La particula divina

Historia da física dende Demócrito, coa sua hipótesi sobre os átomos como partículas invisibles e indivisibles, ata o bosón de Higgs, que sería a famosa partícula divina do título.

O premio novel de física Leon Lederman (ex-director do Fermilab) escribe un libro moi entretenido e realmente divertido! Onde fai un repaso fantástico e con gran sentido do humor da historia da física e os seus principais protagonistas, facendo especial atención a parte experimental do campo. Incluso podemos atopar todo un capítulo dedicado os aceleradores de partículas.

Libro moi recomendado para estudiantes, in realtá per tutti, xa que se pode apreciar como traballa a ciencia a través do método científico, que detrás de importantes descubrimentos está realmente o traballo de moita xente o largo de moitos anos, siglos incluso! A pesar de que o final vaian asociadas a nomes de físico ilustres como Newton, Einstein, Galileo, etc. Que unha interpretación correcta dos resultados experimentais pódeche levar a descubrimentos sorprendentes ou a perder totalmente o rumbo.

En resumen, física e historia en un so libro, ¡que máis se podo pedir!

Probably a discovery: Bad mathematics means rough scientific communication

by Giulio D'Agostini
---
According to the media, in spring of this year the experiment CDF at Fermilab
has made most likely (“this result has a 99.7 percent chance of being correct”[1]) a
great discovery ( “the most significant in physics in half a century”[2]). However, since the very beginning, practically all particle physics experts did not believe that was the case. This is the last of a quite long series of fake claims based on trivial mistakes in the probabilistic reasoning...

The main purpose of this note is to invite everybody, but especially
journalists and general public, most times innocent victims of misinformation of this
kind, to mistrust claims not explicitly reported in terms of how much we should believe something, under well stated conditions and assumptions. (A last minute appendix has been added, with comments on the recent news concerning the Higgs at LHC.)
---

Después hay una interesante discusión aquí (en italiano :)) donde Nicola Farina y Moping Owl explican el significativo de sigma y p-value.

----

Giulio D'Agostini es tambien el autor de este libro

y al fin A defense of Columbo (and of the use of Bayesian inference in forensics) – A multilevel introduction to probabilistic reasoning

The end is near ....

How much is the probability of LHC will destroy the world? ... watch the video and learn!!

Dissecting the Cave Lion Diet

To figure out what these lions hunted, biogeologist Hervé Bocherens and colleagues at the University of Tübingen in Germany, analyzed bone samples from 14 cave lions—found in four caves in France and central Europe—that lived between 12,000 and 40,000 years ago. The team focused on the chemical content of the bone collagen, which is often well-preserved, even in bones tens of thousands of years old. By incinerating a tiny fragment of preserved bone—usually less than a milligram—researchers can identify the molecules inside it and determine an animal's diet.

Scientists have perfected the technique over the years. It was used recently to look at the diet of Neandertals, but this is one of the first studies to use it to look at a nonhuman predator—and the analysis is now sensitive enough to look several steps down the food chain. This enabled Bocherens to determine not only what cave lions ate but also what their prey ate. And that made it possible to tell, for example, whether lions were targeting full-size cave bears or their more vulnerable cubs, because adults and babies eat different diets themselves. "There's a difference between the [chemical] signal of adults and babies," Bocherens says. "Babies drink the milk of the mother."

As it turned out, this distinction was important. Bocherens's analysis, reported in the 6 December issue ofQuaternary International, revealed that the cave lions occasionally ate bear cubs but not adults. Their favorite food, however, was reindeer, which Bocherens and his team determined consumed massive quantities of lichen, much as their modern descendants did. The cave lion diet, Bocherens says, appears to have been much more finicky than that of today's lions, which eat just about anything they can catch.

Vacas, cerdos, guerras y brujas

E agora un pouco de antropoloxía con Marvin Harris. Este libro sorprendeume gratamente e quero recomendar a sua lectura a tutti. O autor, Marvin Harris, trata de explicar algunhas das costumes máis extrañas da sociedadea partire de bases materiais e económicas.
¿Porque os hindus consideran as vacas sagradas? ¿Porque os xudeos e musulmáns non comen cerdo? ¿Podemos dar unha resposta a aparición do machismo, das guerras, da volencia e consumismo actual estudando tribus primitivas que a simple vista teñen costumes que parecen irracionais? ¿Existe algunha relación entre as bruxas e as tradicións mesiánicas?
As explicacións que ofrece Harris son moi interesantes e polémicas, por iso me gustou tanto o libro, a pesar de todo sempre trata de buscar explicacións racionais os diferentes estilos de vida que trata no libro, o cal me leva a famosa frase: "consistency is better than true"

El gen egoísta e El relojero ciego

Hola Rapaces,

Aqui van un par de libros de divulgación científica escritos por Richard Dawkins sobre a evolucion, son El gen egoísta e a sua continuación El relojero ciego.

