Spending Control

The urge to write this blog came up when my wife and I were doing early spring cleaning and realized how much stuff we bought despite the efforts to minimize them. I need to remind myself.

I figure sometime ago that spending control is more important than saving plan. On practical level, saving plan is not realistic since it makes me starved. In contrast, spending control teaches me to learn who I am.

My other argument for this spending-control strategy is that whatever I buy is likely worth nothing after the purchase. To test that theory, you can go to IKEA to buy the sofa you've been dreaming about and try to sell it on Calgary Kijiji - a free online marketplace - for the same purchase price, and see if there is someone interested in buying.

As a result, I don't buy clothes unless I need to replace ones that are completely worn out. I keep only two pairs of shoes - one for running, the other for work. I don't wear a wristwatch anymore since my cellphone tells time. My prescription glasses were bought 16 years ago and I still wear them.

I learned the hard way. I bought a new car 9 years ago and learned that it was difficult to sell it one year later when I needed money. The satisfaction of owning a new car also wore out very quickly for me. I never liked forking out $450 every month for the next 5 years. I realized then that I was poor and not cut out for expensive stuff. I told myself that I would never buy a new car again since any new car depreciates very fast.

I am also motivated by my life philosophy. Less is more. My dream is to fit all my clothing and personal amenities in one backpack, and I am still working on it.

On Bullshit: Excerpts

One of the most salient features of our culture is that there is so much bullshit. Everyone knows this. Each of us contributes his share. But we tend to take the situation for granted ... Nonetheless it should be possible to say something helpful, even though it is not likely to be decisive. Even the most basic and preliminary questions about bullshit remain, after all, not only unanswered but unasked.

In the old days, craftsmen did not cut corners ... These craftsmen did not relax their thoughtful self-discipline even with respect to features of their work that would ordinarily not be visible. Although no one would notice if those features were not quite right, the craftsmen would be bothered by their consciences. So nothing was swept under the rug. Or, one might perhaps also say, there was no bullshit.

It is just this lack of connection to a concern with truth–this indifference to how things really are–that I regard as of the essence of bullshit ... It does seem that bullshitting involves a kind of bluff. It is closer to bluffing, surely than to telling a lie ... Lying and bluffing are both modes of misrepresentation or deception ... Now the concept most central to the distinctive nature of a lie is that of falsity: the liar is essentially someone who deliberately promulgates a falsehood ... Bluffing, too, is typically devoted to conveying something false. Unlike plain lying, however, it is more especially a matter not of falsity but of fakery. This is what accounts for its nearness to bullshit.

This points to a similar and fundamental aspect of the essential nature of bullshit: although it is produced without concern with the truth, it needs not be false. The bulshitter is faking things ... A person who undertakes to bullshit his way through has much more freedom. His focus is panoramic rather than particular. He does not limit himself to inserting a certain falsehood at a specific point, and thus he is not constrained by the truths surrounding that point or intersecting it. He is prepared, so far as required, to fake the context as well.

Someone who ceases to believe in the possibility of identifying certain statements as true and others as false can have only two alternatives. The first is to desist both from efforts to tell the truth and from efforts to deceive. This would mean refraining from making any assertion whatever about the facts. The second alternative is to continue making assertions that purport to describe the way things are, but that cannot be anything except bullshit.

Bullshit is unavoidable whenever circumstances require someone to talk about without knowing what he is talking about. Thus the production of bullshit is stimulated whenever a person's obligations or opportunities to speak about some topic exceeds his knowledge of the facts that are relevant to that topic ... Closely related instances arise from the widespread conviction that it is the responsibility of a citizen in a democracy to have opinions about everything, or at least everything that pertains to the conduct of his country's affairs. The lack of any significant connection between a person's opinions and his apprehension of reality will be even more severe, needless to say, for someone who believes it his responsibility, as a conscientious moral agent, to evaluate events and conditions in all parts of the world.

The contemporary proliferation of bullshit also has deeper sources, in various forms of skepticism which deny that we can have any reliable access to an objective reality, and which therefore reject the possibility of knowing how things truly are ... Rather than seeking primarily to arrive at accurate representations of a common world, the individual turns toward trying to provide honest representations of himself ... As conscious beings, we exist only in response to other things, and we cannot know ourselves at all without knowing them ... Facts about ourselves are not peculiarly solid and resistant to skeptical dissolution. And insofar as this is the case, sincerity itself is bullshit.

(The above paragraphs are taken verbatim from the book On Bullshit by Harry Frankfurt. They form a concise summary for us who want to cut the bullshit.)

Value of Education

Education is a way to learn from the past and to chart our future.

For me the value of education is to fight boredom. Brain is one of our organs and it needs regular exercise. We go to gym to make our body healthy. Where do we go to have brain exercise?

