Aliceland

Migration!

2005-12-16T19:27:00.000+05:30

I am planning to migrate to Wordpress.com (and, thanks Abi for the tip). The main advantage I found with Wordpress is that they allow categorisation of posts. So, I do not need to maintain two different blogs, and it makes easier for people to navigate through the blog based on their topics of interest. In addition, wordpress also allows for private (and password-protected) posts. The new blog is called Entertaining Research--the Alicious adventures of a Malkanthapuragudi-an. It will take a while for the new blog to be customised; in the meanwhile, any comments or suggestions you may have are welcome! See you there!

The new firefox experience!

2005-12-12T20:05:00.000+05:30

Here is an essay from Wired News about the firefox hacks that you must have!

Singing Neanderthals - Yet another review!

2005-12-11T21:42:00.000+05:30

Through PTDR, I learnt about another review of the singing Neanderthals--this time around by Ellen Dissanayake. The book is getting such nice reviews, next time I visit strand, I should check if they have a copy!

Description of computer languages!

2005-12-11T17:46:00.000+05:30

Paul Graham has this nice description of computer languages in terms of the problems that they fix. Worth taking a look

Future of HTML!

2005-12-09T15:37:00.000+05:30

Part 1 of a two part essay on the future of HTML; link via /.

Wanna read about evolution?

2005-12-07T15:14:00.000+05:30

An Update
Here is another humorous post via Pharyngula--Just don't miss it. It is so funny, I have not stopped laughing yet!

The inimitable Pharyngula, who never fails to amuse, is out with a reading list for evolutionists--just in case you might be interested. Even otherwise, bookmark or save the post--might come handy sometime!

Breaking the diffraction barrier!

2005-12-07T08:54:00.000+05:30

I was under the impression that the resolution of any optical microscope would be limited by diffraction; apparently, it is not so. The latest PNAS carries an article about breaking the diffraction barrier in flourescence microscopy using photoswitchable proteins. Here is the abstract. By the way, the paper is classified (also) under the key keyword nanoscopy.

I am yet to understand the concept of how they break the diffraction barrier; that might answer the question as to whether this method can be used for the study of non-biological specimens. The paper does contain micrographs of grooves on a glass specimen obtained using their microscope. However, those are obtained by filling the grooves with fluorescing proteins (by absorption). In that case, absorption of a fluorescing medium will be a necessary condition, and, I do not know if metallurgical samples, for example, absorb any such dyes. Any pointers?

The pleasures and profit of googling!

2005-12-06T15:20:00.000+05:30

I was looking for something else when Google Scholar returned me this review article on electron crystallography. It was published six years ago; so, some of the information might be obsolete. However, for a non-biologist like me, the article read nice--with many "contrary to common intuition" nuggets--and was extremely interesting. Further, since the article tries to answer questions like,

(1) What is the minimum number of molecules that is required to obtain a statistically well-defined, three dimensional density map at 0.3nm resolution? (Yes--It is about nano, after all),

(2) What is the smallest molecule for which data can be merged at 0.3 nm resolution, and,

(3) What is the role of crystals in electron crystallography, etc.,

it might still be relevant. So, in case you have an afternoon free and would like to read something interesting outside your area of specialisation, here you go!

Two links from /.

2005-12-06T03:41:00.000+05:30

Apparently, caffeine prevents liver disease, and, Branden Robinson, one of the maintainers of Debian answers a nice mix of personal and Debian specific questions. So, grab a cuppa and head over to Tux Journal. Here are some of the questions that might interest you: for the answers, of course, you should head to the Tux Journal.

3) Why a person could move to Debian? What are the advantages? What could he do with Debian? And what he couldn't in place of other GNU/Linux distributions?
6) Are there some problems to porting Debian on others architecture?
7) What are your favourite programming languages? Why do you use them?
8) How many hours do you code in your daily life?
12) Could Debian become the premier home-user and desktop operating system?

Would love to watch that!

2005-12-05T06:14:00.000+05:30

Apparently, a movie has been made documenting the process of software creation: link via /.. That reminded me of those wonderful videos of the problem solving sessions of Prof. Knuth (appropriately titled "Aha" sessions) from Stanford Center for Professional Development.

Third revision of GPL!

2005-12-01T19:09:00.000+05:30

According to Boing Boing, the next version of GPL is getting drafted; and, what is more,

The new GPL is pretty controversial, but it could plug some major holes, like the one that allows people to use trusted computing to technically comply with the license by publishing their code, but to subvert its purpose by keeping your computer from running the code if you change it.

All you free software fans might wanna take a look at it!