Ambos libros están escritos de forma amena e deixando moi claras as bases sobre as cales se apoya a teoría da evolución. En ambos libros trata con moito detalle a función do azar na evolución das especies, xa que este punto suele ser motivo de bastante confusión sobre para os que somo profanos no campo da evolución. Por exemplo esta afirmación (errónea) de Sir Fred Hoyle: “Tengamos en un desguace las piezas necesarias para construir un Boeing 747, desmontadas y desordenadas. Entonces llega un tornado y atraviesa la zona. ¿Cuál es la posibilidad de que después nos encontráramos allí el avión completamente montado y listo para volar?”. La probabilidad de este suceso, es la misma –o incluso mayor- de la que el ADN se formara de manera casual”. Esta mesma frase sería repetida por un premio novel de medicina con respecto o posible orixen do cerebro como órgano complexo formado por selección natural. Se queredes saber onde falla o argumento do 747 recoméndovos leer os libritos!

Enjoy!

Neutrinos again

Neutrinos are a source of surprises. Opera detector at Gran Sasso have announced the measurement of higher-than-light speed of neutrinos produced at CERN and detected 730 km away in Gran Sasso laboratory. Neutrinos arrive 60 ns earlier than light.

See article in arXiv: 1109.4897.

La proporción áurea

Hola rapaces,

Como interesante lectura veraniega acabo de zamparme un libro de divulgación sobre o número áureo:
La Proporción áurea de Mario Livio
Editorial Ariel.
ISBN 978-84-344-4495-9

De forma amena fai un recorrido histórico sobre este coñecido número irracional:
Phi: 1,6180339887
No libro faise referencia a sua aparición e estudio sobretodo nas matemáticas, empezando por Euclides, pero tamén na física, bioloxía, arquitectura, pintura e arte en xeral.

É un libro moi interesante e de recomendada lectura!

Gonzalo.

Olimpíada Internacional de Matemática

Hola Rapaces,

Os días 16-24 xulio celebrouse o IMO 2011 en Amsterdam. Páxina web.
Un veciño noso, Pablo Boixeda , obtivo a medalla de bronce.
Como sudoku veraniego aquí tendes un link os problemas que tiveron que resolver os rapaces.
Como bonus tamén vos podedes baixar os problemas dos outros anos.

Gonzalo.

Desafios Matematicos

Hola rapaces,

dende fai unhas semanas na páxina web de El Pais para celebrar o centenario da Real Sociedade Matemática Española, diversos matemáticos de toda España plantexan diferentes desafíos matemáticos cada semana, para resolvelo tamén temos unha semana!.
O premio é unha coleccion de libros de matematicas (of course!)
Os problemas son moi entretenidos, o desta semana chámase, "Cuadrados que suman grandes cifras"

Aqui tendes a lista de tódolos desafíos: Desafios matemáticos.

Gonzalo.

Lytro camera: Shoot first, focus later

A new camera may be able to make even the foggiest of photos turn out sharp and full of life. The Lytro camera launched Tuesday and has a post-focus feature, letting you adjust the depth of the photo after you’ve taken it.

Picture gallery

The antineutrino vanishes differently

Researchers report a possible difference between muon neutrino and muon antineutrino disappearance, which if confirmed will have serious implications for our current theoretical understanding.

CPT symmetry, the combination of charge conjugation, parity inversion, and time reversal, is a fundamental symmetry of particle and nuclear physics and is considered sacred. It is conserved in field theories that explain the strong, weak, and electromagnetic interactions. In the lepton sector, CPT symmetry requires that muon neutrino disappearance oscillations be identical to muon antineutrino disappearance oscillations in vacuum. A test of CPT symmetry was recently performed by the MINOS experiment at Fermilab, which, due to its magnetic field, is the first experiment to distinguish μ^- and μ⁺ tracks and separately measure the disappearance of muon neutrinos and muon antineutrinos [1]. (Previous experiments have measured a mixture of neutrino and antineutrino oscillations.) Remarkably, as reported in Physical Review Letters, MINOS appears to observe a difference between muon neutrino and muon antineutrino disappearance [1].

