before. Lately, I’ve been taking another look at this fascinating dataset, specifically at the questions on morality. The chart below provides an analysis of responses to the question “Is abortion justifiable?” These responses ranged from 1 (“never justifiable”) to 10 (“always justifiable”). I looked at the most recent data for Australia and the United States, plus one European country (the Netherlands) and one African country (Zambia), using recursive partitioning with the rpart package of R, together with my own tree-drawing code.

Attitude data such as this is often explained using political orientation, but political orientation is itself really more of an effect than a cause. Instead, I used age, sex, marital status, education level, language spoken at home, number of children, and religion as explanatory variables, with some grouping of my own. Demographic weightings were those provided in the dataset.

For the United States (US), the overall average response was 4.8 (as at 2011, having risen from 4.0 in 1995). However, among more religious people, who attended religious services at least weekly, the average response was lower. This group was mostly, but not entirely, Christian, and the area of the box on the chart gives an approximate indication of the group’s size (according to Pew Forum, this group has been slowly shrinking in size, down to 36% in 2014). The average response was 3.0 for those in the group who also engaged in daily prayer, and 4.3 for those who did not. Among those who attended religious services less than weekly, the responses varied by education level. The average response was 4.8 for those with education up to high school; 6.9 for those with at least some tertiary education who were Buddhist (B), Hindu (H), Jewish (J), Muslim (M), or “None” (N); and 5.4 for those with at least some tertiary education who were Catholic (C), Orthodox (Or), Protestant (P), or Other (Ot).

For Australia (AU), the overall average response was 5.8 (as at 2012, having risen from 4.3 in 1981), with a pattern broadly similar to the US. Here the “more religious” category included those attending religious services at least monthly (but it was still smaller a smaller group than in the US). The average response was 2.7 for those in the group who also engaged in daily prayer, and 4.6 for those who did not. The group most supportive of abortion were those attending religious services less than monthly, with at least some tertiary education, and speaking English or a European language at home. Those speaking Non-European languages at home clustered with the religious group (and those with at least some tertiary education speaking Non-European languages at home are a growing segment of the population, increasing from 6.2% of adults in the 2011 Census to 8.3% of adults in the 2016 Census).

For the Netherlands (NL), the overall average response was 6.5 (as at 2012). Those most opposed to abortion either attended religious services at least weekly (3.2), or were Hindu or Muslim (3.3). Then came those who either attended religious services monthly (5.2), or who attended religious services less often, but were still Catholic (C), Orthodox (Or), Protestant (P), or Other (Ot), and had not completed high school (5.3). The group most supportive of abortion were those attending religious services less than monthly, with at least some tertiary education, and who were Buddhist, Jewish, or “None” (7.9).

For Zambia (ZM), opposition to abortion was strong, with an overall average response of 3.2 (as at 2007). It was highest for those whose marital status was “separated” (4.5), and lowest for those aged 28 and up whose marital status was anything else (2.8).

Of the explanatory variables I used, all except sex, age, and number of children were important in at least one country. However, sex was important for “Is prostitution justifiable?” or “Is violence against other people justifiable?” Age was important for “Is homosexuality justifiable?” or “Is sex before marriage justifiable?” Number of children was important for “Is divorce justifiable?” or “Is suicide justifiable?” For example, here is an analysis of attitudes to divorce:

Powers of 10: the Australian version

In the footsteps of the classic short film, we explore the powers of 10 (click to zoom).

We begin with a classic NASA photograph of the Earth seen from Saturn, with a field of view (in the distance) about 100,000,000 km across. We zoom in by a factor of 10 to see the Earth and the Moon beside it. After three more such jumps (to 10,000 km), the Earth fills the frame. Three further jumps (to 10 km) zooms in on Melbourne, Australia. Two more jumps show us the city centre (1 km) and St Paul’s Cathedral (100 m). Another two jumps (to 1 m) give us a small boy on the grass beside the Cathedral. Two more give us the iris and pupil of his eye (1 cm) and a small patch of his retina (1 mm). Finally (at 100 µm or 0.1 mm), we see red blood cells inside a blood vessel in his retina. Fifteen jumps in all, zooming in by 1015.

New solar car teams #4: ATN

ATN Solar Car Team  (click: ) is a new Australian Cruiser-class solar car team. They are attempting something I have never seen done before – design and construction of a solar car by a team distributed across a continent. According to the initial press release:

I will be very interested to see if they can make this work and which virtual team tools and techniques they will use to do so. So far, ATN Solar Car Team has produced a number of quite different design concepts. The video below shows one of the more interesting ones, and has produced many admiring comments:

Note: Independently of this effort, the experienced Team Arrow will continue as a Cruiser-class team based in Brisbane (also associated with QUT).

Australian plant families revisited

This visualisation (revising an older post) shows the sizes of major Australian plant families, compared to world totals (based on slightly old data from here).

Australia’s 836 orchid species are only 3% of the world total, but Australia has 89% of the Goodeniaceae.

Plants illustrated include the Golden Wattle and Sturt’s Desert Pea.

Something different

This picture illustrates the ill-fated expedition to Australia described in H.P. Lovecraft’s horror story The Shadow Out of Time. The images in the montage are edited versions of public-domain pictures, and include this copy of the Necronomicon. The complete image is © Anthony Dekker.

