2. Facets of material behaviour: mechanical behaviour of materials

In the previous blog we talked about how there are various facets to material behaviour. We are interested particularly in the mechanical aspects. What do we mean by the mechanical behaviour of materials?

Basically mechanics is the study of movement of objects. In many situations would like to know where a particular object will be at a later time. For example,  when a football is struck for a pass, we may want to move towards and intercept it during a game. It appears that humans (and most other animals) are very good estimating this movement in many simple cases. However, when the motion of an object is more complicated, such as the path of a person walking on a spinning carousel, a more careful description is required.

As a first step, it was proposed by Newton that the motion of bodies is determined by a quantity called "force" acting on them. To be more precise, the change in velocity of an object in a given time is due to the direction and quantity of the force acting on it. Based on this description it's possible to calculate the positions of objects ranging from trucks on highways to planets in the solar system.

So far we've been talking about the motion of "rigid bodies". That is, while the whole body may move from place to place, the parts of the body don't change their positions relative to each other. Such a process is called the deformation of a body. Bodies do deform quite often and we need to be able to describe that as well. For example, if a basketball is bounced on the ground, it moves without deformation till it touches the ground. During contact with the ground it actually changes shape and becomes flatter. During this time, the parts of the basketball are moving relative to each other and the basketball deforms. The study of such a process is called the Mechanics of Deformable Bodies. 

In the next blog, I will describe how deformable bodies are studied.

From the teacher we learn one part...

This is nice subhashitam (wise saying) in samskritam which I like a lot.

The student learns one fourth from the teacher, and one fourth from own intelligence.

One fourth is learnt from one's friends and a fourth with the passage of time.

This tells us about how we learn. We learn from our teacher. But then we need to continue to think about what we have learnt. Our innate intelligence does some more work for us in this process. We also then need to discuss what we have learnt with our friends and classmates. They will usually say things differently and this gets us thinking and to understanding. Finally, we are able to understand things over time which we may not have at the time of learning. So there is no reason to be frustrated if we can't understand things right away. Also, even if we did think we understood something, we usually get a different perspective and maturity of understanding over time. We need to approach our learning with patience.

1. Facets of material behaviour: introduction

My research area is in understanding the mechanical behaviour of materials. In the course of the next few blogs, I will try to describe what we know and what remains to be studied in this research area.

Materials are the basis of civilisation. In fact, the kinds of materials humans use has even been used to classify the various historical eras of humankind. For example, societies which used primitive stone tools were called Palaeolithic (from Paleo - old + Lithic - stone). They were followed by stone using societies which were more sophisticated and were called Neolithic. These were followed by the bronze ages and Iron Age (from about 1300 BCE). Even now we still use Iron and steel the most. However, the current age is sometimes also called the Silicon age due to the wide use of this material in fabricating computer chips. Steel is still the most common structural material.

We use different facets of material behaviour for various purposes. We may burn materials to obtain heat and their chemical behaviour becomes important then. We may use materials for their ability to reflect light to make mirrors and their optical properties become important. Or we may use materials to keep the cold out and their thermal properties play a key role. Alternatively, we use materials to conduct electricity based on their electrical properties. But, perhaps most importantly, we use materials to support things (tables, chairs, buildings, aeroplanes) and their mechanical behaviour is the important aspect to understand for these purposes.

In each of the above facets of material behaviour, we are constantly trying to do better. Can we get more heat from burning less material? Can the optical properties be made to last longer? Can we keep the cold out with lighter material? And so on. Engineers are constantly looking out for something better all the time.

In the next blog, I will describe some more detailed aspects of the mechanical behaviour of materials and what we are looking for.

Discussion on a Teacher's day article asking teachers to reflect

A colleague forwarded an article in a newspaper which seemed to ask teachers to reflect on their role as teachers:

https://indianexpress.com/article/opinion/columns/teachers-must-have-their-day-5966774/

I didn't read it initially but when several colleagues commented that they thought it was well written, I decided to read it as well. It literally made no sense to me so I wrote up a review of the article and forwarded it to my colleagues. I reproduce my review here:

I just read the article to see what I could reflect on to improve as a teacher. To be perfectly honest, I thought this article was quite poorly written.  The article has no coherent structure and does not lead to any explicitly stated points.