I get bored when I don't know what to do. It happens when (i) problems around me are too difficult or too easy for me to solve, (ii) I don't have money to spend, or (iii) I don't have someone to talk to. I can do nothing for the second reason, but the other two reasons are related to our brains.

If one is not educated, he will not know how to occupy his mind. Put it mildly, he does not know how to waste his time well. He has little interest in activities that make his brain sweat. He does not like brain exercise. He just wants to be entertained. What often happens is that he settles for spending money to fight boredom. He thinks spending money buys a cure for boredom. That's why we have the term "retail therapy".

I am not saying an uneducated man cannot be a hard worker. They are not correlated as far as I can see. An educated man can be lazy; in fact, a highly educated man is often lazy since he thinks he can solve world problems by just thinking about it or daydreaming or writing a blog ;-(

What I am saying is a person with education knows how to waste his time. He reads books and thinks about stuff that interest him. This activity gives him knowledge, ideas, motivations, and hopefully a plan of actions. When he thinks about all these things - I can assure you - he will not get bored.

A lack of education also causes one to believe problems in this world are not interconnected. The perspective will be narrow and one-dimensional. He then believes that there is no point to worry about this world since to comprehend it is beyond his wildest imagination. He can be easily misled and manipulated by political parties, advertisements, con-artists, among others, since other people do the thinking for him (or not).

What is funny though is that too much education can cause one to think these problems are too complex to solve. He overthinks them and wants to map out everything in his head. He does not act unless he knows everything. This is unfortunate. Education does not free him, instead it imprisons him. Instead of taking the first small step of action, he worries about the biggest problem in a far distance future. He becomes a constant worrier (not a warrior).

We Make Our Own Problems

Traditional market - Pasar Gede in Solo - is more enjoyable than a supermarket.

Life is absurd. How can it not be? Let me give you an example.

This world is now such that you can find almost any product you can imagine. From disposable plastic stirrers to disposable marathon running shoes. They create convenience. Our lives become easier and more enjoyable. In turn, manufacturing and trading of goods and services create wealth for us to buy more products.

Our lives have indeed become easier and more enjoyable in the past century. The market economy - although imperfect - sustains creation-destruction cycles. Producers that cannot follow changing consumer habits and demands will perish.

The notion of competition comes from our needs to secure raw materials for manufacturing, skills to execute manufacturing processes, and money to buy products. Added to this mixture is the awareness that resources and skills are finite. Some countries are so worried they are willing to go to war or manufacture conflicts to get resources.

Competition then leads to progress. A person or a country needs to generate progress in order to compete. Otherwise, he or it will lose in a battle to secure resources, skills, and money.

The relentless pursuit of efficiency and competition collides with our wish to have enjoyable lives. It demands we work very hard - or else, we don't make enough money to satisfy our shopping needs - in order to lead comfortable lives. We get stressed out to be comfortable, which is a first indication of this absurdity.

Hundreds of stores in Ambassador Mall in Jakarta sell consumer electronics.

We reconcile this contradiction by compartmenting our lives. We work hard during the day and we enjoy our lives in the evening. It happens also in our lifetime scale when we say to ourselves we will get our freedom - that is, retirement - when we reach 55, or 65, or maybe never. Another indication of the absurdity.

What I find amusing is that the stuff of living we enjoy essentially do not change with time. Our brain chemistry has not changed. We like spending time with friends and families. Some do sports, some like eating, and so on. These activities are relatively inexpensive, yet we embellish them to look more expensive and desirable. Because of these embellishments, the cycle of work -> money -> purchases -> perceived status -> work -> ... cannot be stopped easily. We spin in a vicious cycle.

Buta

Aku yakin dunia kiamat
Penuh murka maksiat
Perang mesti kukibarkan
Begitu kata pemimpinku

Aku tadi dilarang istri
Terjang seberang desa
Siapa lagi akan berangkat
Aku tegakkan kebenaran

Jika aku tikam kamu
Karena kita beda agama
Pasti Tuhan akan bangga
Aku yang setia puja

Aku lari berbalut darah
Menang aku telah raih
Bukti padu cinta suciku
Aku tagih janji surgaku

Crash Coffee

Got for free from Starbucks and used once in a blue moon

Making coffee using percolator or even more complicated machines - those expensive Italian capuccino machines - is not my cup of tea (pun intended). I like my stuff simple. I prefer kopi tubruk (crash coffee, literally translated).

I pour coarsely ground coffee and piping hot water onto my cup. Put sugar or milk and stir. Kopi tubruk is ready to serve in < 1 minute with a minimum utensil and dishwashing after that.

Having ground coffee float at the top also helps decide when I can drink my coffee. When the float sinks to the bottom, it is time to drink. Not too hot, just the way I like it.

I like loose leaf tea as well, especially Japanese genmai cha (brown rice tea), although I prefer Earl Grey tea when drinking tea with sugar.

