Fuente: Lourdes Luengo
jueves, 19 de noviembre de 2009
Construyendo ADN
Fuente: Lourdes Luengo
martes, 17 de noviembre de 2009
El origen de la vida
viernes, 6 de noviembre de 2009
Alimentación y salud
Fuente: ExpoNAO
miércoles, 4 de noviembre de 2009
Estructura de las proteínas
sábado, 31 de octubre de 2009
Pompeii: The last day - Pompeya: el último día
"You could hear women lamenting, children crying, men shouting. There were some so afraid of death that they prayed for death. Many raised their hands to the gods, and even more believed that there were no gods any longer and that this was one unending night for the world."
—Pliny the Younger, circa A.D. 97 to 109
WHAT HAPPENED HERE
August 25, A.D. 79
It all lasted 19 hours.
Then, there was only a long, deathly silence. Pompeii lay buried for nearly 1,700 years. It wasn't until 1748 that archaeologists began slowly uncovering the ancient city, preserved under 9 feet of volcanic ash and frozen in time by Pliny the Younger's vivid report.
About three-fifths of the city has been liberated from the solidified volcanic ash and pumice that engulfed it. But many questions remained unanswered for a long time.
What was life like under the volcano? What exactly did happen that summer day in A.D. 79? Here we take a look into the latest findings.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcAh-t94x0wuX33tNU4mIKYWJMJXf5FcxeLSWILlhXW51jHgGiEKAeDZgkOy7PLmBoqgtpAVYw7-zw6zt6WMRNpShczXtbHwqDbeZdZX3ETNvKWbV7vZAtohp66wiarnh44071deb0PCpe/s200/pompeya.jpg)
WHY IS VESUVIUS LOCATED WHERE IT IS? GLOBAL PERSPECTIVE
Vesuvius is near a place where one section of the Earth's surface is being pushed down below another section. These sections are called plates. When plates grind against one another two things can result--earthquakes and volcanoes. Volcanoes begin to form when the rocks of the lower plate get pushed deep into the Earth. There they are heated, until they melt, forming magma, one kind of liquid rock. Because magma is less dense than the solid rock around it, it is pushed upward. If this magma finds a weak place at the Earth's surface, it may break through and form a volcano.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhor8Ke0FrWsYIBwW1KbQgzVG3nMKypiFHo9nOQgfCZlIPua486D3Q0Lal4hyGQnBQRe0T__luvZ1Kj2kJAmDBptwOrECPz9Xc2vVzpB5-Ng6YRCEpHarQavUXIXhXci2xsuwRXFJgttYrt/s320/subductionS.jpg)
Subduction
WHAT KIND OF VOLCANO IS VESUVIUS? VOLCANO TYPES
Vesuvius is a stratovolcano (or composite volcano), made up of alternate layers of ash and lava. Stratovolcanoes normally have two different kinds of eruptions. One kind produces mostly ash and cinders. The other kind produces lava. In Vesuvius these two types of eruption have not been seen to happen together.
INSIDE A VOLCANO
This is a type of volcano called a stratovolcano. You can see how this very tall volcano has been built up by layers of ash and lava from previous eruptions. The volcano is currently dormant. But it is about to re-awaken!
Because it is lighter than solid rock, magma (molten rock) has been rising to form a huge pool, called a magma chamber, beneath the volcano. The volcano will erupt when gases held within the magma burst out explosively, now that they are under less pressure than when the magma was deeper within the earth.
The explosive escape of the gases from the magma causes a violent eruption which literally "blows the top" off the volcano. Gas, blobs of magma (now called lava), chunks of rock, and fine debris called volcanic ash are blasted upwards. (The ash, because it is very light, may reach heights sufficient to endanger jet airplanes.)
Because the fragments of rock and ash (pyroclastics) are heavier than air and may not mix with enough air to remain high aloft, they may surge down the sides of the volcano as dangerous "pyroclastic flows."
Within the flow, heavier particles sink and the lighter particles and gases are displaced upwards. The flow meanwhile surges along like a boiling cloud. Pyroclastic flows can travel at speeds greater than 100 miles per hour and can be as hot as the inside of a kiln. Such flows killed 29,000 people in the 1902 eruption of Mount Pelée, Martinique.
WOULD YOU SURVIVE?
The volcanic eruption of Mount Vesuvius in A.D. 79 caught most of the Roman population off guard. Would you have made it?
martes, 27 de octubre de 2009
El Departamento adquiere nuevos libros
lunes, 26 de octubre de 2009
Fases lunares
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgz4n9JBlSA9TXNPSNofSbiyjzJTXiCws1kE97YcGdBHSmEGgawyjq-RZ_Kb6knambSlf0FX8TyM-PHPXr7m55Tz9JaXICkl5ZuQBgxmz6ISFSdGOqlhHQUM1LanMX8YuA0JF3BW7zX7s/s400/luna_gif.gif)
martes, 20 de octubre de 2009
Microorganisms
sábado, 17 de octubre de 2009
Presentación flash sobre el interior de la Tierra
miércoles, 14 de octubre de 2009
martes, 13 de octubre de 2009
Arquímedes y la corona del Rey Hierón
"Cuenta la leyenda que Hierón II, rey de Siracusa en el siglo III a.C. le planteó a Arquímedes el siguiente problema: cierto orfebre le había fabricado una corona de oro pero el rey no estaba muy seguro de que el artesano hubiese obrado rectamente; podría haberse guardado parte del oro que le habían entregado y haberlo sustituido por plata o cobre, así que Hierón encargó a Arquímedes averiguar si la corona era de oro puro.
Arquímedes no sabía qué hacer. El cobre y la plata eran más ligeros que el oro. Si el orfebre hubiese añadido cualquiera de estos metales a la corona, ocuparían un espacio mayor que el de un peso equivalente de oro. Conociendo el espacio ocupado por la corona (es decir, su volumen) podría contestar a Hierón, lo que no sabía era cómo averiguar el volumen de la corona.
Arquímedes siguió dando vueltas al problema en los baños públicos y de pronto se puso en pie como impulsado por un resorte: se había dado cuenta de que su cuerpo desplazaba agua fuera de la bañera. El volumen de agua desplazado tenía que ser igual al volumen de su cuerpo, por tanto para averiguar el volumen de cualquier cosa bastaba con medir el volumen de agua que desplazaba.
Arquímedes corrió a casa, gritando una y otra vez: "¡Lo encontré, lo encontré!" (¡EUREKA, EUREKA!). Llenó de agua un recipiente, metió la corona y midió el volumen de agua desplazada. Luego hizo lo propio con un peso igual de oro puro; el volumen desplazado era menor. El oro de la corona había sido mezclado con un metal más ligero, lo cual le daba un volumen mayor, por lo que el rey ordenó ejecutar al orfebre."
Original: http://concurso.cnice.mec.es/cnice2005/93_iniciacion_interactiva_materia/curso/materiales/intro.htm