My experiences with kinfe sharpening

My father is a particularly fastidious man when it comes to the many kitchen knives we have at home. While the stereotypical middle-aged American man has an attraction to power tools, my father has a fondness for kitchen knives. Occasionally, he would browse the imported wares of an upmarket knife boutique, picking up various implements and admiring them. The knives at home are always kept very sharp.

Having grown up in a home with a kitchen of very sharp knives, I find blunt knives a major potong stim factor in any kitchen.

Over the last 2 years, as I’ve been living alone, I’ve refined my knife sharpening skills remarkably. Initially, I used the same strokes I have observed my father use. They produced acceptable, but not fantastic results. Over time, as I experimented with various sharpening strokes, I discovered various styles that suited my hand better. The cutting edges became sharper.

My current kitchen, small as it is, has three ceiling lights, making it a very well lit kitchen. Over the past six months, I learned to observe a knife under the light, picking up clues pertaining to the degree of sharpness and refinement of the final polish. The cutting edges continued getting sharper.

Occasionally, for the fun of it, I cut a few really thin slices of my food. A translucent slice of fish here or a vanishingly thin film of tomato there is satisfying confirmation that the job is done. On the other hand, a mangled edge on a kiwi suggests a return to the sharpening stone.

Today, the knife was a little blunt, and I decided to do a quick job just to keep myself happy for the meal’s preparation, after which I can do a proper sharpening. With a few quick strokes using what I hoped would suffice, it was done in less than a minute. An inspection under the lights revealed no flaws, and so I went back to the chopping board.

Cutting with a renewed edge always has a refreshing zing to it, a sort of startling smoothness of action. Slide the cutting edge along its victim, and it instantly bites into the surface.

To my utmost surprise, the knife was exceptionally sharp. It sliced thawed chicken fillet with an ease never seen before. In the end, I sliced the chicken into absurdly thin slices with an average thickness of 1.5mm. It appears I have stumbled upon a different approach to cutting edge polishing.

Spectecular. I then proceeded to slice the chilli into little red rings of a half millimetre thickness.



*potong stim- Busting a bubble (Malay), translated literally, “cutting steam”, cutting similar in context as seen in a “power cut”.

The Moon Problem

LCF commented in my June 27 post:

In regard to the "big moon" pictures shown in magazines/books/BBC that you were referring to, sometimes they [are taken] in two separate shots. The fist one, with a telephoto aim at the moon. The second shot (without advancing the film after the first shot) aiming at the scenery. Then, you can get nice night scenery with big moon as background.

This is definitely a valid method to capture a photograph with an oversized lunar body, but I feel that it’s blatant cheating. There are also some potential problem that the photographer needs to watch out for.

The moon and scenery must not occupy the same area on the film, else the resulting (double) image would be a moon shining through the ghost of the Alps/ the Parthenon/ the Kek Lok Si.

As a consequence, the photographer cannot make the moon rise out from behind the Alps/Parthenon/ Kek Lok Si without some serious tricks with Photoshop.


I would propose an alternative method that is 'real', but requires some research as to the times of moonrise/set.

In the example given below, the photographer is in a bleak, monochromatic desert preparing to capture some depressing images of a moonrise over a white landscape. There is a straight road that seems to stretch on to infinity, with evenly spaced street lamps along one side of the road. Power and communication lines run along the tops of the lamp posts.



Click to view large size image

Along the road are 3 men. The one nearest to the photographer looks to be a super-aggressive character. Look, he already has his middle finger waving at the photographer. The second man looks constipated, and the third man is too far away in the distance to figure out the long object in his hand. My conjecture is that they are all miserable because there were no women in the scene.

The moon has just risen over the horizon. Using his SLR camera, the photographer zooms to 105mm (3x zoom) and snaps this first image. The first man is still rude as ever, the second man still needs a laxative suppository, and the third man is not well defined.

The photographer removes his 105mm lens, and snaps on a massive 350mm lens for 10x magnification. He then snaps the second image. As a direct consequence of the magnification, the man, the moon and the streetlamps are all magnified.

It turns out that the third man is holding a Japanese katana. The second man is not in the picture- while the photographer changed lenses, the first man turned around and gave the constipated man a rude finger gesture. Annoyed, the constipated man walks over to the first man and promptly kills him.



Click to view large size image

Referring to the second image, we see that the third man in the distance had been magnified to a more normal size. However, the moon had also been magnified, and now it looks like a damn big sphere in the sky.

In conclusion, it is easy to make the moon look like a damn big sphere in the sky. Use a huge telephoto lens; zoom in on a distant object to make it look like it’s quite nearby, and the moon will look like a damn big sphere in the sky. Refer to the pictures here. I’m pretty sure the first image is a very far shot of the city using a telephoto lens assembly on a double dose of Viagra.



Epilogue:

When the photographer got the photos printed, he brought them to his magazine’s press office. There, he told his editor and other journalists this:

You know, that day I went into the Siberian wasteland to take some photos of the moonrise. Then, all of a sudden, a massive pink spacecraft came right up to the moon and stuck a long tube-like thingy into it. It seemed to be pumping stuff into the moon, because I saw the moon inflate like a balloon before a birthday party. This happened while I was changing the lenses on my camera, and I couldn’t take any photos.

Anyway, the thing inflated the moon more and more…until it was three times its original size. Wah lau…cau ci bai…I was so shocked you know. Suddenly the moon ruptured, and beige coloured fat-free Caesar dressing spewed all over the landscape. It was very horrible.

Out of nowhere, several tanker trucks appeared, and with some sort of vacuum hose, sucked up as much of the salad dressing as they could, and then as quickly as they had materialised, they disappeared into the desert air.

I tell you…something is seriously wrong.

To which the editor simply said, “Bullshit. Talk cock lah, you.”


Endnote:
The 2 images were drawn with assistance from a straight edge and a compass (for the ‘large’ moon). A reasonable degree of accuracy was achieved by overlaying the paper for the magnified image over the wide-angle drawing, thus using the same vanishing point and horizon.

In principle, the magnification was done by considering the wide-angle image using polar coordinates with the vanishing point as the pole. Magnification was done by simply multiplying the radial distances by a certain factor while keeping the same angular displacements (relative to the horizon).



Cite this article as:
Tan Yee Wei(2005), "The Moon Problem", from "Snippets of This and That"
http://tanyeewei.blogspot.com/2005/06/moon-problem.html

Yuck, its "fat free"

I made a salad. The dressing was a “99% Fat Free Caesar Dressing” that came straight out of the fridge. In my defence, the normal dressing was not available, hence settling for the fat free alternative.

When cold, this particular fat free dressing became a viscous, gooey gel quite unlike salad dressings that are served to human beings. Look, that blob of dressing even holds a pointed tip. Gross stuff…



Ideally, dressings should be inviscid* and have low surface tension. These characteristics would allow the dressing liquid to spread and smear over the many vegetable surfaces present in the salad.

Normal dressings behave perfectly fine at high AND low temperatures. This fat-free stuff is not looking very promising; when cold, it looks like jelly, or hair gel, or a perverted blend of mayonnaise and semen. If I want jelly I can very well get my own jelly.



Here’s the ingredients list transcribed from the label.

INGREDIENTS Contains wheat, barley, fish and milk as indicated in bold type. Water, cane sugar, vinegar, maize maltodextrin, lemon juice (3%), maize thickener (1442), salt, vegetable gums (415, 460, 466), worchestershire sauce (wheat, barley, fish, colour (150c)), parmesan cheese (1%) (contains milk), flavour, spice(0.05%), colour(171).



It turns out that mayonnaise is used in great quantities when making Caesar dressing. So this is what fat-free does- replacing mayonnaise with carbohydrates and gums.



Maltodextrin:

Maltodextrin is a moderately sweet polysaccharide used as a food additive, unrelated to barley malt. It is produced from corn starch and is usually found as a creamy white hygroscopic powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose.

-Wikipedia

Maltodextrin is a very simple and flavorless carbohydrate. It is rapidly absorbed by the body and contributes to rapid uptake by muscle tissues of key nutrients that have been depleted by exercise. In this role it has an anabolic effect in rapidly refilling glycogen reserves.

-Everything2

Current products use either maltodextrin or corn-syrup solids as fat replacers. Both maltodextrin and corn-syrup solids are hydrolyzed starch. Maltodextrin and corn-syrup solids impart a smooth texture that mimics the mouthfeel and structural attributes of fat crystals.

