martes, 3 de febrero de 2009

Darwin


Charles Robert Darwin FRS (12 February 1809 – 19 April 1882) was an English naturalist[I] who realised and demonstrated that all species of life have evolved over time from common ancestors through the process he called natural selection. The fact that evolution occurs became accepted by the scientific community and much of the general public in his lifetime, while his theory of natural selection came to be widely seen as the primary explanation of the process of evolution in the 1930s,[1] and now forms the basis of modern evolutionary theory. In modified form, Darwin’s scientific discovery remains the foundation of biology, as it provides a unifying logical explanation for the diversity of life.[2]
At Edinburgh University Darwin neglected medical studies to investigate marine invertebrates, then the University of Cambridge encouraged a passion for natural science.[3] His five-year voyage on HMS Beagle established him as an eminent geologist whose observations and theories supported Charles Lyell’s uniformitarian ideas, and publication of his journal of the voyage made him famous as a popular author. Puzzled by the geographical distribution of wildlife and fossils he collected on the voyage, Darwin investigated the transmutation of species and conceived his theory of natural selection in 1838.[4] Although he discussed his ideas with several naturalists, he needed time for extensive research and his geological work had priority.[5] He was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay which described the same idea, prompting immediate joint publication of both of their theories.[6]
His 1859 book On the Origin of Species established evolutionary descent with modification as the dominant scientific explanation of diversification in nature.[1] He examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals. His research on plants was published in a series of books, and in his final book, he examined earthworms and their effect on soil.[7]
In recognition of Darwin’s pre-eminence, he was one of only five 19th-century UK non-royal personages to be honoured by a state funeral,[8] and was buried in Westminster Abbey, close to John Herschel and Isaac Newton.[9]

lunes, 26 de enero de 2009

Solar energy


Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.
Solar power technologies provide electrical generation by means of
heat engines or photovoltaics. Once converted its uses are only limited by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, hot water, thermal energy for cooking, and high temperature process heat for industrial purposes.

domingo, 25 de enero de 2009

screwdriver


The screwdriver is a device specifically designed to insert and tighten, or to loosen and remove, screws. The screwdriver is made up of a head or tip, which engages with a screw, a mechanism to apply torque by rotating the tip, and some way to position and support the screwdriver. A typical hand screwdriver comprises an approximately cylindrical handle of a size and shape to be held by a human hand, and an axial shaft fixed to the handle, the tip of which is shaped to fit a particular type of screw. The handle and shaft allow the screwdriver to be positioned and supported and, when rotated, to apply torque. Screwdrivers are made in a variety of shapes, and the tip can be rotated manually or by an electric or other motor.
A screw has a head with a contour such that an appropriate screwdriver tip can be engaged in it in such a way that the application of sufficient torque to the screwdriver will cause the screw to rotate

jueves, 13 de noviembre de 2008

martes, 11 de noviembre de 2008

viernes, 7 de noviembre de 2008

martes, 4 de noviembre de 2008

Birthday Carla and haLloWeen

nur, lucia, CARLa, maria, lidia, silvia, andrea, iris and mee!

birthday beautiful....

party (y)




os quierooo!


kiiss!