<p>Sus fundadores quieren que imagines que Alcamy es algo así como lo que resultaría de <strong>mezclar la Wikipedia, con Reddit y Coursera</strong>. De momento esta plataforma está en beta, pero continúa creciendo a buen ritmo. </p>
<p>Para empezar a aprender sobre algún tema simplemente debes suscribirte a él y seguir la cantidad de recursos disponibles al ritmo que quieras. Puedes <strong>crear una cuenta con tu email o simplemente iniciar sesión con Facebook</strong>. Puedes suscribirte a todos los temas que quieras y también puedes contribuir a un curso conforme avances en él. </p>
<p>Todos los cursos son organizados por la comunidad, cuentan con recursos que van desde artículos a proyectos, vídeos, y presentaciones visuales. <strong>Junto a cada curso se añade un quiz</strong> para probar activamente el conocimiento obtenido. Y, por supuesto siempre puedes acudir a la comunidad por ayuda, o para discutir el material. </p>
<p>En Genbeta | <a href="http://ift.tt/2r2cBJp cursos gratis universitarios online para formarte en mayo</a></p>
Compartir Alcamy, la plataforma de aprendizaje online que quiere ser como un hijo entre Reddit y la Wikipedia
<p class="wpematico_credit"><small>Powered by <a href="http://ift.tt/2mkPqnk; target="_blank">WPeMatico</a></small></p>
” data-medium-file=”” data-large-file=”” class=”wp-image-57627 size-full” src=”http://ift.tt/2rLnoVk” alt=”” width=”1548″ height=”1064″ srcset=”http://ift.tt/2rLnoVk 1548w, http://ift.tt/2s0ThMT 125w, http://ift.tt/2szYBnh 768w” sizes=”(max-width: 1548px) 100vw, 1548px”/>Bodleian Library, Oxford“Earthquake and Eruption of the Mountain of Asayama” in Japan in 1783, from an account by Isaac Titsingh, 1822
Oxford in late spring: blossom falling, trees greening, students cycling, tourists gawping—a stable, seasonal scene. But in the attractive spaces of the new Bodleian Weston Library, suddenly the world doesn’t seem so stable any more. There’s a sound of rushing wind and crackling fire, visions of flames, almost a whiff of sulphur.
The curators at the Bodleian brought out its treasures and raided the archives of Oxford colleges for “Volcanoes: Encounters through the Ages.” The show opened with a fragment of a scroll carbonized in the great eruption of Vesuvius that destroyed Pompeii two thousand years ago. It’s extraordinary to stand before this, an apt symbol for a library, murmuring of the frailty of the written word in the face of elemental forces. The whole exhibition tingled with this contrast, as we follow the struggle of men and women to comprehend, explain in words, depict in pictures, the pulsing red-hot power beneath the earth. The oldest document in the show was the manuscript of a fifteenth-century life of the Irish monk St. Brendan, with marginal sketches of a volcano in the North Atlantic, perhaps the first such image in Western literature. As David Pyle tells us in the wide-ranging book, rather than catalog, that accompanies the show, Brendan and his companions set sail to discover the Promised Land, and on their travels encountered strange beasts and wild islands, “rugged and rocky, covered with slag, without trees or grass but full of forges. As they passed by a savage rushed to the shore, carrying tongs with a burning mass of slag of great size and intense heat.”
No wonder volcanoes, like sea-monsters, are the stuff of legends. Over two million years ago the early people of the Rift Valley in Ethiopia were making tools from volcanic rocks, obsidian and basalt, while prehistoric cave dwellers drew fountains of red droplets to mimic volcanic fires. In the sixth century BCE, the philosophers Heraclitus and Pythagoras were discussing the existence of a core of fire in the earth, and a century later Empedocles brooded on a molten layer rising to the surface in nearby Etna, the supposed scene of his later suicide. Plato and Aristotle too, wrote of volcanoes—underground rivers of fire, and subterranean winds—while much later, in Roman poetry, the dramatic eruptions of Etna in 122 BC and 44 BC found a place in the poetry of Virgil and Ovid.
The eyewitness accounts evoked in the Bodleian run from the famous letters of Pliny the Younger, about the eruption of Vesuvius in Naples in 79 BC—well known in the classical world—to the vulcanologists of today. As the seventeen-year-old Pliny looked across the bay, he saw a cloud rising into the sky from the mountain top, like a pine tree, he wrote, rising on a trunk to a great height and splitting into branches; then ashes fell, with chunks of pumice and blackened stone, and a dense black cloud spread like a flood over the land. When night fell, the darkness was lit with sheets of fire. For Pliny and for Brendan, and for later observers across the world, the sense of mystery and awe remained. Lava seemed like the fiery vomit of angry gods and gaping vents the mouth of Hell.