A bit of futurity!

2005-11-28T17:31:00.000+05:30

Interested in nano-medicine, and knowing why it would be a blessing and a curse? Here is an article published in Salon titled Nanomedicine's brave new world which might interest you. The article has many rather fascinating passages like this one:

A machine that "shreds" a billion bases of DNA a day could burn through the human genome in 72 hours. Yet we fully expect that this phenomenal accomplishment will be eclipsed within a few years by nanoengineering. Around the world, research teams are closing in on single-molecule DNA sequencing technology. One group has published a design for an instrument that could place a million single-molecule sequencers on a device the size of a postage stamp. To accomplish this, each sequencer will have an operating volume of one zeptoliter -- much less than one billionth of one billionth of a liter! There can be no doubt that within a few years, most individuals will have their genome sequenced and encoded as part of their medical record. And this is just the beginning.

Happy reading!

Another update: Melting mechanisms!

2005-11-27T23:46:00.000+05:30

Do you rememeber the earlier post about melting mechanisms? Here is a very interesting letter by Wang et al published in the May 2005 issue of Philosophical Magazine Letters [vol. 85, no. 5, pp. 213-219(7)], in which they propose a vacancy decomposition induced lattice instability to explain melting. Here is the abstract:

Vacancy decomposition kinetics in crystals at elevated temperatures is analysed. It is found that lattice instability is induced by a significantly enhanced vacancy decomposition at a critical temperature ( T *). The critical temperature coincides with the kinetic instability limit (kinetic limit of superheating) of crystals in a variety of metals determined from the homogeneous nucleation catastrophe model.

While we are on the topic, there is also this paper by Mei et al published in the April 2005 issue of Philosophical Magazine Letters [vol. 85, no. 4, pp. 203-211(9)]; this one is about the kinetic limit of supercooling induced by semicoherent interfaces. Here is the abstract:

The superheating behaviour of embedded particles induced by semicoherent interfaces has been observed in many circumstances. In this paper, a phenomeno- logical model for melt nucleation on misfit dislocations at a semicoherent interface is proposed. A kinetic limit for semicoherent-interface-induced superheating, which is in good agreement with the results of experiments and computer simulations, is derived from this model. Calculations and analyses based on the model reveal that melting prefers to initiate at the semicoherent interface and that superheating of embedded particles is possible for a melt nucleation contact angle less than 90°. Among the matrix-dependent parameters, the contact angle and the shear modulus of the matrix are found to be dominant in determining the superheating of embedded particles.

Not surprisingly, both these papers originate from the same group in Shenyang, China, and both are worth taking a look at.

An update: vacancies and stress!

2005-11-27T23:13:00.000+05:30

Svoboda et al have published a paper in the 1st September 2005 issue of Philosophical Magazine Letters [vol. 85, no. 9, pp. 473-479(7)] on the vacancy mediated stress relaxation in misftting precipitates. Here is the abstract, in case you might be interested.

Vacancy diffusion is investigated as a mechanism for relaxation of the elastic strain energy caused by a misfitting inclusion. The kinetics of reduction of the total eigenstrain by the deposition or removal of an atom layer along the interface is derived. The time evolution, as well as an estimate for the characteristic time of the relaxation process, is presented. The relaxation times are compared with recent in situ measurements of stress relaxation times in aluminum with small lead-alloy inclusions after their solidification. Experimentally observed relaxation times and those theoretically predicted agree very well.

The experiments that are being referred to are the same ones that we discussed earlier.

Young-Laplace or Gibbs-Thomson equation

2005-11-27T19:49:00.000+05:30

"Every idea in the study of phase transformations can be traced to Gibbs" is a favourite quote of Abi. The latest American Journal of Physics carries an article about the Young-Laplace equation and its derivation, which, in metallurgical literature goes by the name of Gibbs-Thomson equation. I found the following paragraph about the merits of local derivation quite interesting.

A more important point is the character of Young's and Laplace's equations. Because they are local conditions that apply to any portion of the surfaces, a local derivation is more appropriate. From the global approach, one might think that the total energy of the system must be minimal for these equations to be valid, which is not true. The condition of minimum energy is restrictive. If the contact line moves slowly enough (see Sec. III E), Young's equation is obeyed even if the rest of the system (far from the contact line) is not in equilibrium. In contrast, a rigorous global derivation must minimize the energy at constant entropy or the Helmholtz free energy at constant total volume. These additional constraints to the minimization problem should be irrelevant for the derivation of a local equation. Although necessary in the global approach, they may be a source of confusion about whether sigmai is the surface Helmholtz or Gibbs' free energy. (In this respect, the paper by Tolman is enlightening.) In the local approach, the surfaces move without any constraint. In particular, the local derivations are valid even for a nonequilibrium state where the temperature is not homogeneous.

