[1312.2007] The Amplituhedron:
"Perturbative scattering amplitudes in gauge theories have remarkable simplicity and hidden infinite dimensional symmetries that are completely obscured in the conventional formulation of field theory using Feynman diagrams. This suggests the existence of a new understanding for scattering amplitudes where locality and unitarity do not play a central role but are derived consequences from a different starting point. In this note we provide such an understanding for N=4 SYM scattering amplitudes in the planar limit, which we identify as ``the volume" of a new mathematical object--the Amplituhedron--generalizing the positive Grassmannian. Locality and unitarity emerge hand-in-hand from positive geometry."
'via Blog this'
Thursday, July 31, 2014
Why is Space 3D?
A friend got me thinking about this basic question, here I write ideas related to it.
There is a perception issue to begin with. If your rooms are not cubes, like most people's, from my city of birth, you may not know what 3D is. Then you have to go to a technical high school like I did, and then you learn everything about vectors, having fun with it, like I did. I still remember explaining to a friend, who was absent that day, these ideas. I was really excited. We had already studied Cartesian Geometry in a previous lesson. All the abstract frame, was in my head, by the time I was a teenager.
Now I am over sixty, and I still don't know, why it is so. I do not feel bad, because nobody does.
Now I know much more, I even personally met one actor of this narrative. Let me start there:
Manoj Prasad, was a very young, and famous person, when I met him. He discovered, with his professor Michael Sommerfield, what we now call, the Bogomol'nyi-Prasad-Sommerfield monopole. Neat exact solution, to a Non-Abelian field. To this day nobody has seen one of these, in the real world, so far it only exists in our minds.
As it turns out, these exact solutions exist in 3D, and through the magic of the gauge field, involve time as well. We know we live in 3 huge spatial dimensions, and something inside, or prior to us, maybe the so-called strings, has been around during a huge time. To be exact 13.798±0.037 billion years, according to Wikipedia.
Why?
It gets curiouser and curiouser, as Alice in Wonderland says.
Enter Roger Penrose, unfortunately I have not met him personally, but two friends did. One was his contemporary, Jerzy Plebanski, and the other is younger than I, Gerardo Torres del Castillo.
Penrose loved complex variables, like I did. He was studying mathematics in England, and had the insight, that a set of two complex manifolds together, would make a neat mathematical representation, of the four dimensional macroscopic space, we were born in. This proposal goes by the name of Twistor Theory.
To finish this note, I link to the computer calculations done by a Japanese group, as reported a few years back.
You can read about it in Discover Magazine.
There is a perception issue to begin with. If your rooms are not cubes, like most people's, from my city of birth, you may not know what 3D is. Then you have to go to a technical high school like I did, and then you learn everything about vectors, having fun with it, like I did. I still remember explaining to a friend, who was absent that day, these ideas. I was really excited. We had already studied Cartesian Geometry in a previous lesson. All the abstract frame, was in my head, by the time I was a teenager.
Now I am over sixty, and I still don't know, why it is so. I do not feel bad, because nobody does.
Now I know much more, I even personally met one actor of this narrative. Let me start there:
Manoj Prasad, was a very young, and famous person, when I met him. He discovered, with his professor Michael Sommerfield, what we now call, the Bogomol'nyi-Prasad-Sommerfield monopole. Neat exact solution, to a Non-Abelian field. To this day nobody has seen one of these, in the real world, so far it only exists in our minds.
As it turns out, these exact solutions exist in 3D, and through the magic of the gauge field, involve time as well. We know we live in 3 huge spatial dimensions, and something inside, or prior to us, maybe the so-called strings, has been around during a huge time. To be exact 13.798±0.037 billion years, according to Wikipedia.
Why?
It gets curiouser and curiouser, as Alice in Wonderland says.
Enter Roger Penrose, unfortunately I have not met him personally, but two friends did. One was his contemporary, Jerzy Plebanski, and the other is younger than I, Gerardo Torres del Castillo.
Penrose loved complex variables, like I did. He was studying mathematics in England, and had the insight, that a set of two complex manifolds together, would make a neat mathematical representation, of the four dimensional macroscopic space, we were born in. This proposal goes by the name of Twistor Theory.
To finish this note, I link to the computer calculations done by a Japanese group, as reported a few years back.
You can read about it in Discover Magazine.
[1312.7878] Into the Amplituhedron
[1312.7878] Into the Amplituhedron:
"We initiate an exploration of the physics and geometry of the amplituhedron, starting with the simplest case of the integrand for four-particle scattering in planar N=4 SYM. We show how the textbook structure of the unitarity double-cut follows from the positive geometry. We also use the geometry to expose the behavior of the multicollinear limit, providing a direct motivation for studying the logarithm of the amplitude. In addition to computing the two and three-loop integrands, we explore various lower-dimensional faces of the amplituhedron, thereby computing non-trivial cuts of the integrand to all loop orders."