I still don't get it though why coffee making should be as complicated as it is today. Tea is a lot simpler. I often use tea to wash my camping bowl when camping; I drink the tea and the bowl is clean.

Math = Beauty

Math is a powerful tool to make sense of this world. It self-regulates and tells me I did stupid things if I was not consistent. I have to remember my assumptions as I work through calculations. If these assumptions contradict each other, then math simply tells me so.

It happened this afternoon. I was trying to get a physics formula from a series of calculations. I got the formula, but then I realized that there was a contradiction in one of the assumptions. So I had to throw out the formula even though it was exactly the formula I was looking for.

I know my previous calculations were garbage, I needed to think of another path.

I found the path and also got the formula I was looking for. This time, it has no contradiction. I got another payoff: the path gives a clearer and more elegant answer.

I remember buying that "Godel, Escher, Bach" book to understand the beauty of math when I was undergrad, but I never finished reading it. It is too complicated for me. A more satisfying read is "Why Beauty is Truth" as it also tells about history of symmetry. Books that teach me how to appreciate beauty in math.

I sometimes tell students to have faith in math. That is, we have to allow math to run its course and not to interfere with its process. Try not to have expectations when doing calculations. When there is no contradiction, math will simply show its beauty.

Lives We Want

I believe each of us has two life paths. One is what I have, I chose; one that you chose and have. We chose these lives because we know they promise comfortable lives. Not easy I know, but mostly pleasant. Predictable.

Such life is like a nest under a shade of a big tree. It never sees a snowstorm or a monsoon rain. It is sheltered but secluded. It can lull us. For some it may define what life really is.

The other one is what I didn't choose. The one you didn't choose. The one that fills my dreams. You know, this is the life that your heart always tells you to live, but you didn't have the courage to do it. The dream life I still don't have and want to chase.

I know though the life I want to live. But it will take time to get there. I only hope I have enough time.

Crystal Symmetry

A primitive cubic unit cell with 8 corner atoms. (Created using CrystalMaker software.)

In undergraduate mechanical engineering program, students start connecting macroscopic concepts - such as temperature, pressure, stress - they learn from solid mechanics, fluid mechanics and thermodynamics with microscopic objects - bonding energy, crystallography, dislocations - when they study materials science.

One challenging topic in materials science is crystallography. It has to do with how we characterize and classify arrangements of atoms in three-dimensional space. It is mathematically abstract. We classify different atoms by paying attention to the symmetries of these arrangements.

Symmetry is not a thing, it is a process done to these atomic arrangement. The process changes an arrangement of these atoms to another arrangement without changing how these atoms relate to each other in space.

To study symmetry of atoms in a solid, we imagine the atoms to be arranged in a regular three-dimensional pattern. Because these atoms are placed periodically, we can come up with a building block, a unit volume that can be cloned as many times as required to create a solid of any size we want. This building block is called a unit cell. We call a solid that has a periodic arrangement of atoms a crystal.

One periodic way to arrange atoms in a crystal is to place them at 8 corners of a cubic unit cell. Each corner atom contributes 1/8 of an atom, so one cubic unit cell is occupied by 1 atom. We need to imagine we have other unit cells surrounding the first unit cell forming a crystal filled with atoms. For illustration, however, I just show one unit cell with 8 corner atoms (shown above). I am going to use this cubic unit cell to explain the crystal symmetry idea.

A cubic unit cell viewed squarely onto one of its 6 faces.

The picture above shows the cubic unit cell viewed squarely onto one of its 6 faces. One process that can change the arrangement shown is to rotate it by 90 degree about an axis at the center of the face. We get a new arrangement but this arrangement is identical to the before-rotation arrangement. We thus say that the cubic unit cell obeys the 90-degree-rotation symmetry. We don't call the 180-degree rotation a symmetry of the cubic unit cell since it can be reproduced by two 90-degree rotations. We don't call the 360-degree-rotation a symmetry of the cubic unit cell since it is trivial.

The 6 faces of the cubic unit cell can be divided into 3 groups, and each group has 2 faces. We can perform the 90-degree operation to each face group. So there are total 3 90-degree rotation symmetries.

Another symmetry that the cubic unit cell has is a mirror symmetry. The square face above has four mirror planes. One mirror plane exchanges the 2 left corner atoms with the 2 right corner atoms. Another mirror plane exchanges the 2 top corner atoms with the 2 bottom corner atoms. The other two mirror planes exchange the corner atoms face diagonally. Since there are those 3 groups of faces, there are thus a total of 12 mirror symmetries.

A cubic unit cell viewed along the body diagonal direction.

The cubic unit cell also has rotation and mirror symmetries operating on an axis running body diagonally as shown above. It has a 120-degree rotation symmetry. There are 3 body diagonal axes in the cubic unit cell, so there are 3 120-degree rotation symmetries.

