Wednesday, May 28, 2014
Astronomy Picture of the Day
Astronomy Picture of the Day
Astronomer Biography: Kip Thorne
Kip S. Thorne was born in 1940 in Logan, Utah, and later received his Bachelors of Science from the California Institute of Technology in 1962. He went on to receive his Doctorate from Princeton University in 1965 and went back to CalTech in 1967 to become an Associate Professor in Theoretical Physics and worked his way up to become the Feynman Professor of Theoretical Physics in 1991. His contributions to modern astronomy have been focused mainly on gravitation physics and astrophysics with an emphasis on black holes, relativistic stars, and gravitational waves. His research in the late 60s and early 70s set the basis for the theory of pulsations of relativistic and their emission of gravitational waves. In the 70s and 80s, he worked with other astrophysicists to develop mathematical formalism and the analysis of the generation and detection of gravitational waves. He is the cofounder of the Laser Interferometer Gravitational Wave Observatory, or LIGO, which works mainly in identifying the source of gravitational waves. In the realm of gravitational wave detection, Thorne has invented the back-action-evasion approach to quantum nondemolition measurements of the quadrature amplitudes of harmonic oscillatorsn which has been used in association with other astrophysicists to interpret relativistic theories of gravity. Thorne also predicted the existence of red supergiant stars with neutron-star cores. He developed the general relativistic theory of thin accretion disks around black holes, and using this theory he deduced that with a doubling of its mass by such accretion a black hole will be spun up to 0.998 of the maximum spin allowed by general relativity. Thorne then formulated the hoop conjecture in 1972, which states that any object of mass M, around which a hoop of circumference 8 pi GM/c2 can be spun, must be a black hole. He aided in the development of the membrane paradigm for black holes and which was used to clarify the "Blandford-Znajek" mechanism in which black holes may power some quasars and active galactic nuclei. He went on to show that the entropy of a black hole of known mass, angular momentum, and electric charge is the logarithm of the number of ways that the hole could have been made. Thorne has also identified a universal physical mechanism that may always prevent spacetime from developing closed timelike curves. His research with astrophysicists Mike Morris and Ulvi Yurtsever has showed that traversable Lorentzian wormholes can exist in the structure of spacetime only if they are threaded by quantum fields in quantum states that violate the averaged null energy condition and this has lead to the exploration of of quantum fields and their ability to possess extended negative energy. Furthermore, Thorne has invented tools for visualizing spacetime curvature, such as frame-drag vortex lines and tidal tendex lines. Combining these tools with numerical simulations, Thorne and colleagues are currently exploring the nonlinear dynamics of curved spacetime, triggered when spinning black holes collide. Thorne was elected to the American Academy of Arts and Sciences in 1972, the National Academy of Sciences in 1973, and the Russian Academy of Sciences and the American Philosophical Society in 1999. He has been awarded the Lilienfeld Prize of the American Physical Society, the Karl Schwarzschild Medal of the German Astronomical Society, the Albert Einstein Medal of the Albert Einstein Society in Berne, Switzerland, the UNESCO Niels Bohr Gold Medal from UNESCO, and the Common Wealth Award for Science, and was named California Scientist of the Year in 2004. For his book for nonscientists, Black Holes and Time Warps: Einstein's Outrageous Legacy (Norton Publishers 1994), Thorne was awarded the American Institute of Physics Science Writing Award, the Phi Beta Kappa Science Writing Award, and the (Russian) Priroda Readers' Choice Award. In 1973 Thorne coauthored the textbook Gravitation, from which most of the present generation of scientists have learned general relativity theory. Fifty-two physicists have received the PhD at Caltech under Thorne's personal mentorship.Most recently, Thorne has worked with filmmaker Christopher Nolan in the production of the film Interstellar which his based on his publication of astrophysical research.
http://www.its.caltech.edu/~kip/scripts/biosketch.html
http://www.cco.caltech.edu/~kip/scripts/shortbio.html
Thorne, Kip S., Charles W. Misner, and John A. Wheeler. General Relativity. N.p.: n.p., 1968. Print.