'via Blog this'
"We initiate an exploration of the physics and geometry of the amplituhedron, starting with the simplest case of the integrand for four-particle scattering in planar N=4 SYM. We show how the textbook structure of the unitarity double-cut follows from the positive geometry. We also use the geometry to expose the behavior of the multicollinear limit, providing a direct motivation for studying the logarithm of the amplitude. In addition to computing the two and three-loop integrands, we explore various lower-dimensional faces of the amplituhedron, thereby computing non-trivial cuts of the integrand to all loop orders."
'via Blog this'
[hep-th/9707009] BPS Monopoles
[hep-th/9707009] BPS Monopoles:
"We review classical BPS monopoles, their moduli spaces, twistor descriptions and dynamics. Particular emphasis is placed upon symmetric monopoles, where recent progress has been made. Some remarks on the role of monopoles in S-duality and Seiberg-Witten theory are also made."
'via Blog this'
"We review classical BPS monopoles, their moduli spaces, twistor descriptions and dynamics. Particular emphasis is placed upon symmetric monopoles, where recent progress has been made. Some remarks on the role of monopoles in S-duality and Seiberg-Witten theory are also made."
'via Blog this'
[1210.3382] Generalized BPS magnetic monopoles
[1210.3382] Generalized BPS magnetic monopoles:
"We show the existence of Bogomol'nyi-Prasad-Sommerfield (BPS) magnetic monopoles in a generalized Yang-Mills-Higgs model which is controlled by two positive functions. This effective model, in principle, would describe the dynamics of the nonabelian fields in a chromoelectric media. We check the consistency of our generalized construction by analyzing an explicit case ruled by a real parameter. We also use the well-known spherically symmetric Ansatz to attain the corresponding self-dual equations describing the topological solutions. The overall conclusion is that the new solutions behave around the canonical one, with smaller or greater characteristic length."
'via Blog this'
"We show the existence of Bogomol'nyi-Prasad-Sommerfield (BPS) magnetic monopoles in a generalized Yang-Mills-Higgs model which is controlled by two positive functions. This effective model, in principle, would describe the dynamics of the nonabelian fields in a chromoelectric media. We check the consistency of our generalized construction by analyzing an explicit case ruled by a real parameter. We also use the well-known spherically symmetric Ansatz to attain the corresponding self-dual equations describing the topological solutions. The overall conclusion is that the new solutions behave around the canonical one, with smaller or greater characteristic length."
'via Blog this'
[0711.1037] Generalizations of MICZ-Kepler system
[0711.1037] Generalizations of MICZ-Kepler system:
"We discuss the generalizations of the MICZ-Kepler system (the system describing the motion of the charged particle in the field of Dirac dyon), to the curved spaces, arbitrary potentials and to the multi-dyon background."
'via Blog this'
"We discuss the generalizations of the MICZ-Kepler system (the system describing the motion of the charged particle in the field of Dirac dyon), to the curved spaces, arbitrary potentials and to the multi-dyon background."
'via Blog this'
[1004.4579] Generalized MICZ-Kepler system, duality, polynomial and deformed oscillator algebras
[1004.4579] Generalized MICZ-Kepler system, duality, polynomial and deformed oscillator algebras:
"We present the quadratic algebra of the generalized MICZ-Kepler system in three-dimensional Euclidean space E3 and its dual the four dimensional singular oscillator in four-dimensional Euclidean space E4. We present their realization in terms of a deformed oscillator algebra using the Daskaloyannis construction. The structure constants are in these cases function not only of the Hamiltonian but also of other integrals commuting with all generators of the quadratic algebra. We also present a new algebraic derivation of the energy spectrum of the MICZ-Kepler system on the three sphere S3 using a quadratic algebra. These results point out also that results and explicit formula for structure functions obtained for quadratic, cubic and higher order polynomial algebras in context of two-dimensional superintegrable systems may be applied to superintegrable systems in higher dimensions with and without monopoles."
'via Blog this'
"We present the quadratic algebra of the generalized MICZ-Kepler system in three-dimensional Euclidean space E3 and its dual the four dimensional singular oscillator in four-dimensional Euclidean space E4. We present their realization in terms of a deformed oscillator algebra using the Daskaloyannis construction. The structure constants are in these cases function not only of the Hamiltonian but also of other integrals commuting with all generators of the quadratic algebra. We also present a new algebraic derivation of the energy spectrum of the MICZ-Kepler system on the three sphere S3 using a quadratic algebra. These results point out also that results and explicit formula for structure functions obtained for quadratic, cubic and higher order polynomial algebras in context of two-dimensional superintegrable systems may be applied to superintegrable systems in higher dimensions with and without monopoles."
'via Blog this'
[1312.5415] A renormalization group method for studying the early universe in the Lorentzian IIB matrix model
[1312.5415] A renormalization group method for studying the early universe in the Lorentzian IIB matrix model:
"We propose a new method for studying the early universe in the Lorentzian version of the IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. This method is based on the idea of renormalization group, and it enables us to study the time-evolution of the universe for much longer time than in the previous work, which showed that the SO(9) rotational symmetry is spontaneously broken down to SO(3) after a "critical time". We demonstrate how this method works in a simplified model, which is expected to capture the behaviors of the original model when the space is not so large. In particular, we present clear evidence that the three-dimensional space expands exponentially after the critical time in this simplified model."