There are also 3 mirror symmetries for each body diagonal axis, so there are 9 mirror symmetries.

A cubic unit cell viewed from the face diagonal direction.

Along the face diagonal direction, the cubic unit cell looks like above. We can rotate this picture 180-degree and the arrangement of atoms does not change. There are 2 axes of this 180-degree rotation for each face group. There are thus 6 180-degree rotation along its face diagonal axes.

There is 1 inversion symmetry about the center point of the cubic unit cell. This inversion symmetry exchanges one corner atom with another one body diagonally away from each other.

The total symmetry operations the cubic unit cell has is therefore

a) 3 90-degree rotation on its faces
b) 12 mirror symmetry operations on its faces
c) 3 120-degree rotation along its body diagonal axes.
d) 6 180-degree rotation along its face diagonal axes.
e) 1 inversion symmetry about the cubic center.

I so far identified 25 symmetry operations for the cubic unit cell. Are there others you can find?

Running for My Life

Hiking trail near Rockbound Lake, Alberta

I try to at least run once a week when things get hectic. It is better to run three times a week as it helps maintain habit. A once-a-week habit can be cruel to my body: it aches all over in the first 20 minutes.

One thing I really enjoy doing when running is emptying my mind. I don't listen to iPod when running so I can hear my rueful breathing. Huffing, puffing, and all. The beauty of it though is that the huffing and puffing focuses my mind and at the same time relaxes it. Actually I don't need to do anything; my mind just on its own relaxes and focuses on the pain I feel every step.

Anyway, in that state of mind, I always get reminded that I can only do what my mind and body can deliver optimally. Nothing more. It does not matter anymore what people see and think because I am alone running and cannot pretend I can run faster than I can. Running - as it turns out - teaches me how to maintain endurance in this game of life.

There is no need to be faster or slower since, if I pretend, it will catch up to me one way or another. So I don't envy when I see people can run faster. He must either train harder or has a better genetic material. Running teaches me not to envy what other people have and can do. Running teaches me to be happy with myself.

Running is a simple activity and gives me a lot of pleasure. I don't need to spend a lot of money to have tons of fun. Sure, I sweat a lot but those endorphins do wonder to my brain. The longer I run the less pain I feel. They also make me feel happy even if I am dog tired.

I like running since I don't have to win or lose. I am not happy when I become slower, but I like the steady pace I make. Trudging along the path. Slow meditative steps I make. It suits me just fine.

Minimize My Living Cost

One way for me to practice living simply and beatifully is to minimize my living cost. Yeah, we know that, don't we? But it is very difficult to PRACTICE it. Just LoOk ArOUnD US. We bought SO MuCH StufF and ended up not using most of them. They are parts of our collections: cards, books, shoes, jackets, and the rest. They fill up our living space and make us want a larger space. And the cycle of living large continues.

I try to instill this value to my sons. At the fundraising to help Merapi eruption victims and Mentawai tsunami victims yesterday, my eight year old son and I sold smoothie. It was his idea and I jumped in since I have been wondering how to teach him the value of MONEY = WORK. The cost was $80 for ingredients - milk, strawberry, yogurt, banana - and menu sign. It was busy 2 hours as I was making smoothies non-stop and I saw him busy receiving money. Good, I said to myself; he is learning how money is made.

We made $149 and one-half went to the fundraising cause. I doubled his profit so he made $140 as a part of the deal he would be selling the smoothie.

This morning he asked me to go to his game store to get the Little Big Planet 2 game. He brought with him old games, and some were valued at 50 cents or less. So he learned another lesson. His brother gave him $25 coupon. He figured out at the end he spent $25 from his money. GooD, I said to myself.

Minimizing my living cost also frees me to do what I want later in life. I don't want to bear a HuGE mortgage when buying home. I don't want to carry TOO much StuFF when I travel. Why create burden? Why be a BeaST of BurDEN?

If I am poor, then I Don't WoRRY too much since my cost is low. If I make some money, I can SaVE to do other THings, like TRAVELing and eXPLORing this WORLD. That's my DREAM.

Can Online Teaching Replace University Classroom?

Coffee shop in Jakarta could become a classroom for an online learning

I regularly feel the urge to write blogs from my teaching materials. I find them a good way to flush these teaching materials out of my memory bank. When I finish writing it, I feel both satisfied and tired. Much like at the end of every teaching I do in front of class.

One good thing about blogging teaching materials is that I don't have to repeat it. I can imagine saying to my imaginary online students: well, they are on my blog, please read it, and contact me if you have questions.

If students can be motivated to read the material first, then the professor-student interaction will always be Q&A sessions. Discussions take place, instead of mostly one-way communication. That would be lovely.

