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)


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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.