-Food Product Design

Maize thickener 1442 (hydroxy propyl distarch phosphate):

Thickener and stabiliser
Thickener: Thickeners produce viscous solutions or dispersions and are used to impart body, improve consistency, or stabilise emulsions. They include suspending and bodying agents, setting agents, gel builders, bulking agents, etc.

Stabiliser: Stabilisers produce viscous solutions or dispersions and are used to impart body, improve consistency, or stabilise emulsions. They include suspending and bodying agents, setting agents, gel builders, bulking agents, etc.

-www.chm.bris.au.uk

Vegetable gum 415 (xanthan gum):

Xanthan gum is mainly considered to be non-gelling and used for the control of viscosity due to the tenuous associations endowing it with weak-gel shear-thinning properties. It hydrates rapidly in cold water without lumping to give a reliable viscosity, encouraging its use as thickener, stabilizer, emulsifier and foaming agent.

-www.lsbu.ac.uk

*inviscid- having no or negligible viscosity


Sources:

Sarah Anderson, "A Rough Guide to E-Numbers", University of Bristol.

"Maltodextrin", Everything2

"Maltodextrin", Wikipedia

Mauro & Wang (2001), "The Breakfast of Champions", "Food Product Design"

Martin Chaplin(2005), "Xanthan Gum", "Water Structure and Behavior", London South Bank University

My First Night Cityscape Photographs

Melbourne on Sunday night. The buildings are really quiet and unlit. The over-lit yellow building is the Flinders Station. Click to enlarge (164 kB).



This is across the river from the Flinders Station. Click to enlarge (228 kB).


I still remember my first attempt at night time cityscape photography. It was in the December of 2000, one month after my SPM, when I was visiting an aunt in Brisbane. Aunt brought us for a tour along the Brisbane River on the City Cat, a high speed ferry service of catamarans prowling the river. Apart from being a tourist attraction of sorts, the City Cat is actually a proper public transport service that the locals use, even to get to work.

The boat blasted along the river surface at great speed. In the central business district, commercial buildings were lit like commercial buildings at night. I made my night cityscape attempt there, on a speed boat bumping on the river surface, using the family’s Pentax 35mm point-and-shoot camera with about 3x optical zoom. The photos were a blurry haze of white and yellow streaks over a black background. Bad.

Ok, so it’s a daft idea to shoot night scene photographs from a speed boat.


My second attempt was in Hong Kong, June of 2001. The Victoria Peak was a tourist trap of sorts, with a cable car running up to a huge tourist trap building at the top of the hill, complete with overpriced restaurants and pointless pseudo-designer boutiques. The view was actually quite breathtaking, if the cold wind did not already take it away. The lights of Hong Kong were spread some way below, with Tsim Sa Tsui across the causeway.

I was still using the Pentax 35mm point-and-shoot. Finding a suitable wall, I braced myself and the camera against it as best as I could, and hit the shutter. Damn, it was a very long exposure, the city being so far away and all. The photographs turned out rather fuzzy and unsatisfactory.

I so need a tripod!


My third attempt at night cityscape photography was on my second trip to Hong Kong, in December 2002. I pestered my mother till she agreed to pay for my tripod. Woo! And so I went tripod shopping along Nathan Road (I think). After some hunting and bargaining, I got the price down to HK$140 from some previously stratospheric price. I still don’t know if I had been fleeced; never been tripod shopping since then.

One night, I took a walk from the hotel over to the edge of Tsim Sa Tsui with my old friend the 35mm Pentax and my new tripod. Across the water was Hong Kong island with its magnificent lights. The shutter clicked, and the film drum whirred.

When we got the photos printed, I was over the moon about the photos. The lights were so sharply defined! Look at how proper and un-hazed the buildings appear. And look at the city’s reflection off the water! Granted, the composition was nothing special, but I finally captured a city’s lights. It was a remarkable moment.

Me acting funny at billboards

Some days ago, I saw an article at BBC about the moon appearing to be larger than usual these few days. Sure enough, I saw the (apparently) huge moon on Saturday night while walking home after sending a guinea pig to a 24 hour vet and finding upon arrival that it was already dead. Exactly 7 days in my care and it dies; my cousin would never trust me with her animals anymore.

Anyway, back to the lunar business. It was just a bit after moonrise, and next to the skyscrapers, the moon was definitely not to be ignored. Potentially magnificent photographic opportunity!

Today, I checked the Melbourne Planetarium for the moon’s behaviour for today. Most relevant to me were these 2 bits of information:

Moon rise at 9.55pm for Saturday night
Moon rise at 106 degrees (16 degrees South of East)

After consulting a map of Melbourne for a suitable location for a “moonrise over river” shot, I decided I’ll leave my place at 9.30pm and take a leisurely stroll across the city to the Yarra River.


I waited at Batman Av on the North bank of the Yarra River

The Moon rise was spectacular to the eye. Very low in the sky, it was a rusty red disc obscured by trees. When it was in proper sight, I realised that the digital camera had only 3x optical zoom- definitely insufficient. The 35mm film camera, an Olympus iS-1000, had 4x, but that was still not enough to stare straight at the moon. Drat…so much for the walk. At times like this, the Olympus C7**UZ series with its massive 10x optical zoom would be most handy.

Well, no close-up moon rise photos unless I get hold of a decent telephoto lens assembly, which is not likely at all. I’ll do some night scene shots then, since I’m already in the city centre with a tripod and 2 cameras.

I saw a set of billboards at the Arts Centre. These boards are illuminated by bright lamps placed at a walkway just below the boards. An interesting idea came to me:
What if I mount the camera on a tripod and point it at the board with a 10s timer, and posed myself in front of the lamp? A self portrait in silhouette, splashed all over a billboard.

It did not work- my shadow would inevitable blot out the entire light beam. And as such I resorted to plain finger gestures. What a bore.





The boards. Top image from melbourne.com.au



The lighting mechanism.



A rude finger. A feisty one, isn’t she?



A dog head, but I messed up my fingers, so it looks like a pair of blunt scissors now.


I walked around the city for 2.30 hours, snapping many pictures- some good, mostly not; some interesting, mostly not. More to come.

Guns of Navarone- a film review

Click on poster to view Wikipedia entry

A World War 2 film produced in 1961, the plot is set in the early 1940s. Guns of Navarone tells of a pair of huge German guns strategically located in a cave on the Greek island of Navarone, controlling the Aegean Sea.

With an ex-mountaineer among them, a team of 6 commandos scale an unguarded cliff face to enter the occupied Greek island of Navarone. The plot gets interesting when one among them seriously injures himself in a fall while climbing the cliff. Do we leave him here, and allow him to receive German medical treatment, and potentially revealing our plans, or do we carry him around on a stretcher, potentially slowing the team? Or do we put a bullet through his head? The problem is eventually resolved, but only temporarily, and the issue stays with us throughout the movie.

Another theme that is seen intermittently is the angst of war. Transcribed here is one particularly moving exchange by Captain Mallory, the leader, and Corporal Miller, the angsty one.

“Well to hell with getting the job done. I've been on a hundred jobs and none of them changed the course of the war. There'll be a thousand wars, and there'll be a thousand more until we all kill each other off completely. I don’t care about the war anymore; I care about Roy.”

“And what if Turkey comes into the war on the wrong side?”

“So what? Let the whole bloody world come in and blow itself to pieces. That’s what it deserves.”

The plot is interesting as the main characters all have their own little bit of history and sub-plots, all while they go about trying to put the Guns of Navarone out of commission. Unsurprisingly, among the commandos and the local rebels, there is an informer keeping the Germans up to date. To make things more exciting, a Greek member in the team feigns innocence when the entire team is captured by the Germans. Was it all planned, or was it simply a stroke of luck? This question lingers, and is not properly answered at the conclusion of the film.

Acting is generally good. The one that stands out is David Niven for his role as Corporal Miller. Miller’s emotional outbursts are very well portrayed, and one can feel a dose of reality in it, even though this is nothing more than a film.

Sometimes, German soldiers are portrayed to be slightly slow and retarded. However, this is not very common/obvious, and is acceptable.

Another noteworthy point is that this is not a patriotism film like many flag flying, anthem blaring (mostly US) war films. I don’t think God Save the Queen was played once in this film. Your viewing experienced will not be interrupted by uplifting (irrelevant) scenes of neat rows of men standing at attention to a flag being hoisted up a pole.