'via Blog this'
"We propose a new method for studying the early universe in the Lorentzian version of the IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. This method is based on the idea of renormalization group, and it enables us to study the time-evolution of the universe for much longer time than in the previous work, which showed that the SO(9) rotational symmetry is spontaneously broken down to SO(3) after a "critical time". We demonstrate how this method works in a simplified model, which is expected to capture the behaviors of the original model when the space is not so large. In particular, we present clear evidence that the three-dimensional space expands exponentially after the critical time in this simplified model."
'via Blog this'
Wednesday, July 30, 2014
U.S. Economy Grew at 4% Rate in Second Quarter, Beating Expectations - NYTimes.com
U.S. Economy Grew at 4% Rate in Second Quarter, Beating Expectations - NYTimes.com:
"The United States economy rebounded heartily in the spring after a dismal winter, the Commerce Department reported on Wednesday, growing at an annual rate of 4 percent from April through June and surpassing economists’ expectations."
'via Blog this'
"The United States economy rebounded heartily in the spring after a dismal winter, the Commerce Department reported on Wednesday, growing at an annual rate of 4 percent from April through June and surpassing economists’ expectations."
'via Blog this'
Tuesday, July 29, 2014
Why Can’t the Banking Industry Solve Its Ethics Problems? - NYTimes.com
Why Can’t the Banking Industry Solve Its Ethics Problems? - NYTimes.com:
"The financial crisis that nearly brought down the global economy was triggered in no small part by the aggressive culture and spotty ethics within the world’s biggest banks. But after six years and countless efforts to reform finance, the banking scandals never seem to end."
'via Blog this'
"The financial crisis that nearly brought down the global economy was triggered in no small part by the aggressive culture and spotty ethics within the world’s biggest banks. But after six years and countless efforts to reform finance, the banking scandals never seem to end."
'via Blog this'
Monday, July 28, 2014
Ultra-high-energy cosmic ray - Wikipedia, the free encyclopedia
Ultra-high-energy cosmic ray - Wikipedia, the free encyclopedia:
"In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray particle with a kinetic energy greater than 1018 eV, far beyond both its rest mass and energies typical of other cosmic ray particles."
'via Blog this'
"In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray particle with a kinetic energy greater than 1018 eV, far beyond both its rest mass and energies typical of other cosmic ray particles."
'via Blog this'
U.S. and Europe Agree to Escalate Sanctions on Russia - NYTimes.com
U.S. and Europe Agree to Escalate Sanctions on Russia - NYTimes.com:
"FRANKFURT — The United States and Europe put aside their differences and agreed on Monday to sharply escalate economic sanctions against Russia in a set of coordinated actions driven by the conclusion that Moscow has taken a more direct role in the war in Ukraine."
'via Blog this'
"FRANKFURT — The United States and Europe put aside their differences and agreed on Monday to sharply escalate economic sanctions against Russia in a set of coordinated actions driven by the conclusion that Moscow has taken a more direct role in the war in Ukraine."
'via Blog this'
Sunday, July 27, 2014
Tax Avoidance du Jour: Inversion - NYTimes.com
Tax Avoidance du Jour: Inversion - NYTimes.com:
"In recent decisions, the conservative majority on the Supreme Court has made clear its view that corporations are people, with all the attendant rights. They are entitled to free speech, which in their case means spending lots of money to bend the political process to their ends. They are entitled to religious beliefs, including those that mean denying benefits to their workers. Up next, the right to bear arms?"
'via Blog this'
"In recent decisions, the conservative majority on the Supreme Court has made clear its view that corporations are people, with all the attendant rights. They are entitled to free speech, which in their case means spending lots of money to bend the political process to their ends. They are entitled to religious beliefs, including those that mean denying benefits to their workers. Up next, the right to bear arms?"
'via Blog this'
After Rejecting a Cease-Fire, Hamas Proposes a New One - NYTimes.com
After Rejecting a Cease-Fire, Hamas Proposes a New One - NYTimes.com:
"JERUSALEM — Israel and Hamas went back and forth on Sunday over proposals for a humanitarian lull in the fighting in Gaza, underscoring the external and internal pressures on both sides."
'via Blog this'
"JERUSALEM — Israel and Hamas went back and forth on Sunday over proposals for a humanitarian lull in the fighting in Gaza, underscoring the external and internal pressures on both sides."
'via Blog this'
Eight hundred dead Palestinians. But Israel has impunity - Comment - Voices - The Independent
Eight hundred dead Palestinians. But Israel has impunity - Comment - Voices - The Independent:
"Impunity is the word that comes to mind. Eight hundred dead Palestinians. Eight hundred. That’s infinitely more than twice the total dead of flight MH17 over Ukraine. And if you refer only to the “innocent” dead – ie no Hamas fighters, young sympathisers or corrupt Hamas officials, with whom the Israelis will, in due course, have to talk – then the women and children and elderly who have been slaughtered in Gaza are still well over the total number of MH17 victims."