But the conclusion was far more interesting:

In spite of the merits of the local approach, Gibbs' derivation (global approach) seems aesthetically more appealing because all laws governing equilibrium (thermal, chemical, and mechanical equilibrium) are deduced at once. We conclude that the global approach is more suitable if one is interested in the equilibrium conditions of a fluid system, whereas a local approach is preferred for the derivation of Laplace's and Young's equations.

A pedagogical article; well worth the efforts of reading.

Mystique of physics

2005-11-27T19:25:00.000+05:30

The latest issue of American Journal of Physics carries Millikan Award lecture of John S. Rigden. An extremely interesting essay - here are some sample quotes:

Against this rich background I ask: Could the people of the 21st century reverse the transformation that occurred 200 years ago by rejecting the methods of science in favor of the assertions by authority?

It is not my purpose to examine the challenges that now confront the science instructor and the science classroom. Today, a number of state legislatures, many state departments of education, and many, many local school boards are currently exerting their authorities as they consider actions that would mandate what is taught and how it is taught in the science classroom. Equally troubling, the very definition of science is being challenged with the goal of bringing into the science classroom material that lies outside the scope of the current definition. This could change science as we know it.

I believe these challenges are serious.

The crucial issue is not the belief in a Divine Designer; in fact, to examine the intricacies of Nature and to see evidence of design is thoroughly rational. The Divine Designer belief is, per se no threat to science. If, however, it is denied that physical laws drive natural processes, if it is denied that physical laws initiate chains of cause and effect that culminate in the beautiful world we observe, if it is denied that science is mechanistic and deterministic, and if these denials become part of the science classroom, then science as we know it is dead. Are the delicate filigrees of frost on a cold window pane caused by anything other than natural mechanism driven by physical law? Are the cosmic wonders revealed by the Hubble space telescope anything other than physical laws working over billions of years?

...

Debates pitting faith-based beliefs against empirical-based beliefs, have not worked and, in my judgment, will not work. They have not worked because, as always, debates degenerate into point-counterpoint exchanges that only embolden the debaters. Debates heat emotions, but freeze minds. In the context of passionate belief, debating is a negative strategy.

Finally,

On July 7, 2005, the Roman Catholic cardinal archbishop of Vienna, Christoph Schönborn, laid out the position of the Catholic Church on the subject of evolution. However, the argument the cardinal developed was more general than evolution and implicitly, it embraced all science. In the New York Times the cardinal began by quoting the late John Paul II. "We believe," said the Pope, "that God created the world according to his wisdom. It is not the product of necessity whatever, not blind fate or chance." Cardinal Schönborn concluded: "Scientific theories that try to explain away the appearance of design as the result of `chance and necessity' are not scientific at all, but...an abdication of human intelligence."

Both the Pope and the cardinal denied necessity. Both the Pope and the cardinal are mistaken. If you believe that the physical world is a consequence of physical law, then what we observe is the consequence of necessity. Masses attract out of necessity; energy is conserved out of necessity; the neutron decays out of necessity; and out of necessity, DNA in the gametes determines the characteristics of the resulting organism. There is no choice, there are no alternatives. The laws of physics undergird all science; if the laws of physics, operating out of necessity, are denied in any tributary of science, then the main stream of the entire scientific enterprise is dangerously compromised.

The Enlightenment showed that Reason and the reasoned approach to unlocking the secrets of Nature had enormous appeal to Homo Sapiens, the thinking animal. The physicists of the 19th century brought physics to the forefront of people's thinking and left them with the confidence that the claims of physics could be believed. I suggest we relumine the Enlightenment. I suggest we emulate 19th-century physicists. I suggest we capitalize on the mystique of physics. I suggest we provide students with positive examples that demonstrate what physicists believe and why they believe it.

A nice read; it also contains many ideas to think about and a bit of history, if you are so inclined.

Just can't wait...

2005-11-27T18:53:00.000+05:30

This review is so tempting, I just can not wait to lay my hands on the book.

Mechanical behaviour of metallic glasses

2005-11-26T19:19:00.000+05:30

The latest Scripta Materialia carries a viewpoint set on the mechanical behaviour of metallic glasses. Probably, the preface by Prof. Hufnagel is a nice place to begin. To quote from this preface:

Thus, now seems to be an appropriate time to take stock of what we have learned, and to lay out visions for the future of metallic glasses, in terms of both practical applications and new research directions. These are the goals of this viewpoint set, and the papers have been selected with them in mind.

