How I would teach Math

Having become a student again, I recently got this urge to teach, and have been applying around for a teaching position. If I were to conduct a class in math (or a subject that uses math extensively), I’d keep reminding myself of the following, which all came to me sitting through lectures:

1. I’d choose a good textbook. Students need very good/excellent texts, so that they can study at their own pace. Every lecture should be covered by text that the student can go back to if they miss a point or don’t understand things at first hearing. Lectures are a bad way to introduce hard concepts. Bullet-point presentations are even worse, because the teacher can now go faster through the prepared text. Distributing bullet-point presentations as course materials is unsatisfactory. They should be treated only as course outlines (see next point). There is no substitute for a course textbook. Spend time and effort choosing it (them).

2. I’d be very specific about the course curriculum. Students who want to read ahead or even finish the course materials earlier should be able to do so. The students should always be informed in advance about the coverage of the next class session, so that those who want to read ahead, or who need to miss class, may do so without missing the lessons.

3. I’d make students spend their class and off-class hours learning course concepts by reading through the text carefully and applying course concepts by solving problems/exercises. The only way to learn is to accumulate “flying hours”, i.e. hours of practice. Here are some ways to encourage stepping through examples and problems: a) give easy, graded take home exams after each class session, which call help pull up the students’ average; b) compile a set of, say 100-200 problems that will cover the entire course curriculum, with 3 or more questions per topic, and distribute this problem set at the start of the course; c) announce to the class in advance that all exams (midterms, finals, others) will be picked at random from this problem set (i.e., if they take the time to learn to solve the entire set, they will surely get excellent marks.)

4. I’d encourage students to ask questions. Most students are shy about asking questions for fear of sounding stupid. To encourage them, make them write their questions on a piece of paper, signed with an alias (so the teacher may follow the progress of the alias.)

5. I’d help clear away obstacles to the students’ self-learning. In particular, the teacher should be immediately available to help them get out of dead-ends. This occurs when a concept is so intractable to them that they can not grasp it without help, and they are unable to make any further advance until this learning block is cleared away. Thus, in class, students should either be working on problems or asking the teacher’s help in clearing away such blocks. The teacher can use the questions and the written answers to exercises to identify which concepts are most difficult for students and to conduct special lectures about these concepts.

6. I’d conduct a math class like a swimming class. The coach stays dry, standing by the pool side. The students are in the water, learning to swim. In math, the pool is the chalk and blackboard, pencil and paper.

7. I’d give exams that are fair. Stick closely to the text as much as possible. Do not ambush students with surprise topics or trick questions. As a rule: ask many easy questions, a few hard ones. Give students a second chance; if most did not get a mid-terms problem, ask it again in the finals. Think of it as a bonus question.

Prof may go to jail for popularizing philosophical works

Major controversy has erupted after the French and Argentinian governments went after a philosophy professor for popularizing Spanish translations of philosophical texts. Prof. Horacio Potel is accused of violating “intellectual property rights” and faces a prison term of one month to six years. Much of the discussion is in Spanish and therefore inaccessible to the English-speaking world. Here’s a translation of one report from the Spanish-language online newspaper Clarin.com

February 28, 2009

France intervened to shut down an Argentinian site popularizing philosophical works

It acted through the Book Chamber. The site posted Derrida texts. Solidarity support on the Facebook network.

By Andres Hax

Derrida, the French author who shaped the thinking of the last thirty years with key works like “politics of friendship” and “the writing and the difference”, among others.

In the late nineties, when the Internet was completely novel, professor of philosophy at the University of Lanús, Horacio Potel, began posting texts of Friedrich Nietzsche at a personal site. In his words, it was a non-profit publishing and stewardship effort. Soon he added two more sites, with texts by the German philosopher Martin Heidegger and the Frenchman Jacques Derrida. This tiny digital library – which also includes biographies, links and essays – has been consulted, according to his logs, by more than four million people since its inception and ranks high among search engines: in Google, if you type Jacques Derrida Argentina, the first hit is the Wikipedia entry and the second is the former site of Potel, www.jacquesderrida.com.ar.

For Potel, this laboriously-compiled collection has become a nightmare: after the intervention of the French Embassy in Argentina, a criminal case filed by the Argentina Book Chamber for violation of Intellectual Property Law 11.723 has forced him to take down the Derrida texts from his site and deal and face a possible “prison term ranging from one month to six years.”

