Saturday, February 25, 2017

Teaching Physics

What we know about physics can be summarized in very compact form. Classical electrodynamics is a subject that remains of immense practical importance as well as foundational for the modern field theories of particle physics and relativity. The equations that describe it can occupy less than a fourth of one of these lines of text. See, e.g., the tensor and differential form versions of Maxwell's equations in this Wikipedia article.

Chad Orzel recently wrote a post on teaching so-called Modern Physics, which is conveniently summarized as the physics discovered between 1899 and 1950. In particular he makes the case for teaching the history of the discoveries. His point is that you can learn a lot from understanding how the laws of physics were discovered and why we believe them - but read Chad's version, he's a good writer.

The alternative method, and it's also used a lot in physics, is to just write down the equations and then develop the mathematical techniques one can use to deduce their consequences. If one picks up a graduate level book in classical electrodynamics (e.g., Jackson's Classical Electrodynamics) that's mostly the approach you will get. In the US, anyway, physics students tend to get a three-layer approach to electricity and magnetism, starting with experimental results and formulation in calculus of integral equations in a General Physics course, with an intermediate layer from a book like Griffiths and Jackson as a sort of finale.

The historical approach can be instructive, but it can also be slow to recapitulate all the steps and there is a mountain of mathematical technique to learn.

Friday, February 24, 2017

Whose Jobs do the Robots Get?

Paul Krugman:

Izabella Kaminska has a thought-provoking piece on the real effects of technology on wages, in which she argues that much recent innovation, instead of displacing manual workers, has displaced high-paying skilled jobs. As it happens, I sort of predicted this 20 years ago, in a piece written for the Times magazine’s 100th anniversary (authors were asked to write as if it was 2096, and they were looking back.)

I argued then that menial work dealing with the physical world – gardeners, maids, nurses – would survive even as quite a few jobs that used to require college disappeared. As it turns out, big data has led to more progress in something that looks like artificial intelligence than I expected — self-driving cars are much closer to reality than I would have thought, and maybe gardening robots and post-Roomba robot cleaners will follow.

Lawyers, pathologists, translators are all getting heavily hit, but I suspect that robotics is getting much closer to being an equal unemployment opportunity. Many medium skill jobs like truck and taxi driver have less than ten years left, and fast food employees could well decimated soon too.

Monday, February 20, 2017


Temperatures in the high Arctic are finally nearly down to normal after having spent the previous three months 5 C or more above normal. There are still almost two months of hard winter up there so Santa may not want to break out his swim suit for a bit.

In the Antarctic, sea ice extent is at record lows for the satellite era, while the Arctic is nearing sea ice max at levels barely above record lows for the date.

Advice for the FP

As early as the mid-third century BC, the Indian emperor Ashoka erected large stone pillars or signboards in Kandahar, Afghanistan, as well as in other cities, on which he displayed edicts on how good behavior or the Buddhists’ dharma could be spread. He counseled his subjects that “piety and self-control [exist] in all philosophical schools. But the most self-possessed are [those people] who are the masters of their tongues. They neither praise themselves nor belittle their fellows in any respect, which is a vain thing to do. … The correct thing is to respect one another and to accept the lessons of each other. Those who do this enlarge their knowledge by sharing what others know.”66

Starr, S. Frederick. Lost Enlightenment: Central Asia's Golden Age from the Arab Conquest to Tamerlane (p. 81). Princeton University Press. Kindle Edition.

Of course the fool is immune to advice.

New NSC Chief

H. R. McMaster is the real deal.

He's a soldier scholar who is used to telling truths to power.

Sunday, February 19, 2017


A Chinese visitor to Samarkand in the century before the Arab invasion wrote in his notes the following observation on young people there: “All the inhabitants [of Samarkand] are brought up to be traders. When a young boy reaches the age of five they begin to teach him to read, and when he is able to read they make him study business.”1 Another Chinese visitor, equally astonished, observed that young Central Asian men were not allowed to participate in trading trips abroad until they were twenty, prior to which time they were expected to be absorbed in study and training.2

These observant contemporaries enable us to understand something very important about the lost world of Central Asia before the Arab conquest: the high level of literacy that prevailed there. The mass destruction of books and documents carried out by the Arabs leaves us particularly dependent on the reports of outsiders like these.