The general enthusiasm for any new class of materials sometimes leads to grandiose claims for the potential of the materials in question. By now, however, enough data has been gathered on a variety of amorphous alloys that we can attempt to replace the hyperbole with more reasoned speculation.

...

In summary, I believe that this viewpoint set provides a useful snapshot of the current state of knowledge of mechanical behavior of metallic glasses. I fully expect that the future will see continued advances both in our understanding of fundamental aspects of mechanical behavior, as well as new applications of metallic glasses and metallic-glass-matrix composites.

An issue worth taking a look at if your interests are mechanical behaviour and/or metallic glasses.

Pope and mathematician!

2005-11-26T18:59:00.000+05:30

Here is a very interesting profile of a Pope who was also a mathematician. Reminded me of what Prof. N. Mukunda used to say about Riesz (I think); a fine mountaineer who also happended to be an analyst!

Return of the singing Neanderthal

2005-11-26T18:28:00.000+05:30

Nature reviews The Singing Neanderthals; here is an earlier post about the book.

Institute colloquium of Prof. KC!

2005-11-23T17:34:00.000+05:30

At the Institute, three to four faculty members are asked to give the Institute Colloquium every year; and, it is considered an honour to be asked. Today, Prof. Kamanio Chattopadhyay, Tata Chem Chair Professor and Chairman of the Department of Metallurgy gave the colloquium.

Prof. KC's talk was about forms, patterns, and crystal structures (or, in short, microstructures) as a result of ordering and repulsion at the atomic level. It was one of the nicest lectures that I have heard. The micrographs that were flashed were of very high quality. Prof. KC also brought out many of the issues and their resolution in microstructural evolution in a simple and easy-to-understand manner. Probably the overcast skies and the rainy weather was the reason for the relatively thin attendance; but, I would not have missed the lecture for anything.

One long argument...

2005-11-21T18:41:00.000+05:30

Here is Prof. EO Wilson on Darwin's one long argument, namely, Intelligent Evolution. The essay is wonderful with some extrordinary drawings; a not-to-be-missed piece. You can also download the pdf version of the article, if you are so inclined. Not surprisingly, the essay discusses (and ends with a reference to) evolution and religion:

In any case, the dilemma to be solved is truly profound. On the one side the input of religion on human history has been beneficent in many ways. It has generated much of which is best in culture, including the ideals of altruism and public service. From the beginning of history it has inspired the arts. Creation myths were in a sense the beginning of science itself. Fabricating them was the best the early scribes could do to explain the universe and human existence.

Yet the high risk is the ease with which alliances between religions and tribalism are made. Then comes bigotry and the dehumanization of infidels. Our gods, the true believer asserts, stand against your false idols, our spiritual purity against your corruption, our divinely sanctioned knowledge against your errancy. In past ages the posture provided an advantage. It united each tribe during life-and-death struggles with other tribes. It buoyed the devotees with a sense of superiority. It sacralized tribal laws and mores, and encouraged altruistic behaviors. Through sacred rites it lent solemnity to the passages of life. And it comforted the anxious and afflicted. For all this and more it gave people an identity and purpose, and vouchsafed tribal fitness — yet, unfortunately, at the expense of less united or otherwise less fortunate tribes.

Religions continue both to render their special services and to exact their heavy costs. Can scientific humanism do as well or better, at a lower cost? Surely that ranks as one of the great unanswered questions of philosophy. It is the noble yet troubling legacy that Charles Darwin left us.

Link via PTDR.

I got into computers...

2005-11-21T17:46:00.000+05:30

because I was forced to; and, here are some geeks telling how they got into computers. At least one of the stories (by Karl Fogel) is really cool; link via BoingBoing.

Physics Nobel 2005 controversy

2005-11-19T18:33:00.000+05:30

I did not know about this Physics Nobel prize 2005 controversy; Frontline discusses the contributions of Prof. ECG Sudarshan, and Prof. Sudarshan's response.

Bed-time (technical) reading

2005-11-18T20:20:00.000+05:30

Your interests might be in knowing the mathematics behind voting models; Einstein's theory of Brownian motion; materials, spintronics and smart structures; the contributions of Hans Bethe to solid state theory; ancient Indian mathematics and astronomy; biology, John Maynard Smith, and evolution. Whatever it be, this is the place to go! And, do not miss this gem of a review by Prof. R. Gadagkar.

Such pleasures, sister... only Resonance can offer!