ASC 4: Testing

It is critically important that solar-car teams clock up test kilometres before the big race. This is partly because of what engineers call the “bathtub curve.” Failures in any piece of technology are common at the start, but then level out to a low constant failure rate during the object’s lifetime (and of course, once the object starts to wear out, failures increase again).

In the business world, short warranties are used to cover that early failure-prone period. In racing, it’s essential to make sure that the car is out of that early period before the race begins. Therefore, the top teams test, test, and test some more!

Here is a montage of recent solar-car testing, which I have already posted to Twitter:


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True Stories – a book review


True Stories: And Other Essays by Francis Spufford

I recently finished True Stories: And Other Essays by Francis Spufford – a collection of real gems by a man who can truly write. A selection of essays, book reviews, and other non-fiction works, this book is divided into the thematic sections “Cold,” “Red,” “Sacred,” “Technical,” and “Printed.” The section “Technical,” for example, includes a piece on British engineering, together with a wide-ranging essay on Babbage’s “Difference Engine No. 2,” reconstructed by the Science Museum, London. Babbage never completed this device, of course, and perhaps could not have done so, given the technological limitations of his time. This leads Spufford into a general reflection on counterfactual history, drawing also on the novel The Difference Engine.

The section “Cold” includes several pieces on polar exploration, such as an introduction written for The Worst Journey in the World (a memoir of the 1910–1913 British Antarctic Expedition), and a piece on Ernest Shackleton. I’ve been fascinated by polar exploration since childhood, so I found these particularly interesting.


Grotto in an iceberg, photographed during the 1910–1913 British Antarctic Expedition (image credit)

The section “Red” deals largely with the former Soviet Union. It includes an explanation of Spufford’s fictional documentary book Red Plenty, and the essay “The Soviet Moment,” which is still online at The Guardian: “It was not the revolutionary country people were thinking of, all red flags and fiery speechmaking, pictured through the iconography of Eisenstein movies; not the Stalinesque Soviet Union of mass mobilisation and mass terror and austere totalitarian fervour. This was, all of a sudden, a frowning but managerial kind of a place, a civil and technological kind of a place, all labs and skyscrapers, which was doing the same kind of things as the west but threatened – while the moment lasted – to be doing them better. American colleges worried that they weren’t turning out engineers in the USSR’s amazing numbers. Bouts of anguished soul-searching filled the op-ed pages of European and American newspapers, as columnists asked how a free society could hope to match the steely strategic determination of the prospering, successful Soviet Union. … The loudest and most important lesson of the Soviet experience should always be: don’t ever do this again. Children, don’t try this at home. … Yet we’d better remember to sympathise with the underlying vision that drove this disastrous history, because it is basically our own.

The section “Sacred,” obviously, deals with religion (Spufford is an English Anglican). It includes a critique of Richard Dawkins, a reflection on C. S. Lewis, and a record of travels in Iran. The New Humanist still has online the essay beginning “Allow me to annoy you with the prospect of mutual respect between believers and atheists. … No? No. Because the idea of atheism as an extravagant faith-driven deviation from the null case goes against one of the most cherished elements in the self-image of polemical unbelief: that atheism is somehow scientific, that it is to be adopted as the counterpart in the realm of meaning to the caution and rigour of the scientific method.


Spufford visited the Sheikh Lotfollah Mosque in Isfahan, Iran (image credit)

Finally, the section “Printed” includes miscellaneous introductions and book reviews, including an introduction to The Jungle Book, a review of the Mars trilogy, and an obituary of Iain M. Banks. This last section reflects Spufford’s wide-ranging interests in technology, exploration, and imagination. For me, at least, it established a connection of sorts with the author: we read the same things; we are brothers.


The last section of True Stories includes a review of the Mars trilogy by Kim Stanley Robinson

See The New York Times and the New York Journal of Books for other reviews of True Stories. I’m giving it four stars overall, although several of the individual essays deserve five. This book was a delight to read.

* * * *
True Stories: And Other Essays by Francis Spufford: 4 stars


Solar car team composition

The chart above shows 2017 team composition for the Eindhoven and Bochum solar car teams (divided by study major, not team responsibility). Not surprisingly, electrical and mechanical engineering students are the core of both teams (about half in each case) Yet there is also considerable diversity, because the business side of a solar car team requires other skills too. The Bochum team also includes a media unit, which explains the large “other” category (one of the team photographers is a biology student, for example).

The chart was constructed by parsing web pages, which may have introduced errors (also, I guessed a bit with the German words). But the main point stands – solar car teams require a diverse set of skills.