However, I see little incentive for students to read the material first in the classroom delivery model. Why bother? Professors are expected to deliver lectures; they get paid for doing exactly that. This classroom model is what makes university tuition fees expensive. Buildings need to be erected, full time professors need to be hired.

Which leads me to another question: Can online teaching replace classroom model? There are already many online learning materials. Youtube, Wikipedia, online universities, MIT OpenCourseWare project, and various other sites. I don't think it is difficult for any student to come up with an online study plan for a particular topic or course. I don't think either that learning math or physics online is impossible just because they are mathematical. Video, slides, phone conversations can all be delivered online.

Can an online teaching model be effective? I believe it can be more effective when it is accompanied by the Q&A sessions, or at least as effective without these Q&A sessions. The online model is clearly more efficient. It might even simplify learning process of millions of undergraduate students. What does "simplify" here mean?

Monsoon rain washing quadrangle in Department of Physics, ITB

Students might be persuaded to take fewer courses in an online learning environment since they have more freedom to tailor their individual study plans. I used to live in a dorm in my first year undergraduate and remember arts & sciences students took fewer courses than us - engineering students - since they had freedom to choose (and we don't).

Taking more courses does not mean better understanding. My engineering undergraduate years were always in a rush. Doing homeworks, assignments, term projects, preparing exams. Time moved so fast: exams came and went. I had no time to think and reflect on what I studied. I see my students now feel that way. 20 years separate us and there is no difference. I don't like it.

I had time to think and reflect when I only had to take 2-3 courses per term. This happened in graduate school. I started seeing connections among courses I took in undergraduate and I remembered then that my language became more simple.

Students would actually love fewer courses, I am sure, but professional associations and accreditation boards want to uphold standards. These standards often mean the course load tends to bulge over time rather than gets simpler and leaner.

The US has a market driven university system, where both private and state universities coexist. I think a "drive to simplify" in higher education will occur first in the US, not in Canada. MIT and other prestigious universities might at some point expand their online learning projects into full-fledged online teaching business branches that would compete at a local level with universities around the world. This could be one of the last globalization waves, I guess. (Well, the really last two would be really tough to implement: globalization of free labour movement and state governance.)

I don't see any possibility of self simplification within a university since the world has indeed become more complex. There are always valid arguments to add more courses, or at least keep the number of courses the way they are now. One way to simplify as a response to this pressure is to create more specific programs. Instead of simplifying, it will lead to provincialism.

Only market forces will do this; that is only pressure from students will change things around. Or when MIT and its peers start offering their undergraduate degrees locally at cheaper tuition fees. Or when companies start hiring people based more on their skills than diplomas. Who knows.

Teaching during my sabbatical in ITB, Indonesia (when I still had my hair)

Mechanical Characters of Metals

Stress-strain curve of a metal obtained from a tensile test

From its stress-strain curve we can tell a lot about mechanical properties of a metal. Such stress-strain curve is produced routinely in a tensile testing done in many labs around the world. The curve behaves linearly initially and the slope of this linear portion is equal to its Young's modulus. A rigidity of a metal can be attributed to its large Young's modulus. Aluminum is often the most optimum metal as it offers sufficient rigidity, cheap cost, and light weight.

Deformation in the linear regime is called elastic deformation since the metal would return to its original shape when the loading is removed. This elastic deformation originates from the distance change between two adjacent atoms in a crystalline metal. It is possible for a metal to be not crystalline; we say it is a polycrystalline since it is composed of many small crystals. The region between two adjoining small crystals in a polycrystalline metal is called grain boundary and can disrupt the elastic deformation process, so that the elastic deformation terminates prematurely.

In any case, elastic deformation terminates when dislocations in the metal start moving. Dislocations arise from imperfections that emerge when the metal is processed and fabricated. It is impossible to have a 100% pure elemental metal; it can easily incorporate impurity atoms - such as oxygen, nitrogen, and hydrogen - and vacancies are always present. Vacancies are atomic-size bubbles and when they bunch together they will create a dislocation. Larger or smaller impurity atoms than the host elemental metal can also create dislocations.

It takes energy to move these dislocations since they have to break chemical bonds. When they move, they have to push aside nearby atoms. This creates a friction, and thus require a minimum energy before they can move. The metal is said to develop plastic deformation when these dislocations move. The threshold energy density corresponds to the upper yield strength.

Since these dislocations are distributed randomly and are usually bunched up near grain boundaries, the stress will fluctuate rather wildly as the dislocations move. In the stress-strain curve, this region is called discontinuous yielding. A metal that does not have many dislocations will have a smooth curve around the yield strength. After the dislocations can move more easily, we get a uniform elongation in the plastic deformation region and the elongation continues until the metal breaks.

When the loading is removed, the metal no longer returns to its original shape once plastic deformation occurs. The dislocations, in other words, do not remember their original positions. The energy spent for the loading is now stored in the metal.