This film being rather old, do not expect fancy special effects with propagating flame fronts and shock waves. Also, its one of the earlier colour films and the colour is not as intense as modern productions. However, it might be a good thing not to be distracted by these little bagatelles. Concentrate on the acting and storyline!

The verdict:
Definitely worth your time, all 150 minutes of it. The plot goes along well.

Calibrating a rice cooker

Table of contents:

Introduction

The rice cooking process

The model

Experimentally determining the parameters

Summary

Cite this article

Cooking rice can prove difficult for inexperienced persons (like me). I find it a tricky business fiddling with the water levels to make rice of suitable wetness. Making edible rice is dead easy. Making reasonably decent rice is not hard. Making good rice is doable, once in a while. However, making perfect rice in a consistent fashion requires experience and a certain touch, none of which I happen to possess.

There must be a better way than this fiddly, inconsistent, unreliable and occasionally emotional way of learning to make rice by trail and error. It gets emotional when one is hungry and the rice turns out to be hard, translucent bits of starch granules fused together into little shrapnel fragments.

There are various guidelines for cooking rice. Some recommend that the depth of water should be double (or triple or whatever) that of the rice grains, while others recommend that the water level above the level of rice should be 1cm (or 2 cm or whatever). Of course, these guidelines are only valid within a small range (a range that the person recommending the guideline is familiar with). If you are cooking 1cm deep of rice, both guides would recommend 2cm of water. What if you want to cook for more guests, and need 6cm of rice? Do you add 12cm of water or 7cm of water?

Presented below is a method to calibrate a rice cooker. It involves modelling the rice cooking process with some valid simplifications, and the data collection will be a straightforward process



The rice cooking process:

Cooking of rice involves dry, uncooked rice grains absorbing some water while being heated at about 100 degrees C. Traditionally, rice is steamed in a bowl filled with uncooked rice and an amount of water. Below this bowl of rice will be some boiling water. Steam from the boiling water then heats the rice to 100 degrees C. We should note that there are two seperate bodies of water- one to be boiled to produce steam, and another that would be absorbed into the rice.

Modern rice cookers do away with this business of separating the boiling water and absorbed water. As such, one would need to add a certain amount of excess water into the rice cooker to allow for some boiling. Otherwise, if one sticks to the usual proportions used in rice steaming, the electric rice cooker will inevitably produce overly dry rice, and possibly tears from a certain hungry person.



The model:

Simplifying assumptions:

Assume that the heating process from ambient (room) temperature to boiling temperature is reasonably fast, and no significant amount of cooking occurs during the heating up phase.

Assume that the rice cooker will boil water for a fixed length of time. This is analogous to someone steaming a bowl of rice for a fixed length of time, irrespective of the number of servings that is being cooked.

Assume that the water boils at a constant temperature.

Assume that heat supply to the water and rice is at a constant rate.

As a consequence of these simplifying assumptions, the amount of water that is boiled to steam is constant, irrespective of the quantity of rice being cooked.

It is perfectly reasonable to assume that the amount of water absorbed into the rice grains is proportional to the amount of rice. The amount of water absorbed by 2 cups of dry rice is precisely double the amount absorbed by 1 cup of dry rice.

The amount of water that needs to go into the electric rice cooker is thus the amount that will be absorbed by the rice, plus the amount that will be boiled to steam during the cooking process.

In general, the amount of water needed can be expressed as a linear equation:

(Amount of water needed) = (Amount of water absorbed per unit dry rice) x (amount of dry rice) + (amount of water boiled)

These can be expressed in any unit you desire. For example, 3/4 cup of water for every cup of dry rice, and 1 inch deep of extra water to boil. Or 56 kiddie pools of water for every kiloton (million kilograms) of dry rice, and 300 gallons to boil.

Experimentally, there are 2 variables that need to be determined- the quantity of water boiled, and amount of water absorbed for each unit of dry rice.

At this point, it is noteworthy to mention that the amount of water per unit of rice is only dependent on the kind of rice used, and the water boiled is only dependent on the model of rice cooker employed. When you buy a different variety or rice, the only variable that needs to be tuned is the water per unit rice. Likewise, changing rice cookers will mean that the amount of water boiled changes.



Experimentally determining the 2 variables:

We will first find out how much water is boiled by the rice cooker as it is the easier variable to determine.

Fill your rice cooker with a precisely known quantity of water. “Cook” this vat of water as you would cook rice. When the cooking is complete and after everything has cooled to a safe temperature, measure the quantity of remaining water, precisely. Obviously, the quantity of water boiled is the difference between the start and end quantities. For convenience’s sake, we will call this quantity of water B (for boiled).

Cook some rice. Precisely measure the volume of dry rice (245ml, for example, or 1.05 cups). We will refer to this volume of dry rice as R (for rice). Add water to the rice, measuring it as you add. We will refer to this quantity of water as W (for water added).

As of now, our equation is
W = kR + B, where k is the amount of water absorbed for each cup/ml/gallon/ton of rice

If you had been a good boy/girl and had measured all previous quantities (B, R and W) to a reasonable accuracy, it would be an easy matter finding the value of k for this particular batch of rice. k = (W-B)/R

Was the rice good? If you want drier rice, reduce k. For wetter rice, increase k. In the process of optimising your value of k for this particular variety of rice, it is best to keep a record of your past values of k and some remarks like “too damn wet”, “bone dry” or “slightly wet”. With the aid of your history of attempted k values and corresponding results, it will be easy to approach the ideal quantity of water. And then you would have perfect rice, every time.



In summary:

The rice cooker boils a fixed amount of water. For the rice to be good, it must absorb a certain quantity of water. Water added into the cooker must be the sum of these 2 quantities of water.

First determine the amount of water boiled. Then find the quantity of water absorbed that will result in good rice.



Cite this article as:
Tan Yee Wei(2005), "Calibrating a rice cooker", from "Snippets of This and That"
http://tanyeewei.blogspot.com/2005/06/calibrating-rice-cooker.html

Back to table of contents

How I disproved the existence of the week

I’m done with my exams this semester.

At the moment, I’m taking a few days off before restarting work on my major project. We’ve got plenty to catch up on for that one.

It appears that today is Friday, but it feels very much like a Sunday.
From the above sentence, we say that Fridays and Sundays are one and the same (statement 1).

On the other hand, most people tell me the days are ordered in this manner:
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday, Monday… (statement 2)

Combining statement 1 and 2:
Monday, Tuesday, Wednesday, Thursday, Sunday, Saturday, Sunday, Monday… (statement 3)
Note that we can freely interchange the Fridays and Sundays from statement 2 due to the relationship given in statement 1.

However, the order of days as given in statement 3 violate that given in statement 2. Hence, the truth of statements 1 and 2 are mutually exclusive (statement 4): they cannot be true at the same time.

I would rather believe what I sense rather than plainly agreeing to what others tell me. So statement 1 is true and statement 2 is false. (statement 5)

[We’re short on time here. I’ll just jump a few steps ahead and you can figure out the intermediate proofs at your own pace.]

And thus, it should be clear that the days of the week as presented in statement 2 do not exist.
Q.E.D.*



On another note, I borrowed something from the mathematics library this afternoon:

A Primer of Analytic Number Theory
From Pythagoras to Riemann

by Jeffrey Stopple
Cambridge University Press, United Kingdom, 2003.

Should be an interesting read. I am partly familiar with both Pythygoras and Riemann. Everything in between should fall into place like a well oiled yau zha kuai into a bowl of bak kut teh. Actually, that's flawed reasoning, and a horrid analogy to boot.



Q.E.D.- "quod erat demonstrandum", Latin for "that which was to be demonstrated"

Silly Pranks 1

It was the third day of Chinese New Year, and it was going to be a quiet night at our grandparent’s place.

My cousins, brother and I were in the midst of a particularly slow game of mah-jong when we decided to go for a “drive”.

“Take the bag of bombs,” someone reminded someone else. The bombs in question were little balls of about 25 mm across, with explosive powder in a plastic outer shell and a fuse protruding ominously. Calling them firecrackers would be slander- they don’t crack; they go BANG! Retailing between RM30 to RM50 per bag of 100 balls, these bombs are available from most illegal fireworks dealers near you.

We piled into a car, and cruised around various residential areas that were not too near from where we staying. It was thought that putting one of those bombs into a dustbin and closing the lid would produce interesting effects.