The charge against Potel cites the law prohibiting the “editing, selling or reproduction by any means or in any medium, a published or unpublished work without permission from its author or his heirs.” The legal language is not debatable. Having posted online Derrida’s texts – protected by copyright – Potel infringed on copyrights. “This law exists to protect cultural works,” says Carlos de Santos, president of the Argentina Book Chamber, to Clarin. “The Chamber has always acted in defense of intellectual property rights. Without intellectual property rights, publications cannot possibly exist. And I believe the possibilities for intellectual work will be less,” he concluded.

The Argentina Book Chamber’s case was initiated by a complaint from Derrida’s publisher (Les Editions de Minuit) and the intervention of the French Embassy in Buenos Aires. According to cultural attaché Jean-François Gueganno “The gold standard in these cases is intellectual property. If you write a piece, you own the text and nobody can post them on a site to be accessed freely without the author’s consent”. Potel defends himself: “It was never my intention to make a profit. In 1999 I was fascinated by the unlimited possibilities the network offered for knowledge exchange. These sites are a lot of work for me and it is a tragedy for me that I have to remove them.”

The case has provoked widespread protest in cyberspace, highlighting the gray area between popularization and piracy. On the Potel page in Facebook, hundreds of users worldwide have expressed outrage at the “censorship”. One user summed up the opinion of the cyber-citizens: “What is happening is an outrage to the culture of human rights. An obscene display of the mechanisms of control, surveillance and punishment.”

(See original story in Spanish here: http://www.clarin.com/diario/2009/02/28/sociedad/s-01867515.htm)

SRI Pilipinas Song

This song is dedicated to all farmers who have successfully tried the System of RIce Intensification (SRI) and are now trying to convert their neighbors to the method. Sing to the tune of “Magtanim Ay Di Biro”. Awit ng SRI-Pilipinas

isinulat ni Roberto Verzola (sa himig ng Magtanim Ay Di Biro) Refrain: Halina, halina, mga kaliyag, tayo’y magsipag-palay lahat. Magbago tayo ng kaisipan; S-Rr-I ang subukan. (Ending: S-Rr-I Pilipinas) Contra-refrain: (kasabay ng Refrain) Sa organic SRI, kalusuga’y gaganda; gastos ay bababa, kabuha-ya’y sasagana. Sa ingles, “system of rice intensification” sya; tawaging Sipag-Palay sa mga magsasaka. I. Magtanim ay masaya, maghapong kumakanta. Uupo kung pagod na; tatayo kung puwede pa. II. Inaamag na ka-nin, sa pulot patatamisin. Pitong araw ang hintayin, I.M.O. ay gagawin. Refrain/Contra-refrain III. Ang dayami’y ipunin, sa I.M.O. ay diligin. ‘Sang buwan lang na bulukin, isabog na sa bukirin. IV. Gawin mong uling ang ipa, sa kama’y pampataba. Sampung kilo’y ipunla, isang ektarya kasya na. Refrain/Contra-refrain

V. Sampung araw na idad, punla ay ililipat. Puno ay isa-isa; layo’y sampung pulgada VI. Ang tanim huwag ibabad; mabubulok ang ugat. Tatlong araw basain; isang linggong patuyuin. Refrain/Contra-refrain VII. Sa tuwing sampung araw, weeder ipambubungkal. Ang damo’y matatanggal; ang ugat, mahahanginan. VIII. Gawa natin ay may saysay, Kung suwi’y kumakapal. Kung ito’y doble bilang, Puwede nang ipagyabang! Refrain/Contra-refrain IX. Kung namumulaklak na, tubig papasukin na. Saya natin ay ikanta; asahang ani’y maganda. X. Kung SRI kabisado na, tanim gawing iba-iba. Palay, gulay, puno pa, Pagkain at pambenta. Tapos.

BNPP: Mark Cojuangco failed to prove his case

[A shorter version of this article was published on March 15, 2009 by the Philippine Daily Inquirer, Talk of the Town Section, p.A14. I am posting here the full article as submitted. The portions left out by the PDI editors, presumably to fit the piece into the available space, are marked in blue.]

Rep. Cojuangco failed to prove his case to rehabilitate BNPP

by Roberto Verzola*

Rep. Mark Cojuangco of Pangasinan faced an enormous challenge when he boldly proposed the recommissioning of the 620 MW Bataan nuclear power plant (BNPP). He should have realized that he took on a huge burden of proof with his proposal, for at least two reasons:

1. The public is well acquainted with the BNPP’s well-documented history of corruption under the Marcos martial law regime ranging from substandard construction materials and practices to presidential bribes, as described in the book Debts of Dishonor.

