World Solar Challenge: lighter and lighter

The chart above shows car weights (in kg) for the World Solar Challenge Challenger class, since 2001. In spite of the increasing safety standards and the shift from 3 wheels to 4, weights have trended steadily downwards, which says something about the strength-to-weight ratio of modern composite materials.


Which is the best World Solar Challenge team?

Recently, I saw that someone had asked on the Internet which the best team in the World Solar Challenge was.

For the WSC Challenger class, this is not a difficult question. Nuon Solar Team owns the race, and has won six times out of eight this century (although “uneasy lies the head that wears a crown”). The more interesting question is: who is second? There are four main contenders for that honour.

A few years ago, I would have placed Tokai University second. They won the race in 2009 and 2011. However, unless they can reverse the trend, their star seems to be falling.

Michigan are very definitely the best US team. However, they have pointed out themselves that they suffer “the curse of third,” and thus far lack the je ne sais quoi that it takes to win (of course, when they find it, Nuon had better watch out).

The star of Solar Team Twente is rising. They worked their way up to second place in 2015. They could win this year.

Finally, the Belgian team from KU Leuven is also moving up, and I expect them to do very well this year also.

In the WSC Cruiser class, “best” is a fuzzier concept. However, Eindhoven, Bochum, and UNSW/Sunswift have all done consistently well, with Eindhoven winning the last two races.


What makes Australians happy?

Lately I’ve been exploring demographic and social data, including looking at the Australian data in the World Values Survey. Of particular interest are data on self-reported happiness. Among women, financial stress and poor health contribute to unhappiness, as might be expected. Socially conservative women report being happier, and single women report being less happy. Finally, women who attend religious services once per week or once per month are happier than those who do not attend religious services, or those who attend religious services more than once per week. This is broadly consistent with literature on the effects of religion on mental health.

Among men, financial stress and poor health act in the same way as for women. In terms of marital status, however, it is separated men who are the least happy. Male happiness is also closely tied to employment status, with unemployed (and, to a lesser extent, self-employed) men reporting more unhappiness.


Gender and Health

Lately I’ve been exploring demographic data related to women’s health. Among other things, this involved looking at the Australian data in the World Values Survey, which includes a self-reported measure of health. For women, this depends on a number of other variables, including age:

For men, the age effect is weaker:

Presumably, this is because male health problems are more likely to be fatal, which is why there is an excess of women amongst the elderly, as indicated by Australian census data:


Marching for Science #5

Further to my previous comments on the Science March, the graph below shows the (somewhat dubious) attendance estimates from Wikipedia for various cities (excluding vague counts like “thousands”), compared to the power-law predictor 0.47 D1.49 P0.78, where D is the fraction of the relevant state voting for Clinton last year (from Wikipedia), and P is the city population (also from Wikipedia).

The population P predicts 56% of the variance in turnout (not surprisingly), and D an additional 7%. Both factors were significant (p = 0.000000055 and p = 0.014 respectively). Prediction could probably be improved by using metro area population numbers for the cities, by using metro area election results (rather that state results), and by adding factors indicating the number of other marches in the relevant state (Colorado Springs, for example, was rather overshadowed by Denver) and the presence of universities (Ann Arbor, for example, is a university town). But the basic messages seem to be: Democrat voters do not like Donald Trump and Large cities attract large crowds. It would be interesting to compare the numbers here against other recent political marches which focused on different issues.


The Harp Twins

Someone recently pointed me at Camille and Kennerly Kitt, the so-called “Harp Twins” (above). I admire anybody who “thinks outside the box,” and these young women have clearly left the “box” of traditional harp-playing several light-years behind.

Their rather eclectic oeuvre includes film, game, and TV tie-ins (from e.g. Lord of the Rings or The Legend of Zelda); rock, folk, and pop classics (like “Hotel California” or “House of the Rising Sun”); metal (from bands like Iron Maiden or Metallica); and other music (such as “Amazing Grace” and “Scarborough Fair”). They have just started releasing their own compositions. The chart below summarises their releases by genre (data taken from Wikipedia, so probably incomplete).


Stories of the Past and Future

Inspired by a classic XKCD cartoon, the infographic above shows the year of publication and of setting for several novels, plays, and films.

They fall into four groups. The top (white) section is literature set in our future. The upper grey section contains obsolete predictions – literature (like the book 1984) set in the future when it was written, but now set in our past. The centre grey section contains what XKCD calls “former period pieces” – literature (like Shakespeare’s Richard III) set in the past, but written closer to the setting than to our day. He points out that modern audiences may not realise “which parts were supposed to sound old.” The lower grey section contains literature (like Ivanhoe) set in the more distant past.