One of the books I am currently reading is Roberto Piazza‘s Soft Matter (see here and here for reviews) . In the book, there is a short paragraph on zeolites which left me wishing for more information. In particular, there was no illustration of a zeolite. A quick image search convinced me that this topic is a perfect fit for my blog.
So what is a zeolite? Zeolites form a class of minerals composed of aluminium, silicon, and oxygen. They form a very regular arrangement of pores which makes them highly useful in industrial applications.
After discussing the dihedral group, it is time to post my images of how Klein introduces the symmetry groups of the tetrahedron, the octahedron and the icosahedron.
By duality, this also handles the case of the dodecahedron (it is the dual of the icosahedron) and that of the cube (it is the dual of the octahedron) and thus all the Platonic solids are covered.
The Census of Marine Life is one of the truly big scientific endeavours of our time. Together with loads of scientific results, it produced incredible images of an alien world, largely unknown and full of wonders.
The NOAA maintains a website with many quotes along the lines of the following:
» Man’s perpetual curiosity regarding the unknown has opened many frontiers. Among the last to yield to the advance of scientific exploration has been the ocean floor. Until recent years much more was known about the surface of the moon than about the vast areas that lie beneath three-fourths of the surface of our own planet. «
— In Submarine Geology (1948) by F. P. Shepard. p. 1.
The situation was not much different when the Census of Marine Life started and this is one of the reasons why life from the deep can still astonish and inspire us.