Wednesday, March 25, 2015

Cosmic Rays

My first job, was  as a laboratory assistant, at the Mexican Nuclear Energy Commission in 1970. I was then a senior, at the department of Communications, and Electronics Engineering, at Escuela Superior de Ingeniería Mecánica y Eléctrica, of the Instituto Politécnico Nacional (IPN) in Mexico City. I worked at the Plasma Physics Laboratory. My boss, Mario Vázquez Reyna, under the direction of Manuel Sandoval Vallarta, a pioneer in Cosmic Ray Physics in Mexico, had built electronic detectors. I studied plasma magnetic confinement at the laboratory. During that year, I decided to study Physics instead of electronics. I did not want to build detectors for others, I wanted to propose the needed observations, to prove ideas in Physics.

The opportunity came along, in the field of cosmic rays, with the invitation to join the Pierre Auger Observatory in 1994. I was on a sabbatical leave from the Autonomous University of Puebla, at the Fermi National Laboratory in Batavia, Illinois, My professor Arnulfo Zepeda Domínguez, was invited, by the Nobel laureate James Cronin, from the University of Chicago, to join this international collaboration; and professor Zepeda invited me. The university in Puebla had very good conditions to join this effort. I was working at the Escuela de Ciencias Físco Matemáticas, which was started by professor Luis Rivera Terrazas, precisely to join  international efforts in modern physics. There were  Physics, Mathematics, Electronics, and Computer Science departments.

As soon as I went back to Puebla, I talked with my friend Alberto Cordero Dávila. With his experience at the Instituto Nacional de Astrofísica Óptica y Electrónica in the nearby town of Tonantzintla, he immediately proposed the kind of instrument to use for the light collecting part of the observatory, the Schmidt Camera, which was adopted by the collaboration.

There is a surface detector part of the Auger Observatory, working together with the optical one mentioned above. Here my friend, Humberto Salazar Ibargüen, took the initiave. Professor Salazar obtained his Ph.D. working at the General Relativity Group of professor Jerzy Plebanski, at the Centro de Investigación y de Estudios Avanzados of IPN. He addressed the many technical problems, to build water tank detectors, with Cherenkov phototubes.

Eventually this work led to its inclusion, in the list of top ten best science breakthroughs of 2007 in Science Magazine.

I am happy to report news, for a bigger step forward for Mexican Cosmic Ray Physics, which owes a lot to my friend Humberto.

The HAWC experiment is actually in Puebla.

We can read from the link above.

The High Altitude Water Cherenkov Experiment or High Altitude Water Cherenkov Observatory (also known as HAWC) is a gamma-ray observatory located on the flanks of the Sierra Negra volcano in the Mexican state of Puebla at an altitude of 4100 meters, at 18°59′41″N 97°18′30.6″W. HAWC is the successor to the Milagro gamma-ray observatory in New Mexico, which was also a gamma-ray observatory based around the principle of detecting gamma-rays indirectly using the water Cherenkov method.

I am humbled by the work done by my friends in Mexico.

Arnulfo Zepeda told me that Manuel Sandoval Vallarta, conveyed to him, his wish, that Cosmic Ray Physics in Mexico must continue.

Professor Eduardo Piña Garza spent some time with us at Puebla. He had studied the motion of electrically charged particles in the Earth's magnetic field; continuing the work of Carlos Graef Fernández. I can attest to the high caliber of professor Piña, because I was fortunate to publish an article with him.

Mario Vázquez Reyna, and Manuel Sandoval Vallarta, would've been as happy as I am, for the Mexican contribution to Cosmic Ray Physics. 

