Final words on the European Solar Challenge

Further to my post on the European Solar Challenge results, here is a graph of the lap counts during the 24 hour track race (with thanks to Nigel for the data). Twente had an explicit strategy of not driving excessively fast, and braking as little as possible, in order to keep their recharge times to just one hour. This certainly paid off for them! The graph also shows those teams that had trouble of various kinds.

Ecological networks and the Australian dingo

I’m excited at the publication of a joint paper on network ecology, with a focus on the Australian dingo: “Trophic cascades in 3D: Network analysis reveals how apex predators structure ecosystems” (by Arian D. Wallach, Anthony H. Dekker, Miguel Lurgi, Jose M. Montoya, Damien A. Fordham & Euan G. Ritchie, and appearing in Methods in Ecology and Evolution).

Associated with this publication is an animation I put together for the paper showing how the ecological network changes if the role of the dingo as apex predator is weakened. I’m grateful to my ecologist co-authors at the opportunity to contribute my mathematical skills to such an interesting project.

European Solar Challenge 2016 Results

Circuit Zolder seen from above (imagery: Landsat, car photo: Anthony Dekker)

The European Solar Challenge at Circuit Zolder this year had an interesting format, with a 24 hour endurance track race, a competition for the fastest lap time, a chicane challenge, and a presentation about the car. Requiring a balance between speed, cornering ability, and battery capacity, the track race seemed to provide a fair competition for both Cruiser-class and Challenger-class cars.

Twente won the track race, with 278 laps (ahead of the Tesla with 273 laps), followed by Punch Powertrain from Leuven (262) and the PowerCore Suncruiser from Bochum (258). The Thyssenkrupp Sunriser from Bochum ran the fastest lap (3:03.063), followed by their Solarworld GT (3:09.990) and the Swiss Solar Energy Racers (3:19.891). The chicane challenge was won by the Solarworld GT, and the presentation by Twente.

The chart below shows the updated and official team points. The bars labelled “Total” on the left are the sum of all the other bars. Teams with zero points are not shown. Congratulations to all the teams, especially Twente, who won overall, Punch Powertrain, who came second, and the Thyssenkrupp Sunriser, which came third!

World Solar Challenge: the board game!

Readers of this blog will know that I am passionate about science / technology / engineering / mathematics education, and that I am passionate about board games, and that I am passionate about solar car racing (with the ESC and the Sasol Solar Challenge coming up soon). Wouldn’t it be great if those three things could be combined?

Well, now they can! To assist solar car teams with education/outreach efforts, I’ve put together a simple board game based on the World Solar Challenge, and aimed mostly at kids. It looks like this:

The online game store (faciliated by the wonderful people at The Game Crafter) has a free download link for the rules, should anyone wish to take a look. I also have a few other educational games there.

Computational anthropology – Sororities and colour rules

A recent blog post about US sororities published the above slide from Sigma Delta Tau, dating from 2013 and outlining a palette of acceptable dress colours.

Founded a century ago, Sigma Delta Tau is a historically Jewish sorority with an interest in philanthropy. Their slogan is “empowering women,” and in some way that I cannot possibly understand, this is achieved partly through extremely detailed guidelines on attire. However, the slide above does make a good case study in computational anthropology.

Whenever we have a set of OK/Not OK pronouncements like these, decision tree learning is a good tool for extracting the underlying pattern (I used the rpart package in R). For colours, we can perform analysis using hue, saturation, and value. In this case, the first restriction computed by the tool (and reinforced in the text of the slide) is “don’t go too light” – the sorority requires a colour value below about 79. The second restriction in the decision tree is “not too blue” – specifically a hue lower than about 182. Saturation is not identified as important in the decision tree analysis.

The diagram below highlights the acceptable colour region and the specific examples from the slide above. Of course, this only gives clarity to what the social rule is. It does not explain why the social rule exists, or what social goals the rule might achieve. For that, we must turn to traditional anthropology – although even here, social simulation can provide computational assistance.