Verificando a teoría atómica cun experimento caseiro

Con unha simple caixa de cartón e un CD podemos verificar experimentalmente que o mundo está feito de átomos e que se rixen polas reglas da mecánica cuántica!
O experimento e a sua explicación teórica están perfectamente ilustrados neste blog:
Ciencia explicada

Geiger USB: Auger@Home

Encontre un contador Geiger que pueden conectar a su puerto USB

http://www.sparkfun.com/products/9848

para hacer demostraciones de rayos cosmicos mientras estan de viaje, a su compañero de asiento en el bus por ejemplo.

Otros usos: Un live feed con la radiacion que hay en este momento en tu oficina

http://pachube.com/feeds/22279

Y lo mejor de todo: Como generador de numeros aleatorios , para tu montecarlo favorito

http://www.sparkfun.com/tutorials/132

a 150 dolares el detector... con 1000K dolares se puede armar un array de detectores conectados a la red, que con un gps para el timing cada uno y la interfaz adecuada... Auger World Wide?

o Auger@Home / Auger@school

(de hecho, los detectores los pueden pagar las escuelas que participen, por ejemplo)

Seria para buscar eventos de muy alta energia, buscando coincidencias en un area grande.

Bueno, ya delire. Pero lindo el geiger usb no?

Computer security: Is this the start of cyberwarfare?

Inside the lab, the team began by dropping Stuxnet into a simulated networking environment so that they could safely watch what it did. The sheer size of the virus was staggering: some 15,000 lines of code, representing an estimated 10,000 person hours in software development. Compared with any other virus ever seen, says O Murchu, "it's a huge amount of code".

Equally striking was the sophistication of that code. Stuxnet took advantage of two digital certificates of authenticity stolen from respected companies, and exploited four different 'zero day vulnerabilities' — previously unidentified security holes in Windows that were wide open for hackers to use.

---

Over the next few months, however, as Langner and others continued to work with the code, the evidence began to point away from Bushehr and towards a uranium-enrichment facility in Natanz, where thousands of centrifuges were separating the rare but fissionable isotope uranium-235 from the heavier uranium-238. Many Western nations believe that this enrichment effort, which ostensibly provides fuel for nuclear power stations, is actually aimed at producing a nuclear weapon. The malware code, according to Langner and others, was designed to alter the speed of the delicate centrifuges, essentially causing the machines to spin out of control and break.

A Big Surprise from the Edge of the Solar System

Las sondas Voyager de la NASA han llegado a la periferia del sistema solar, y allí se han encontrado con algo totalmente inesperado: "The Voyager probes appear to have entered a strange realm of frothy magnetic bubbles" En la entrada se explica que estas burbujas magnéticas pueden ser producidas por el campo magnético del sol que se extiende por todo el sistema solar.

Y lo que es más importante puede tener consecuencias para los rayos cósmicos. Ya que parte del flujo de rayos cósmicos podría quedar atrapado dentro de las burbujas magnéticas.

Podéis encontrar todos los detalles en la página de la NASA.
En el mismo enlace podéis ver un vídeo donde se explica a través de animaciones como se producen las burbujas magnéticas.

La hipótesis de Riemann

Una de las charlas del congreso de matemáticas, Los problemas del milenio, Barcelona 1-3 Junio 2011, fue sobre la hipótesis de Riemann. En la excelente página la mula francis le dedican una entrada comentando la charla de Ricardo Pérez. En la entrada podeis encontrar dos documentos muy interesantes:

Un articulo, en español, que complementa la charla haciendo un resumen de todos los avances que se han producido en las matemáticas desde que Riemann publicó su hipótesis. Es un artículo técnico pero se lee muy bien. Enlace aquí.

El otro articulo es incluso más interesante ya que habla de física! Es un Rev. Mod. Physics donde se hace un resumen de todos los problemas de física donde aparece la función zeta de Riemann, aqui teneis el enlace.

Y para acabar con Riemann y los números primos os recomiendo un libro que lei recientemente:

La música de los números primos del matemático francés Marcus du Sautoy, ref.