World thinkers 2015: the results

Our top five thinkers: from left, Russell Brand, Naomi Klein, Thomas Piketty, Yanis Varoufakis and Paul Krugman. © David Fisher/Rex, Mars Jerome/JDD/SIPA/Rex, Ben Cawthra/Rex, P Anastasselis/Rex
With nearly 3,000 votes cast, the results of Prospect’s world thinkers 2015 poll are now in. Voters came to the Prospect website in large numbers through Twitter and Facebook, and from many countries around the world.
The top 10 of last year’s poll was dominated by thinkers—including the winner, economist and philosopher Amartya Sen—whose work focused on the social, political and environmental challenges posed by economic growth in the developing world. However, Sen and others, notably the economists Raghuram Rajan and Kaushik Basu, are absent from this year’s list, which rewards impact over the past 12 months. In their place in the top 10 are thinkers who are wrestling, in different ways, with the dysfunctions of what some persist in calling the “developed world.”
2014 was Thomas Piketty’s year—as of January 2015, his book Capital in the Twenty-First Century had sold a remarkable 1.5m copies worldwide in several languages—and this is reflected in the French economist’s position at the top of our list. The past year has also been one in which anxieties about the economic, social and political costs of inequality have moved up the political agenda.
Several of the other thinkers in the top 10—particularly Yanis Varoufakis, Naomi Klein, Paul Krugman and Russell Brand (whose inclusion on the original list of 50 attracted considerable media coverage,some of it even favourable)—share similar concerns. It is striking, too, that they are all, broadly speaking, on the political left. One economist who has spoken out against Piketty and in defence of the “1 per cent,” the American Greg Mankiw, came near the bottom of the poll.
As was the case last year, there are two women in the top 10, Klein and Arundhati Roy (in 2013, there were none). And the presence of Hilary Mantel, Rebecca Solnit and Mona Eltahawy in the top 20 suggests that feminist critique of various kinds is experiencing a resurgence.
Many thanks to all those who voted. Do let us know what you make of the results on Twitter @Prospect_UK or in the comments.

Tuesday, March 24, 2015

Charlatans, Cranks, and Cooling -

Charlatans, Cranks, and Cooling -

"Branko Milanovic notes Lee Kwan Yew’s explanation of the success of Singapore and other Asian economies; partly Confucian culture, partly air conditioning. If you’ve ever tried to walk around Singapore, you know whereof he speaks."

'via Blog this'

Monday, March 23, 2015

Hydrogen Bomb Physicist’s Book Runs Afoul of Energy Department -

Hydrogen Bomb Physicist’s Book Runs Afoul of Energy Department -

"PHILADELPHIA — For all its horrific power, the atom bomb — leveler of Hiroshima and instant killer of some 80,000 people — is but a pale cousin compared to another product of American ingenuity: the hydrogen bomb."

'via Blog this'

Monday, March 16, 2015

California has about one year of water left. Will you ration now? by Jay Famiglietti

Given the historic low temperatures and snowfalls that pummeled the eastern U.S. this winter, it might be easy to overlook how devastating California's winter was as well. As our “wet” season draws to a close, it is clear that the paltry rain and snowfall have done almost nothing to alleviate epic drought conditions. January was the driest in California since record-keeping began in 1895. Groundwater and snowpack levels are at all-time lows. We're not just up a creek without a paddle in California, we're losing the creek too.

 Data from NASA satellites show that the total amount of water stored in the Sacramento and San Joaquin river basins — that is, all of the snow, river and reservoir water, water in soils and groundwater combined — was 34 million acre-feet below normal in 2014. That loss is nearly 1.5 times the capacity of Lake Mead, America's largest reservoir.

Statewide, we've been dropping more than 12 million acre-feet of total water yearly since 2011. Roughly two-thirds of these losses are attributable to groundwater pumping for agricultural irrigation in the Central Valley. Farmers have little choice but to pump more groundwater during droughts, especially when their surface water allocations have been slashed 80% to 100%. But these pumping rates are excessive and unsustainable. Wells are running dry. In some areas of the Central Valley, the land is sinking by one foot or more per year.