Starr, S. Frederick. Lost Enlightenment: Central Asia's Golden Age from the Arab Conquest to Tamerlane (p. 62). Princeton University Press. Kindle Edition.


Eleven hundred years ago, Central Asia was the intellectual and cultural center of the world. It's cities were the wealthiest in the world, and mathematics, astronomy, architecture, art and literature had a golden age of enlightenment. No city was richer than Balkh, in what is now Afghanistan.

To approach Balkh today is a sad experience. Where ancient visitors reported on vineyards, citrus groves, and fields of sugar cane, there is only sagebrush and dust, relieved by an occasional hollyhock in the lower-lying areas. Similarly, far to the north in Central Asia, the vast reaches of Khwarazm in Uzbekistan and Dehistan in Turkmenistan were once alive with castles surrounded by farmland but are today bleak deserts, utterly devoid of plant life.

Starr, S. Frederick. Lost Enlightenment: Central Asia's Golden Age from the Arab Conquest to Tamerlane (p. 35). Princeton University Press. Kindle Edition.

The Balkh river, which once supported cargo boats to and from the Oxus and Aral Sea is now dry.

What happened is a now familiar story of ecological destruction. It started in the Bronze Age with deforestation to build and feed foundries, and with sheep and goats which can chew grass short enough to kill it. The final catastrophe, though, came with the reckless Soviet exploitation of irrigation to grow cotton. This turned the Aral Sea into a vast salt flat, and was only slightly less devastating to the Caspian.

Saturday, February 18, 2017

Opinions on the Shape of the Earth Differ...

Kyrie Irving:

Good thing he has a very high basketball IQ.

Or he could be having a bit of fun with us. Or maybe has never looked out of an airplane window.

Friday, February 17, 2017

One State Solutions

Our FP indicates that the so-called two-state Israel Palestine conflict is passe. So what does that leave?

Apartheid, with Palestinians as a permanent underclass.

Genocide, with Israel becoming an outlaw state.

One person, one vote, with Israel likely to become an Islamic state.

Anybody want to guess what's most likely, or suggest a better alternative?

My personal favorite is that the Palestinians convert en masse to Southern Baptists. This would pose a pretty puzzle for Israel.

Which Enemy?

A recurring theme in the history of fallen nations is that some factions in a local dispute see advantage in allying with an aggressive outsider against their local enemies. In this fashion a few British adventurers conquered India, Cortez conquered the Aztecs, Rome invaded Britain, and Persia subdued Babylon.

So too today, the Republican Party of the United States seems prepared to tolerate massive interference in our electoral process and other corrupt practices in the hope of enacting the unpopular wishes of their plutocratic masters. Paul Krugman today:

The story so far: A foreign dictator intervened on behalf of a U.S. presidential candidate — and that candidate won. Close associates of the new president were in contact with the dictator’s espionage officials during the campaign, and his national security adviser was forced out over improper calls to that country’s ambassador — but not until the press reported it; the president learned about his actions weeks earlier, but took no action.

Meanwhile, the president seems oddly solicitous of the dictator’s interests, and rumors swirl about his personal financial connections to the country in question. Is there anything to those rumors? Nobody knows, in part because the president refuses to release his tax returns.

Maybe there’s nothing wrong here, and it’s all perfectly innocent. But if it’s not innocent, it’s very bad indeed. So what do Republicans in Congress, who have the power to investigate the situation, believe should be done?


Paul Ryan, the speaker of the House, says that Michael Flynn’s conversations with the Russian ambassador were “entirely appropriate.”

Devin Nunes, the chairman of the House Intelligence Committee, angrily dismissed calls for a select committee to investigate contacts during the campaign: “There is absolutely not going to be one.”

Jason Chaffetz, the chairman of the House oversight committee — who hounded Hillary Clinton endlessly over Benghazi — declared that the “situation has taken care of itself.”

