This has been, so far, the most intense shriveling movement in transport history, when the maximum available speed raised from 700 km/h with jets to the supersonic speed of Concorde.
Considering, in a simplified model, terrestrial speed of 100 km/h, say on a motorway or by train, the slope of cones takes this geometry. During this Concorde period, terrestrial speed was 15 times slower than the maximum available speed.
This image is very close to the idea of the chestnut that I announced in 2007. High quality image download link.
Very excited when I first saw it on my computer screen. This is the first time this image, which I had in mind for years, finally materializes.
Unfortunately it has proven very difficult, for me at least, to control cones geometry. In addition in Cesium it is not possible to draw geometries under the surface of the globe. the problem is that, conceptually, the time-space relief map model, everything occurs under the surface.
An exchange with Cesium developers has indicated an alternative choice: the library three.js, which has less limitations for our purpose.
At that time the model is not finished as illustrated by the incomplete bottom of facets. A triangle is missing but all the networks are visible, since they form the structure on which the relief is drawn. Relief comes as a surface along the deformed road network. Three terrestrial transport modes are represented here: classic road, motorway (mode 6) and high-speed rail (mode 3).
By lack of available color printer in the CESA laboratory, analog photo of computer screen was one of the few possible options to realize this cartography. Later we used print-screen software to produce bitmap images, and even later developed the software MapNod to produce direct vectorial images in the WMF format.