“There’s one!” indeed there was a promising dustbin- a smallish, light weight plastic one. And nobody appeared to be awake in nearby houses. I drove up to it.

“Do you want to light it?”
“Ok. You hold the lid open, and when I drop it in you shut it.”
“Leave the car doors open. I’ll come in from this side, and you go round to that door.”
“Drive the car a little bit ahead.”
“Ok. You two get down; we’ll move ahead and then open the doors for you.”
“Remember to open the doors.”
“Don’t do anything until I’m ready. Wait till I’m off the brakes and holding at first gear.”

And so the planning went, meticulously.


Finally, we were ready. I had let off the brake, engaged first gear and holding the car on the clutch. From the rear view mirror, they were visible, one with the dustbin lid, the other with a lighter. Just as they were to do it, one of them was overcome by a giggling fit, and infected it upon the other. Watching from within the car, we had our silly giggles. A few more false starts, they finally got their laughter suppression act together and got the bomb inserted and sealed.

They ran towards the car, smiling like monkeys.

When the explosion came, a sudden flash lighted the bin from the inside, the bin hopped some millimetres off the ground, and the lid flew a few feet into the night sky. Dense white smoke began to issue from the opening of the dustbin like water vapour from a cooling tower.

We laughed like idiots.



to be continued...


[Help- "one of them was overcome by a giggling fit". Is it overcome or overcame? Why?]

A cooling tower with a plume of condensed water droplets.

Happy Birthday

One more thing before i forget:

A very happy brithday to ob!ique.

Its been 23 years since 22nd June 1982.

Go send her greeting messages.

A Pause

Thermofluids 4 (436-432)
Thursday, 23rd June 2005
9.30am - 12.30pm
Royal Exhibition Building

BRB after that.



Synonyms for "pause":

abeyance, break, break-off, breather, breathing space, breathing spell, caesura, cessation, coffee break, comma, cutoff, deadlock, delay, discontinuance, downtime, five, freeze, gap, gridlock, halt, happy hour, hesitancy, hesitation, hiatus, hitch, hush, interim, interlude, intermission, interregnum, interruption, interval, lapse, layoff, let-up, lull, pausation, recess, respite, rest, rest period, stand, standstill, stay, stillness, stopover, stoppage, suspension, ten, time out

-from thesaurus.com

Through a Glass, Darkly

[Achtung*: bandwidth intensive post of 3 images totalling to ~260kb. If you load the larger images, that will add about 375 kb to your load. Proceed with prudence]

Macro-shots of a pair of compass through the lens of my spectacles, in colour and monochrome. Colour seems to lend some character and ambience to the image while black and white highlights the shapes and lines.



Click to view large image (158 kb)
f.2.8, 1/80 sec


Click to view larger image (216 kb)
f.2.8, 1/25 sec


Which do you prefer?

Digital cameras continue to amaze me- the close up image is a crop of the full sized, 3.2 megapixel image, sharpened slightly on Photoshop to clean up any aberrations from the spectacles' lens.



f.2.8, 1/25 sec


All images captured using Canon Powershot A70 and resized on Photoshop. Crop and Sharpen also used for the last image.

Post title inspired by Jostien Gaarder's book of the same title. I have yet to get hold of that book; Sophie's World comes highly recomended.




*Achtung - attention; caution (German)

Wet Mercedes

Mercedes-Benz W124 E280

It was the twelfth day of January
A breeze blew gently
Rainwater precipitated from the clouds
Atmospheric relative humidity at 100%
The plants rejoiced

The rain stopped; the clouds dispersed
The sky brightened- 3 F-stops, to be precise
Water droplets all around the photographer
All it takes is a good eye to find the detail
And the camera does the remainder

I'm not sure what the 2 blocks of text above can be called. Referring to them as poetry will be insulting to many people.

21/6/05-
silencers tells me that Deviant Art would classify them as freeflow poetry.
Ob!ique recomends that they be called a prose.

I'm deprived of yam cha sessions

My friends studying in the Northern Hemisphere are all on summer holidays and many are currently back in Malaysia.

The old gang is now complete (with the exception of me, of course) and are having very frequent yum cha sessions. I suddenly miss the mamak.

To contradict myself, I don’t actually miss the mamak per se. The mamak is a tool for friends to meet and actually spend time together. And a damn good tool too! For the price of one iced lime tea, you get a glass of iced lime tea and the rights to occupying your table until closing time. (I’ve never actually seen closing time. 5am? 6am? Someone enlighten me.) There are also options available like various kinds of roti, naan, rice, curries… the list goes on, extending to lamb chop, clay pot noodles and anything else one can possibly think of.

Its probably like those Italian/ French cafés where people sip lattes late into the afternoon, except that mamaks operate at night, and most people would probably sip teh tarik and pick at roti canai.

So I don’t actually miss the mamak as it is, but the company of old friends.


Incidentally, I just read a post by Diana:

Sometimes people think being abroad is soooo much fun. I'd say - it depends. Back home I had the freedom of taking the car out and just going places yamcha etc. Here although there's (fairly) efficient public transport, it still a hassle to get to places. Shops close waaay too early and its abit too quiet.. Of course there's the good things as well..I'm probably just missing some good 'ol yamcha sessions.

I completely agree with her, down to the point about the car. How I miss the fancy footwork when driving a manual vehicle… fancy but mostly pointless exercises like heel-and-toe double clutch, or a gear shift without the clutch*.


*This is actually doable, crazy as it sounds. More on that another time…


Sources:
Diana, "Jumble of Thoughts", from http://xaverri.blogspot.com, 18th June 2005

On the Fuel Efficiency of Engines

[18th June edit: added index of contents for this long post. They are links that will magically teleport you to the correct paragraph!]

Table of contents:

Introduction

The 4 strokes of an internal combustion engine

Pumping work introduced with example

How the throttle affects pumping work

Engine revs and power generation potential

Engine revs and power absorbtion

Normal driving

The pros and cons of using a huge engine

The fuel economy of a small engine with the power potential of a huge engine

Cite this article

There are 2 well known ways to save on petrol-
Use low revs
Don’t buy cars with big engines.

Lets justify these pieces of advice. First, we will take a close look at the common internal combustion engine found in motor cars, and then move on from there.

The internal combustion engine operates by 4 repeating steps (strokes)-
(a) Induction (sucking in air and fuel)
(b) Compression
(c) Combustion
(d) Exhaust (venting hot air and combustion products)



Combustion is where the power generation takes place. The air-fuel (A/F) mixture that has been compressed is ignited, which expands and drives the crankshaft to rotate. The other 3 steps absorb power.

Induction and exhaust use the most power. For an illustration, breathe through your mouth. Close your mouth to leave a tiny gap, as small as possible. Breathe in and out rapidly. The smaller the hole, the more energy needed to pump air in and out, and the faster you tire out. This is sometimes termed the pumping work, which is the work you need to do to pump fluid through a restriction.

The throttle pedal which your right foot operates is connected to the throttle. This throttle is nothing more than a blockage in the air pipe leading into the engine. It is like a door set in the middle of a corridor. The more you open the door, the more draft (of air and fuel) that comes blowing through.

In this illustration, the left diagram shows an end view through the throttle body, with the partially open throttle plate visible. The right diagram is a side cut-away view. The partially open throttle plate is visibly inclined. If the plate is vertical, it completely blocks the passage; if horizontal, the throttle is open at maximum, and this full open is also called wide open throttle (WOT).

Apart from the throttle, other contributors to pumping work are the various flow restrictions such as the air filter, piping lengths, inlet valves, exhaust valves and silencer/ catalytic converter.

Every portion which the air passes through reduces the air pressure, contributing to pumping work of the engine.

Engine sizes are usually measured by their displacement. A 2.7 litre engine will suck in 2.7 litres of air every 2 turns of its crank shaft. When it is revving at 4000 revolutions per minute, it will suck in 5400 litres of A/F mixture every minute (4000 x 2.7 / 2 = 5400). After combustion, it will then be vented out through the exhaust pipe.

Say you are cruising along a stretch of highway when a sudden urge to accelerate overcomes you. What do you do? Drop down one or two gears and floor the pedal, of course! Why drop a gear?

In general, an engine will produce more power when it is revving faster, up to a limit. When revving at 2500 rpm, a 2.7 litre engine sucks in 3375 litres of A/F mixture every minute; at 6000 rpm, it takes in 8100 litres every minute. Obviously, when it takes in more A/F mixture, it can burn more fuel, hence produce more power. Going one gear down makes the engine rev faster, thus giving the potential to produce more power.

