The interior structure of the Earth, similar to the outer, is layered. The Earth has an outer silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. Scientific understanding of Earth's internal structure is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanic activity, analysis of the seismic waves that pass through the Earth, measurements of the gravity field of the Earth, and experiments with crystalline solids at pressures and temperatures characteristic of the Earth's deep interior.
The deepest layers are composed of heavier materials; they are hotter, denser and under much greaterpressure than the outer layers.
The "skin" of Earth, called the crust, is very thin like the skin of a peach. It is so thin, in fact, that we have to magnify a small piece of our sketch of Earth to see any detail at all. There are two types of crust, oceanic and continental. As you might suspect from the names, oceanic crust is usually found under the oceans, and continental crust is found on the continents.The thin oceanic crust is composed of primarily of basalt and the thicker continental crust is composed primarily of granite. The low density of the thick continental crust allows it to "float" in high relief on the much higher density mantle below.
Earth’s mantle is thought to be composed mainly of olivine-rich rock. It has different temperatures at different depths. Rocks in the upper mantle are cool and brittle, while rocks in the lower mantle are hot and soft (but not molten). Rocks in the upper mantle are brittle enough to break under stress and produce earthquakes. However, rocks in the lower mantle are soft and flow when subjected to forces instead of breaking.
Earth’s Core is thought to be composed mainly of an iron and nickel alloy. The core is earth’s source of internal heat because it contains radioactive materials which release heat as they break down into more stable substances.The core is divided into two different zones: outer core that is liquid and the inner core that is solid.
Castles first appeared in Britain sometime after 1066, when William the Conqueror won the battle of Hastings. The early castles were made of wood. Norman invaders invented the moat and bailey. A moat is a ring of water surrounding a castle. If someone wanted to get over the moat, someone inside the castle would have to let down the drawbridge, a kind of door. Drawbridges had to be cranked down by someone inside the castle.
Castles were dark and cold, but everyone wanted to live in them. Castles offered protection from enemies. But castles were too expensive for everyone to live in. The workers might have had to destroy whole forests to build part of a castle. During the 10th century, lords began to build castles out of stone.
The word castle comes from a Latin word meaning "fortress," which is smart, because that is what a castle is. European castles developed from fortified camps built by the ancient Romans and from fenced villages of prehistoric Europeans.
Castles became important in western Europe in the late A. D. 900's and 1000's. They played a great role in the military system called feudalism. In the Middle Ages, Europe was divided into many small states, and local conflicts were common. A castle helped a king or a vassal defend the land around where the castle stood. It also provided a home for the nobles and their families and servants.
The walls surrounding a castle could be up to 33 feet thick! Nobles were really serious about defense. Why were there spiral stairs in a tower? If a castle was under attack, the knights defending the towers would have more space to move their swords.
By 1500, castles became much less important in Europe. Cannons were invented, so it was easy to knock a castle down. Also, many nobles wanted more comfy housing.
Como ya sabéis para cada trimestre hay un pequeño trabajo de investigación que lo tenéis que presentar en formatopowerpoint o similares.En el archivo adjunto vienen las normas básicas y fecha de entrega, así como una relación de posibles temas
This is a picture from an article called "The Rescue Hug". The article details the first week of a set of twins.
Apparently, each were in their respective incubators, and one was not expected to live. A hospital nurse fought against the hospital rules and placed the babies in one incubator.
When they were placed together, the healthier of the twins reached out an arm over the sister in an endearing embrace. The smaller baby's heart stabilized and her temperature rose to normal.
Let us not forget to embrace those whom we love.
Esta es una foto de un artículo llamado "El Abrazo de Rescate". El artículo detalla la primera semana de un par de gemelas. Al parecer, se les colocaron en incubadoras separadas, y a una de ellas, por su debilidad, se le daba pocos días de vida. Una enfermera del hospital peleó contra las reglas del hospital y las colocó juntas en una misma incubadora.
Al poco tiempo, la más sana de los gemelas alcanzó con su brazo a su hermana más débil en un entrañable abrazo. El corazón de este bebé se empezó a estabilizar y su temperatura corporal alcanzó la normalidad
No olvidemos a abrazar aquellos a quienes nos importan.