Marey diagrams
Étienne-Jules Marey was a 19th century French scientist, photographer and polymath who was key in the development of cardiology, physical instrumentation, and laboratory photography. He was also a pioneer in establishing a variety of graphical techniques for the display and interpretation of data.
Marey developed the graphical train schedule with stations separated vertically in proportion to geography, such that the slope of the line reflects the speed of the train - the steeper the line, the faster the train. It is also more recently been called a stringline chart. It is the feature image on this post.
Marey diagrams, or charts, are still used by train and public transport agencies to track their trains, as well as occasionally publishing the diagrams for public use as timetables.
In one particular modern case, a Marey diagram was instrumental in identifying a rogue train on Singapore's Mass Rapid Transit system (MRT) that was causing mysterious train failures on its Circle Line. Sixty different trains slowed down unexpectedly, and sometimes even emergency brake to a complete stop between stations, upsetting train schedules, resulting in disgruntled commuters who would have to switch to bus shuttles.
Plotting the trains with faults gave Marey charts like this one:
By analysing a number of such faulty train diagrams, the engineers were able to identify a "rogue train" that was nearby when the faults in other trains occurred. This rogue train disrupted the other trains' communications, and sometimes activated their emergency brakes. Once this rogue train was taken out of service, the faults stopped. There is a more detailed description of the data analysis process and the diagramatic breakthrough in How The Power Of Data Resolved SMRT's Circle Line Breakdowns.
Additional technical curves
Engineers, technical, and business people use various graphs to plot technical and technological phenomena. We present a couple additional ones:
S curve
Everett Rogers’ 1962 work Diffusion of S explains how, why, and at what rate new ideas and technology spread; The paper introduced the term 'early adopter'. It shows that rates of adoption tend to follow an S-shaped pattern as it is affected by innovations, communication, social influences and other factors. This is a simpler, clearly graph of the effect than what was shown in a previous Miscellany: ***
This concept was later developed by the Gartner company into their Gartner Hype Cycle Curve, which we also looked at in that same Miscellany.
Competency - Confidence curve, aka the Dunning-Kruger Effect, feat. Mount Stupid
Non-technical people, politicians, people in other sectors, and the person at the pub do not know the complexity behind most technologies or systems, be they software, hardware, or political, social, or environmental systems. For example, the solution to traffic congestion is often proffered, especially by politicians, as "One more lane, bro". But that ignores the complications of limited urban space, the magnitudes higher costs of tunnelling or elevating a road, the fact that more road lane space induces more driving, more parking, more accidents, and more pollution. All this can be charted, approximately.
Dunning-Kruger Effect
In order for many individuals to recognize their lack of knowledge, they would require the very knowledge they lack. We often don't know what we don't know. In many cases, such individuals are also blessed with an inappropriate confidence, buoyed by something that feels like knowledge. In simple terms, people are ignorant of what they don’t know. In Rumsfeldian terms, an Unknown Unknown.
Less competence in most people usually leads to more confidence. This initial peak of overconfidence is colloquially called Mount Stupid. Despite this catchy, widespread name, the Dunning-Kruger Effect is not about being stupid, in most cases, but about not knowing any better.
At first impression, most people have a simplistic take on a problem, and proffer a simplistic solution. Add lanes, add a motorway, add another suburb. But cumulatively, these affect other parts of the city. Not immediately, but after decades, city region's traffic often congeals into motorway traffic stoppages, pollution becomes noticeably bad, stress from driving everywhere increases, and poorer health results.
Modern modern systems are designed to appear and work simply, but most often contain a lot of hidden algorithms, data analysis, inclusion of other factors, and interconnexion with other complex systems.
However, Hofstadter's Law states that things always takes longer than expected, even when Hofstadter's Law is taken into account.
Jevon's Paradox
If a system is made more efficient, people will use it more, eliminating any overall efficiency gain.
Khazzoom-Brookes Postulate
This postulate argues that as improvements in energy efficiency lower the effective cost of energy, relative to what otherwise would have prevailed, the resulting price reduction results in more of the good being consumed. This is related to, and an instantiation of, Jevon's Paradox.
Managers General of London Transport
London Passenger Transport Board Chairmen
- Lord Ashfield 1933–1947
- Lord Latham 1947
London Transport Executive Chairmen
- Lord Latham 1948–1953
- Sir John Elliot 1953–1959
- Sir Alexander Valentine 1959–1963
London Transport Board Chairmen
- Sir Alexander Valentine 1963–1965
- Sir Maurice Holmes 1965–1969
London Transport Executive Chairmen
- Sir Richard Way 1970–1975
- Sir Kenneth Robinson 1975–1978
- Ralph Bennett 1978–1980
- Sir Peter Masefield 1980–1982
- Sir Keith Bright 1982–1984
London Regional Transport Chairs
- Sir Keith Bright, 1984–1988
- Sir Neil Shields, 1988–1989
- Sir Wilfrid Newton, 1989–1994
- Sir Malcolm Bates, 1999–2001
- Bob Kiley, 2001
- Sir Malcolm Bates 2001–2003
TfL Commissioners of Transport
- Bob Kiley 2001–2006
- Peter Hendy 2006–2015
- Mike Brown 2015–2020
- Andy Byford 2020–2022
- Andy Lord 2022–present
Department for Transport's lineage
- Ministry of Transport (MoT) 1919–1941
- Ministry of War Transport 1941–1946
- Ministry of Transport (again) 1946–1953
- Ministry of Transport and Civil Aviation 1953–1959
- Ministry of Transport (yet again) 1959–1970
- Department for the Environment (DoE) 1970–1976
- Department of Transport (DTp) 1976–1997
- Department for the Environment, Transport and the Regions (DETR) 1997–2001
- Department for Transport, Local Government and the Regions (DTLR) 2001–2002
- Department for Transport (DfT) 2002–present
Not all miles are the same
The origin of the word mile comes from the Latin mille meaning 1,000 Romans defined the mile as 1,000 paces, by which they meant two steps, left and right. As a reference this very much depended on the gait of the individual stepping the distance out. A more definitive measure was required, but several were devised:
Statute mile - Queen Elizabeth I decreed by Act of Parliament a mile to be eight furlongs, 80 chains, 320 rods, 1,760 yards or 5,280 feet. Once passed into statutory law in 1592, this became the 'statute mile'.
International mile - As the science of measurement improved over the centuries, it was recognised that different countries used slightly different values for feet and yards, thus altering the length of a mile. An international agreement defined the foot to be 30.48 centimeters, making the international mile 1,609.344 meters exactly (also called an international statute mile). The US statute mile, also known as a survey mile, is 1/8 inch longer.
Nautical mile – the nautical mile is defined as 1 percent of 1 degree of the Earth's circumference. However in the twentieth century it was determined that Earth isn't completely spherical, being slightly larger around the equator, so some nautical miles were larger than others. In 1954, the international nautical mile was set at 1.1508 statute miles. One knot is one nautical mile per hour, or 1.15 miles per hour.
Abbreviated mile - the official abbreviation of the statutory mile and survey mile is ‘mi’. However, despite the best efforts of the US National Institute of Standards and Technology, this is rarely seen outside of its publications.
Country miles - most western European countries had their own historical definition of a mile, all based on the Roman mille.
Loyalty miles - these are difficult to accumulate, sometimes vanish before you can use them, are difficult to quantify, and even more difficult to exchange or sell. Most frustratingly, they rarely equate to a consistent distance, so your mileage will vary greatly.
Régularité, Rapidité, Sécurité – Paris Métro inter-war slogan.
Fin
