"In 1858, August Mobius dreamt up a shape with a single surface and only one edge. The Mobius strip has fascinated children and scientists alike since then.
How small can these shapes be? In December 2003, German chemists made a molecular Mobius strip out of a benzene-like ring modified with a belt-like carbon structure. Since then, various groups have produced increasingly bizarre Mobius-type molecules, including one that can switch back and forth from a Mobius to an ordinary strip when zapped with light.
Of course, the obvious choice of material with which to make Mobius molecules is graphene. But this particular trick has eluded chemists, an omission that clearly irks. Now Douglas Galvao from the Universidade Estadual de Campinas in Sao Paolo, Brazil, and buddies have decided to grip the bull by the horns and calculated the properties that Mobius carbon might have."New form of "Mobius" carbon predicted - Technology Review
Monday, June 27, 2011
Farewell Lieutenant Columbo
"Peter Michael Falk (September 16, 1927 – June 23, 2011) was an American actor, best known for his role as Lieutenant Columbo in the television series Columbo. He appeared in numerous films and television guest roles and was nominated for an Academy Award twice (for 1960's Murder, Inc. and 1961's Pocketful of Miracles), and won the Emmy Award on five occasions (four for Columbo) and the Golden Globe award once. Director William Friedkin, when discussing Falk's role in his 1978 film The Brink's Job said that "Peter has a great range from comedy to drama. He could break your heart or he could make you laugh.""
Image created with labyrinthine tiling (see http://staff.polito.it/amelia.sparavigna/rendering/index.html, http://arxiv.org/abs/cs/0609084).
Friday, June 24, 2011
Hot quarks break free
"Physicists in the US, India and China have calculated that quarks and gluons can break free from their confinement inside protons and neutrons at a temperature of around two trillion degrees Kelvin – the temperature of the universe a fraction of a second after the Big Bang. The researchers arrived at this figure by combining the results of supercomputer calculations and heavy-ion collision experiments. They say that it puts our knowledge of quark matter on a firmer footing."
Quarks break free at two trillion degrees - physicsworld.com
Wrinklons
"A new quasiparticle called the "wrinklon" could help explain why materials as diverse as graphene and household curtains wrinkle in much the same way – despite their very different length scales. The particle has been introduced by researchers in Belgium, France and the US as a result of measurements on a wide range of materials on length scales from micrometres to metres. While the work may not lead to more attractive curtains, wrinkles do turn out to affect the electronic properties of graphene and the analysis could therefore influence the development of graphene-based devices."
Voyager mission at the edge of the solar system
"Recent data from the spacecraft have shown a gentle decrease in the velocity of the solar wind at the heliopause – the outer boundary of the heliosheath – not the abrupt discontinuity predicted by current theories. Also, scientists looking at other data from both Voyager 1 and Voyager 2 have found that the magnetic field in the heliosheath is a tumultuous foam of magnetic bubbles, as compared to the graceful arcs of magnetic field lines they had expected."
More surprises for the Voyager mission at the edge of the solar system - physicsworld.com
Thursday, June 23, 2011
Khufu’s second solar boat revealed
"Today, hundreds of foreign and Egyptian journalists along with photographers, cameramen and TV presenters flocked to the Giza Plateau, where Minister of State for Antiquities Zahi Hawass, Chargé d’Affaires at the Japanese Embassy to Egypt Masami Kinefuchi, and the chief executive representative of the Nitori Holding Company, Akio Nitori, unveiled King Khufu’s second solar boat. This boat was first discovered in 1954 by Egyptian architect and archaeologist Kamal El-Malakh with fellow archaeologist Zaki Nour during routine cleaning at the southern side of Khufu’s Great Pyramid. The first pit was found under a roof of 41 limestone slabs. Removing one of these slabs, a cedar boat, completely dismantled but arranged in the semblance of its finished form, was found along with layers of mats, ropes, instruments made of flint and some small pieces of white plaster with 12 oars, 58 poles, three cylindrical columns and five doors."
Wednesday, June 22, 2011
Documentos de Antonio Raimondi serán restaurados y digitalizados
"Se recuperarán libretas, acuarelas, planos y láminas hechas por el sabio.