Descending the steep slopes of Genting or Cameron, one often comes across reminder signs to “guna gear rendah”. Why would we want to use a lower gear? Again, it is to rev the engine faster.

A fast revving engine sucks in and vents out more air, as already illustrated above. However, if we do not need much power, we only depress the throttle pedal lightly. The throttle is only opened slightly, and the opening for A/F mixture to enter the engine is small. Compare the throttle to your mouth. Open it wide and breather through it quickly. Now, close the throttle (lips) to nothing more than a pin hole, and it is apparent that a great deal of energy needs to be spent just to pump air in through the small opening. It is now obvious (I hope) that an engine can produce more power at high revs, but can also absorb a lot of power at high revs. By using the engine to absorb power via the pumping action at the throttle, one needs not stand on the brakes all the time.

Most of the time, we do not use cars to race with idiots, nor is it used to go down Genting very frequently. It’s often caught in dense traffic, pottering around at about 60km/h. In these conditions, we are not concerned with power output, nor do we want it to absorb lots of work. What we would like is for the engine to produce the required amount of power using the least amount of petrol. The throttle pedal would probably be depressed less than 1/6 the way down, and the throttle itself would be only open partially to allow a little A/F mixture into the engine to produce a little (just enough) power.

If we use a low gear, the engine will rev quickly, and thus suck in more air. Remember that the throttle is only open partially; hence sucking a lot of air through it will need lots of energy. This pumping work is absorbed from the engine, which converts energy from fuel into work output at the driveshaft. The conclusion: pumping work is a waste of petrol (good money). Use a higher gear, and the engine revs slower, sucking in less A/F mixture, resulting in less pumping work.

Return again to the mouth-throttle comparison. Close your mouth to a small gap, and suck air in s.l.o.w.l.y. Now, maintain the same throttle opening, but suck fast. You will notice that the force required to suck air in slowly is considerable less than a high flow. If you do not faint from a lack of oxygen, you can do it slowly all day without getting tired.

If we replace the 2.7 litre engine with a monster 5.5 litre thing, it is obvious that it can produce more power than the 2.7 unit. But it can also absorb more power than the 2.7 unit. At 1500 rpm, they each take in 2025 and 4125 litres of A/F mixture every minute. At 6000 rpm, the figure rises to 8100 and 16500 litres per minute, respectively. If we were cruising at 60 km/h in dense traffic, both only need to produce enough power to over come friction to move our car at 60km/h. However, the 5.5 litre engine needs to suck in much more air through the throttle compared to the 2.7 litre engine. Hence, the 5.5 litre car needs more petrol to sort out the pumping work.

Thus, we see that the 2 bits of advice mentioned earlier are indeed justified.



And for the best of both worlds...

What if we need the power potential of a large engine and the cruising economy of a small unit? General Motors have made available a technology called Displacement on Demand (DoD), while Honda has developed Variable Cylinder Management. Both these technologies shut off half of the engine’s cylinders during low load operation by not opening the intake and exhaust valves of these cylinders. With air trapped in these cylinders, they behave like springs, absorbing work, and then returning most of it with every rotation of the crank shaft. This means that only half the air is being sucked into the engine through a constricted throttle, and the pumping work is reduced significantly.



Cite this article as:

Tan Yee Wei (2005), "On the Fuel Efficiency of Engines", from "Snippets of This and That". http://tanyeewei.blogspot.com/2005/06/on-fuel-efficiency-of-engines.html

Back to index

What an exciting read!

Here is a brilliantly executed account of a first-timer’s experience at a race track. While accounts of track days are commonplace in the media, it is a very rare occurrence to find a fantastic narration that makes you want to go to one yourself.

I musn't brake or lift off, even though it's downhill and I'm picking up speed, because I know from Calum that I can take this flat-out, and it's uphill now, and I've made it through the corners and… Oh my God, here are two Porsche 911s, a Radical SR3, a Caterham Seven and an Ariel Atom up my backside. I can see them all quivering in my vibrating rear-view mirror, but they're not pushing me yet; I'm praying for a straight to let them by, and thank goodness here's one. I move over, and stick my left arm out to wave them on, but they're all through before I can lift my hand, and here comes the Dunlop bridge!

I marvelled at the difference between boy racers and racing drivers: the former hustle you through bends, itching to get past, and so completely miss their lines and lurch around on ragged laps. The racing drivers, meanwhile, hold back to let you sort out your turn then power past in beautifully executed manoeuvres.

-Read the full text

The Daily Telegraph has a very well written weekly motoring section that is worth inspecting.


Source:
Erin Baker, "Tracks of My Tears", Motoring, The Daily Telegraph, 4th June 05, United Kingdom.

Stuff in general

While chatting to my brother on MSN yesterday, he mentioned that my parents were in Kuala Pilah [1]. Grandfather had taken a fall.

Most times, a fall associated with the older generation would be a worrying thing. As people age, bone mineral density decreases. In women, this is more pronounced at and after menopause due to a sharp decrease in oestrogen in that period. In men, the mineral density reduction is more gradual, but still not to be neglected [2]. As a result of mineral density reduction, bones become less stiff and have lowered fracture toughness. To add to these troubles, a fractured bone in old people recovers much slower than in younger folk.

Grandfather was making an illegal turn on his motorbike when he was knocked over by another motorcyclist. An ambulance brought him to the hospital, and he was discharged after treatment and some observation. It was nothing more serious than some stitches and bruises.

I guess he would be quite chafed by the fact that he would not be able to go wild boar hunting with his friends while his wounds recover. The motorcycle would take a while to repair too, so he cannot just ride out of the house to go yumcha with his kaki.

Already his mid-eighties, grandfather was once faced with a sceptical police officer when renewing his gun licence. Unconvinced of my grandfather’s capabilities, the officer invited him to the balai’s shooting range to see how he would do. The officer was suitably impressed, and there have been no further problems as far as we know.



In other news, I’ve completed all assignments for this semester. I had rushed to complete the Combustion and Air Conditioning assignment yesterday. Just in time too! I finished it just 10 minutes before the Canadian Grand Prix started at 3am.

This morning, I remembered that today is a public holiday. How would I submit this assignment? I checked my email message again.

As stated in class the submission date for the thermo assignment was extended [from June 6th] to midday Thursday June 16th.

I must have missed that class (no surprises there). And there it was, Thursday, not Monday. As usual, my memory has never served me well. On a more positive note, I’ve been immensely enlightened on the subject matter of Combustion and Air Conditioning after ploughing though the assignment.



In yet other news, I recently dined at a Chinese restaurant that targets the white Australian segment of the market. It was an interesting experience, interesting not being a positive nor negative attribute, but plainly something which arouses the curiosity.

Here are a few characteristics of that particular restaurant:

It’s dimly lit. The ceiling is painted a mild shade of purple, and a soft glow of purple neon light comes from behind the plasterwork to add to the ambient lighting.

Decorative pieces are a mix of modern Western art and Chinese sculpture.

White tablecloths! White decoration is traditionally used for sombre events like funerals (白事 – white business)

Wine goblets at each seat.

Waiters go around unfolding napkins and putting it on your lap.

Most waiters are Chinese. They speak with a East or South-East Asian accent, not the Australian bred Asian accent (some international students seem to find the ABC accent [3] distasteful- must hear to believe). They speak English to the customers (mostly white Australians), although I believe if you throw Cantonese or Mandarin at them they can take it with no problems.

Food is served in large, wide, white ceramic plates. The food is heaped in the middle of the dish, with lots of clean, white space on the plates.

In more other news (last one), I saw a leng lui recently. Not the big breasts, long legs kind that would make hamsap people snap around to stare at her cleavage kind of leng lui, but of a more subtle [4] variety. She was rather short, and not thin as a wire-hangar fashion model. Her face was framed by mane of thick, very black, slightly wavy hair of neck length, parted slightly off centre at the top of the scalp. Her eyes were strikingly clear- the whites had a slight, even pearlescent quality about them, while the dark brown irises were clearly defined. Her mouth was slightly wider and lips were slightly pinker than those of the general population. Her complexion was fair, but not pale; the skin tone retains the yellowish tinge of people of East-Asian origins.

In summary, not a sexed-up bombshell, but simply a very beautiful lady.