Tornado visto desde el aire

Hola,
aqui podeis ver un tornado espectacular visto desde un helicóptero.

http://www.bbc.co.uk/news/world-asia-pacific-13593871

Messi lidera la genial exhibición de fútbol alegre y coral de los de Guardiola ante el Manchester United - El equipo azulgrana, tetracampeón de Europa

Bye Bye Comet! [HD Video]

NASA video captured May 10-11, 2011

SOHO watched as a fairly bright comet dove towards the Sun in a white streak and was not seen again after its close encounter (May 10-11, 2011). The comet, probably part of the Kreutz family of comets, was discovered by amateur astronomer Sergey Shurpakov. In this coronagraph the Sun (represented by a white circle) is blocked by the red occulting disk so that the faint structures in the Sun's corona can be discerned. Interestingly, a coronal mass ejection blasted out to the right just as the comet is approaching the Sun.

Pendulum Waves

Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and random motion. One might call this kinetic art and the choreography of the dance of the pendulums is stunning! Aliasing and quantum revival can also be shown. More info here

LO QUE PASA POR TU MENTE CUANDO ALGUIEN DICE "VAMOS A TOMAR ALGO"

Lisboa

¿Y si pudieras ver los gigantes chorros de radio de Centaurus A?

Averigua come se verían los espectaculares chorros de radio de CenA aqui.

Yuri

Se estreno una película con una simulacion de lo que Yuri Gagarin vivio. Es un documental interesante.

http://www.youtube.com/watch?v=RKs6ikmrLgg

Where are the neutrinos?

IceCube, which was completed in December 2010, is a kilometer-cubed array of photodetectors that have been drilled down into the Antarctic ice cap. Neutrinos typically fly through the array without leaving a trace, but occasionally one will collide with a nucleus and create a charged particle that emits light as it moves through the ice. The IceCube team compared 13 months of their data (collected when the array was half finished) to observations of 117 GRBs measured independently over the same time period. Contrary to expectations, no high-energy neutrinos were detected within a half-hour of each GRB. Theorists may need to rethink their models of GRBs, as well as look for other possible sources for the highest energy cosmic rays.

(full text article here)

Domenico Pacini, uncredited pioneer of the discovery of cosmic rays

During a series of experiments performed between 1907 and 1911, Domenico Pacini (Marino 1878-Roma 1934), at that time researcher at the Central Bureau of Meteorology and Geodynamics in Roma, studied the origin of the radiation today called "cosmic rays", the nature of which was unknown at that time. In his conclusive measurements in June 1911 at the Naval Academy in Livorno, and confirmed in Bracciano a couple of months later, Pacini, proposing a novel experimental technique, observed the radiation strength to decrease when going from the surface to a few meters underwater (both in the sea and in the lake), thus demonstrating that such radiation could not come from the Earth's crust. Pacini's work was largely overlooked. Hess was awarded the Nobel Prize in Physics in 1936, two years after the death of Pacini, who had become a full professor of Experimental Physics at the University of Bari.

Google Translate for Animals

(be sure to watch the video)

Translate for Animals is an application for Android phones that recognises and transcribes words and phrases that are common to a species, like cats for example. To develop Translate for Animals, we worked closely with many of the world's top language synthesis teams, and with leaders in the field of animal cognitive linguistics, including senior fellows at the Bodleian Library in Oxford.

Hadronic multiparticle production at ultrahigh energies and extensive air showers

Ralf Ulrich, Ralph Engel and Michael Unger

Phys. Rev. D 83, 054026 (2011) [21 pages]

Studies of the nature of cosmic ray particles at the highest energies are based on the measurement of extensive air showers. Most cosmic ray properties can therefore be obtained only from the interpretation of air shower data and are thus dependent on predictions of hadronic interaction models at ultrahigh energies. We discuss different scenarios of model extrapolations from accelerator data to air shower energies and investigate their impact on the corresponding air shower predictions. To explore the effect of different extrapolations by hadronic interaction models we developed an ad hoc model. This model is based on the modification of the output of standard hadronic interaction event generators within the air shower simulation process and allows us to study the impact of changing interaction features on the air shower development. In a systematic study we demonstrate the resulting changes of important air shower observables and also discuss them in terms of the predictions of the Heitler model of air shower cascades. It is found that the results of our ad hoc modifications are, to a large extent, independent of the choice of the underlying hadronic interaction model.

Mapa de la gravedad terrestre

De los datos recogidos por el satélite GOCE se ha obtenido un mapa de la gravedad terrestre.
Gravitatoriamente hablando....la tierra tiene forma de "patata"!!

link a noticia aqui

'O nnapulitano in action (leccion num. 1)

Proceedings de la reunión del grupo

REVIEW (36 pp.)