The Bochum car (photo: Anthony Dekker)


The R100 and the R101

An instructive saga in the history of engineering is the story of the British airships R100 and R101. As part of a grand social experiment, the R100 was built by private industry (it was designed by Barnes Wallis), while the R101 was built by the British government (specifically, by the Air Ministry, under Lord Thomson). The R100 worked fine, and made a test flight to Canada in August 1930 (the trip took 78 hours). Here is the R100 over a Toronto building:

The R100 was huge. Here is a size comparison of the R100 (219 m long) and an Airbus A380 (73 m long):

While the government-built R101 used servo motors to control its gigantic rudder, the R100 team had worked out that the rudder could actually be operated quite easily by hand, using a steering wheel and cables. The government-built R101 was beset by poor choices, in fact. It contained overly heavy engines, a steel frame, and too much dead weight overall. After construction, the R101 had to be lengthened by inserting a new 14-metre section in the centre, in order to increase lift. This alteration caused a number of problems. Its design also allowed the internal hydrogen-filled gasbags to chafe against the frame, there were serious problems with the outer covering, and several “innovative” design ideas were never properly tested.

There was enormous political pressure for the R101 to fly before it was ready to do so. On the evening of 4 October 1930, it departed for India with a crowd of VIPs on board. It never arrived, crashing in bad weather over France, and bursting into flames. The disaster led to the R100 also being grounded, and the British government abandoned any thoughts of flying airships (as the rest of the world was to do after the Hindenburg disaster).

There are all kinds of lessons to be drawn from the saga of the R100 and the R101. One of them is that optimism is not a viable strategy for safety-critical engineering. Another is that engineers test things. As Kipling says, “They do not preach that their God will rouse them a little before the nuts work loose.” A third is that risky designs and fixed deadlines simply do not mix.


A History of Science in 12 Books

Here are twelve influential books covering the history of science and mathematics. All of them have changed the world in some way:


1: Euclid’s Elements (c. 300 BC). Possibly the most influential mathematics book ever written, and used as a textbook for more than 2,000 years.


2: De rerum natura by Lucretius (c. 50 BC). An Epicurean, atomistic view of the universe, expressed as a lengthy poem.


3: The Vienna Dioscurides (c. 510 AD). Based on earlier Greek works, this illustrated guide to botany continued to have an influence for centuries after it was written.


4: De humani corporis fabrica by Andreas Vesalius (1543). The first modern anatomy book.


5: Galileo’s Dialogue Concerning the Two Chief World Systems (1632). The brilliant sales pitch for the idea that the Earth goes around the Sun.


6: Audubon’s The Birds of America (1827–1838). A classic work of ornithology.


7: Darwin’s On the Origin of Species (1859). The book which started the evolutionary ball rolling.


8: Beilstein’s Handbook of Organic Chemistry (1881). Still (revised, in digital form) the definitive reference work in organic chemistry.


9: Relativity: The Special and the General Theory by Albert Einstein (1916). An explanation of relativity by the man himself.


10: Éléments de mathématique by “Nicolas Bourbaki” (1935 onwards). A reworking of mathematics which gave us words like “injective.”


11: Algorithms + Data Structures = Programs by Niklaus Wirth (1976). One of the early influential books on structured programming.


12: Introduction to VLSI Systems by Carver Mead and Lynn Conway (1980). The book which revolutionised silicon chip design.

That’s four books of biology, four of other science, two of mathematics, and two of modern IT. I welcome any suggestions for other books I should have included.


When the towers fell


The World Trade Center towers (photo: Carol M. Highsmith)

I continue to see bizarre and ill-informed conspiracy theories on the Internet about the 2001 collapse of the World Trade Center towers (above). This is in spite of the detailed investigations of, and voluminous reports on, the event.


Steel softens at temperatures well below the melting point of 1400°C

In fact, it has long been known that structural steel buildings like the World Trade Center can collapse due to fire. In 1967, the structural steel roof of McCormick Place in Chicago collapsed because of softening due to a fire. This collapse began only about 30–45 minutes after the fire was reported.


The World Trade Center under construction (photo: Eric Shaw White)

In the case of the World Trade Center, this fundamental problem with structural steel was combined with building-specific design flaws. Still, in my view, concrete construction is simply safer. Concrete resists fire far better than steel, and locating fire escapes inside a thick concrete core assists evacuation, should that be needed. The 9/11 conspiracy theories are just silly, though.


A concrete tower under construction in Australia (photo: Erin Silversmith,)


Disasters in science #3

Engineers have a moral obligation to take great care with safety-related issues. As Kipling says, “They do not preach that their God will rouse them a little before the nuts work loose. They do not teach that His Pity allows them to leave their job when they damn-well choose.