'via Blog this'
"Impunity is the word that comes to mind. Eight hundred dead Palestinians. Eight hundred. That’s infinitely more than twice the total dead of flight MH17 over Ukraine. And if you refer only to the “innocent” dead – ie no Hamas fighters, young sympathisers or corrupt Hamas officials, with whom the Israelis will, in due course, have to talk – then the women and children and elderly who have been slaughtered in Gaza are still well over the total number of MH17 victims."
'via Blog this'
Saturday, July 26, 2014
What Is News? - NYTimes.com
What Is News? - NYTimes.com:
"FORT-DAUPHIN, Madagascar — WITH the world going crazy, I tried running away from the news. It didn’t work."
'via Blog this'
"FORT-DAUPHIN, Madagascar — WITH the world going crazy, I tried running away from the news. It didn’t work."
'via Blog this'
Why the Border Crisis Is a Myth - NYTimes.com
Why the Border Crisis Is a Myth - NYTimes.com:
"EL PASO — TO hear the national news media tell the story, you would think my city, El Paso, and others along the Texas-Mexico border were being overrun by children — tens of thousands of them, some with their mothers, arriving from Central America in recent months, exploiting an immigration loophole to avoid deportation and putting a fatal strain on border state resources."
'via Blog this'
"EL PASO — TO hear the national news media tell the story, you would think my city, El Paso, and others along the Texas-Mexico border were being overrun by children — tens of thousands of them, some with their mothers, arriving from Central America in recent months, exploiting an immigration loophole to avoid deportation and putting a fatal strain on border state resources."
'via Blog this'
Militants Resume Firing Rockets Into Israel From Gaza - NYTimes.com
Militants Resume Firing Rockets Into Israel From Gaza - NYTimes.com:
"GAZA — Militants resumed firing rockets into Israel from Gaza around two hours after the end of a 12-hour ceasefire, the armed wing of Islamist group Hamas said."
'via Blog this'
"GAZA — Militants resumed firing rockets into Israel from Gaza around two hours after the end of a 12-hour ceasefire, the armed wing of Islamist group Hamas said."
'via Blog this'
A Brief Cease-Fire Gives Gazans and Israelis a Chance to Take Stock - NYTimes.com
A Brief Cease-Fire Gives Gazans and Israelis a Chance to Take Stock - NYTimes.com:
"BEIT HANOUN, Gaza Strip — Families across the Gaza Strip emerged from shelters and returned to their homes during a 12-hour cease-fire on Saturday to survey the damage to their neighborhoods, collect belongings and help dig bodies from the rubble, as Secretary of State John Kerry met in Paris with Arab and European diplomats to urge that the humanitarian truce be extended for at least another 12 hours."
'via Blog this'
"BEIT HANOUN, Gaza Strip — Families across the Gaza Strip emerged from shelters and returned to their homes during a 12-hour cease-fire on Saturday to survey the damage to their neighborhoods, collect belongings and help dig bodies from the rubble, as Secretary of State John Kerry met in Paris with Arab and European diplomats to urge that the humanitarian truce be extended for at least another 12 hours."
'via Blog this'
Friday, July 25, 2014
Death in the Peace Corps: A Trail of Medical Missteps - NYTimes.com
Death in the Peace Corps: A Trail of Medical Missteps - NYTimes.com:
"BRENTWOOD, Calif. — Nick Castle had just graduated from the University of California, Berkeley, when he loaded up his backpack with Mandarin-language books and set off for rural China to teach in the Peace Corps. Seven months later, in January 2013, a 2 a.m. telephone call jolted his parents awake."
'via Blog this'
"BRENTWOOD, Calif. — Nick Castle had just graduated from the University of California, Berkeley, when he loaded up his backpack with Mandarin-language books and set off for rural China to teach in the Peace Corps. Seven months later, in January 2013, a 2 a.m. telephone call jolted his parents awake."
'via Blog this'
As Ukraine Forces Make Headway, Russia Is Said to Step Up Role - NYTimes.com
As Ukraine Forces Make Headway, Russia Is Said to Step Up Role - NYTimes.com:
"KIEV, Ukraine — Russia has stepped up its direct involvement in fighting between the Ukranian military and separatist insurgents, unleashing artillery attacks from Russian territory and massing heavy weapons along the border, Ukrainian and American officials say."
'via Blog this'
"KIEV, Ukraine — Russia has stepped up its direct involvement in fighting between the Ukranian military and separatist insurgents, unleashing artillery attacks from Russian territory and massing heavy weapons along the border, Ukrainian and American officials say."
'via Blog this'
Thursday, July 24, 2014
Don’t Teach Math, Coach It - NYTimes.com
Don’t Teach Math, Coach It - NYTimes.com:
"MADISON, Wis. — PEOPLE ask me all the time how they can get their kids excited about math. That ought to be a softball for me, because I teach math for a living. I wake up excited about math."
'via Blog this'
"MADISON, Wis. — PEOPLE ask me all the time how they can get their kids excited about math. That ought to be a softball for me, because I teach math for a living. I wake up excited about math."
