Friday, February 20, 2009

Long distance guidance

Here is my tribute to John Stallings on the eve of a trip to India:
I first met John Stallings in early 1967, when he visited Tata Institute of Fundamental Research to give a lecture course on Polyhedral Topology and I was asked to write up his lecture notes. I was a third year research student at that time mainly interested in Algebraic Topology and Differential Topology learnt though some unpublished notes of Samuel Eilenberg and John Milnor. I knew about John's work on Poincare conjecture and that some papers of William Browder were inspired by John's work. In prepartion for his visit, I worked through some papers of J.W. Alexander, J.H.C. Whitehead, E.C. Zeeman's notes from I.H.E.S and some papers of John on engulfing. For two months, I was in constant contact with John discussing his lectures, showing my notes, helping with shopping and a sight-seeing trip to Lonawala. He was unassuming and notes writing turned to be easy except for a couple of appendices where my reading of Whitehead helped. Most of the time, he gave me his own notes and what all I had to do was number the lemmas and add symbols on the stencils. It turned out be somewhat messy and some of the elegance of his presenation was lost in misprints. Surprisingly at the end, he offered joint authorship which I politely declined. He also gave a seminar which seemed very nice until a point when he said 'by waving hands twice, we have the result' and this was probably my introduction to Combinatorial Group Theory.. There was some correspondence soon about his lecture notes, his leaving Princeton for Berkeley and I continued to read his papers. They always seemed very elegant with neat ideas and easy to read with unpleasant technical difficulties tucked away in a half page somewhere. Slowly I found that only were his theorems useful but their generalizations too and when these did not work, one could often go back to his techniques.
Just before Stalling left Bombay, I asked whether he could suggest some problems for my thesis. I think that I wanted to prove some embedding theorems following his ideas in the lecture notes about an alternate argument in the proof of s-cobrdism theorem avoiding the Whitney trick. But what all he said was that somebody named Papakyriakopoulos did some great work. I never sudied any thing in 3-dimensional topology before and after he left, I started reading "On Dehn's lemma and Asphericity of Knots", the first paper on 3-maniflods which I read. To round it off, I read a few more papers and got stuck in 3-manifolds for a long time. Meanwhile, possibly around the end of 1967, he sent a preprint of 'Groups with infinitely many ends' which is probably my main introduction to Topological Group Theory. Though my fascination with higher dimensional topology continued, I found myself returning to Stallins papers and ideas. I do not remember any papers of mine not influenced by Stallings except possibly one on cut points which built on the impressive work of Brian Bowditch. But even here, one of Stallings students Bill Grosso, seemed to have many of the basic ideas but not proofs.
Meeting such a first rate mind at an early part of my career has inflenced me and he kept an affectionate interest in me through out my career. The acquintance with Stallings and miswriting his notes seemed to have made me a member of the Stallings community and I always felt welcomed by his students and friends.

Tuesday, February 17, 2009

Links, February 17th

On the eve of a visit to Kolkata, a disturbing report In support of Johann Hari .

The Indian Railway King (via Nanopolitan). Jeffrey Witsoe gives a quick overview of Lalu's record in Bihar Challenges and Opportunities Facing India's Poorest State.

Swat: A Critical Analysis (via Chapati Mystery)

Sunday, February 15, 2009

Memorial for John Stallings

Rob Kirby from Berkeley informs:
"There will be a memorial for John on March 1, 2009, at 2-4pm in 1015 Evans. (In case you have not heard, John died on 24 Nov., 2008, see Wikipedia and a NYTimes obit )"

How to recognize science

A new site Understanding Science.
From the write up New resource for teachers, public on how to recognize science when you see it in (via Evolutionary Psychology Discusion Group):
"If you think you know what science is and how science works, think again. A new University of California, Berkeley, Web site called "Understanding Science" ( paints an entirely new picture of what science is and how science is done, showing it to be a dynamic and creative process rather than the linear - and frequently boring - process depicted in most textbooks.
"The goal was to present (the concept) that testable ideas are right at the center of science, and if you don't generate testable ideas, then you are really not doing science," Kuldell said.