Just the other day Republicans were hot in pursuit of potential scandal, and posed as ultrapatriots. Now they’re indifferent to actual subversion and the real possibility that we are being governed by people who take their cues from Moscow. Why?

Well, Senator Rand Paul explained it all: “We’ll never even get started with doing the things we need to do, like repealing Obamacare, if we’re spending our whole time having Republicans investigate Republicans.” Does anyone doubt that he was speaking for his whole party?

The point is that you can’t understand the mess we’re in without appreciating not just the potential corruption of the president, but the unmistakable corruption of his party — a party so intent on cutting taxes for the wealthy, deregulating banks and polluters and dismantling social programs that accepting foreign subversion is, apparently, a small price to pay.

To B* or not to B

* Blog, that is.

One reason that I've been increasing reluctant to write anything on the blog is the near certainty that anything I write will be met with a mostly off topic, inane, or otherwise annoying rejoinder from a notorious internet troll. I hate to suppress dissent, but I also dislike the idea of my blog becoming a forum for Exxon, the FSB, or general crackpottery. Comments?

Thursday, February 16, 2017

Saturday, February 11, 2017

Tie-ing Times

The NYT has a piece today on our President's seeming inability to properly tie a tie.

Which reminded me of a time when I was in a play at the local university. The costumer asked me if I knew how to tie a tie for my character's costume (I was about 50 at the time), so I asked what knot she wanted, listing a few of the options. Her reply: "OK, I forgot that you were a real person."

I'm not sure that Trump is a real person. At least I hope not.

Friday, February 10, 2017


I wouldn't have pictured Trump as a spelunker, but he just caved big time to China. Kevin Drum has a chronicle:

Behold the greatest negotiator our nation has ever seen:

President Donald J. Trump and President Xi Jinping of China had a lengthy telephone conversation on Thursday evening. The two leaders discussed numerous topics and President Trump agreed, at the request of President Xi, to honor our "one China" policy.

Follow the link for the play by play.

UPDATE: (from NYT)

“Trump lost his first fight with Xi and he will be looked at as a paper tiger,” said an adviser to China’s State Council.

Annihilating Truth

The fountain of lies that is Trump's White House might be the product of a deranged personality, but it also has a sinister logic. Charles Sykes, writing in The New York Times Sunday Review, takes a look at how alt-reality came to dominate modern right-wing discourse:

For years, as a conservative radio talk show host, I played a role in that conditioning by hammering the mainstream media for its bias and double standards. But the price turned out to be far higher than I imagined. The cumulative effect of the attacks was to legitimize those outlets and essentially destroy much of the right’s immunity to false information. We thought we were creating a savvier, more skeptical audience. Instead, we opened the door for President Trump, who found an audience that could be easily misled.

The news media’s spectacular failure to get the election right has made it only easier for many conservatives to ignore anything that happens outside the right’s bubble and for the Trump White House to fabricate facts with little fear of alienating its base.

Unfortunately, that also means that the more the fact-based media tries to debunk the president’s falsehoods, the further it will entrench the battle lines.

For me, the most telling observation was this comment from Putin critic and former world chess champion Gary Kasparov:

The point of modern propaganda isn’t only to misinform or push an agenda. It is to exhaust your critical thinking, to annihilate truth.

Those of us who have been in the climate wars are very familiar with this tactic. But now every aspect of reality is fair game.

Thursday, February 09, 2017

Your Republican Party Today

From Josh Marshall:

College Republicans at Central Michigan University handed out Valentine's Day cards mocking Jews who died in the Holocaust. "my love 4 u burns like 6,000 jews" ... really.

So, Lee, what were you saying about me being hysterical?

Wednesday, February 08, 2017

Corrupt Practices

I haven't heard a peep from all those who were so exercised about Hillary's supposed conflicts of interest lately. Cat's clearly got their tongues.

