World Solar Challenge 2019 Revisited: some additional charts

Revisiting the World Solar Challenge, the chart below shows distance/speed plots for seven WSC teams (for other teams I was either missing some GPS data, or did not have access to explanatory social media). Distances shown are road distances (not geodesic), while speeds are estimated from distance and time information (because speeds were not included in the GPS data that was kindly supplied to me). As a result of data limitations, the compulsory 30-minute stops at Katherine etc. are shown by sharp speed dips, but not necessarily ones that drop all the way to zero.

Vattenfall (3) had a devastating battery fire; Top Dutch (6) were the best new team, finishing 4th; Agoria (8) won the Challenger class; Twente (21) tragically crashed while in the lead; Sonnenwagen Aachen (70) were one of two teams to come back from a serious crash and still finish; Blue Sky (77) were the 11th and last Challenger team to reach Adelaide on solar power; and Kogakuin (88) were the other team to recover from a major crash.

Night stops in the chart above are marked in red. Photos are from their tweet posted minutes before the fire and from a tweet posted shortly afterwards.

Control stop times for Vattenfall: Katherine: Sunday 12:19:21, Daly Waters: Sunday 15:59:21, Tennant Creek: Monday 11:45:23, Barrow Creek: Monday 14:51:01, Alice Springs: Tuesday 9:30:33, Kulgera: Tuesday 12:51:41, Coober Pedy: Wednesday 8:39:31, Glendambo: Wednesday 12:40:58, Port Augusta: Wednesday 16:44:32.

The chart shows Top Dutch’s multiple stops just out of Tennant Creek with battery problems. Top Dutch finished 4th, and won the WSC Excellence in Engineering Award.

Control stop times for Top Dutch: Katherine: Sunday 12:16:27, Daly Waters: Sunday 15:57:03, Tennant Creek: Monday 12:12:55, Barrow Creek: Monday 15:28:35, Alice Springs: Tuesday 10:39:32, Kulgera: Tuesday 14:41:40, Coober Pedy: Wednesday 12:00:43, Glendambo: Wednesday 15:48:50, Port Augusta: Thursday 10:47:39, Adelaide: Thursday 15:30:00.

Night stops in the chart above are marked in blue. Agoria had a virtually perfect race, winning the Challenger class. Visible in the chart after Coober Pedy is the 80 km/h speed limit imposed by the WSC on Wednesday morning after wind gusts caused multiple crashes.

Control stop times for Agoria: Katherine: Sunday 12:17:04, Daly Waters: Sunday 16:05:54, Tennant Creek: Monday 11:55:56, Barrow Creek: Monday 14:56:40, Alice Springs: Tuesday 9:46:28, Kulgera: Tuesday 13:10:50, Coober Pedy: Wednesday 9:22:36, Glendambo: Wednesday 13:05:06, Port Augusta: Wednesday 16:51:59, Adelaide: Thursday 11:52:42.

Twente’s tragic crash (due to a strong wind gust) occurred at about 2165 km from Darwin, just before Coober Pedy. Photos are from a tweet posted the day before the crash and from a tweet posted shortly afterwards. I was one of the people that signed the car after the crash. Twente won the Promotional Award, for their excellent media.

Control stop times for Twente: Katherine: Sunday 12:08:43, Daly Waters: Sunday 15:32:39, Tennant Creek: Monday 11:33:01, Barrow Creek: Monday 14:31:33, Alice Springs: Tuesday 9:17:16, Kulgera: Tuesday 12:40:40.

Sonnenwagen Aachen stopped for five hours to repair their car on Wednesday, just before Coober Pedy, after the car was blown off the road (their first priority was the driver, of course). There was another stop between Glendambo and Port Augusta, due to a broken shock absorber that had been damaged in the crash (Western Sydney Solar Team kindly helped get them back on the road). Sonnenwagen Aachen finished 6th. They also won the Safety Award and and the Spirit of the Event Award (for not giving up).

Control stop times for Sonnenwagen Aachen: Katherine: Sunday 12:27:34, Daly Waters: Sunday 16:09:06, Tennant Creek: Monday 12:17:32, Barrow Creek: Monday 15:12:27, Alice Springs: Tuesday 9:52:06, Kulgera: Tuesday 13:31:00, Coober Pedy: Wednesday 15:08:20, Glendambo: Thursday 9:35:27, Port Augusta: Thursday 14:49:06, Adelaide: Friday 10:03:48.

Blue Sky (Toronto) had several brief stops of a few minutes (including for electrical issues on Monday), but no particularly dramatic events. They were also slowed somewhat by clouds on Wednesday morning. Blue Sky finished 11th (the last Challenger team to reach Adelaide on solar power).

Control stop times for Blue Sky: Katherine: Sunday 12:49:29, Daly Waters: Monday 8:03:38, Tennant Creek: Monday 14:42:34, Barrow Creek: Tuesday 9:54:44, Alice Springs: Tuesday 14:23:40, Kulgera: Wednesday 11:00:30, Coober Pedy: Thursday 10:34:55, Glendambo: Thursday 15:01:18, Port Augusta: Friday 10:53:25, Adelaide: Friday 15:47:10.

Kogakuin was forced to stop with an overheated motor just after Katherine. They also crashed twice due to strong winds. The second, more serious, crash was due to a mini-tornado or willy-willy just before Glendambo (see their report here), and required overnight repair in town on Wednesday night. Kogakuin finished 5th. They won the CSIRO Technical Innovation Award, for their hydropneumatic suspension. Their dramatic after-race video is here.