Testing, however, is intertwined with exploration and discovery - the "cowboy" aspect of science, in the words of one project advisor - review of hypotheses and theories by skeptical peers, and actual application of the science to real world problems.

Within the Web site, personal stories contributed by top scientists around the country illustrate the interplay of exploration, peer review and outcomes, and demonstrate the different pathways to discovery taken in different fields of science, from biology to cosmology."
P.S. Another interesting link from Evo.Psychology group:
Group decisions in humans and animals: a survey.

Saturday, February 14, 2009

Informal economy to the rescue?

From The Age articleSlum economy offers hope in Delhi by Matt Wade:
"The Indian economy relies much less on exports than other developing countries and so is much less exposed to the collapse in consumer demand in the US and Europe.

Exporters have been hit much harder and there are reports that hundreds of thousands of jobs have been lost.

This eventually might threaten micro-manufacturers such as Kalimuddin, as export-oriented garment makers shift their product to the domestic market and drive down prices.

Naeem and Kalimuddin operate in the vast "informal economy", meaning they are outside the purview of the tax system, corporate regulation and labour laws.

Tens of millions of informal-sector workers are vulnerable to exploitation but the economy benefits from their vague employment status.

Delhi economist Dr Kanhaiya Singh says they will help cushion Indian from the global slump. "The labour market is highly flexible in the informal sector — it can adjust very quickly," he says."

Tuesday, February 10, 2009


and browsing through some interesting books like Sheldon Pollock's The Language of the Gods in the World of Men: Sanskrit, Culture, and Power in Premodern India. Two of the reviews are
here and here. As the reviews explain, the book is concerned with "two great moments of transformation in culture and power in premodern India. The first occurred around the beginning of the Common Era, when Sanskrit, long a sacred language restricted to religious practice, was reinvented as a code for literary and political expression... The second moment occurred around the beginning of the second millennium, when local speech forms were newly dignified as literary languages and began to challenge Sanskrit for the work of both poetry and polity, and in the end replaced it."
Like the reviewers above, I find the book interesting but not convincing.
P.S. Some of the issues addressed by Sheldon Pollock are discussed in an earlier essay "Literary History, Indian History, World History in a 1995 issue Social Scientist which also has interesting articles by S. Nagaraju and Velcheru Narayana Rao on the rise of vernacular languages.
P.P.S (14th February) Having more or less finished reading the book (browsed through some pages)I think that it is a wonderful book for its stupendous scholarship, critique of many existing theories and finally for the questions that it raises.

Wednesday, February 04, 2009

Cheap laptops?

India unveils $10 laptop!. But Atanu Dey is skeptical.
P.S. More information at Nanopolitan:Price of hype ... .

Monday, February 02, 2009

What are the experts saying about the financial crisis?

Gulzar Natarajan in Limits of macroeconomic policy making?:
"Unfortunate as it sounds, after reading reams of analysis of the ongoing financial and economic crisis, I cannot but get a distinct sense of helplessness, even hopelessness, about our present predicament."
In a similar vein "Paul Samuelson: Financial Crisis Work of 'Fiendish Monsters'":
"Q: What should be the appropriate spending policy this time around?

A: ...I don't know whether your roads, whether your railroads are or are not in need of new things. ... If you're very foolish you will spend where the lobbyists want you to, like building bridges to nowhere. But there are plenty of things, from windmills to nuclear plants, that are useful and worth spending money on.

Spending in the direction of the poor part of the population (is important) because those are the people who are most likely to re-spend. If you primarily spend in the direction of your millionaires, that won't make any difference."
And Toxic Leaders.
Somewhat better news:
Maybe De-Coupling Isn’t Dead links to Rogoff: The Exuberance of India.
Blanchard roundtable: In conclusion:
"We don't sound like expert diagnosticians debating which of several potential infections could be causing a patient's trouble. We sound like witch doctors who can't agree on just where in the body the lifeforce can be found."
And Refuted Economic Doctrines #1-5.