It’s not easy trying to describe a person’s face while keeping the descriptions accurate and beautiful. Note that the verb here is try.


Notes:
[1] If you visited the link, I would advice you NOT to choose Kuala Pilah as a tourist destination. Unless you know people there, you will be bored to death in a matter of hours.
[2] Prof. Ian Holdaway, “Bone Densitometry- a patient’s guide”, Medic8, 2005
[3] Australian Born Chinese.
[4] Synonyms for ‘subtle’, from thesaurus.com :

attenuate, attenuated, deep, delicate, discriminating, ethereal, exquisite, faint, fine, fine-spun, hairline, hair-splitting, illusive, implied, inconspicuous, indirect, indistinct, inferred, ingenious, insinuated, mental, nice, penetrating, profound, refined, slight, sophisticated, suggestive, tenuous, thin, understated

Some points to consider

[edit 13 June- Recomendation: read the original text by ob!que. Perhaps surprsingly, it is not about Western culture but the Malaysian diaspora (brain drain)]

Quoted from ob!ique:

I have a few issues about this. Mostly questions really and they sorta sound like this:

What makes you think being from a Western culture/country is advantageous/privileged?

What makes the West so great? Has the media influenced us all to believe that?

What is so embarassing with being Asian and from a developing state that nobody has heard of?

Can you not see how ignorant some people are as to not even know anything outside their little mindsets?

Cultural plurality giving way to Western hegemony - does that sound right to you, at all?

Read the full article here.

Question answered

On 10th June, a question was posed:

A ball is rolled over a horizontal, rough surface with an initial velocity of 5 m/s. Friction will cause the ball to decelerate at a constant rate of 0.5 m/s2. Calculate the distance travelled by the ball in the first 12 seconds.

Hint: substituting t=12 into s = 0.5at^2 + ut does not work. v(t) is a piecewise continuous function.

First, we will plot the graph of v-t:



Notice that the ball stops moving completely once it comes to a halt. The v(t) function is piecewise continuous- there is constant deceleration in the first 10 seconds, and everything after that is v=0.

Expressed as an equation:



If v(t) did not hold still at 0 after t=10, it would be a rather disturbing phenomena- a ball rolled along a horizontal floor surface would slow down to a halt, and then speed up in the opposite direction indefinitely.

Thus, after the ball has come to a halt, there will be no further displacement. The total displacement in the first 12 seconds is the same as the displacement in the first 10 seconds.

If we insist on doing the integral:

End of the Age of Oil, part 3

End of The Age of Oil is a narration set somewhere in the future (~2070). Chapter 1 discusses the wasteful lifestyles of citizens in developed economies during the 20th century. Chapter 2 is set in the early decades of the 21st century, and shows some of the implications of oil exhaustion to the lifestyle of the population.

Suggestions for future plot direction, topic of discussion, feedback are most welcomed valued.

End of The Age of Oil

Chapter 3:
Social changes

As oil prices rose, it became a terrible burden for the general population to drive. In light of this, public transport became incredibly efficient by 20th century standards. Electric trolleybuses become the favoured means of public transport, not only for its lack of emissions, but also because it used electric power generated from renewable and nuclear sources. The streets became free of rumbling, honking, humming and burbling automobiles, and the air over cities worldwide took on a clarity never seen in decades.

This turnaround in air quality turned out to be a blessing for amateur, backyard astronomers. Observant veterans noted that several previously undistinguishable star systems had revealed themselves to be the binary stars they are.

In spite of this apparently happy development of efficient public transport, peaceful urban streets, clean air and visible star systems, there was a constant, niggly threat of food security for states, families and individuals. If oil supplies were exhausted before a suitable hydrogen source was found, fertiliser and food production would be threatened.

In this respect, the food & population policies of states took on an additional dimension characterised by 2 opposing attitudes- “make less babies; we don’t want our numerous great-grandchildren to starve” and “have all the babies you want, but make sure you contribute to the fertiliser research program”.

Several states which took the “make less babies” stance enforced a one-child policy similar to 19th century China. Most parents were culturally unprepared for this change. Lavishing excessive attention on their only child, they gave rise to a generation with a disproportionately large number of socially-inept, self-centred and obnoxious little bastards who always got what they wanted. In these states, staunch believers of “no contraceptives” religions had very little sex, and were generally grumpy people. Most states prudently stood somewhere between the “make less babies” and “contribute to fertiliser research” attitudes.

For the majority of the inhabitants of developed states, their world and basis of existence had been cars, ordinateurs, air conditioners, microwave dinners, plastic bags, televisions and reality-TV. With the looming oil exhaustion upon them, a few began to see the insignificance and impermanence of their high-rolling lifestyles. “What is the point of clinging on to these trivial and temporary characteristics anyway?” they asked. “Yeah, we will lose them pretty soon anyway. No point fretting over them.”

A class of semi-ascetic people began to emerge from the middle-class of developed economies, eschewing in varying degrees dependence on fossil fuels, plastics and unnecessary convenience. Of course, necessity is subject to interpretation, and some found polymer condoms necessary while others thought of them as nothing more than an endangered plastic product.




*ordinateur - computer (French)

Previous chapters:
Chapter 1
Chapter 2

Nude pictures of compass, pencil & ruler threesome.

I think I’m getting high on the study break. With three blog updates a day, it would seem like I’m already on retirement benefits.

I was playing with a camera, and posed some stationery pieces in sexually explicit positions.

My compass used to belong to my mother. She acquired it sometime in her student years, presumably in secondary school. The compass is about 36 to 40 years old.



Click to view large image. Here for Deviant Art post.

Note the beautifully crosshatched and bevel-edged bezel ring.




Click to view large image. Here for Deviant Art post.

Rotring rulers kick arse! For some reason, they are a pleasure to use.

The ruler played no part in creating the circle. It was merely tagging along with the compass and pencil.

A few notable things that happened in the past 6575 days

The Earth has made 18 circuits around the sun.

The Soviet Union collapsed.

Williams F1 won the Constructors Championship six times. details

Poincaré's conjecture was finally proven after 100 years. details

My brother was born.

Another brother was born (not simultaneously nor immediately after the previous)

A very happy 18th birthday to Yee Hou!

ps. 365 x 18 is not 6575. You need to include 5 leap days occuring on the 29th February of 1988, 1992, 1996, 2000 & 2004.

Physics very hard meh?

In the course of one’s education, it is perhaps inevitable that one would come upon remarks of this nature: “Mathematics/physics/chemistry is such a difficult subject! There is only one correct answer. If I mess up somewhere along the way then I’ll definitely get it wrong. No middle route between correct and wrong. That’s why I prefer economics/sejarah/marketing.”

Of course, most of these remarks are not as elegantly phrased as my example; they usually come in the form of semi-coherent moans and complaints.

If anyone had thought they could scrape through physics by plainly memorising equations, they would have either been wrong or possessed a very good memory.

While there is only one answer to a properly phrased problem, this solution can be approached from more than one way. Let’s illustrate this by considering a very common problem found in SPM-level physics.

A ball is rolled over a horizontal, rough surface with an initial velocity of 5 m/s. Friction will cause the ball to decelerate at a constant rate of 0.5 m/s2. Calculate the distance travelled by the ball in the first 7 seconds.

The first equation that comes to mind would be s = 0.5at^2 + ut. Where in our case a= -0.5, t= 7, u= 5. What if the nervous problem solver cannot remember the equation in full? Is she fucked?

Hell no! At least, not if she has some creativity.

From an extensive knowledge of SPM-level calculus, she knows that displacement is the area under the curve of a velocity-time graph. And so she plots the graph. At t=0, v=5; at t=1, v=4.5; at t=2, v=4…and so on till t=7, v=1.5. It turns out to be a straight line with a slope of -0.5 and intersecting the v-axis at 5.




And thus, using some fundamental geometry, she calculates the area below the v-t plot from t=0 to t=7. Splitting the area into a rectangle and triangle, their respective areas are 7 x 1.5 and 0.5*3.5*7. Thus the total distance travelled is 22.75

This method being too absurdly simple, she tries to find the area properly by means of integration. Having already seen the velocity-time plot, she can express it as an equation v= -0.5t + 5. The area under v between the bounds of t=0 and t=7 can be found by integrating v with respect to t with the limits t=0 and t=7.

After integrating and before substitution of the limits, she notices something that will change her life forever:



That’s the equation! s = 0.5at^2 + ut. That equation is derived from this integral, and fitted for a lower limit of t=0. I’ve got it! Woot!

