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Night of Stars 2011
s chemistry with the Universe!
February 26
THE UNIVERSE AND CHEMICAL
knowledge of heaven is closely linked to the construction and advancement of all cultures. Particularly the Mesoamerican civilizations, such as the Toltec, Mayan and Mexican, were noteworthy for the detailed observation and precise positioning and movement of the bright objects in the night sky, creating calendars and rituals associated with the cosmic cycles and linking them to build their cities, ceremonial centers and their social organization, of which vestiges remain striking.
Throughout the history of mankind, the stars shining in the night sky have been both a source of fantasy as a reference to the cycles of nature. Ancient civilizations had collected all his information with the unaided eye and using geo-referenced and very simple buildings and instruments, made with stones and wood. Development optical instruments, such as the telescope, and ideas that helped to understand how these luminous objects are formed after the sixteenth century. We know the composition of matter of which consist of objects that populate the sky and we can distinguish the differences between the many types of stars, galaxies and clusters of galaxies.
The telescope, physics, calculus and geometry were founding of modern astronomy, the facts and reasoned explanations. But there was also a sequence of ideas and tools, not always related to each other, which allowed us to penetrate into the nature intimate luminous objects in the night.
These include the ideas and discoveries of Isaac Newton, who in 1666 experienced the amazing phenomenon of light colors that amaze even people, like the rainbow, or which are also significant when projected crystals when the light hits them.
Newton Prism
In a controlled environment, Newton had a beam of light through a glass prism noting that decomposed in color, demonstrating that white light is the inclusion of all colors. This phenomenon is what we call "spectrum of light." This prism would henceforth be an essential tool in chemistry and astrophysics.
little more than half a century after the discovery of Newton, a young man who was orphaned at age 11, Joseph Fraunhofer, which grew on the observation of the crystals working as an apprentice in a china shop, placed the prism Newton behind the eyepiece of a telescope. In 1814 noted that the color spectrum caused by the decomposition of sunlight through the prism had a number of black lines in the bands of colors, which are called Fraunhofer lines in his honor. What were those lines?
Fraunhofer bands
In 1859, Gustav Kirchhoff and Robert Bunsen, a pair of curious and enthusiastic chemicals, devised an instrument base of lenses and the prism of Newton but rather to observe celestial bodies, they used to observe materials exposed to the flame of a lighter. The chemicals noted in his experiments than any material exposed to flame could be seen The same phenomenon of the lines in the colored bands observed by Fraunhofer to the Sun, also found that each element exposed to flame, whose emission was captured by the lens, always had the same banding pattern, allowing them to infer that each element has a sort of fingerprint bands in the spectrum of light.
Top: spectroscopic device. Bottom: Spectra of different elements
In 1862, amateur astronomer William Huggins proposed the chemist William Allen Miller used the new technique spectroscopy to analyze the light from stars and nebulae. In their light spectra found the characteristic lines of the same chemical elements on Earth studied in the laboratory by Bunsen and Kirchhoff years ago. They also found that some nebulous objects (now called galaxies) showed characteristic spectra of the stars, while the spectra of other nebulous objects (now called nebulae) were characteristic of gases. Since then the techniques of spectroscopy have been an integral part of modern astronomy giving "birth" to the intimate nature of celestial matter.
Spectrum core of the galaxy M84
Physicists and astronomers of that time could not determine the relative concentrations of different elements. We had to wait until the twentieth century, the development of quantum mechanics and atomic physics to quantify the relative abundance of the elements in the various celestial bodies.
now know that the origin of most elements due to the evolution of stars that spread across the Universe. This implies that the chemical composition of celestial objects can be used as a guideline for studying the evolution of the Universe itself. The determinations of the abundances of the elements in celestial objects provide information about the chemical evolution of the Universe.
Above: Illustration of a forming star with a protoplanetary disk of gas and polvo.Abajo: Illustration of the end of the life of a star initiating its outbreak
stars generate their energy through nuclear reactions in its interior and produce new elements, are continuously cosmic alchemists transmute the elements. The low-mass stars like the Sun, are responsible for producing much of the carbon, nitrogen and helium in the Universe, supernovae are responsible for the production of materials such as iron, chromium and manganese, the massive stars born with more than nine solar masses are responsible for the production of oxygen, neon, magnesium, azufe, argon and silicon.
During the first four minutes following the Big Bang that gave birth to the Universe for 13 thousand 700 million years ago, only made the most of hydrogen and helium.
http://www.nochedeestrellas.org.mx/
Interviews:
Night of Stars: José Franco pepe@astro.unam.mx, Jean Thève jean.theves @ diplomatie.gouv.fr ;
Astrochemistry: Barbara Pichardo Silva barbara@astroscu.unam.mx , Manuel Peimbert mailto: peimbert@astroscu.unam.mx