Gracias al convenio firmado entre el Archivo General de la Nación (AGN) y la Asociación Educacional ‘Antonio Raimondi’ será posible restaurar y digitalizar la colección del sabio italiano, que data de los años 1852 a 1869, anunció el ministro de Cultura, Dr. Juan Ossio Acuña. "
Documentos de Antonio Raimondi serán restaurados y digitalizados
Gracias al convenio firmado entre el Archivo General de la Nación (AGN) y la Asociación Educacional ‘Antonio Raimondi’ será posible restaurar y digitalizar la colección del sabio italiano, que data de los años 1852 a 1869, anunció el ministro de Cultura, Dr. Juan Ossio Acuña. "
Thursday, June 16, 2011
Peer pressure keeps planets young...
"Two US astrophysicists claim they have answered an important question about how planets form: why don't young planets get pushed into their companion stars before they have a chance to grow? It turns out that a little company is enough to keep them there, say the researchers, who argue that multiple planets moving through a rocky disk can prevent one another from falling into the star."
Peer pressure keeps young planets growing - physicsworld.com
Tuesday, June 14, 2011
On sunspots and solar flux
Recurrence plots of sunspots, solar flux and irradiance
by AC Sparavigna
The paper shows the recurrence and cross recurrence plots of three time series, concerning data of the solar activity. The data are the sunspot number and the values of solar radio flux at 10.7 cm and of solar total irradiance, which are known as highly correlated. To compare the series, the radio flux and irradiance values are monthly averaged. Recurrence plots display the oscillating behaviour with remarkable features. Moreover, cross recurrence plots help in identifying time lags between the sunspot number maximum and the maximum of radio or irradiance signals, in circumstances where the data values are highly dispersed. Image processing is useful too, in enhancing the monitoring. An interesting behaviour is displayed by cross recurrence plots of irradiance, which are not symmetric with respect to the line of identity.
by AC Sparavigna
The paper shows the recurrence and cross recurrence plots of three time series, concerning data of the solar activity. The data are the sunspot number and the values of solar radio flux at 10.7 cm and of solar total irradiance, which are known as highly correlated. To compare the series, the radio flux and irradiance values are monthly averaged. Recurrence plots display the oscillating behaviour with remarkable features. Moreover, cross recurrence plots help in identifying time lags between the sunspot number maximum and the maximum of radio or irradiance signals, in circumstances where the data values are highly dispersed. Image processing is useful too, in enhancing the monitoring. An interesting behaviour is displayed by cross recurrence plots of irradiance, which are not symmetric with respect to the line of identity.
Hygroscopic properties of volcanic ash
Hygroscopic properties of volcanic ash
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L11802, 4 PP., 2011
doi:10.1029/2011GL047298
GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L11802, 4 PP., 2011
doi:10.1029/2011GL047298
by P. Kumar T. L. Lathem A. Nenes J. Dufek I. N. Sokolik M. Trail A. Russell
Volcanic ash is hygroscopic
Water vapor adsorption is the main proceess controlling ash hygroscopicity
The results can be parameterized in a simple correlation for use in models
"Limited observational data exists on the physical interactions between volcanic ash particles and water vapor; yet it is thought that these interactions can strongly impact the microphysical evolution of ash, with implications for its atmospheric lifetime and transport, as well as formation of water and ice clouds. ...The hygroscopicity of the ash particles is quantified by their ability to uptake water and nucleate into cloud drops under controlled levels of water vapor supersaturation. Evidence presented strongly suggests that ash uptakes water efficiently via adsorption and a simple parameterization of ash hygroscopicity is developed for use in ash plume and atmospheric models."
Volcanic ash is hygroscopic
Water vapor adsorption is the main proceess controlling ash hygroscopicity
The results can be parameterized in a simple correlation for use in models
"Limited observational data exists on the physical interactions between volcanic ash particles and water vapor; yet it is thought that these interactions can strongly impact the microphysical evolution of ash, with implications for its atmospheric lifetime and transport, as well as formation of water and ice clouds. ...The hygroscopicity of the ash particles is quantified by their ability to uptake water and nucleate into cloud drops under controlled levels of water vapor supersaturation. Evidence presented strongly suggests that ash uptakes water efficiently via adsorption and a simple parameterization of ash hygroscopicity is developed for use in ash plume and atmospheric models."