The maximum loading that the metal can withstand before it breaks is called tensile strength. The breaking strength is called fracture strength. The strain value at fracture strength is called fracture strain. A metal that is ductile will have a large fracture strain, i.e., large elongation.

This mechanical behavior of a metal is analogous to how a person might respond to a life stress. When the person is subjected to a small stress, he will be able to bounce back to his normal, unstressful state. He can alter his behavior and even character, however, when the stress exceeds some value. There is a stress limit as well a person can take. Characters that are used to describe mechanical behavior of a metal are similar to people's characters: strength, hardness, rigidity, toughness.

Strength has to do with how much stress a metal can take and is proportional to its tensile strength. Hardness has to do with how much stress a metal can take before it produces plastic deformation and it is thus proportional to its yield strength. Rigidity is proportional to its Young's modulus. Toughness has to do with how much energy a metal can absorb and is proportional to the area under the stress-strain curve. A person is said to be tough if he can take physical (and sometimes mental) abuses. We can learn a lot about people by studying mechanical characters of metals.

All Season Runner

What I got after a 1 hour, -25 C running in Calgary

Yesterday I took my best friend for winter gear shopping. It reminds me of my learning to find the best running gear for different weathers. It took probably a year for me to feel confident in deciding what to wear while running in all 4 seasons. To make things worse, Calgary is notorious for its daily weather changes. It is not unusual in the summer to have -4 C in early morning and 20 C at noon. People who have lived in Calgary long enough will say they have seen snow in all months of a year.

So I was happy to share my experience with him since he also does not enjoy exercising in a gym. I don't like exercising in a gym; I tried and gave up. Running in a treadmill bores me. Running in a loop bores me too. Outdoor is the only choice for me.

The toughest running gear decision to make is of course for winter. There are two variables I have to pay attention to: temperature and wind speed. I divide the temperature in 2 ranges. My body feels the range 0 to -15 C differently from the range -15 to -30 C. If the wind really picks up though, the -15 C temperature can feel like -30 C. I always check the weather before heading out. You have to try these ranges yourself and change them according to how your body responds.

I wear 3 layers for the warmer (0 to -15 C) range. The base layer is a short-sleeve polyester T-shirt. I never wear cotton as it retains sweat. The second layer is a thin thermal insulator, such as a merino wool zippered sweater. Having a zipper is useful since I can regulate my core body temperature. The third layer is the outside layer and acts to block wind. A light nylon wind breaker jacket will do for me. Warm toque and gloves are essential. I wear light running tights.

For the colder (-15 to -30 C) range I wear a long-sleeve polyester T-shirt as the base layer. The second layer is the same: a merino wool zippered sweater. The third layer is a thin soft shell jacket to provide additional thermal insulation. The outer layer remains the light wind breaker jacket. Warm toque and super-warm gloves are essential. Warmer running tights are required and I usually wear my cold winter biking tights.

I run a one-way route and come home using an LRT. The safer way is to run a loop so that you don't need to worry about removing sweat after running. I prefer a long, scenic route so I have to suffer a bit when walking from LRT to home with wet clothing (sometimes in a -20 C weather).

I don't need to bring water if I run for 1 hour. For a two-hour running I buy water from convenience store when running in city; it is more practical and water can freeze easily if I don't use a heavy insulated bottle. I am a minimalist runner.

My fall (15 to 0 C) running gear consists of the merino wool sweater and the short-sleeve T-shirt. Or the wind breaker jacket and the short-sleeve T-shirt. I wear the latter if rain is forecast. I find this temperature range is the best running temperature. It doesn't overheat my body and I can run faster. I definitely wear running shorts if the temperature hovers around 10 C or warmer. Toque is not needed. Light gloves are only when temperature is around 0 C.

Summer running gear (15 C or above) is downright minimalist: sleeveless T-shirt and running shorts. When the temperature reaches 30 C or hotter though, bring water. I use a Camelbak when running for 1-2 hours in Indonesia. Sunglasses and a hat might help.

How about shoes? I swear by Asics shoes. That's it, it is a marriage for life. I love Gel Trabuco and Gel Kahana series. They are good for Indonesian summer and Canadian winter. It dries quickly in rains and does not slip easily in packed snow and ice. I use two socks for winter: the inside is the low-friction socks to prevent blisters and the outside is a light insulating kind.

Outsmarted

Winter in Oklahoma

The place I stayed in Oklahoma did not have an internet connection. There was no ethernet plug, no modem connection, no wireless. Two wireless networks my laptop scanned were password protected. The only time I had connection was when I had breaks during work. It was like that for the three days I was there.

I felt I was disconnected from the world. I could not read online newspaper articles, google information, update my blogs, check friends on Facebook, and get emails continuously. I was not able to check online maps, so I found it very difficult to familiarize with streets and directions around the places I stayed and went. I felt I didn't know what was going on in the world. Instantly.