Control stop times for Kogakuin: Katherine: Sunday 12:18:43, Daly Waters: Monday 8:03:13, Tennant Creek: Monday 13:16:26, Barrow Creek: Monday 16:15:52, Alice Springs: Tuesday 11:03:53, Kulgera: Tuesday 14:32:15, Coober Pedy: Wednesday 12:04:23, Glendambo: Thursday 9:45:18, Port Aug: Thursday 14:18:47, Adelaide: Friday 9:53:00.

For comparison, here is the distance/time chart I did before. In that analysis, higher means slower, and the arrival times (in Darwin time) can be read out on the right:


Hello to the American Solar Challenge

For diehard solar car fans, I’ve produced a draft teams list for the American Solar Challenge in July next year. It will get regularly updated, of course.

Nach dem Spiel ist vor dem Spiel.


Quantum supremacy – or not?

Google recently published a paper in Nature entitled “Quantum supremacy using a programmable superconducting processor.” They claim to have used 53 qubits to solve a task that would take about 10,000 years on a classical supercomputer.

Some caution seems necessary in interpreting this claim, however. First, it does not refer to any of the practical tasks that people would like quantum computers to solve. And second, IBM claims that 2.5 days is a more realistic estimate for the time required on a classical supercomputer. It does seem that “quantum supremacy” is not quite here yet (see also what Scott Aaronson has to say).


Photo: IBM 50-qubit quantum computer (credit: Ian Hughes, 2018)


Spineless by Juli Berwald: a book review


Spineless by Juli Berwald (2017)

I recently read Spineless: The Science of Jellyfish and the Art of Growing a Backbone by Juli Berwald (not to be confused with Spineless by Susan Middleton). Part memoir and part science writing, this book is very well-written, and moderately full of information about the oft-ignored jellyfish clan (some readers will find the combination of autobiography and science not to their liking). The book cover appears to be mostly derived from this Haeckel print:

I myself was fascinated by the jellyfish in the Monterey Bay Aquarium, but I did not fall in love with jellyfish the way that Juli Berwald did. This book does not quite do the job either, perhaps because of the distractions of the (not all that compelling) autobiographical material. It also seemed difficult to reconcile the author’s concerns about global warming with her high-carbon lifestyle.


Sea nettles at the Monterey Bay Aquarium (photo by “Omegacentrix”)

Still, this book is well worth a read. Other reviews of the book are linked from the author’s Wikipedia article.

* * *
Spineless by Juli Berwald: 3 stars


Farewell to the World Solar Challenge

This ends my World Solar Challenge 2019 coverage. I will begin covering the American Solar Challenge in a few months. Meanwhile, regular science content resumes.

Summary of WSC additional awards:

  • CSIRO technical innovation award: Kogakuin, for their hydropneumatic suspension.
  • Safety award: Sonnenwagen Aachen, who crashed.
  • Spirit of the Event award: Sonnenwagen Aachen, for not giving up.
  • Promotional award: Solar Team Twente, for their excellent media.
  • Excellence in engineering award: Top Dutch, for their wonderful car.

World Solar Challenge Cruiser Scores Revisited

Above (click to zoom) are the World Solar Challenge 2019 Cruiser practicality scores. Image credits are as per my illustrated list of teams. That list also includes practicality score guesses – but I did a poor job of guessing (a correlation of only 0.75 with actual scores). That reflects the change in practicality scoring this year, with several of the less subjective elemehts removed. Four cars this year had higher practicality scores than when they last appeared:

  • Minnesota (team 35) from 57 to 76.3 (a surprisingly large change, although it is a very nice car)
  • Flinders (team 14) from 46.7 to 63.7 (this team did make many improvements)
  • HK IVE (team 25) from 45.2 to 63.4 (this team did make many improvements)
  • Lodz (team 45) from 79.1 to 82.4 (a surprisingly small change, given the extensive improvements)

Two cars had lower practicality scores than when they last appeared:

  • Bochum (team 11; they fielded this car in 2015) from 80.5 to 75.1 (a surprising score, given the fantastic interior)
  • Sunswift (team 75) from 80 to 69.5 (also surprising, although they did take the rear seats out)

The chart above (click to zoom) shows final Cruiser scores (including practicality) in the style of my previous chart. The score is calculated as a product S = D × H × (1 / E) × P × 0.99l. The chart shows the components of the score on a logarithmic scale, so that multiplying and dividing score components corresponds to adding and subtracting bars. For each team, there are 6 bars (the 6th bar, in a darker colour, is the total score):

  1. The distance travelled in km (D). Teams given credit for completing the entire course score ahead of others.
  2. The weighted average number of humans (H) in the car (so that the product D×H is the number of person-kilometres). A small tick mark above the bar shows the number of seats in the car, which is the maximum possible value of H for that team.
  3. The nominal external energy usage (E) in kWh (initial battery capacity, plus metered charging along the way). This bar is negative, because we are dividing by E.
  4. The practicality score divided by 100. This bar is negative, since the highest possible value is 1.0 (this means that longer bars mean lower values). A tick mark under the column shows the lowest practicality score across all six teams, which is 0.534.
  5. The lateness factor (0.99l), where l is the number of minutes of late arrival, plus the number of demerit points.
  6. The total score (S). The score itself is shown over the bar. It can be seen by inspection that this bar is the sum of the others.

Well done, Eindhoven!