'via Blog this'
Left Coast Rising - NYTimes.com
Left Coast Rising - NYTimes.com:
"The states, Justice Brandeis famously pointed out, are the laboratories of democracy. And it’s still true. For example, one reason we knew or should have known that Obamacare was workable was the post-2006 success of Romneycare in Massachusetts. More recently, Kansas went all-in on supply-side economics, slashing taxes on the affluent in the belief that this would spark a huge boom; the boom didn’t happen, but the budget deficit exploded, offering an object lesson to those willing to learn from experience."
'via Blog this'
"The states, Justice Brandeis famously pointed out, are the laboratories of democracy. And it’s still true. For example, one reason we knew or should have known that Obamacare was workable was the post-2006 success of Romneycare in Massachusetts. More recently, Kansas went all-in on supply-side economics, slashing taxes on the affluent in the belief that this would spark a huge boom; the boom didn’t happen, but the budget deficit exploded, offering an object lesson to those willing to learn from experience."
'via Blog this'
Study Gives Hope of Adaptation to Climate Change - NYTimes.com
Study Gives Hope of Adaptation to Climate Change - NYTimes.com:
"As we pour heat-trapping gases into the air, we’re running an experiment. We’re going to see what a rapidly changing climate does to the world’s biodiversity—how many species shift to new ranges, how many adapt to their new environment and how many become extinct."
'via Blog this'
"As we pour heat-trapping gases into the air, we’re running an experiment. We’re going to see what a rapidly changing climate does to the world’s biodiversity—how many species shift to new ranges, how many adapt to their new environment and how many become extinct."
'via Blog this'
Obama to Urge End to Loophole Letting Firms Shield Profits Abroad - NYTimes.com
Obama to Urge End to Loophole Letting Firms Shield Profits Abroad - NYTimes.com:
"LOS ANGELES — President Obama on Thursday will call for Congress to end a tax loophole that allows big corporations to designate a foreign country as their official address, avoiding American taxes while maintaining their presence in the United States."
'via Blog this'
"LOS ANGELES — President Obama on Thursday will call for Congress to end a tax loophole that allows big corporations to designate a foreign country as their official address, avoiding American taxes while maintaining their presence in the United States."
'via Blog this'
Ukraine Prime Minister Resigns, as Kiev Moves Toward Elections - NYTimes.com
Ukraine Prime Minister Resigns, as Kiev Moves Toward Elections - NYTimes.com:
"KIEV, Ukraine — Prime Minister Arseniy P. Yatsenyuk, a pro-Western technocrat who has guided the Ukrainian government through the tumultuous months since the ouster of President Viktor F. Yanukovyvch, resigned abruptly on Thursday, after the governing coalition of Parliament collapsed."
'via Blog this'
"KIEV, Ukraine — Prime Minister Arseniy P. Yatsenyuk, a pro-Western technocrat who has guided the Ukrainian government through the tumultuous months since the ouster of President Viktor F. Yanukovyvch, resigned abruptly on Thursday, after the governing coalition of Parliament collapsed."
'via Blog this'
Wednesday, July 23, 2014
An Idiot’s Guide to Inequality - NYTimes.com
An Idiot’s Guide to Inequality - NYTimes.com:
"We may now have a new “most unread best seller of all time.”
Data from Amazon Kindles suggests that that honor may go to Thomas Piketty’s “Capital in the Twenty-First Century,” which reached No. 1 on the best-seller list this year. Jordan Ellenberg, a professor of mathematics at the University of Wisconsin, Madison, wrote in The Wall Street Journal that Piketty’s book seems to eclipse its rivals in losing readers: All five of the passages that readers on Kindle have highlighted most are in the first 26 pages of a tome that runs 685 pages."
'via Blog this'
"We may now have a new “most unread best seller of all time.”
Data from Amazon Kindles suggests that that honor may go to Thomas Piketty’s “Capital in the Twenty-First Century,” which reached No. 1 on the best-seller list this year. Jordan Ellenberg, a professor of mathematics at the University of Wisconsin, Madison, wrote in The Wall Street Journal that Piketty’s book seems to eclipse its rivals in losing readers: All five of the passages that readers on Kindle have highlighted most are in the first 26 pages of a tome that runs 685 pages."
'via Blog this'
Open Source and the Challenge of Making Money - NYTimes.com
Open Source and the Challenge of Making Money - NYTimes.com:
"Remember how the open source software movement was supposed to be like Woodstock, with everybody sharing and everything free? An entire economy where you gave a little to get a lot, in a place of love and software?"
'via Blog this'
"Remember how the open source software movement was supposed to be like Woodstock, with everybody sharing and everything free? An entire economy where you gave a little to get a lot, in a place of love and software?"
'via Blog this'
Why Do Americans Stink at Math? - NYTimes.com
Why Do Americans Stink at Math? - NYTimes.com:
"When Akihiko Takahashi was a junior in college in 1978, he was like most of the other students at his university in suburban Tokyo. He had a vague sense of wanting to accomplish something but no clue what that something should be. But that spring he met a man who would become his mentor, and this relationship set the course of his entire career."
'via Blog this'
"When Akihiko Takahashi was a junior in college in 1978, he was like most of the other students at his university in suburban Tokyo. He had a vague sense of wanting to accomplish something but no clue what that something should be. But that spring he met a man who would become his mentor, and this relationship set the course of his entire career."
'via Blog this'
Tuesday, July 22, 2014
War and Media in the Gaza Strip - NYTimes.com
War and Media in the Gaza Strip - NYTimes.com:
"Alleged gunfire at an Al Jazeera bureau in Gaza on Tuesday was hardly a boon to the Israeli Defense Forces’ public image – and this was only the latest installment in a string of P.R. debacles facing the Jewish state."
'via Blog this'
"Alleged gunfire at an Al Jazeera bureau in Gaza on Tuesday was hardly a boon to the Israeli Defense Forces’ public image – and this was only the latest installment in a string of P.R. debacles facing the Jewish state."
'via Blog this'
Monday, July 21, 2014
Capital in the Twenty-First Century (II)
List of some authors presented by Piketty in his Introduction:
These are not all, he presents a view of the European world in its transit from Feudalism to Capitalism. He emphasizes the lack of data of previous authors, and tools to use them. Armed with these data he was able to discover, what he calls "The Fundamental Force for Divergence: 
.
This is not an equation of Nature, like Newton's equations of motion, it rather expresses an empirical fact. For all the data he has compiled, the rate of capital reproduction, r, is bigger than the rate of growth, g. One simple way to state it, is that one is better off with acquired capital, than working for a salary. He predicts that if nothing is done about this, i.e. tax regulations, inequality will keep growing, with possible destabilizing effects.
More Eyes on the Skies
The future, it is often said, belongs to those who plan for it. And astronomers have been busy working the proverbial smoke-filled rooms (or whatever passes for them today) where the destiny of big science is often shaped and crisscrossing one another in airports on fund-raising trips. Now they are about to have something to show for it.
More than a decade after competing groups set out to raise money forgargantuan telescopes that could study planets around distant stars and tune into the birth of galaxies at the dawn of time, shovels, pickaxes and more sophisticated tools are now about to go to work on mountaintops in Hawaii and Chile in what is going to be the greatest, most expensive and ambitious spree of telescope-making in the history of astronomy.
If it all plays out as expected and budgeted, astronomers of the 2020s will be swimming in petabytes of data streaming from space and the ground. Herewith a report card on the future of big-time stargazing.
On June 20, officials from the European Southern Observatory blew the top off a mountain in northern Chile called Armazones, breaking ground for what is planned to be the largest, most powerful optical telescope ever built. Known as the European Extremely Large Telescope, or E-ELT, it will have a segmented mirror 39 meters (about 128 feet) in diameter, powerful enough to see planets around distant stars. By comparison, the largest telescopes now operating are 10 meters in diameter.
The European Southern Observatory is a consortium of 14 European nations and Brazil, which has agreed to join but is still waiting for its Parliament to ratify the move. Brazil’s official entrance would put the group more than 90 percent of the way toward the $1.5 billion in 2012 dollars the telescope is projected to cost, enough to begin big-ticket items like a dome, said Lars Christensen, a spokesman for the consortium.
The telescope should be ready on June 19, 2024. “We’ll all be back here,” said Tim de Zeeuw, the group’s director general, at the groundbreaking.
That’s not the only mega telescope project out there. Two years ago, another group of astronomers blasted away the top of another mountain in Chile, Las Campanas, where they plan to build the Giant Magellan Telescope. That telescope will have at its heart a set of seven eight-meter mirrors ganged together to make the equivalent of a mirror 25 meters in diameter. Three of those mirrors have been cast and polished at the University of Arizona, one of nine institutions that make up the Giant Magellan organization. A fourth mirror is on order for next year.
Wendy Freedman, the director of the Carnegie Observatories, one of the spearheads of the Magellan collaboration, said by email that members were now in the final phases of forming a limited liability corporation, the legal and financial entity that will build and own the telescope. To date, the group has raised about $500 million of the $880 million (2012 dollars) needed for their telescope.
She expects construction to begin later this year. “Our plan is to be on the air with the first four mirrors taking early science data in 2021,” she said. “So things are continuing to go very well.”
In Hawaii, there will be no blasting needed, just some grading with a bulldozer, on Mauna Kea, where yet another group of astronomers plans to build a telescope 30 meters in diameter — the simply namedThirty Meter Telescope — on a plateau just below the nearly 14,000-foot summit. Mauna Kea, the highest peak in the Pacific, is already home to 12 telescopes, including the twin 10-meter telescopes at theKeck observatory and a pair of eight-meters, making it the busiest mountain in astronomy.
It is also a sacred place for Hawaiians, many of whose ancestors have been buried up there. As a result, it’s not so easy gaining permission to add yet another telescope, said Michael Bolte of the University of California, Santa Cruz, a co-director of the project, an international collaboration led by Caltech and the University of California and now doing business as Thirty Meter Telescope International Observatory LLC.
Partners in Telescope Making
A billion-dollar telescope capable of outperforming Hubble can’t be built by a backyard stargazer or even a single university. The Thirty Meter Telescope in Hawaii and the Giant Magellan in Chile, both now on the verge of construction, are the products of international teams that have pursued their dreams even through a global recession.