… On July 10, 1934, there was forwarded to me by the Psychological Society the letter which opened the culminating and most horrible phase of the whole mad ordeal. It was postmarked Pilbarra, Western Australia, and bore the signature of one whom I found, upon inquiry, to be a mining engineer of considerable prominence. Enclosed were some very curious snapshots. I will reproduce the text in its entirety, and no reader can fail to understand how tremendous an effect it and the photographs had upon me. …

The “Pilbarra” in this story (and on the map) is presumably Pilbara Road District, an old name for what is now the town of Port Hedland, Western Australia (although the address given by Lovecraft matches a no longer extant street in the nearby ghost town of Cossack). Lovecraft’s story also refers to a precise geographical location: 22° 3′ 14” S, 125° 0′ 39” E. See more on the Australian aspects of the story at Trollunteer. Propnomicon also did some really good props a few years back.

Religion in the Australian Census

Following up on my earlier post, here is a chart of religion in Australia, by age (as per the 2016 Census, with percentages on the vertical axis relating to the population of Australia as a whole, and excluding people with no religion specified). Coloured areas in this chart indicate the total number of people for each religious group:

The changing religious landscape is revealed by the variation with age. For people aged 65, the population is 25% Catholic, 24% secular, 22% Anglican, 16% other Christian, 7% Uniting Church, 2% Buddhist, 1% other religion, 1% Muslim, and 1% Hindu.

For people aged 25, it’s 47% secular, 21% Catholic, 11% other Christian, 8% Anglican, 4% Muslim, 3% Hindu, 3% Buddhist, 2% Uniting Church, and 2% other religion. The chart below shows these relative percentages, for each age cohort.

Immigration and children are keeping the Catholic Church stable in size, but the Uniting Church is in collapse, and the Anglican Church is not doing much better (other data suggests that it’s in collapse outside of Sydney). The “big three” non-Christian religions (Islam, Hinduism, and Buddhism) are more than 10% of the age-25 demographic. The chart also shows the impact of student-driven Indian immigration to Australia over the past decade or so – there is a visible peak for Hinduism around age 33.

There seems to be something odd about the religion given for young children up to age 13 or so – some parents (especially Catholics) seem to be listing young children as “no religion.” This might reflect delayed baptism. However, it also seems that many children lose their childhood religion in late teens and early adulthood.

Mean ages for adults within the different groups are Hindu: 37.1, Muslim: 37.7, secular: 42, other religion: 42.6, Buddhist: 43.5, Catholic: 48.6, other Christian: 50.4, Anglican: 54.8, and Uniting Church: 55.8. The last two groups in particular are skewed towards older people.

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

Australians know that the world is round

Following up on my earth-measuring post, people have known for more than 2,000 years that the earth is round. In 350 BC, Aristotle wrote “The evidence of the senses further corroborates this [that the earth is spherical]. How else would eclipses of the moon show segments shaped as we see them? As it is, the shapes which the moon itself each month shows are of every kind straight, gibbous, and concave-but in eclipses the outline is always curved: and, since it is the interposition of the earth that makes the eclipse, the form of this line will be caused by the form of the earth’s surface, which is therefore spherical. Again, our observations of the stars make it evident, not only that the earth is circular, but also that it is a circle of no great size. For quite a small change of position to south or north causes a manifest alteration of the horizon. There is much change, I mean, in the stars which are overhead, and the stars seen are different, as one moves northward or southward. Indeed there are some stars seen in Egypt and in the neighbourhood of Cyprus which are not seen in the northerly regions; and stars, which in the north are never beyond the range of observation, in those regions rise and set. All of which goes to show not only that the earth is circular in shape, but also that it is a sphere of no great size: for otherwise the effect of so slight a change of place would not be quickly apparent.” (On the Heavens, II, 14).

Around the year 700, Bede wrote “We call the earth a globe, not as if the shape of a sphere were expressed in the diversity of plains and mountains, but because, if all things (terrestrial) are included in the outline, the earth’s circumference will represent the figure of a perfect globe. Hence it is that the stars of the northern hemisphere appear to us, but never those of the southern; while on the other hand, the people who live on the southern part of the earth cannot see our stars, because the globe obstructs their view.” (De Natura Rerum). Australians verify his statement about stars every night.

I have commented previously on how the medieval poet Dante described time zones on a round earth:

In more recent times, we have pictures from space:

Aristotle and Bede mention the stars. Not only do the visible stars vary with latitude, but in the Northern Hemisphere they rotate around Polaris, while in the Southern Hemisphere they rotate around the South Celestial Pole, as in this photograph taken in Chile:

Sailors at sea have long known that the earth is round. From a vantage point 20 metres above sea level, one can see a complete ship 17 km away. Beyond that, the distant ship goes “hull down,” and only the upper parts of it are visible (from 34 km away, the lower 20 metres of a distant ship will be hidden). Closer to sea level, the distance is much less. This photo, taken in Spain by “Santifc,” shows the phenomenon (and similar observations can be made at some Australian beaches):

And, of course, the aircraft flight times to and from Australia can only be explained by the fact that the earth is round: