Vector Analysis and Quaternions by Alexander MacfarlaneBy “Vector Analysis” is meant a space analysis in which the vector is the fundamental idea; by “Quaternions” is meant a space-analysis in which the quaternion is the fundamental idea. They are in truth complementary parts of one whole; and in this chapter they will be treated as such, and developed so as to harmonize with one another and with the Cartesian Analysis1. The subject to be treated i...

In the 21st century, political debates appear to center on fundamental conflicts between “the people” and “elites.” Most of these discussions emphasize strategies to protect and empower the oppressed masses against a predatory ruling class. Much of classical political thought, however, was written from an aristocratic point of view: that is, it ascribed paramount importance to the question of elite formation. Assuming inequality as a permanent feature of human associations, what virtues wo...

Reconegut com el millor escriptor contemporani de natura, Robert Macfarlane ha dirigit la seva mirada cap als rius per intentar comprendre com «viuen». Com la majoria de nosaltres, té un rierol a prop de casa seva. D'aquest riu ho sap tot: com interactua amb el territori, com atreu la vida i busca l'equilibri amb plantes i animals, com ha esdevingut imprescindible per al seu paisatge vital. Però per a aquest llibre Macfarlane viatja a tres indrets remots: a la selva nebulosa que acull les ...

De Robert Macfarlane s'ha dit que és el millor escriptor de natura d'aquesta generació. A Sota terra, considerada ja la seva obra culminant, narra els seus descensos cap a les fosques profunditats de la terra i del temps: des de cambres funeràries prehistòriques fins a recents cementiris nuclears, passant per coves marines amb pintures rupestres a l'Àrtic, laberíntiques catacumbes a París, mines de sal sota el ma...