“I think we’re finally free and clear to build on that site,” Dr. Bolte said in an interview, saying they had chosen an unobtrusive spot for the telescope. He expects to begin grading a road to the site this summer as soon as the project clears its last hurdle with the Hawaiian authorities.
The Thirty Meter Telescope will cost $1.2 billion in those same 2012 dollars. By early next year, when India and Canada are expected to become full members of the corporation, Dr. Bolte said, they will have 85 percent of the money needed; they are still looking for more partners. A grand groundbreaking ceremony is being scheduled for Oct. 7.
“It’s a crazy science,” Dr. Bolte said, ticking off the names of historical benefactors of astronomy and telescope financiers, “that facilities at the forefront tend to be built with private money,” something that rarely happens in, say, physics.
Big Mirrors, Big Views
The view from these new telescopes, astronomers say, should be spectacular.
A telescope’s ability to gather light is determined by the area of its primary mirror. For a long time, the five-meter Hale reflector on Palomar Mountain, in San Diego County, was considered the practical earthly limit, but in the 1980s, astronomers devised ways to build bigger, thinner, mirrors that would not sag, leading to a bevy of eight-meter mirrors as well as the two 10-meter Kecks. The Magellan, the smallest of the new breed, however, will be six times as powerful as the Kecks in scooping up distant dim starlight; the others will be even more powerful.
The Hubble Space Telescope is only 94 inches, about 2.4 meters in diameter. It gains its power not from size but from being above the atmosphere, which blurs and filters the light from stars.
Increasing their powers even more, the new telescopes will be equipped with a technology that did not exist the last time around: adaptive optics, the ability to adjust the shape of the mirrors to minimize or cancel the effects of the atmospheric turbulence that causes stars to twinkle. The result, astronomers say, is that these telescopes will be able to detect fainter objects than Hubble can, like planets or bits of galaxies coming together, and more clearly.
A Boom in Chile
The inauguration of these new telescopes, early in the next decade, will further enshrine the Atacama Desert in Chile, which is bone-dry, high, dark and blessed with remarkably steady air, as the center of world astronomy. The region already is home to, among other observatories, the Atacama Large Millimeter/sub-millimeter Array, or ALMA, an international project that is the world’s most expensive radio telescope, and the European Southern Observatory’s Very Large Telescope, an array of four eight-meter telescopes near the site of the coming Extremely Large Telescope.
The whole neighborhood, in fact, is booming. But for red tape, construction was also supposed to have started this month on theLarge Synoptic Survey Telescope on Pachón Mountain, in, yes, Chile. That telescope, a joint project of the National Science Foundation and the Department of Energy, is eight meters in diameter. That mountain was dynamited back in 2011. The project director, Steve Kahn of Stanford, said that a news release was already written and waiting for the moment when the project, officially the LSST Corporation, receives formal approval from the National Science Foundation to start spending money.
“I am sure we will get started officially soon, but unfortunately, this process isn’t over until it is over,” Dr. Kahn wrote in an email.
A ceremony for laying the “first stone” is planned for next spring in Chile, he said.
The National Science Foundation has budgeted $473 million to build the telescope. The Energy Department is kicking in $165 million for a 3,200-megapixel camera, which will produce an image of the entire sky every few days and over 10 years will produce a movie of the universe, swamping astronomers with data that will enable them to spot everything that moves or blinks in the heavens, including asteroids and supernova explosions.
Among the Stars
What about outer space, where the stars actually are?
It was front-page news two years ago when the National Reconnaissance Office, which operates spy satellites,gave NASA two space telescopes the same size and design as a Hubble that had been sitting in a warehouse. Some astronomers, notably the former astronaut and Hubble repairman John M. Grunsfeld, NASA’s associate administrator for science mission, suggested that one of these could be used to jump-start a mission to study dark energy.
The National Academy of Sciences had ranked that mission atop the to-do list for this decade, but it was ambushed by the rising cost of NASA’s James Webb Space Telescope (more on that later).
A committee from the academy has recently endorsed the idea of using the spy telescope, which is 2.4 meters in diameter, for the mission, instead of the originally envisioned one-meter telescope. The academy agreed that the bigger telescope would enhance the scientific returns of the mission, now known as Wfirst-AFTA, for Wide Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets, but warned that it could increase the cost and complexity. Congress directed NASA to spend $56 million on the mission in the last fiscal year, 2014, and the proposed budget for 2015 includes about $14 million.
If this keeps up, said David Spergel, an astronomer at Princeton who is involved with the academy and the telescope, the mission could start as early as 2023, near the time the European Space Agency will send up its own dark energy probe, known as Euclid. By then, he said, the mission’s name would probably be less of a mouthful. “The good thing about Wfirst-AFTA,” Dr. Spergel wrote in an email, “is that there is no way that we will keep that name.”
Among the possibilities that NASA is studying closely is adding a coronagraph to the telescope. Coronagraphs are basically opaque disks that were invented to black the intense light from the sun so astronomers could study the feathery faint corona of hot gases streaming outward from it. Exoplanet hunters are eager to deploy them to look for planets around distant stars. Getting a coronagraph on the dark energy telescope would be a valuable step toward a future mission, once known as the Terrestrial Planet Finder and now known by the placeholder name of New Worlds Telescope, long a dream of exoplanet hunters, that would be able to study Earthlike planets for signs of habitability, weather and life.