European Solar Challenge 2016 Update

Below, once again, are the 12 solar car teams that will be competing in the European Solar Challenge this year, with revised links to their websites and social media. The ESC will be held at Circuit Zolder in Belgium from September 23 to 25 this year. It will be a 24 hour endurance track race, competing against a (non-solar) Tesla Model S (however, teams may charge their car from mains power up to two times, if they stop for an hour to do so). About half the points for the ESC will come from the number of laps of the track completed. Other points will come from the fastest lap time, a timed chicane challenge on the 23rd, and a presentation about the car. Follow the event on Facebook and Twitter.

Circuit Zolder seen from above (imagery: Landsat, car photo: Anthony Dekker)

The 24 hour track race starts at 13:00 on the 24th, and sunset will be at 19:32 that evening. The sun will rise again at 07:30 the next morning, and the race will continue until 13:00 on the 25th. Long-range weather forecasting suggested that the weather might be cloudy that weekend, but a more up-to-date forecast suggests sun (see diagram below). See also this nearby weathercam (about 8.5 km away, and facing towards the racetrack).

Advance weather forecast for the 24 hour track race

DE  Bochum University of Applied Sciences 

This team came 3rd in the Cruiser class at WSC 2015. Bochum are fielding three teams at ESC (racing the Solarworld GT, which drove around the world in 2011/12; the PowerCore SunCruiser from WSC 2013; and the beautiful ThyssenKrupp SunRiser from WSC 2015).


GB  Cambridge University 

This team came 22nd in the Challenger class at WSC 2015. Their car has an interesting teardrop design.

TR  Dokuz Eylül University / Solaris 

This team came 25th in the Challenger class at WSC 2015.

CO  EAFIT / Cambria 

This is a new team. They have posted a nice team overview video.

IT  Futuro Solare 

This appears to be a relatively new team. Read more about them here. Their car is called Archimede in honour of the famous mathematician of that name, who was a native of Syracuse, the team’s home town.

TR  Istanbul Technical University 

This team came 17th in the Challenger class at WSC 2013. They will be racing a rebuilt version of one of their old Challenger class cars, not the more recent Cruiser shown below.

IT  Onda Solare 

This team came 10th in the Challenger class at WSC 2013, and 10th in the 2015 Abu Dhabi Solar Challenge. They came 2nd in the Evolución class at the 2016 Carrera Solar Atacama.

BE  Punch Powertrain Solar Team 

This team came 3rd in the 2015 Abu Dhabi Solar Challenge, and 5th in the Challenger class at WSC 2015. They will be racing Indupol One, their entry from WSC 2013.

CH  Solar Energy Racers 

This team came 5th in the Challenger class at WSC 2013, and 11th in the 2015 Abu Dhabi Solar Challenge. They also participated in this year’s American Solar Challenge. They will be racing their SER-1 car, which was their entry in the 2011 WSC.

NL  Solar Team Twente 

This team came 2nd in the Challenger class at WSC 2015. Their Red One is the fastest entry in terms of raw speed. Whether that is enough to win the challenge remains to be seen.

Here is the scoring matrix for the event:

  Chicane Fastest Lap 24-hour Race Presentation
1st 20 20 50 10
2nd 15 15 40 8
3rd 10 10 30 6
4th 5 5 20 4
5th 0 0 10 2

This post last updated 11:29 on 23 September 2016 AEST

West European Solar Party

Solar Team Eindhoven has been hosting WESP 2016, the West European Solar Party.

If the pictures on Facebook are any indication, everybody had a good time. Since “wesp” is Dutch for “wasp,” several people turned up in appropriate costume. Building and racing solar cars is a stressful business, so the teams certainly deserved a party!

Teams attending the event included (among others):

Lodz Solar Team (some of them)

Nuon Solar Team (some of them)

Aliens, C. S. Lewis, and the Fermi paradox

A blog post on the Fermi paradox someone linked me to reminded me of an essay by C. S. Lewis entitled “Religion and Rocketry.” In that essay, Lewis gives an interesting analysis of the possibilities for non-vegetable alien life, and the religious implications that such life might have. For example, such aliens (if they exist) might be simply animals.

The xenomorphs of the Alien film series are not evil – they are simply (very) dangerous animals.