As difficult as it may be to face, the simple fact is that California is running out of water — and the problem started before our current drought. NASA data reveal that total water storage in California has been in steady decline since at least 2002, when satellite-based monitoring began, although groundwater depletion has been going on since the early 20th century.

Right now the state has only about one year of water supply left in its reservoirs, and our strategic backup supply, groundwater, is rapidly disappearing. California has no contingency plan for a persistent drought like this one (let alone a 20-plus-year mega-drought), except, apparently, staying in emergency mode and praying for rain.

In short, we have no paddle to navigate this crisis.

Several steps need be taken right now. First, immediate mandatory water rationing should be authorized across all of the state's water sectors, from domestic and municipal through agricultural and industrial. The Metropolitan Water District of Southern California is already considering water rationing by the summer unless conditions improve. There is no need for the rest of the state to hesitate. The public is ready. A recent Field Poll showed that 94% of Californians surveyed believe that the drought is serious, and that one-third support mandatory rationing.

Second, the implementation of the Sustainable Groundwater Management Act of 2014 should be accelerated. The law requires the formation of numerous, regional groundwater sustainability agencies by 2017. Then each agency must adopt a plan by 2022 and “achieve sustainability” 20 years after that. At that pace, it will be nearly 30 years before we even know what is working. By then, there may be no groundwater left to sustain.

Third, the state needs a task force of thought leaders that starts, right now, brainstorming to lay the groundwork for long-term water management strategies. Although several state task forces have been formed in response to the drought, none is focused on solving the long-term needs of a drought-prone, perennially water-stressed California.

Our state's water management is complex, but the technology and expertise exist to handle this harrowing future. It will require major changes in policy and infrastructure that could take decades to identify and act upon. Today, not tomorrow, is the time to begin.

Finally, the public must take ownership of this issue. This crisis belongs to all of us — not just to a handful of decision-makers. Water is our most important, commonly owned resource, but the public remains detached from discussions and decisions.

This process works just fine when water is in abundance. In times of crisis, however, we must demand that planning for California's water security be an honest, transparent and forward-looking process. Most important, we must make sure that there is in fact a plan.

Call me old-fashioned, but I'd like to live in a state that has a paddle so that it might also still have a creek.

Jay Famiglietti is the senior water scientist at the NASA Jet Propulsion Laboratory/Caltech and a professor of Earth system science at UC Irvine.

The New Optimism of Al Gore -

The New Optimism of Al Gore -

"NASHVILLE — Al Gore wants to make a point about cellphones, and he has a helpful set of slides on his laptop. “Do you want to see that?” he asks, and starts to turn the MacBook around.


'via Blog this'

Friday, March 13, 2015

[1408.1934] A Rapidly Spinning Black Hole Powers the Einstein Cross

[1408.1934] A Rapidly Spinning Black Hole Powers the Einstein Cross:

 "Observations over the past 20 years have revealed a strong relationship between the properties of the supermassive black hole (SMBH) lying at the center of a galaxy and the host galaxy itself. The magnitude of the spin of the black hole will play a key role in determining the nature of this relationship. To date, direct estimates of black hole spin have been restricted to the local Universe. Herein, we present the results of an analysis of ∼ 0.5 Ms of archival Chandra observations of the gravitationally lensed quasar Q 2237+305 (aka the "Einstein-cross"), lying at a redshift of z = 1.695. The boost in flux provided by the gravitational lens allows constraints to be placed on the spin of a black hole at such high redshift for the first time. Utilizing state of the art relativistic disk reflection models, the black hole is found to have a spin of a∗=0.74+0.06−0.03 at the 90% confidence level. Placing a lower limit on the spin, we find a∗≥0.65 (4σ). The high value of the spin for the ∼109 M⊙ black hole in Q 2237+305 lends further support to the coherent accretion scenario for black hole growth. This is the most distant black hole for which the spin has been directly constrained to date."

'via Blog this'

Thursday, March 12, 2015

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