And then there is the most expensive and high-flying “big eye” of all, NASA’s James Webb Space Telescope, which Nature magazine once called “the telescope that ate astronomy.” Named for a former administrator of NASA, it is the successor to Hubble (which is still going strong, thank you), but is almost three times its size, with a 6.5-meter-diameter mirror that will have to fold out like a flower in orbit.
The Webb telescope was supposed to be launched this year, but was late and burned past its $5 billion budget like one of NASA’s rockets, devouring money that could have gone toward other projects. The House Appropriations Committee once voted to cancel it, but the project was reinstated with a budget cap of $8 billion and a launch date of 2018.
Since then, no news has basically been good news for Webb. It is still on track for 2018, NASA says. In July the agency reported that it had finished testing the framework that will hold the leaves of the telescope mirror and scientific instruments in place.
Heat and Light
The Webb telescope was built to study the first stars and galaxies that emerged in the hundred million years or so after the Big Bang, a missing period in cosmic history. It is therefore designed to record infrared radiation rather than visible light because objects at that distance and vintage are flying away from us so fast, by the rules of the expanding universe, that their light has been “redshifted” to longer wavelengths.
As it happens, infrared, or heat radiation, is an excellent way to study planets, which tend to emit more heat than light. Astronomers have long hoped that spectroscopic observations of an exoplanet atmosphere might reveal the signatures of life, such as oxygen or chlorophyll.
Recently, some astronomers have suggested they might even be able to see industrial pollution as well, in particular chlorofluorocarbons, the greenhouse gases that also destroy ozone. Over a few millenniums of industry, the thinking goes, some of these gases could build up to levels detectable from far away and stay that way for 50,000 years.
It would be ominous, however, Henry W. Lin, a student at Harvard, and his colleagues wrote in a paper submitted to The Monthly Notices of the Royal Astronomical Society, if astronomers see the markers of pollution around some distant planet but no indications of present life. That detection, they wrote, “might serve as an additional warning to the ‘intelligent’ life here on Earth about the risks of industrial pollution.” The future belongs to those who plan and care for it.
Last but hardly least is the Hubble Space Telescope, which has been providing humanity with matchless cosmic postcards from its perch above the sky ever since it was launched in 1990 and first fixed in 1993. Hubble was last visited and serviced by astronauts — presumably for the final time — in 2009. Matt Mountain, the director of the Space Telescope Science Institute, reports that it is doing well. A recent NASA review concluded, he said in an email, that “Hubble is operating at or near the highest level of performance and scientific productivity in its history.”
Recent estimates of its orbit suggest that it will re-enter Earth’s atmosphere no earlier than 2027 and may probably stay up well into the 2030s. Its main instruments are likely to still be working in 2020. That means the Hubble will still be operational when the Webb telescope goes up in 2018.
“It looks like it,” Dr. Mountain said. “We are certainly setting our planning that way.”
Capital in the Twenty-First Century (I)
Thomas Piketty has started a conversation. I am just one, among the hundreds of participants. I wrote an introductory note, here. This is the second of a series. The Contents of the book is as follows:
Acknowledgements ' vii
Introduction ' 1
Part One: Income and Capital
1. Income and Output ' 19
2. Growth: Illusions and Realities ' 72
Part Two: The Dynamics of the Capital/Income Ratio
3. The Metamorphoses of Capital ' 113
4. From Old Europe to the New World ' 140
5. The Capital/Income Ratio over the Long Run ' 164
6. The Capital-Labor Split in the Twenty-First Century ' 199
Part Three: The Structure of Inequality
7. Inequality and Concentration: Preliminary Bearings ' 237
8. Two Worlds ' 271
9. Inequality of Labor Income ' 304
10. Inequality of Capital Ownership ' 336
11. Merit and Inheritance in the Long Run ' 377
12. Global Inequality of Wealth in the Twenty-First Century ' 430
Part Four: Regulating Capital in the Twenty-First Century
13. A Social State for the Twenty-First Century ' 471
14. Rethinking the Progressive Income Tax ' 493
15. A Global Tax on Capital ' 515
16. The Question of the Public Debt ' 540
Conclusion ' 571
Notes ' 579
Contents in Detail ' 657
List of Tables and Illustrations ' 665
Index ' 671
The book is entertaining, with examples taken from popular culture, both modern, and from centuries back. I in particular liked his mention of Forbes Magazine list of billionaires. He mentions, both Carlos Slim, and Bill Gates, without getting into a debate about who deserves what, and more interested in how the accumulation of capital happened.
I consider this to be a very important work. I illustrate with one thought. A week from now, we are remembering the catastrophic decision by a few men to go to war a hundred years ago. That year, the distribution of wealth, was similar to what we have now, after a lull in the accumulation of capital, the world witnessed the creation of a huge middle class in Europe and the US, but now we are back to those levels of inequality that might have caused the war: Who assures us, that the same type of men, won't take us to war over Ukraine or Israel now?
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