Alternatively, the aliens might have “the power to mean by ‘good’ something more than ‘good for me’ or even ‘good for my species.’” Of course, knowing about good does not mean that the aliens are good. They might be irredeemably evil, in which case it is better if we never meet them.

Orcs in the fiction of J.R.R. Tolkien are irredeemably evil (artwork: Antoine Glédel).

On the other extreme, there may be alien species that have never turned from good to evil. C. S. Lewis’ own novel Out of the Silent Planet describes three such species, and in “Religion and Rocketry,” he describes the rather sad results that our contact with such species could have: “We know what our race does to strangers. Man destroys or enslaves every species he can. Civilized man murders, enslaves, cheats, and corrupts savage man. Even inanimate nature he turns into dust bowls and slag-heaps. There are individuals who don’t. But they are not the sort who are likely to be our pioneers in space.

C. S. Lewis’ Out of the Silent Planet describes three fictional alien species living on Mars: the hrossa, the séroni, and the pfifltriggi. All are free from evil.

The most interesting option is that of aliens who, like us, have tasted both good and evil. Writers of fiction have concentrated on this kind of alien, because they often lead to more interesting storylines, and because they hold up a mirror in which we can see some part of ourselves. However, that does not mean that such aliens exist. And if they do exist, the final resolution of evil in their species, Lewis suggests, may or may not be related to that in ours.

Underneath the makeup, Klingons are creatures much like ourselves. A little too much like ourselves to be truly plausible.

Of course, if we ever meet aliens like ourselves, and those aliens are stronger than we are, things might go as badly for the human race as they did for the Native Americans. One might dream of the opportunity “to interchange thoughts with beings whose thinking had an organic background wholly different from ours (other senses, other appetites), to be unenviously humbled by intellects possibly superior to our own yet able for that very reason to descend to our level, … to exchange with the inhabitants of other worlds that especially keen and rich affection which exists between unlikes.” But perhaps it’s best if that remains merely a dream, and that any (hypothetical) aliens remain far, far away.

The novel Footfall, by Larry Niven and Jerry Pournelle, presents a slightly more plausible alternative – aliens that have evolved from herd animals. However, things go badly for the human race when they decide to “stomp” us.

Avoiding any aliens that might be out there is particularly sensible if reality resembles some of the nastier fictional alien scenarios, such as those involving the Borg, Daleks, Berserkers, or Vang. Indeed, some people have suggested that the presence of powerful implacably hostile aliens might explain the failure of SETI to find any extraterrestrial intelligent life. On the other hand, silence might just mean that there’s nobody out there.

If “resistance is futile,” it might be safer to stay very, very quiet.

Why vaccinate?

Why do we vaccinate children? To prevent some horrific diseases that have haunted the human race for centuries. These diseases have not gone – they are still lurking in the darkness, and have already started to reappear in towns with low vaccination rates. Here is a brief reminder of five diseases that no sane person would want to see return.


Diphtheria is caused by a toxin-producing bacterium. It kills between 50 and 200 out of each thousand people who catch it.


Measles is caused by a virus. In the US, it kills about 2 out of each thousand people who catch it (in the rest of the world, more like 7 out of each thousand). However, it can also cause brain damage, deafness, blindness, and other complications in the survivors. It is extremely infectious – far more so than Ebola or the flu. And cases are trending upwards in the USA as a result of non-vaccination.


Rubella (German measles) is of concern not only because of the harm it can do to those who catch it, but because it also causes miscarriages and birth defects in pregnant women.


Pertussis (whooping cough) can leave children weak for a long time. It is particularly deadly in young infants, and low vaccination rates are responsible for the deaths of babies in some areas. See here for a rather disturbing video of a baby in intensive care.


Poliomyelitis (polio) is caused by a virus, which can cause permanent paralysis of various muscles. The 1950s saw serious epidemics that have now been largely forgotten. Unfortunately, attempts to eradicate polio have stalled in certain parts of the world.

Polio survivors (photo: RIBI Image Library)

Worldwide, each minute of every day and night, three children under five die from vaccine-preventable diseases like these. So “jab for life,” mums and dads!