Black Angus cows; they are cute, aren't they?

I felt lonely and turned on teve to accompany me in the evening while making presentation slides. I think that is what internet - all communication technologies in general - does. It makes me weaker to fight loneliness. I cannot stand being alone. The internet becomes a close friend. It makes me feel I always have someone to talk to when around it and I crave it when it isn't around.

I sold my smartphone last year. It made me check emails, chats, Facebook status and comments everytime. It ruled me. It wasn't good. I remember that as I tell myself it is actually good to not have internet connection sometimes. It is true. I am more productive.

I learned also that I was better suited to using paper in most information recording and retrieval activities. I use a paper calendar, for example. I can scan quickly my weekly schedule without having to scroll a tiny screen. I can write down quickly with my hand what I plan to do. No need for a keyboard. I always think my cursive handwriting is neat anyway.

Percuma

yang tampak sudah hilang

yang hilang bersatu awam

yang awam berupa suci

yang suci menabur pedih

yang pedih berlalu pergi

yang pergi diam kembali

Bukan Waktu Biasa

Bryce Canyon National Park, Utah

Sekali kamu teriak
Kan kutampar telak
Walau tangan kita
Berlumur darah

Ini bukan waktu biasa
Berdua menari kaca
Menentang arus
Menghantam baja

Bualanmu kali ini
Aku mau dengar
Lalu kita terjun
Berpisah semua

Tahan napasmu
Lupakan yang enak
Selamat datang
Abadi slamanya

Contact Point of a Rolling Tire Does Not Move

How to read tire codes. Copied from this website that has additional info on tire.

That's right. Although a tire moves, the contact point between the tire and the surface does not move. This fact often confuses students. They see the tire gains distance as it moves, so how come the contact point of a tire does not move while the tire gains distance? Let me offer a simple explanation to this problem.

When a tire rolls and completes one full revolution over a time interval t, its perimeter covers a distance of 2πR, where R is the tire radius. The speed v of the tire is equal to the distance covered 2πR divided by the time interval t. That is, v = (2π/t)R. The quantity (2π/t) is called angular velocity and is typically denoted as ω.

The tire speed ωR causes the tire to gain distance. It moves. The center of the tire also moves with this speed, which can be confirmed by experiment. The contact point moves and gains distance as well. But the speed of the contact point is zero (i.e., it does not move). How come?

The key to understand this confusion is that a single point on the tire perimeter touches the surface only once every one full revolution. When it touches the surface, it becomes the contact point. But it leaves the surface as soon as it touches it. This contact point thus has zero velocity as it never moves relative to the surface. It just touches and goes fleetingly. If you follow the path of motion of this point, you get a curve called cycloid (click for animation).

Since there is always available one point on the tire perimeter touching the surface as the tire rolls, then you can always match one such contact point - that does not move - with the center of the tire that moves with the speed ωR. Hence, the statement that the contact point of a rolling tire does not move.

Beauty & simplicity

Suwuk Beach, Central Java, Indonesia

I haven't talked about what beauty & simplicity mean to me. Let me explain.

I am in awe of beauty. Beautiful math. Beautiful food. Beautiful creatures, big and small. Beautiful nature. I am nervous around them as I appreciate them. I eat beautiful food quickly as a result. Does beautiful food taste good? From my experience it always does.

Beauty is difficult to quantify, maybe it has to do with symmetry when looking at a geometrical pattern. Or proportion when glancing at a female body. Or elegance for a math equation. But symmetry, proportion, and elegance need further elaboration. So there you go.

But beauty can create or require excess. It can become gaudy, lavish. This excess needs to go.

Simplicity removes the excess. Simplicity for me suggests quality and functionality.

Beauty tends to overwhelm. Simplicity aims to clarify. Beauty shows up willingly in nature, people, things, although we still prefer to pay a lot of money to get it. Simplicity needs work but saves money.

Let me give an example. One of my postings is about whether an all wheel drive car is needed for Canadian winter driving. A beautiful solution would be just that: "symmetrical all wheel drive" motto of one car manufacturer says it all. It is not simple though: the engine drives all four wheels, is heavier, and is more expensive and less fuel efficient. Can it be simplified? I found out yes. Winter tires simplify it.

When beauty and simplicity come together, it is simply beautiful!

Car & Tire for Canadian Winter

Near Golden, BC, on Trans Canada Highway

I finally got to drive Calgary-Vancouver (click for map) in winter 2010. I saw at least 10 accidents along Trans-Canada Highway and most of them were roll over accidents, suggesting tire slip as the primary cause. I have experienced bad snow storms while driving, although luckily not during the Calgary-Vancouver trip.