2. Three major official studies had already found the Bataan nuclear power plant (BNPP) unfit to operate: a technical study by a team of over 15 nuclear experts assembled by the NUS Corporation in 1988; a second study, also under the term of President Corazon Aquino, by another team of 50 nuclear experts commissioned in 1990, who submitted a 28-volume report; and a third review conducted after a proposal to revive the BNPP was raised under the term of President Fidel Ramos, which again led the government to decide otherwise. These are historical facts, and the documents which became the basis for these decisions are presumably gathering dust in some government archives.

Rep. Cojuangco has failed to prove his case:

1. He completely ignores earlier official studies, which were prepared by experts who actually made a detailed inspection of the BNPP itself. Instead, he justifies his proposal with miscellaneous factoids on nuclear power plants in other countries, selectively culled by him and his staff from the Web and Wikipedia.

2. In the Feb. 2 public hearing conducted by Congress, he could neither cite nor present detailed technical, economic or financial feasibility studies on the BNPP itself, obviously because he has not done any.

3. His claim that “in the 50-year history of the nuclear power industry in the West, including the Three Mile Island incident, not a single person has been killed or injured” is so blatantly false it boggles the mind that a congressman would expose himself so. A simple Internet search easily reveals the following deaths from nuclear plant accidents outside of Chernobyl: one death in Rhode Island, USA in 1964; two in Virginia, USA in 1986; two in Japan in 2000 (from a 1999 accident); another four in Japan in 2004; two in Pakistan in 2008. These results do not include injuries, which are presumably more numerous. I was a resource person at the Feb. 2 hearing in Congress when he made a similar “no-deaths” claim, and I directly told him he was wrong, as a simple Web search would show. He still made the same claim at the Feb. 20 Kamayan sa EDSA Forum, where I was also a resource person, and I again called his attention to the false claim. Yet, he obstinately repeats this false claim in his March 8 Inquirer piece.

4. At least three published scientific studies (Wing 1996; Chang 2003; Kaatsch 2007) show that the incidence of leukemia and other cancers, especially among children, is higher within a 5-10 km radius of nuclear plants.

5. His $1 billion BNPP rehabilitation cost estimate comes from a questionable method based on comparable coal plant costs, instead of detailed cost estimates of actual services and materials for nuclear plants.

6. He claims that the BNPP will provide the cheapest electricity without giving any actual figures or providing any supporting financial study. He cites cheap nuclear electricity in France, the U.S. and elsewhere, ignoring the fact that their nuclear industries are heavily subsidized for nuclear bomb production and related military goals.

7. His warnings of a possible power crisis in 2012 is based on overestimated demand projections made before the global recession that is currently in progress.

8. His Inquirer piece forces on the public a false “either-or” choice between nuclear and fossil fuels, ignoring such viable options hydro, geothermal, biomass, and wind. Solar photovoltaic (PV) cells may still be expensive today. But remember that PV cells are made of silicon, the same semiconductor material used in computers, LCD projectors, digital cameras and other electronic equipment. With the entry of China into PV production, expect PV prices – now approaching $1/watt peak (or $620 million for 620 MWpeak) – to drop dramatically in the next few years. The lower prices will result in increased demand and larger-scale production, which will reduce prices even more.

9. While the rest of the world wants to subsidize renewable energy sources to increase demand and hasten a drop in prices, Cojuangco’s bill will instead tax renewables to subsidize nuclear power, which is bizarre.

For details and other arguments, please check the site https://rverzola.wordpress.com.

*Roberto Verzola is a convenor of the Philippine Greens and co-author of the book Debts of Dishonor (1991) on odious debts, which include the BNPP debt.

Carbon footprint of various sources of electricity. Lowest: run-of-the-river hydro

A 2006 UK study by the Parliamentary Office of Science and Technology compares the life-cycle carbon footprints of a number of energy sources. The study can provide a good starting point for research, in connection with the Philippine debate whether or not to rehabilitate the Bataan nuclear power plant (BNPP), as proposed by Congressman Mark Cojuangco of Pangasinan.

Here’s a summary of the UK study carbon footprint findings, in terms of grams of CO2 equivalent per kWh of electricity generated:

1. Coal: >1,000
2. Coal with gassifier technology: <800
3. Oil: 650
4. Gas: 500
5. Biomass: 93
6. Photovoltaic: 58
7. Photovoltaic in sunny countries of southern Europe: 35
8. Wave energy: 25-50
9. High-density biomass with gassification: 25
10. Hydro with dams: 10-30
11. Wind: 5
12. Nuclear: 5
13. Hydro, run-of-the-river (no dams): <5

The study also projects the impact of technology trends on future carbon footprints:

1. Coal footprint may be halved
2. Carbon capture and storage (CSS) may reduce coal footprint by 90%
3. Biomass with CSS has potential for up to -420 “negative” carbon emissions
4. Using very low grade uranium can raise nuclear footprint to 7
5. Other technologies may reduce their carbon footprint by using low-carbon energy during the production phase.

