Daily Archives: June 11, 2012

Brian Greene: ¿Es nuestro universo el único universo?

En el corazón de la cosmología moderna hay un misterio: ¿Por qué nuestro universo parece tan exquisitamente preparado para crear las condiciones necesarias para la vida? En este ‘tour de force’ por algunos de los mayores descubrimientos de la ciencia, Brian Greene muestra cómo en la idea alucinante de un multiverso puede estar la respuesta al enigma.

Brian Greene is perhaps the best-known proponent of superstring theory, the idea that minuscule strands of energy vibrating in a higher dimensional space-time create every particle and force in the universe. Full bio »

Translated into Spanish by Sebastian Betti
Reviewed by Jaime Gonzalez Magallanes
Comments? Please email the translators above.



Hace unos meses se otorgó el premio Nobel de física a dos equipos de astrónomos por un descubrimiento catalogado como una de las observaciones astronómicas más importantes de la historia. Y hoy, después de una breve descripción de ese hallazgo, les hablaré de un marco conceptual muy polémico para explicar su descubrimiento. A saber, la posibilidad de que más allá de la Tierra, de la Vía Láctea y de otras galaxias lejanas, podríamos encontrar que nuestro universo no es el único, sino que es parte de un vasto complejo de universos al que llamamos multiverso.

Pero la idea de multiverso es rara. Digo, muchos nos hemos criado con la idea de que "universo" quiere decir "todo". Y digo la mayoría pensando como mi hija de cuatro a?os que me ha oído hablar de estas ideas desde que nació. El a?o pasado la tenía en brazos y le dije: "Sophia, eres a quien más amo en el universo". Me miró y dijo: "Papi, ¿universo o multiverso?" (Risas)

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Director Emeritus Leon Lederman departs Fermilab

Fermilab Director Emeritus Leon Lederman sits in front of Wilson Hall. Photo: Reidar Hahn

This article first appeared in Fermilab Today on June 8, 2012.

Fermilab’s Leon Lederman is leaving the laboratory that he served for ten years as its director and for many more as an internationally renowned physicist and science education pioneer.

The directorate is hosting a farewell reception for Lederman today at 3 p.m. on the 2nd-floor crossover. He leaves Batavia, Ill. for Driggs, Idaho. His last day at the lab is Monday, June 11.

Lederman’s early award-winning research in high-energy physics brought him into national science policy circles and in 1963 he proposed the idea that became the National Accelerator Laboratory. In 1977 Lederman led the team that discovered the bottom quark at Fermilab. The following year he was named director and his administration brought Fermilab into its position of scientific prominence with the achievement of the world’s most powerful superconducting accelerator, the Tevatron. He served as director until 1989.

Lederman is the recipient of some of the highest national and international honors bestowed to a scientist. His awards include the 1965 National Medal of Science and the 1972 Elliott Cresson Medal, given by the Frankin Institute. In 1982 he received the prestigious Wolf Prize, an annual prize given by the Wolf Foundation in Israel. He received the 1988 Nobel Prize in Physics for the discovery of the muon neutrino and was honored with the Enrico Fermi Award in 1992. And just this year, he was recognized for his distinguished scientific career with the 2012 Vannevar Bush Award, given to exceptional lifelong leaders in science and technology.

Lederman advocated for math and science education and for outreach to the neighboring communities. He initiated the Saturday Morning Physics lectures and subsequently founded the Friends of Fermilab, the Illinois Mathematics and Science Academy, and the Teacher’s Academy for Mathematics and Science.

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Oscillation results from DeepCore (IceCube sub-detector)

See the press release here.     IceCube DeepCore “sub-detector” sees high-energy neutrino oscillations During a poster presentation at the International Conference on Neutrino Physics in Kyoto, Japan, IceCube post-doc Andreas Gross from the Technical University of Munich, Germany revealed something of interest to the particle physics community: the highest observed energy level of neutrino oscillations. Gross used data from the DeepCore array within the IceCube Neutrino Observatory.  The IceCube DeepCore extension consists of six densely deployed strings of modules and seven normally deployed strings.  DeepCore’s two defining characteristics are the close proximity of the strings and that a number of modules are positioned below 2000m in the ice; at 2100-2450m, modules are below a major dust layer and the ice is extremely clear. DeepCore modules also boast a new photomultiplier tube with approximately 35% more quantum efficiency.  All these factors enable the DeepCore “sub-detector” to track neutrinos with energies as low as 10 gigaelectronvolts (GeV). High and low energy classifications are relative, though, because what IceCube sees on the low-energy side of things is pushing the upper limits for most experiments.  IceCube researchers typically study neutrinos from astrophysical origins that clock in above the 1,000 GeV level.  While 10 GeV is low for IceCube, Nagoya University physicist Yoshitaka Itow tells Nature that the Japanese neutrino experiment Super-Kamiokande’s “energy resolution above 10 GeV is very poor and that above 50 GeV, the experiment cannot resolve the energy of the oscillating neutrinos at all.” The high-energy neutrino oscillations that Gross used in his analysis were between 10 and 100 GeV.  All events consisted of muon neutrinos oscillating in to tau neutrinos.  The results contribute to our understanding of neutrino types and confirm that oscillations take place at higher energies than previously found. A large contingent of IceCubers have deployed to the meeting in Japan, also known as “Neutrino 2012.”  On Friday, June 8, IceCube Principal Investigator and UW-Madison Professor Francis Halzen will chair a session on Experimental Neutrino Astronomy, with several members of the internal IceCube Collaboration presenting. For more information about IceCube DeepCore, we recommend The Design and Performance of IceCube DeepCore by the IceCube Collaboration (source).
A schematic layout of IceCube DeepCore.  The upper diagram shows a top view of the string positions in relation to current IceCube strings.  It includes two additional strings, situated close to the central DeepCore strings, that were deployed in the 2010/2011 austral summer.

La Marina Rusa Epis2

La Marina Rusa Epis2
La Marina Rusa Epis2
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La Marina Rusa Epis1

La Marina Rusa Epis1
La Marina Rusa Epis1
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A Few Questions With Christopher Melton

Christopher Melton talks about how work at SLAC can be like air-traffic control, about data mining and mining towns, and about a job where his boss was, well, kind of like HAL from 2001.


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Photo - Portrait of Christopher Melton, control-room monitor in background

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