Maxwell’s equations: 150 years of light

Note:  This item comes from friend Mike Cheponis.  DLH]

Maxwell’s equations: 150 years of light
A century and a half ago, James Clerk Maxwell submitted a long paper to the Royal Society containing his famous equations. Inspired by Michael Faraday’s experiments and insights, the equations unified electricity, magnetism and optics. Their far-reaching consequences for our civilisation, and our universe, are still being explored
By Jon Butterworth
Nov 22 2015

The chances are that you are reading this article on some kind of electronic technology. You are definitely seeing it via visible light, unless you have a braille or audio converter. And it probably got to you via wifi or a mobile phone signal. All of those things are understood in terms of the relationships between electric charges and electric and magnetic fields summarised in Maxwell’s equations, published by the Royal Society in 1865, 150 years ago.

Verbally, the equations can be summarised as something like:
Electric and magnetic fields make electric charges move. Electric charges cause electric fields, but there are no magnetic charges. Changes in magnetic fields cause electric fields, and vice versa.

The equations specify precisely how it all happens, but that is the gist of it.

Last week I was at a meeting celebrating the anniversary at the Royal Society in London, and was privileged to see the original manuscript, which is not generally on public view.

It was submitted in 1864 but, in a situation familiar to scientists everywhere, was held up in peer review. There’s a letter, dated March 1865, from William Thomson (later Lord Kelvin) saying he was sorry for being slow, that he’d read most of it and it seemed pretty good (“decidely suitable for publication”).

The equations seem to have been very much a bottom-up affair, in that Maxwell collected together a number of known laws which were used to describe various experimental results, and (with a little extra ingredient of his own) fitted them into a unified framework. What is amazing is how much that framework then reveals, both in terms of deep physical principles, and rich physical phenomena.

Fields and Waves

The equations show that electric and magnetic fields can exist even in the absence of electric charges. A changing electric field causes a changing magnetic field, which will cause more changes in the electric field, and so on. Mathematically this is expressed in the fact that the equations can be rearranged and combined to get a new kind of equation, that describes a travelling wave. So not only do the fields become real physical objects – something that Faraday was the first to propose – but they can carry travelling waves. Those waves are electromagnetic radiation. That is, visible light, radio, wifi, X-rays and the rest, depending on the wavelength.


The equations work in three dimensions, and relate fields pointing in different directions to each other. So the electric field in north-south direction depends upon what the magnetic field in the east-west direction is doing, for example. Maxwell wrote it all out component-by-component, direction-by-direction, in twenty seperate equations. These days we use vectors (objects with a length and an orientation, like an arrow) to condense the equations down to four. This makes a symmetry of the equations apparent. Like a sphere, they are the same from any angle. If I rotate the directions so that north becomes east, or southwest, or whatever, so long as I rotate all the axes together, nothing changes and the same equations still work.

Even more than this rotational symmetry, the equations stay the same if I boost my speed. And in particular, the speed of those waves described above stays the same. That is, the speed of light is the same for me, you and everyone, even if we are moving at different speeds relative to each other. This violates Newtonian mechanics, and it required Einstein and his relativity (for which the universality of the speed of light in a vacuum is a founding principle) to sort it out.


Who Turned My Blue State Red?

[Note:  This item comes from friend David Rosenthal.  DLH]

Who Turned My Blue State Red?
Why poor areas vote for politicians who want to slash the safety net.
Nov 20 2015

IT is one of the central political puzzles of our time: Parts of the country that depend on the safety-net programs supported by Democrats are increasingly voting for Republicans who favor shredding that net.

In his successful bid for the Senate in 2010, the libertarian Rand Paul railed against “intergenerational welfare” and said that “the culture of dependency on government destroys people’s spirits,” yet racked up winning margins in eastern Kentucky, a former Democratic stronghold that is heavily dependent on public benefits. Last year, Paul R. LePage, the fiercely anti-welfare Republican governor of Maine, was re-elected despite a highly erratic first term — with strong support in struggling towns where many rely on public assistance. And earlier this month, Kentucky elected as governor a conservative Republican who had vowed to largely undo the Medicaid expansion that had given the state the country’s largest decrease in the uninsured under Obamacare, with roughly one in 10 residents gaining coverage.

It’s enough to give Democrats the willies as they contemplate a map where the red keeps seeping outward, confining them to ever narrower redoubts of blue. The temptation for coastal liberals is to shake their heads over those godforsaken white-working-class provincials who are voting against their own interests.

But this reaction misses the complexity of the political dynamic that’s taken hold in these parts of the country. It misdiagnoses the Democratic Party’s growing conundrum with working-class white voters. And it also keeps us from fully grasping what’s going on in communities where conditions have deteriorated to the point where researchers have detected alarming trends in their mortality rates.