1. First paragraph: "From A to B, from C to D: the ideals have always given meaning to the vocation of teaching" is the first sentence. From A to B usually refers to a range of activity spanning a spectrum. Is Yajnavalkya different from Tagore and Gandhi different from Freire? If so, in what way? As a general reader, am I supposed to know those details? I guessed at the end that the author is pointing to a common thread of a "dialogic" approach in all four and that is the "ideal". So are these the only range of ideals that have ever given a meaning to the vocation of teaching? A mother teaching her child on her lap, fisherperson teaching how to fish, a weaver teaching how to weave do not give meaning to teaching? If so, why not?

2. Second paragraph: The general populace repeats a rhetoric but teachers have lost everything positive about the vocation. Are the rest of the examples in this paragraph of teachers who have lost everything positive about the vocation? Are they not adding any value to the students? If this is the point of the paragraph, surely the author should discuss more? Sure, some of us are "subject experts" (why the scare quotes?) doing routine things? If this is wrong, should every teacher be "general expert" doing non-routine things? How can we do that? Any pointers?

3. Third paragraph: How does our society "reproduce a system in which quite often the wrong people join the vocation"? The rest of the examples in this paragraph point to how people can be demotivated *after* joining the system. There are no pointers to how the wrong people join the system and who these wrong people are. The rest of the examples also do not really show what about the system demotivates the teachers. Why are teachers tired/exhausted/demotivated? Because of election/census duty? Poor salaries? Control by principal or management? If so, some discussion on why this happens is necessary. Just saying it is so adds no value. Also, does not the average person on the street respect their teacher in a genuine fashion even now (however well or badly they fared in their education so far)? If not, does the author have any data about that? Without this data, how can the "illusion" be removed?

4. Fourth paragraph: The first factor is not clear at all. What aspect of Nachiketa would the author want to emerge? What does it even mean to say Nachiketa "emerged"? As far as I remember this story does not talk about any aspect of a teacher's role. Nachiketa himself was very curious about the nature of the self and asked Yama some questions about it. Also, how would the author say a flower has bloomed or it has not? The author has declared it cannot bloom so I guess the question does not even arise.

5. Fifth and sixth paragraphs: Quantification of outcomes is bad? Is it not important to the physical sciences, engineering and medicine? Should we not examine if the student is able to design a structure which does not fail? Should we not examine if they remember interactions between prescribed drugs before they go out to be doctors? Should we not examine if doctoral students are able to publish a thesis and defend it before their peers? Even in the social sciences, is the author claiming that a teacher cannot and should not measure how a student assimilated things learnt in a history class? 

6. Seventh paragraph: Is this a prediction? "This dystopia may not be altogether unreal." This sentence does not make sense. Is it currently real or a prediction? If it is a prediction then what is the meaning of saying it may not be altogether unreal? Shouldn't the author say "It is not farfetched to expect this dystopic situation to arise" or something to that effect? Besides, what about what was said so far in the essay leads into the predictions of this paragraph?

7. Eighth paragraph: The author is now claiming a political situation is causing a totalitarian discourse which is detrimental to "creative ideas". This paragraph mixes up tenses so it's not clear if there will be problems in the future or they are already here. What does this poorly written long sentence mean: "Hence, as the message would be conveyed, it is not a good idea if a teacher encourages what Freire would have regarded as a “problem posing education”, or if, for instance, she asks her students to write a paper on the social construction of a macho “saviour” through the 24×7 “patriotic” television news channels and instantaneity of Facebook and Twitter."? Is the teacher not able to do this currently or will they be stopped from doing so in the future? If they are being stopped currently, how are they being stopped? I'm curious about the mechanism by which one may be stopped, as envisioned by the author.

Finally: ​So how do we "renew the faith in the very meaning of the vocation of teaching"? What is the "very meaning"? How can I "renew faith"? Nothing about this essay has pointed me in any direction. So should I follow this dictum "We are wanderers. We are explorers. We are poets, philosophers, thinkers, visionaries" and "trust myself"? to solve all the problems of how the society has devalued the ideals and how the "wrong people" are in this vocation? And even if I wanted to, how do I implement these dicta?

First thoughts

I'm planning to put down my thoughts here fairly regularly. I hope to cover topics ranging from my research interests to teaching to general thoughts on Science and Philosophy. I really hope to be able to write about my other interests: Samskritam and Tennis as well...