Josh Marshall:


I've been saying for months that the language of 'conflicts of interest' for President Trump is entirely inadequate and frankly silly. The concept of a conflict of interest is one that speaks to a situation in which an overlap or conflict between an individual's personal and professional or public interests makes it impossible for that individual to act in an ethical manner or to appear to be doing so. It has no meaning when the actor - in this case, the President - is openly using his office for personal profit. In other words, it has no meaning when the President refuses to recognize any difference between his public responsibilities and his personal and familial business interests, the state and himself. He recognizes no conflict. Indeed, there isn't one. President Trump is openly using his office to become the billionaire he always wanted to be. And now his Press Secretary has said as much.

Just a few moments ago, Sean Spicer said that Nordstrom's decision to drop Trump's daughter's eponymous clothing line constitutes a political attack on the President and he is within his rights to retaliate.

Here's Spicer:

I think this is less about his family's business and an attack on his daughter. He ran for president. He won. He's leading this country. I think for people to take out their concern about his actions or his executive orders on members of his family, he has every right to stand up for his family and applaud their business activities, their success ... There's a targeting of her brand and it's her name. She's not directly running the company. It's still her name on it. There are clearly efforts to undermine that name based on her father's positions on particular policies that he's taken. This is a direct attack on his policies and her name. Her because she is being maligned because they have a problem with his policies.

This is just the clearest statement of what has been obvious for months. President Trump sees the United States and his family businesses as a fully integrated entity because he is President. Remember, just a few days ago the President's wife argued in court that a disputed and subsequently retracted article damaged her ability to take advantage of the business opportunity of being First Lady. That literally means that her public office is a thing of specifically quantifiable monetary value to which she has been wrongly deprived and for which is seeking compensation. He is the state. He is the business. That may sound dramatic and even hyperbolic. But look at Spicer's own words. They're not.

Friday, February 03, 2017

Tragedy and Farce

A couple of recent events illustrate Trump's failure to plan or think through consequences:

The Yemen Raid (Fred Kaplan):

The Jan. 28 raid on an al-Qaida outpost in Yemen, which resulted in the deaths of a Navy SEAL fighter and several civilians, was approved by President Trump with no advice or consultation from intelligence officers or military commanders, according to officials familiar with the chain of events.

As the New York Times reported on Wednesday, Secretary of Defense James Mattis and Gen. Joseph Dunford Jr., chairman of the Joint Chiefs of Staff, presented the plan over dinner at the White House, on Jan. 25, to Trump, his son-in-law Jared Kushner, and his political strategist Steve Bannon.

The epic Fredrick Douglass fail:

Last month, we celebrated the life of Reverend Martin Luther King Jr., whose incredible example is unique in American history. You read all about Dr. Martin Luther King a week ago when somebody said I took the statue out of my office. It turned out that that was fake news. Fake news. The statue is cherished, it's one of the favorite things in the—and we have some good ones. We have Lincoln, and we have Jefferson, and we have Dr. Martin Luther King. But they said the statue, the bust of Martin Luther King, was taken out of the office. And it was never even touched. So I think it was a disgrace, but that's the way the press is. Very unfortunate.

As for Frederick Douglass, he “is an example,” according to the president, “of somebody who’s done an amazing job and is being recognized more and more.” Not surprisingly, this statement has received a great deal of attention on social media owing to Trump’s failure to identify any of Douglass’s achievements. More problematic is it appears the president believes that the famous abolitionist leader is still alive.

Most of Trump’s address had nothing to do with African-American history or anything having to do with the past. In fact, it is probably not a stretch to suggest that the president has very little interest in history. Unless questioned directly, he rarely reflects on history unless it affects him directly, as in the case of personal stories about his father. Trump used this event to do little more than talk about himself and as an opportunity to discuss current policy and when it comes to the black community that begins and ends with the inner city.

Thursday, February 02, 2017

From Under the Rock

Yet more evidence of all the creeping, crawling things coming from under the rocks Trump has overturned:

Students Give Nazi Salute in Senior Pictures

High-school students in Texas did a Nazi salute in their senior pictures, setting off a firestorm of controversy after the photos spread on social media. A student who witnessed the incident at Cypress Ranch High School told KPRC that the students pictured, about 70 of them, were shouting phrases such as “Heil Hitler” and “Heil Trump.”