In eastern Kentucky and other former Democratic bastions that have swung Republican in the past several decades, the people who most rely on the safety-net programs secured by Democrats are, by and large, not voting against their own interests by electing Republicans. Rather, they are not voting, period. They have, as voting data, surveys and my own reporting suggest, become profoundly disconnected from the political process.

The people in these communities who are voting Republican in larger proportions are those who are a notch or two up the economic ladder — the sheriff’s deputy, the teacher, the highway worker, the motel clerk, the gas station owner and the coal miner. And their growing allegiance to the Republicans is, in part, a reaction against what they perceive, among those below them on the economic ladder, as a growing dependency on the safety net, the most visible manifestation of downward mobility in their declining towns.

These are voters like Pamela Dougherty, a 43-year-old nurse I encountered at a restaurant across from a Walmart in Marshalltown, Iowa, where she’d come to hear Rick Santorum, the conservative former Pennsylvania senator with a working-class pitch, just before the 2012 Iowa caucuses. In a lengthy conversation, Ms. Dougherty talked candidly about how she had benefited from government support. After having her first child as a teenager, marrying young and divorcing, Ms. Dougherty had faced bleak prospects. But she had gotten safety-net support — most crucially, taxpayer-funded tuition breaks to attend community college, where she’d earned her nursing degree.


Quantum entanglement achieved at room temperature in semiconductor wafers

Note:  This item comes from friend David Rosenthal.  DLH]

Quantum entanglement achieved at room temperature in semiconductor wafers
Nov 20 2015

Entanglement is one of the strangest phenomena predicted by quantum mechanics, the theory that underlies most of modern physics. It says that two particles can be so inextricably connected that the state of one particle can instantly influence the state of the other, no matter how far apart they are.

Just one century ago, entanglement was at the center of intense theoretical debate, leaving scientists like Albert Einstein baffled. Today, however, entanglement is accepted as a fact of nature and is actively being explored as a resource for future technologies including quantum computers, quantum communication networks, and high-precision quantum sensors.

Entanglement is also one of nature’s most elusive phenomena. Producing entanglement between particles requires that they start out in a highly ordered state, which is disfavored by thermodynamics, the process that governs the interactions between heat and other forms of energy. This poses a particularly formidable challenge when trying to realize entanglement at the macroscopic scale, among huge numbers of particles.

“The macroscopic world that we are used to seems very tidy, but it is completely disordered at the atomic scale. The laws of thermodynamics generally prevent us from observing quantum phenomena in macroscopic objects,” said Paul Klimov, a graduate student in the University of Chicago’s Institute for Molecular Engineering and lead author of new research on quantum entanglement. The institute is a partnership between UChicago and Argonne National Laboratory.

Previously, scientists have overcome the thermodynamic barrier and achieved macroscopic entanglement in solids and liquids by going to ultra-low temperatures (-270 degrees Celsius) and applying huge magnetic fields (1,000 times larger than that of a typical refrigerator magnet) or using chemical reactions. In the Nov. 20 issue of Science Advances, Klimov and other researchers in David Awschalom’s group at the Institute for Molecular Engineering have demonstrated that macroscopic entanglement can be generated at room temperature and in a small magnetic field.

The researchers used infrared laser light to order (preferentially align) the magnetic states of thousands of electrons and nuclei and then electromagnetic pulses, similar to those used for conventional magnetic resonance imaging (MRI), to entangle them. This procedure caused pairs of electrons and nuclei in a macroscopic 40 micrometer-cubed volume (the volume of a red blood cell) of the semiconductor SiC to become entangled.

“We know that the spin states of atomic nuclei associated with semiconductor defects have excellent quantum properties at room temperature,” said Awschalom, Liew Family Professor in Molecular Engineering and a senior scientist at Argonne National Laboratory. “They are coherent, long-lived and controllable with photonics and electronics. Given these quantum ‘pieces,’ creating entangled quantum states seemed like an attainable goal.”


How NSA continued to spy on American citizens’ email traffic – from overseas

How NSA continued to spy on American citizens’ email traffic – from overseas
Files show agency just moved surveillance offshore
By Iain Thomson
Nov 20 2015

Newly revealed documents (not from Snowden this time) show that the NSA has continued to collect Americans’ email traffic en masse using overseas offices to get around curbs introduced domestically.

Shortly after the September 11 attacks, President Bush authorized the NSA to collect bulk metadata on emails sent by Americans (although not the content) to help The War Against Terror (TWAT). The surveillance was authorized by the US Foreign Intelligence Surveillance Court, which mostly rubberstamped such requests.

But the collection was stopped in 2011, the NSA said, although it still monitored emails from Americans to people outside the nation’s borders. However, a Freedom of Information Act lawsuit started by The New York Times against the NSA’s Inspector General has uncovered documents showing that the NSA carried on collecting domestic data.