When I saw the similarities back in 2000, I was rather excited as well. My fellow students thought it was too much trouble. Probably because they already had the equation memorised to perfection.



Endgame:
Now that you've seen the equations, here is an extension of the problem given above. See if you can get it right.

Calculate the distance travelled by the ball in the first 12 seconds.

Sounds easy? Have a go.
Hint: substituting t=12 into s = 0.5at^2 + ut does not work. v(t) is a piecewise continuous function.

Some wierd-arsed nocturnal activities

High-section turning kick




Chopping kick




Jumping back thrust. Note the slight change in elevation

Someone needs a haircut. I think it's me, considering my hair at the sideburns are horrific (4 cm long).

Mental incapacity

Its 2.04 am on a Wednesday morning, and I’m feeling strangely lethargic and apathetic.

Monday:

9.30pm- I was exhausted from insufficient sleep. Of late, I have been intending to sleep about 7 hours a day, from 5am to 1pm. Unfortunately, the room tends to get too bright (even with the blinds drawn) and I will be unceremoniously roused by solar radiation at about 11.30am. And so I went to sleep at 9.30pm instead of my usual 5am, intending to sleep for about 7 to 8 hours and start Tuesday at 5am.

Tuesday:

2.30am- I woke up. Checked the time, and cursed at my insufficient sleep. Nonetheless, I got up and had my breakfast of bread and coffee. As is the usual case when I’m not in a rush, I took the time to actually brew coffee.

3.00am- Started chatting, blog surfing, and revising for my exams. Also tested my English language skills. “English Genius,” the results proclaimed, which I thought was quite misleading. “Malaysian Genius” would be more appropriate.

5.30am- I was hungry; time for more food. Out of convenience, I made myself a 12 minute meal of salad, soft boiled eggs and toasted bread. Cold salad in the morning is refreshing.

8.00am- Feeling a little lethargic, I stirred 2 teaspoons of Nescafé Espresso and a teaspoon of sugar into some hot water, and topped up with milk. That would be my performance drug. Not having had instant coffee in a few days, I was reminded of why I have not had it for a few days- it tastes bland and acidic.

8.45am- Set out to walk to the exam venue with a friend.

9.30am- Exam starts, scheduled time 3 hours.

12.10pm- Completed exam early due to some unsolvable problems. The day continued on.

6.00pm- Exhausted, I took a nap of 2 hours.

Wednesday:

2.00am- Not feeling rather productive, I opened MS Word and started a new document instead of revising for my exam.

2.27am- I typed this out. Realised I am tired, and need sleep. A glance of this document (written over 23 minutes) will reveal the decaying attention and concentration- starts out with fancy wording, lots of details, expressive. The writing quality then starts to decay into the shit you are currently reading.

2.41am- Finalised my post and finished tweaking the HTML knobs. About to click "Publish Post".

I’ll probably sleep at 3, and wake up at 10. Brunch with more coffee, revision, and leave for my second exam scheduled at 2.15pm Wednesday.

Study lah...what are you doing with this?

-I'm inflating my ego lah, what else?



I saw this test at here. Was quite intimidated by her results and credentials (a writer/editor, it seems). Perhaps the test was too easy, or maybe i really do have some substance. I hope its the latter.

I think i should get back to studying for my exams...

English Genius You scored 92% Beginner, 92% Intermediate, 93% Advanced, and 80% Expert!

You did so extremely well, even I can't find a word to describe your excellence! You have the uncommon intelligence necessary to understand things that most people don't. You have an extensive vocabulary, and you're not afraid to use it properly! Way to go! Thank you so much for taking my test. I hope you enjoyed it! For the complete Answer Key, visit my blog: http://shortredhead78.blogspot.com/.

My test tracked 4 variables How you compared to other people your age and gender: You scored higher than 35% on Beginner You scored higher than 26% on Intermediate You scored higher than 51% on Advanced You scored higher than 72% on Expert

Link: The Commonly Confused Words Test written by shortredhead78 on Ok Cupid

Karatsuba Multiplication

In February, one of my father’s friends who in the automotive industry offered him an Audi A4 over several days for a test drive. After some nagging on my part, Dad accepted the offer and the car was delivered to our house. That’s the benefit of having someone high up in the ladder- they can arrange for test cars to be sent to your house, and for several days too.

The A4 was is a brilliant car.

[Truncated- endless technically oriented drone regarding powerful 1.8 turbocharged engine, remarkable built quality, luxury, attention to detail…]

For those few days, we had 3 cars in the house. Dad used his usual Mercedes E280 to work (he wasn’t really into this A4 thing anyway; it was me who egged him into submission), Mom continued using the Toyota Prado (she wasn’t a big fan of this test drive thing too). Guess who had exclusive use of the A4?

[Truncated- endless gush about the excellent cabin built quality, soft-touch plastics, excellently damped control knobs, remarkable attention to detail, cup-holder…]

[Omitted- my peers’ (brothers, cousins, friends) reaction to the A4]

One fine day when I was visiting some lecturers in Taylor’s College, I parked the car in an inappropriate location. When I got back I noticed that I had been fined. Subang Jaya being the arsehole of a municipality it was, charged a hefty RM 80.00. I had to pay this fine- it was not my car, and if any action was taken, it would make me, my father & my father’s friend look like a bunch of kiamsiap idiots.

And thus I went to pay that stupid fine. I have only myself to blame.

It was crowded, and I had to wait. Having neglected to bring some reading material, I resorted to mental exercises to keep myself occupied. Taking two random, 2 digit numbers, I would multiply them mentally, and check the answer using my phone’s calculator. I was having such fun that the wait did not seem too long.


Karatsuba multiplication

[The following is a mathematics intensive discourse. Knowledge of lower secondary mathematics assumed]

The Karatsuba and Ofman algorithm to 2 digit multiplication is particularly suited to mental calculations compared to mentally doing it the long way using the plain, pencil & paper method we were taught in primary school.

Suppose we have 2 two-digit numbers we want to multiply (each digit represented by an alphabet):
ab x cd

We can rewrite the multiplication by separating the digits:
(10a + b) x (10c + d)

Putting these 2 numbers aside, we now go on to consider two similar systems:
(aZ + b) x (cZ + d)= ac*Z^2 + (ad + bc)Z + bd

Expanding the expression, we see that the middle term (ad + bc) might pose some problems
(a + b)(c + d) = ac + (ad + bc) + ac
(ad + bc) = (a + b)(c + d) - ac - bd

Expanding the expression and re-expressing the equation, we have a potential solution to the (ad + bc) problem in the previous equation above.

Comparing the two-digit multiplication with the generic quadratic equation by letting Z = 10:
(10a + b)(10c + d) = 100ac + 10(ad + bc) + bd

Recall that the problematic middle term (ad + bc) term can be expressed as (a+b)(c+d) – ac – bd.

Thus, the foundations to Karatsuba multiplication have been laid. The following example should illustrate some of the conveniences of the Karatsuba algorithm.

Lets multiply 97 by 56.
Add the digits in the first and second numbers, and multiply them:
(9+7) x (5+6) = 16 x 11 = 176
Multiply the first digits of each number:
9 x 5 = 45
Multiply the second digit of each number:
7 x 6 = 42

Deduct the product of first digits and the product of second digits from the product of the sum of digits:
176 – 45 – 42 = 89. That’s the middle term.

Thus 97 x 56 = 100 * (the product of first digits) + 10 * (the middle term) + (the product of last digits)

To mentally add them, just offset each number by one digit and sum them:

4500
890
+ 42
5432

Have fun!

[This algorithm will be of no use to practitioners of abacus-based mental arithmetic who can perform many two-digit multiplications in a few seconds.]


Comparison between Karatsuba multiplication and long multiplication

Using the example above, 97 x 56, long division will have us perform the following operations:
97 x 6 = (6 x 7) + 10(6 x 9) = 42 + 540 = 582
97 x 5 = (5 x 7) + 10(5 x 9) = 35 + 450 = 485
97 x 56 = 582 + 4850 = 5432



The problem associated with long multiplication is the need to remember long and numbers while calculating other long numbers. Addition of these numbers usually involve carrying remainders over, adding to our troubles. In my experience, it’s the process of storing and recalling these numbers that usually makes mental long multiplication a tediously slow process.