Tuesday, March 25, 2014
Astronomer Biography: Henrietta Leavitt
Henrietta Leavitt
Born in 1868 in Massachusetts, Henrietta Leavitt is often known as the forgotten astronomer. At the age of 20 Leavitt entered the Society for the Collegiate Instruction of Women, now known simply as Radcliffe. While there, she studied a wide variety of topics ranging from differential calculus to philosophy. Thanks to the largely male scientific community, entering her job at the Harvard College Observatory was very taxing, and she ended up with a position called a "computer" whose sole duty was to record the brightness of stars. Leavitt worked alongside other highly educated women who were known as the "Pickering's harem" after their supervisors often misogynistic and bigoted management practices. Despite her lack of recognition, Leavitt worked tirelessly on her research of Cepheid variables. Cepheid variables are stars that shift brightness and dimness over given periods. In 1912, during her vast amounts of research, Leavitt discovered that she was able to relate the period of a given star's brightness cycle to its absolute magnitude. This discovery made it possible to measure the distance of these objects from Earth. Leavitt's breakthrough allowed for many subsequent discoveries to be made, such as Edwin Hubble's assertion that the Andromeda spiral nebula is really not at the edge of our galaxy but nearly 1 million lightyears away, or the method of the parallax measurement of Cepheid variables. Despite this integral contribution to modern astronomy, Leavitt was not given appropriate accolades or credit for her work. Pickering, her supervisor, published her findings under his own name, claiming it was his given right guaranteed by his superiority. Little is known about Leavitt's personal life or her feelings about her lack of recognition. This complacency and timidity was characteristic of well-educated women at the time. A rare breed, they were often shut away by their male peers and very rarely given a real voice in academia. Leavitt died quietly in 1921.
http://cosmology.carnegiescience.edu/timeline/1912
Astronomy Picture of the Day
Astronomy Picture of the Day
Astronomy Picture of the Day
Astronomy Picture of the Day
Astronomy Picture of the Day
Friday, February 28, 2014
Astronomy Picture of the Day
Shown her is the Pleiades star cluster destroying a passing cloud of gas and dust. The Pleiades is the brightest open star cluster that can be seen from Earth and is visible from almost any northern location with the naked eye. The star cluster is devouring a cloud part of Gould's Belt, which is a ring of young star formation in the Milky Way Galaxy. Pressure from the stars' light repels the dust in thenebula, with smaller dust particles being repelled more strongly.Parts of the dust cloud have become filamentary and stratified, as seen in the above deep-exposure image.
Friday, January 17, 2014
Astronomy Picture of the Day
Pictured here is the Orion Nebula which is located 1,500 lightyears from the Earth. This photo is a false-color view that spans 40 lightyears. The photo was constructed using the Spitzer Space Telescope. The center of the nebula contains the Trapezium Cluster and the red hues the protostars. One of the protostars, HOPS 68 was recently discovered to have crystals of the silicate mineral olivine.
Thursday, January 9, 2014
Observations
Date: December 15th, 2013
Time: 7:00 - 9:00 PM
Place: Backyard
Instruments Used: binoculars (10x50)
Sky Conditions: Mostly clear, with some faint & wispy clouds. Moon: full.
Instruments Used: naked eye observations, no binoculars/telescopes
Planets: Venus
Bright Stars noted: Deneb, Alberio, Gamma Andromeda, Betelgeuse, Rigel
Constellations noted: Taurus, Andromeda, Cygnus, Orion, Fornax
Binary Star: Alberio: one star bright blue, the other (lower to right) yellow. Gamma Andromeda: color difference - blue and golden.
Deep Sky Objects: M45, The Pleiades: located in Taurus; seven brightest stars go under the name "The Seven Sisters"
M31, "The Andromeda Galaxy", located in Andromeda
M42, "The Orion Nebula", celestial nursery, located in Orion, four star system known as "The Trapezium"
Observations
Date: October 29th, 2013
Time: 7:00 - 10:00 PM
Place: Casey Key
Sky Conditions: Slightly clear, with a number of relatively high clouds. Moon not present during time of observation, waning cresent.
Instruments Used: binoculars (10x50), telescope 26mm with F10 focal power.
Planets: Venus (neutral filter, quarter phase, slight fluorescent glow)
Bright Stars noted: Vega, Deneb, Altair (Summer Triangle), Antares,
Constellations noted: Lyra, Cygnus, Aquila, Scorpius, Virgo, Bootes, and Hercules. Cygnus ("v" structure found magnitude 5).
Binary Star: Alberio, one star bright blue, the other yellow. Polaris, secondary faint star location approximately 11 o'clock.
Deep Sky Objects: M13: globular, located in Hercules; in the telescope at 100 power, star cluster seen.
M11: open, Wild Duck Cluster. faint, distorted honeycomb-like cluster clouds.
Other: Venus located in constellation Ophiuchus.
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