To get around the restrictions on operating in the USA, the NSA simply started using its overseas offices to do the collection. Stations like RAF Menwith Hill in Yorkshire were tasked with collecting the metadata and feeding it back to the NSA headquarters in Maryland.

There’s no evidence that the content of emails was being examined by NSA analysts. Instead the metadata was used to try and divine linkages between individuals the agency was looking to monitor. But that metadata is very useful.

“We have known for some time that traffic analysis is more powerful than content analysis,” said Dan Geer, chief information security officer of the CIA’s venture capital firm In-Q-Tel.


CNN Punished Its Own Journalist for Fulfilling a Core Duty of Journalism

[Note:  This item comes from friend David Rosenthal.  DLH]

CNN Punished Its Own Journalist for Fulfilling a Core Duty of Journalism
By Glenn Greenwald
Nov 20 2015

CNN yesterday suspended its global affairs correspondent, Elise Labott, for two weeks for the crime of posting a tweet critical of the House vote to ban Syrian refugees. Whether by compulsion or choice, she then groveled in apology. This is the original tweet along with her subsequent expression of repentance:

This all happened after The Washington Post‘s Erik Wemple complained that her original tweet showed “bias.” The claim that CNN journalists must be “objective” and are not permitted to express opinions is an absolute joke. CNN journalists constantly express opinions without being sanctioned.

Labott’s crime wasn’t that she expressed an opinion. It’s that she expressed the wrong opinion: after Paris, defending Muslims, even refugees, is strictly forbidden. I’ve spoken with friends who work at every cable network and they say the post-Paris climate is indescribably repressive in terms of what they can say and who they can put on air. When it comes to the Paris attacks, CNN has basically become state TV (to see just how subservient CNN is about everything relating to terrorism, watch this unbelievable “interview” of ex-CIA chief Jim Woolsey by CNN’s Brooke Baldwin; or consider that neither CNN nor MSNBC has put a single person on air to dispute the CIA’s blatant falsehoods about Paris despite how many journalists have documented those falsehoods).

Labott’s punishment comes just five days after two CNN anchors spent 6 straight minutes lecturing French Muslim civil rights activist Yasser Louati that he and all other French Muslims bear “responsibility” for the attack (the anchors weren’t suspended for expressing those repulsive opinions). The suspension comes just four days after CNN’s Jim Acosta stood up in an Obama press conference and demanded: “I think a lot of Americans have this frustration that they see that the United States has the greatest military in the world. …  I guess the question is — and if you’ll forgive the language — is why can’t we take out these bastards?” (he wasn’t suspended). It comes five days after CNN anchor Christiane Amanpour mauled Obama on-air for not being more militaristic about ISIS (she wasn’t suspended); throughout 2013, Amanpour vehemently argued all over CNN for U.S. intervention in Syria (she wasn’t suspended).

Labott’s suspension also comes less than a year after Don Lemon demanded that Muslim human rights lawyer Arsalan Iftikhar state whether he supports ISIS (he wasn’t suspended); in 2010, Lemon strongly insinuated that all Muslims were responsible for the 9/11 attack when he defended opposition to an Islamic Community Center in lower Manhattan (he wasn’t suspended). During the Occupy Wall Street protests, CNN host Erin Burnett continuously mocked the protesters while defending Wall Street (she wasn’t suspended) and also engaged in rank fear-mongering over Iran (she wasn’t suspended). I could literally spend the rest of the day pointing to opinions expressed by CNN journalists for which they were not suspended or punished in any way.


For More Than 200 Years, America Has Shunned A ‘War On Islam’

For More Than 200 Years, America Has Shunned A ‘War On Islam’
Nov 21 2015

A small but dangerous group of Islamic extremists, operating out of the shadows of brutal dictatorships and striking out at the international community. Multiple undeclared wars over more than a decade that entangle the United States against this group and its allies and occasion rhetoric about the clash of religions and civilizations—rhetoric that a presidential administration is quick to counter with clarity and force. Refugees fleeing these war-torn Muslim nations in search of a new start and better life in America. The turn of the 19th century sure sounds familiar—and has a great deal to teach us here in the 21st.

In the late 18th and early 19th century, a number of North African nations were ruled by dictatorial leaders whose territories came to be known under the collective heading of the Barbary States. These leaders, such as Yusuf Karamanli (who ruled as the Pasha of Tripoli in what would become modern-day Libya), were in league with groups of nautical raiders who frequently attacked ships throughout the Mediterranean and beyond in order to finance their operations, and who came to be known as the Barbary Pirates.