Classical scholars identified the mudpots and sulphur pits in the volcanic system of the Campi Flegrei around Naples as the site of the rivers Phlegethon and Styx and of Lake Avernus, where Virgil’s Aeneas descended to the underworld. A map of the Gulf of Pozzuoli, from a Grand Tour guide, Voyage Pittoresque (1782), shows these vents and craters like the face of the moon. A few years earlier, the diplomat and antiquarian Sir William Hamilton had spent all night on Vesuvius, noting the details of the eruption of March 1766, describing the viscosity of the lava, the cooling, the salts that encrusted the vents.
Ten years later, in 1776—in a ravishing illustration from the supplement to Hamilton’s Campi Phlaegrei—Pietro Fabris painted a column of smoke, heavy with rock, rising from Vesuvius just as Pliny described it, against a clear blue sky, with astonished women gesturing across a bay of absolute calm.
It can be hard to make a library exhibition visually exciting as well as scholarly and informative, but here a series of fabulous prints and engravings and photographs conveyed the sense of awe in the face of the earth’s natural power. In sixteenth-century woodcuts and maps of Iceland steam billows from frozen earth, as Mount Hekla pours out flames and rock, stoked by the fires of “Chaos” below. In 1664, in Mundus subterreneus, Athanasius Kircher speculated boldly about this chaos in the centre of the globe, where Vulcan had his “Elaboratories, Shops and Forges in the Profoundest Bowels of Nature.” Kirchner was the first to try and map the “fire-belching mountains” of the known world, and his vision of them as fed from a central source of heat turns a cross-section of the earth into a whirling wheel of fire, a “Systema Ideale Pyrophylaciorum.”
Other illustrations show the obsessive gathering of surface detail in an attempt to understand the molten depths. In June 1802, when Alexander von Humboldt climbed Chimborazo in the Andes, he drew the mountain in diagrammatic form, noting the hundreds of plants he passed on the way to the summit—broom, cistus, cactus, daphne, Chinchona, pine—until suddenly all vegetation gave way to snow, ice, and fire.
There is something unutterably alluring about the great snow-capped cones—Vesuvius and Etna, Hekla, Mount Helena in Alaska, Fuji in Japan, Cotopaxi in Ecuador, Popocatépetl in Mexico. (The friend I went with kept murmuring a poem learned in childhood, “Chimborazo, Cotopaxi…had stolen my soul away.”) These mountains are, of course, the epitome of the Burkean sublime, their fiery beauty filling the heart with justified terror. Just as romantic travelers posed on high crags or beneath roaring waterfalls so the Bodleian’s prints show eighteenth-century tourists silhouetted against the sky, teetering on the brink above the boiling furnace. A nice comment on this fascination comes with the inclusion of the 1821 children’s book Opie’sWonders, where a crude sketch of a satisfying oceanic explosion is followed by gasping verse:
Well! This is a wonder of wonders to me! Such volumes of fire bursting out from the sea! With lava, and ashes, and sulphurous smell. I’m surpris’d that the sailors can bear it so well! Yet all must desire the eruption to view, And if I were there I might feel anxious too.
Opie’s volcano appears alongside the Sphinx, a wonder of nature balanced by a wonder of art. And the lure of the peaks is matched by the magic of the depths: the disappearance of Santorini linked to the mysteries of Atlantis, the destruction of Krakatoa and the rising of the new island like a tale of the planet’s own rebirth.
Yet volcanoes have fired the path of reason as well as romance. European understanding of their structure and distribution grew with reports from explorers and traders, calling in at the Azores, following the spice routes to the Moluccas, trekking across South America, charting the arc of volcanoes around Hawaii, and the study of volcanoes became a vital feature of Enlightenment theories about the formation of the earth: finds of basalt in the Auvergne in France and in Britain’s Peak District revealed that even these peaceful rural areas had once been a broiling mass.
One vivid print, a display of oriental fireworks, is of the “Earthquake and Eruption of the Mountain of Asayama” in 1783 in Japan, from an 1822 account by the Dutch diplomat Isaac Titsingh, who collected memories of villages igniting and grass aflame. But by the 1820s it had become clear that you did not have to be nearby to feel the effects of great eruptions. The eruption of Laki in Iceland in 1783 sent a rolling fog across northern Europe, with sunsets like blood; a century later, William Ashcroft painted similar sunsets at Chelsea after the eruption of Krakatoa. Similarly, Tambora in Indonesia in April 1815 sent plumes of gas and ash so high that 1816 became known as the “year without a summer,” with darkness stretching from the United States to Asia. That summer, stuck indoors near Lake Geneva, the Shelleys, Byron, and Polidori wrote ghost stories to pass the time: the gloom gave birth to Mary Shelley’s Frankenstein. As this book and exhibition remind us, the store of human effort, exploration and imagination that a great library holds is itself a mighty force, a natural, volcanic power.
Volcanoes: Encounters through the Ages, edited by David M. Pyle, is published by the Bodleian Library and distributed by the University of Chicago Press.