It started interesting between Lake Louise and Revestoke, which is about 230 km stretch. The divided highway from Calgary is no more and there are a lot of trailer trucks as the Trans-Canada Highway is the only major land route to Vancouver. A steep 6% downhill grade stretch at the Kicking Horse Pass greeted us. Reaching Golden, the drive got even more challenging as we approached Rogers Pass which is one of the world's most avalanche prone areas. The grade continued around 6% mostly uphill for about 30 minutes until we reached Rogers Pass. There are 7 avalanche-protection tunnels in this area. I felt the remoteness of this area especially when driving at night. Between Revelstoke and Kamloops, the road levels off somewhat but it meanders wildly around Shuswap Lake. We experienced the steep grade (6-8%) again along the Coquihalla Highway between Kamloops and Hope. Once you reach Hope, it is another 150 km, mostly flat, to Vancouver.

Winter tire is a must for Canadian winter driving

There are several lessons I learned from this experience that I want to share with you.


Do I need a four wheel drive or all wheel drive car for the Calgary-Vancouver winter drive? No. I had been wanting to buy an all wheel drive car for such winter drive, but I found out that it is not necessary. The main reason a front wheel drive is sufficient is that the Trans-Canada Highway is relatively well-maintained and I did not encounter a 100% off-road condition. I won't recommend a rear wheel drive car, however, since it drifts more easily and you may not have enough time to correct it when moving at a high speed on a highway.

Do I need to use winter tires for the Calgary-Vancouver winter drive? Yes. There are in fact several warning signs along the Highway that you need winter tires during winter months (October through May for Canadian Rockies, thank you very much). There is a physics to this. The minimum coefficient of friction between tire and road to maintain a no-slip rolling tire is approximately equal to a third of the road grade. The factor 1/3 comes from the fact that the tire both rolls and its center of mass moves.

A 9% road grade thus requires a minimum static coefficient of friction of 0.03 in order for a rolling tire not to slip. The coefficient of friction between rubber and a bare asphalt - occuring mostly in summer - is 0.25 or larger. When snow covers the asphalt road, the coefficient of friction can dip to 0.05-0.1. It is thus clear that winter tires are required.

Winter tires are also required to protect from slip when the car accelerates or decelerates. Without hitting a gas pedal or brakes, the maximum downhill no-slip acceleration is almost linearly proportional to the vehicle's mass. This maximum downhill acceleration, however, also depends inversely proportional to the vehicle's tire radius. Still, a truck or an SUV can accelerate without slip faster than a subcompact car since the mass ratio of a truck v. a subcompact car is larger than their tire radius ratio.

I drive a compact car, so I know I won't be able to accelerate as fast. I thus have to apply brakes when going downhill to prevent slipping. Applying brakes can induce slip on its own if too sudden, so braking must be gentle. There is nothing wrong with the car. It is just physics.

When you hit the gas pedal or the brake pedal, you apply torque to the tires. The vehicle dynamics changes a lot. Tire design becomes important. (In tech speak, tire's moment of inertia becomes important.) When going downhill, applying brakes increases the minimum coefficient of friction to maintain a no-slip condition, thus destabilizes the vehicle. In other words, decelerating a vehicle too suddenly can cause slip to occur. This is I think the most common mistake a lot of people make when driving in winter. They hit the brake too suddenly and slip ensues.

My math shows that accelerating a bit while going downhill stabilizes the vehicle, i.e., reduces the minimum coefficient of friction. But, accelerating too much can cause slip, so I won't recommend accelerating on downhill. For me this practically means I do not need to panic when going downhill by applying brakes. This requires me to get to the appropriate speed before the downhill stretch begins.

When going uphill, the converse is true. Braking a bit will stabilize the vehicle, but of course I do not want to lose the vehicle's momentum. Hitting a gas pedal destabilizes the vehicle.

The destabilizing effect of accelerating while going uphill and generally downhill shows that it is important to mantain a constant speed on a snow covered road. In fact, a simple strategy I use for winter driving is to maintain car's momentum. It means I do not make sudden swerves, turns, and brakes.

Which other car attributes do I have to pay attention to? Bright head lights and bring enough winter windshield wiper fluid. Bright head lights are essential when you drive at night. It is likely you will drive more than 12 hours to cover the Calgary-Vancouver distance in winter. One keyword here: visibility. You want to be seen clearly by other vehicles and you want to see the road very clearly when the weather is really bad. I also brought blankets, down parkas, snow shovel, snack, drinking water, matches, and even camping stoves and fuel in case of emergency on the road.

Do I still need an all wheel drive car for a winter drive? Only if I want to venture out into a secondary road or lower, that receives no or little snow plowing. For me the main advantage an AWD has over an FWD is a lower risk of traction loss. When I drive over a well maintained road this risk is small. The lower the vehicle speed is the higher risk the traction loss has. Quantitatively, the risk is proportional to the ratio between the wheelbase and the distance between snow covered areas along the road.