The study may be downloaded here or from its original site.

Cojuangco repeats lie: no nuclear plant deaths outside Chernobyl

We must thank the Philippine Daily Inquirer for printing Rep. Mark Cojuangco’s article in their March 8, 2009 issue, Talk of the Town Section. In that article, Cojuangco publicly defends his position to rehabilitate the Bataan nuclear power plant (BNPP) for recommissioning.

There are many questionable claims in Cojuangco’s Inquirer article. But I will only focus on one paragraph:

In the 50-year history of the nuclear power industry in the West, including the Three Mile Island incident, not a single person has been killed or injured. The Chernobyl accident in Ukraine, in the former Soviet Union, where 60 people were reportedly killed, was indeed a tragedy.

When Cojuangco made this claim on Feb. 2, during the public hearing of the Appropriations Committee of Congress, I already corrected him. In my public testimony as a resource person during the same hearing, I addressed myself directly to him and told him he was wrong, because at least four people had died in Japan from a nuclear accident (the current count is actually six). During the Kamayan sa EDSA public forum on Feb. 20, he again made that claim. And since I was also a resource person in that forum, I again corrected him publicly. This is also described in my earlier post, “No nuclear plant deaths outside Chernobyl?“, which cited another case of four deaths in the U.S. in 1986.

Note that Cojuangco also claimed that no single nuclear plant injury has occurred outside Chernobyl. I didn’t even bother to count the injuries anymore.

Having been corrected twice for this false claim about zero deaths in the West, the least Cojuangco could have done is to double-check his facts and to refrain from mentioning it anymore.

I find it incredible that he would repeat the same lie in his March 8 Inquirer article, in public and in print.

Rep. Mark Cojuangco’s actions are truly puzzling. I don’t think he is an inveterate liar. But why would he expose himself so? He has, it seems, become so irrationally obsessed with his pet bill that he doesn’t listen to other people or to reason anymore.

BNPP: Cojuangco persists in nuclear folly

Last March 5, the Committee on Appropriations of the Philippine Congress approved an amendment to the proposed bill that will rehabilitate and recommission the mothballed Bataan nuclear power plant (BNPP).

The amendment funded a “feasibility study” or “validation process” that will determine through technical, economic and financial studies if the BNPP can indeed by operated safely after rehabilitation. The fund allotted was P100 million. Rep. Edcel Lagman, who pushed the fund, called it a “killer amendment” that will ensure that the nuclear plant will remain mothballed.

The response of BNPP proponent Rep. Mark Cojuangco of Pangasinan to Lagman is interesting. This is what an Inquirer.net report says:

“The bill is not only alive, it is healthy,” Cojuangco said in a text message. “I know for a fact that, the plant can be brought back to its original [spefications]. It is a question of how much will it cost.”

Cojuangco’s incredible claim “for a fact” that the plant, which has been idle for more than 22 years, can be restored to its original specifications, clearly shows how the congressman from Pangasinan has lost his bearings and that the BNPP’s restoration has become, to him, a personal obsession. Whether such a restoration will succeed or not is a future event, for which there can be no 100% certainty. How can it be a fact?

But let us assume, for the sake of argument, that US$1 billion will be enough to actually restore the BNPP to its original specifications.

Apparently, Rep. Cojuangco does not even realize that restoring the nuclear plant to its original late 1970s specifications makes certain that the plant will not pass today’s nuclear safety standards.

From the 1980s, 1990s to the 2000s, all kinds of minor and major nuclear accidents have occurred, and safety standards have been updated to minimize the possibility of such accidents from recurring. For instance, volcanology as a science has grown by leaps and bounds since the 1980s, and new international safety guidelines have been drafted that govern the choice of sites, especially where volcanos are concerned. A powerful earthquake in July 2007 led to the closure for more than a year of Japan’s largest nuclear plant (see details here), because 400 drums filled with radioactive waste water tipped over and spilled their contents during the earthquake. We can be sure that safety standards were updated as a result of this accident.

So Rep. Cojuangco’s “fact” that the BNPP can be restored to its original specification is no guarantee that we will have spent our US$1 billion wisely. Yet, Cojuangco says he will still work for his bill’s approval in plenary.

Cojuangco’s irrational obsession with his pet bill will already cost Filipino taxpayers P100 million. If Cojuangco manages to convince his colleagues In Congress to approve his pet bill, Cojuangco’s folly will cost us at least $1 billion more.

At the end, we will have a nuclear plant that may still remain mothballed if it could not meet current nuclear safety standards.

What a waste!