In the game below, you have to identify an object which is partially invisible: only the intersection of the object with the blue plane is shown (the curve in red). You can change the height of the plane using the slider control available in the software. We strongly recommend that before starting the game, you see what are the objects that may appear (this will open a new window). Important: a same object may appear more than one time in the game, in different positions. To play the game again, press the “Refresh” button of your navigator.

According to the Britannic Encyclopedia, the computerized tomography is a diagnostic imaging procedure where a narrow beam of X rays sweeps across an area of the body and is recorded not on film but by a radiation detector as a pattern of electrical impulses. Data from many such sweeps are integrated by a computer, which uses the radiation absorption figures to assess the density of tissues at thousands of points. The density values appear on a television-like screen as points of varying brightness to produce a detailed cross-sectional image of the internal structure under scrutiny. it was conceived by William Oldendorf and developed independently by Godfrey Newbold Hounsfield and Allan MacLeod Cormack, who shared a 1979 Nobel Prize for their inventions. A major advance in imaging technology, it became generally available in the early 1970s.

A computerized tomography scanner.

Tomography of a human head.

The rapid prototyping is an automatic process used to construct physical objects from three dimensional geometric information of a virtual computer model. It consists in adding material in the form of successive planar layers, allowing the manufacturing of complex parts without the necessity of molds and tools. Its applications include the manufacture of mockups, prostheses and mechanical parts. It is the rapid prototyping that provides the technology for the construction of 3D printers. Click on the picture below to see a YouTube video showing the 3D printer ZPrinter 310 in action. You need to be connected in the internet to watch it.

The pictures below illustrate some concrete materials that can be used to explore the cross sections of a cube. They are part of the site MateMatita (Centro Interuniversitario di Ricerca per la Comunicazione e l'Apprendimento Informale della Matematica), that aims to design, develop and promote products such as exhibitions, books, journals, and multimedia materials, and to see how these impact both in formal teaching situations (schools) and on the public in general.