Ruchira Paul on her book reviews

From Bland Book Reviews :-) :
"Namit draws attention to Narayan's impassioned critique of the author's style and my own descriptive plot driven approach to the review of the same novel, Sea of Poppies by Amitav Ghosh. In response to Namit's query I will attempt to explain to our readers why my book reviews come across more as précis style presentations than literary criticisms.

Although an avid reader from early childhood, I have never been a terribly literary person. I treat books very much like meals - to be examined, consumed, deriving whatever nutrition they offer and moving on. Some are relished like gourmet treats, some approached with playful or cautious interest and others summarily rejected after the first bite. No matter how deep an imprint a book leaves on my memory and my psyche, I feel little need to dwell too long on it or to connect it to a past or future reading experience in any formally meaningful way. Although I do recall with precision how a very good book managed to touch me, I don't feel compelled to recount the details of those feelings to others who may or may not agree with my assessment. Reading seems like a very private enjoyment. Therefore the lack of ardor in public."
And more. Bloggers often write about topics about which they do not have much expertise but are not entirely aloof from the topics they discuss, like to share and exchange information with others and move on. Seems like a sensible approach to me.

Sunday, February 01, 2009

Indian mathematics miscellany

Sreenivas Paruchuri, organizer of racchabanda and other sites (and one of the most learned people I know on Indology topics) informs of the arrival of Mathematics in India: 500 BCE-1800 CE by Kim Plofker . Kim Plofter did her Ph.D. in 1995 with
David Pingree and wrote several scholarly articles about Indian mathematics . Many wondered why India has not been able to keep up with these wonderful achievements(see, in particular Kerala school of astronomy and mathematicsand the work of Madhava ). Frits Staal reviews some of this work and comes up with his own speculations in Artificial Languages Across Sciences and Civilizations and the briefer reports The Generosity of Artificial Languages and The Generosity of Artificial Languages in an Asian Perspective . Some excerpts from the later report:
"An illustration of our topics of discussion is the discovery by Madhava of Kerala, Southwest India, who lived around 1400 CE, of infinite power series that are expansions of pi and the trigonometric functions sine, etc. This took place almost three centuries before these same series were re-discovered in Europe by Newton and Leibniz. In Europe, that event led to the infinitesimal calculus, which could not have been expressed without the help of an artificial mathematical language. In India, that revolution in language did not take place: Madhava and his followers continued to write in Sanskrit or Malayalam, the Dravidian language of Kerala. The accompanying illustration depicts, on top, the infinite power series that expresses the circumference of a circle with diameter D (i.e., two times the radius R) in Sanskrit, followed by a translation into English by A. K. Bag. At the bottom is the series in its modern form which is basically the same as what was written by Newton.
Newton's laws were not always written in an artificial form. He formulated in cumbrous Latin, later disambiguated and clarified by Euler, the law of motion that is now taught to children as f = ma.

Absence of artificial notations and especially of the calculus go far towards explaining why modern science did not originate in India or China. Earlier forms of Asian mathematics inspired the algebra of the Arabs but to what extent was that an artificial language? India did develop a formal or artificial language but that was in linguistics and two millennia earlier."
From the longer paper (page 130):

"In Indian mathematics, infinite power series were discovered almost three centuries before it happened in Europe. Indian mathematics is, in this respect, as good as Newton's, but Samskrit was not artificial enough, it was not replaced by equations and the Indian development ground to a halt.
My next conclusion is more tentative. It is elicited by several questions. Indian grocers have combined the use of place value (already to known to the Babylonians) with Indian numerals including the zero that have been called the essential part of the development of civilization. But why did Indian mathematicians use cumbersome expressions derived from linguistics? Was it to add the prestige of the science of language to the humdrum activity of mathematical calculations? Was it because they thought of mathematics itself as a language, good for composing verse and telling stories and useful for doing sums? Was it for excluding outsiders? Was it for several or all of these reasons? I tend to think that India's lingustic skill may have been not merely irrelevant or superfluous, but detrimental to the development of her mathematics- brilliant as it was."
Perhaps the stupendous achievements of Panini have cast a long shadow. Similar questions about science in China (sometimes both China and India) are discussed under
titles like Needham question .