In the final years of the 18th century and throughout the first two decades of the 19th century, the United States was drawn into multiple, semi-undeclared military conflicts with these Barbary Pirates. The first such Barbary War was conducted by the Jefferson administration against Karamanli’s Tripoli between 1801 and 1805, supported by congressional acts that stopped short of declaring war but authorized activities such as seizing ships and supplies. The Second Barbary War (1815) was fought by the Madison administration (with more overt congressional sanction) a decade later against Algiers, which had sided with England during the recently concluded War of 1812 and was continuing to harass American shipping.

The specific causes and histories of each Barbary War, and of the conflicts that led up to and followed them, were various and complex. Yet from the earliest such conflicts the U.S. government had made one thing very explicit and clear: the battles were not in any way between religions or civilizations. In 1796, the Washington administration sent his old Army colleague David Humphreys and other ambassadors to North Africa to negotiate a treaty with the Barbary States; the resulting document came to be known as the Treaty of Tripoli, and was sent to the Senate by new President John Adams and unanimously ratified in the summer of 1797.

That treaty opened with a clear statement of the goal, “a firm and perpetual Peace and friendship” between the nations. And in Article 11, it addressed directly the issue of religion:

As the government of the United States of America is not in any sense founded on the Christian Religion, as it has in itself no character of enmity against the laws, religion or tranquility of Musselmen, and as the said States never have entered into any war or act of hostility against any Mehomitan nation, it is declared by the parties that no pretext arising from religious opinions shall ever produce an interruption of the harmony existing between the two countries.

Those interruptions, when they arose a few years later, had no more to do with religion or a clash of civilizations than did these late 18th century issues.


Nina Eichacker: Lessons from Iceland’s Financial Crisis

[Note:  This item comes from friend David Rosenthal.  DLH]

Nina Eichacker: Lessons from Iceland’s Financial Crisis
By David Dayen
Nov 17 2015

Nina Eichacker is a lecturer in economics at Bentley University. This blog post summarizes her recent Political Economy Research Institute (PERI) working paper “Too Good to Be True: What the Icelandic Crisis Revealed about Global Finance.” Cross posted from Triple Crisis.

Iceland’s 2008 financial crisis should have been foreseen. By 2006, banking and economic data described an overheating financial sector and aggregate economy, and analyses by private and public researchers had reports describing those trends and their likely consequences. However, many were still surprised by the onset of Iceland’s large financial crisis. These events point to the dominance of neoliberal theories about the necessity of financial liberalization, and an assumption that a northern European country would have the institutional sophistication to avoid financial crises like those observed in developing countries that rapidly liberalize their financial sectors. A wider adherence to Keynesian and Minskyian theories of financial crisis would have helped predict Iceland’s crisis, and future such episodes.

One factor that contributed to the Icelandic financial crisis was the lack of financial market transparency. Organizations that could have reported on the conditions of the Icelandic financial marketplace and the state of the Icelandic economy did not. Despite positive reports by Frederic Mishkin and others citing Icelandic institutions’ integrity, (Mishkin and Herbertsson, 2006), the Icelandic state threatened to defund public Icelandic institutions and agencies that published reports contradicting the narrative of a robust financial infrastructure and growth. Iceland’s Chamber of Commerce paid economists like Mishkin hundreds of thousands of dollars to write favorable reports about Iceland’s financial sector and overall economic growth prospects. (Wade and Sigurgeirsdottir, 2010) The Icelandic news media consistently underpublished reports critical of the Icelandic financial sector, while publishing many stories that praised Iceland’s big three banks (Andersen, 2011). Sigurjonsson (2011) identified the root cause of this disparity as the cross-ownership of media company shares by Icelandic financial actors and institutions and financial corporation shares by Icelandic media institutions. The interconnectedness of these industries created conflicts of interest for all involved. The under production of criticism, and the over production of praise for Iceland’s banks skewed public understanding of the nature of Icelandic banks’ activity.

Credit-rating agencies contributed to the notion that Iceland’s financial markets were safer than they were. After Fitch downgraded Iceland’s credit rating, Moody’s upgraded it, increasing broad confidence in Icelandic financial stability. Moody’s upgrade stemmed from the assessment that Iceland was so financially leveraged that its central bank would bail out the big three banks as the lender of last resort. This development further lulled international investors and retail banking customers into trusting Icelandic financial actors with their capital and fueled more Icelandic financial activity.

Global financial institutions forgot that Southern Cone nations in South America had liberalized financial markets with less than stellar results: those banks became less risk-averse, without becoming more efficient. Argentina’s Central Bank offered guarantees on bank deposits, which encouraged more capital inflows; though Chile’s government initially stated that it would not insure deposits, its Central Bank ultimately guaranteed them after several panics early in the liberalization process. Foreign governments’ economic and political pressure for governments and central banks to insure their investments guaranteed moral hazard problems for developing countries considering financial liberalization in the absence of an international financial regulatory body (Diaz-Alejandro, 1983).