High-energy neutrino astronomy: detection methods and first achievements

In the last century, astronomy evolved from optical observation to the multi-wavelength study of celestial objects from radio waves up to x- and γ-rays, leading to a wealth of new discoveries and opening the way to high-energy astroparticle physics. In particular, the recent success of ground-based very-high-energy γ-ray telescopes has opened a new window on the most powerful and violent objects of the Universe, giving a new insight into the physical processes at work in such sources. In the context of high-energy astronomy, neutrinos constitute a unique probe since they escape from their sources, travel undisturbed on virtually cosmological distances and are produced in high-energy hadronic processes. In particular they would allow a direct detection and unambiguous identification of the sites of acceleration of high-energy baryonic cosmic rays, which remain unknown. This report discusses the physics potential of the domain and reviews the experimental techniques relevant for the detection of high-energy (≥TeV) neutrinos. The results obtained by the first generation of such detectors are presented, along with the perspectives opened by new projects and prototypes being currently developed.

DNA waves and water and quantum physics

Recomendables artículos do premio novel de Medicina Luc Montagnier

The emission of low-frequency electromagnetic waves from bacterial DNA sequences, and the apparent ability of these waves to organize nucleotides (the raw material of DNA) into new bacterial DNA, by mediation of structures within water.

O primeiro link fai un resumo do articulo de Montagnier.

aqui y aqui

How to make a big bang...

A toma é parte do Cómo se fixo dunha serie da BBC4 titulada Everything and Nothing sobre a naturaleza física do espacio y a materia.

Storm over the 3000 km2 of the Pierre Auger Observatory, seen in Cosmic Rays

Tormenta solar visto polo SD, scaler data, o 11 Marzo do 2009

XVI Ciclo de Jazz (conciertos gratuitos)

Para los amantes del jazz del grupo....Mas informacion aqui

O Gato sorprendido

O misterioso do caso do gato sorprendido...



Aqui tendes a solucion o misterio...

Moscow has appeared the worst centre of science in the world

the legend to the map (at the very end of the page)

Indiana Jones En busca del arca perdida

Xenial artículo onde se analiza a fisica, ou máis ben a non física, deste peliculón!

http://fisicacf.blogspot.com/2011/03/de-indiana-jones-sus-grandes-bolas.html

Article of my friend on web browsers

ok, here comes the explanation, see also wikipedia

Touch Trigonometry

Gráfico interactivo para calcular el valor de diferentes funciones trigonometricas



http://www.matthewtrost.org/projects/touchtrigonometry/

New core finding method

Keep fit

Recent work has implicated mutations in mitochondrial DNA (mtDNA) in aging, and in humans, endurance training has been linked to health benefits, including increased life expectancy.

Busco un equipo para jugar futbol. Urgente :)

Feliz dia de pi

Como deben recordar, ayer fue 14 de marzo, que en la nomenclatura inglesa es el 3/14

Pues aqui les dejo un video para celebrarlo...y para que se preparen para el 2015

http://www.youtube.com/watch?v=IYM6UEk_ywk

Ultimos 6 GAPS Notes

1. 2011-025 M.Aglietta, S.Gallian, F.Gomez, A.Lucero, S.Maldera, R.Sato, A.Zampieri
   A LED source for Ultra High Energy cosmic ray water Cerenkov detectors
2. 2011-026 Guus van Aar, Sijbrand de Jong, Stefan Grebe, Harm Schoorlemmer, Charles Timmermans
   Indication for heavy nuclei from Centaurus A above 55 EeV
3. 2011-027 Dalibor Nosek, Jana Noskova
   Intrinsic anisotropy at low energies
4. 2011-028 John Kelley, Charles Timmermans
   Calibration of the AERA Phase 1 Digitizer
5. 2011-029 Paul LeBrun
   On Systematics in SD Energy determination and related trans-GZK Anisotropies
6. 2011-030 Frederick Kuehn
   THE ANISOTROPY SIGNAL AROUND CENTAURUS A: PROJECTION AND PRESCRIPTION

Are We in the Middle of a Sixth Mass Extinction?

Inauguro el blog con la recomendacion de las charlas de Susskind sobre varios temas de Fisica.

http://francisthemulenews.wordpress.com/2011/02/25/cursos-de-fisica-teorica-de-leonard-susskind-en-la-universidad-de-stanford-gratis-en-youtube/