Using Karatsuba on the same numbers, the operations are required:
Important numbers have been marked using capital letters.
9 + 7 = 16
5 + 6 = 11
16 x 11 = 176 (A)
9 x 5 = 45 (B)
7 x 6 = 42 (C)
176 – 42 – 45 = 89 (D)
97 x 56 = 4500 + 890 + 42 = 5432



In this example, the numbers are reasonably large, and the sums of digits are in two digits (16 & 11). However, we are always summing 2 numbers less than 9, thus if they turn out to be 2 digits, the first one will always be 1. This summation of digits should be a trivial task.

Multiplying the digits should not be too difficult: we are already equipped with look-up tables to multiply any natural numbers from [0,0] to [12,12]. And as stated above, the first digit of a two-digit sum will always be 1. Remember this product of sum of digits (call it number A)

Multiplying the first digits and last digits is a trivial task and should take no time at all. These will be called numbers B and C.

Subtract B and C from A. This will probably be the most intense operation. However, it can be drastically simplified by doing the subtraction in 2 steps. For examples, 176 – 42 = 176 – 40 – 2 = 134, or 85 – 47 = 85 – 50 + 3 = 38. This will reduce the complexity of calculations to semi-trivial problems that already have look-up tables stored in memory, thus eliminating the need to remember carried numbers and whatever. Call the subtracted number A – B – C = D. The number A is no longer needed, and can be deleted.

Add 100B + 10D + C. Add 10D + C first by mentally offsetting the digits, then add 100B to by offsetting the digits of B by 2 steps. If by now you have forgotten the numbers B and C, it is no problem because they can be obtained trivially by looking at the digits of the original number to be multiplied.
Karatsuba is hideously complicated to describe in words, but when you manipulate the numbers in your mind, things fall into place with surprising ease. Note that all operations involve small numbers with very little of the nasty carrying business.

With a pencil and paper, long multiplication is generally faster because the business of reading and writing avoids the need for slow remember and recall processes.

This is where the abacus will trounce long and Karatsuba multiplication- the read/write operations are sometimes skipped altogether and the processes are just added. For example, adding 1 and 2 does not require the user to read the existing 1, add 2 to it, and write 3. The user simply dumps 2 more into the existing pile, and 3 is the automatic result. At any rate, the read/write speeds are phenomenally fast anyway.



Application of Karatsuba multiplication in simplifying huge multiplications

Say we need to multiply 2 sixteen-digit numbers. Long multiplication will require that we multiply all digits in the first number with all digits in the second number and sum them accordingly. It should be clear now that we will need to perform 16 x 16 = 256 one-digit multiplications.

If we express the 16 digit number abcdefghijklmnop as abcdefgh*100000000 + iklmnopq and repeat for the other 16-digit number, the Karatsuba algotith can be applied. Now, there will be 3 multplications of eight-digit numbers, and thus require only 3 x 8 x 8 = 195 one-digit multiplications. Or, to take it another step further, each eight-digit multiplication can be broken into a set of 3 four-digit multiplications., reducing the number of one-digit multiplications to a mere 3 x 3 x 4 x 4 = 144. However, there is the cost of the additional subtraction and addition steps, and care should be taken to avoid overdoing the recursive Karatsuba.




This lesson in number theory brought to you by Yee Wei.

ps. what a bloody long post! MS Word estimates it to be 1500 words.
Congratulations if you have reached the end. Just for fun, please drop me a note in the comments section to tell me that you've reached The End.

A Meal in 15 Minutes

-A case study in optimisation


For a fancy meal (by student standards, of course) in a short time, the trick is to run several parallel and partly automated processes at once.

Here is a proposed lunch that could conceivably be prepared in 15 minutes-

Soft boiled eggs
Toast
Salad
Coffee/ tea

Soft boiled eggs require the eggs to be immersed in boiling water for 3 minutes.
Toast can be made from existing bread slices using a toaster.
Salad consists of 2-3 lettuce leaves, 1 tomato, 1/4 of a red onion, shredded/powdered cheese, some cut up bits of ham, a suitable dressing from a bottle.
Coffee can be brewed by using a plunger (instant coffee is a last resort); tea infused from a bag in hot water.

Most of the work will be centred on the salad and its preparation.

-Start by boiling water for the eggs. Use hot water from the tap if available to avoid having to heat up cold water (it takes ages).

-Insert (ceramic or glass) salad bowl into freezer.

-Start cleaning and cutting work on the vegetable.

-When water starts to boil, remove some for the plunger coffee/ tea infusion. Add eggs into remaining water. Note the time, and start working on the coffee/ tea. Insert bread into toaster.

-Back to the vegetables.

-3 minutes after the eggs have been started, remove them from boiling water and quench into cold water (stops it from subsequent cooking, and lets you handle them easily). Plunge the filter on the coffee.

-Vegetables should be done by now. Put them into the chilled bowl. Add dressing and shredded/ powdered cheese.

-Take a slice of ham and fold it up arbitrarily, then cut it into bits using a pair of scissors onto the salad.

-Crack eggs into a bowl. Add pepper and soy sauce to taste.

-Remove toast from toaster, and cut into appropriate size (if desired) with the previously used scissors.

-Mix up salad.

-Sweeten and add milk to coffee/tea.

15 minutes.

The washing up should be sufficiently easy. Pot was only used to boil water and eggs- a rinse will suffice. Knife and chopping board were only used for vegetables with no oil content- a rinse will suffice.

This scheme would defeat instant noodles easily. Instant noodles need about 5 minutes, contain only carbohydrates and crap (flavourings, taste enhancers, salt).

I had easily attempted the above without coffee in 15 minutes. The next challenge would be the full thing including coffee, in 10 minutes. With a shart knife and a deft cutting hand, it should not be too difficult. We'll see.

The Kiss (v 1.1)

Another attempt at microfiction. Again, please note that the "I" in the story refers to the narrator, not myself.

Susan's Kiss
by Tan Yee Wei

We had finished our long lunch when Michael ask me the question, “Susan, will you be available this Sunday night? The European Grand Prix will be on at 8.00.” Since meeting Mike, I had started taking a passing interest in what my brother calls the ‘F1 Circus’. It’s one thing watching a live telecast with two commentators, and another thing to have a third, interactive commentator that does not take commercial breaks.

“Will it be any good?” I asked him.
“Most probably. The Nürburgring has fast straights and slow curves strung together for overtaking opportunities, and some technically challenging curves thrown in for good measure. BAR-Honda will be back too.” He gave me a wink- I have an unexplained soft spot for Jenson Button, the promising and slightly cute BAR-Honda driver.
“I’ll trust your judgement. Should we have dinner before that?” I had initially allocated Sunday evening to clean up my manuscript for the editor, but that could wait a few hours.

“Dinner sounds nice. At my place? I try to make a nice meal,” Mike suggested.
“I’ll bring something. Ice-cream?”
“Ok. I’ll see you on Sunday evening then.”

Before we parted, I gave Michael a hug. On impulse, I tipped my toes- I was slightly, just slightly, shorter- and gave Mike a kiss on the lips. What was intended to be a quick peck was starting to turn into a much more engaging affair. As he opened his mouth slightly, a warm, humid, saliva-ish smell typical of oral cavities came to me senses. Immediately after that, a pungent and utterly repulsive odour of decaying vegetation attacked my olfactory nerves.

At once, I shut my mouth with a clap, retracted my face and shoved him away, “Ta ma de! Never brush teeth is it?”

Regaining my composure, I tried to mend the situation, “I’m sorry…slight over-reaction.”


Nothing spoils a good kiss faster than bad breath.

-315 words

Epilogue

The European Grand Prix turned out to be a surprisingly emotional event. At the closing stages of the race, race leader Kimi Raikkonen had an unbalanced tyre that caused his car to vibrate wildly, and blurred his vision. Even so, he managed to hang on to his speed, being only one second a lap slower than his nearest competitor Fernando Alonso.

By the last few laps, the tyre vibration had worsened to the stage where the suspension links (Mike says they are made of resin bonded carbon fibre) were visibly flexing like coconut trees in a storm. Kimi continued to push hard, as Fernando was catching up at a rate of one second per lap.

On Kimi’s last lap of the Nürburgring, his suspension failed from the excessive flexure. In an abrupt explosion of carbon fibre composite bits of front wing, suspension elements and miscellaneous aerodynamic elements, Kimi’s race ended.

I almost cried at the disappointment.

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