Philip Pullman once said, "All we need is the word 'Once...' and we're off." He is referring to the appeal of classics such as "Snow White", "Cinderella" and many Grimm tales.
All right. Everyone take a seat. Now I'm going to tell a story, not from the Brother Grimm. That's my daughter's favorite recently, and it comes from an amusing author in Japan.
Once there was a family of sweet potatoes, and for years this family had lived with routines underneath the ground. My daughter noticed this, and smiled when she found out the sweet potatoes brushed the teeth every morning, went to potty, got hungry now and then, just like her. They hid everything underground, and no one would dare to steal anything from there.
But it wasn't long before the sweet potato family felt a thump. Or earthquake?
"Oh, no," the daddy sweet potato said, "is it a giant there?" Frightened, he slammed the door shut at once and ran back to gather everyone at the living room.
"Oh, papa, that's not a giant. I saw many children above there. Wait, wait! They're knocking at the door."
The children kept on knocking and called, "Come, we found sweet potatoes. Let's pull and get them out."
The sweet potatoes heard a loud crack from above. "Oh, for goodness' sake! Let's line up and prepare for the tug-of-war." Not long afterwards the sweet potatoes felt the pulling force from boys and girls above.
"Heave-ho, heave-ho!"
When the sweet potatoes nearly gave way to the children, I heard my daughter chanting heave-ho together. My daughter watched anxiously for a minute or two, and really wanted to lend a helping hand. But it's too late. The sweet potatoes were losing the game. And on they rolled as though drawn by a giant, along the rope, up the stairs, until suddenly - hop! All the sweet potatoes were pulled out.
Well, what else did you expect? The sweet potatoes ended up being eaten. "Nothing tastes as good as baked sweet potatoes," the children were busy licking out and guzzling every bit of their harvest.
"Someone's been eating my leg."
"There's a bite out of my back - look!"
"And mine."
"And mine."
Everyone could see that the children were enjoying the sweet potato feast. My daughter wasn't, though; she felt sad about the sweet potatoes.
All gone, every one of them. Not really. Surely it couldn't be that simple? Can you hear the sound? Funny sound really.
Boooom. Booooooooooooom. Booooooooooooooooooooom. My daughter pinched her nose. She almost laughed her head off when the boys and girls could not stop farting. They were farting as often as dogs are panting after running for miles.
Now, who is the winner? Round one to the sweet potatoes, I thought.
Friday, July 26, 2013
Saturday, July 13, 2013
Physics
In the middle of the summer holidays, a number of high school students came to my hospital. They sat on either side of the doctor in the clinic, going around with the doctor who saw patients everywhere in the hospital. This could have been the first time they stayed in a public hospital.
I haven't thought much about the high school education before the students joined us. We talked about everything, and then I realized that high-school days are pretty far away in my life. For a moment I was puzzled how much high-school teaching I could still remember.
Not much. Let me think. How about Newton's three laws of motion? The first law states that every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impress'd thereon. Yes, of course, it's all about the kid's resistance to change. No, not changes. They don't like changes. They really don't. Kids react to changes with vehement opposition. My daughter - and many other children, I'm sure - doesn't want to go out after she has started drawing at home, and once in the playground, doesn't want to leave, and by night time, doesn't want to sleep.
Now think about Newton's second law. We're taught that motion doesn't require the action of a force, but a change in momentum does. That is proportional to the force causing it. That's easy to understand. To speed things up we need to push it. Beautiful, I know, but does it mean I have to push my three-year-old daughter? Wait. The third law states that we can't push something (or someone) without it pushing back.
Let me summarise. A force can cause change, and a harder one gives more drastic change, which can backfire because of another force - you guessed it: action and reaction (or rebellion). What an important rule that would be.
I haven't thought much about the high school education before the students joined us. We talked about everything, and then I realized that high-school days are pretty far away in my life. For a moment I was puzzled how much high-school teaching I could still remember.
Not much. Let me think. How about Newton's three laws of motion? The first law states that every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impress'd thereon. Yes, of course, it's all about the kid's resistance to change. No, not changes. They don't like changes. They really don't. Kids react to changes with vehement opposition. My daughter - and many other children, I'm sure - doesn't want to go out after she has started drawing at home, and once in the playground, doesn't want to leave, and by night time, doesn't want to sleep.
Now think about Newton's second law. We're taught that motion doesn't require the action of a force, but a change in momentum does. That is proportional to the force causing it. That's easy to understand. To speed things up we need to push it. Beautiful, I know, but does it mean I have to push my three-year-old daughter? Wait. The third law states that we can't push something (or someone) without it pushing back.
Let me summarise. A force can cause change, and a harder one gives more drastic change, which can backfire because of another force - you guessed it: action and reaction (or rebellion). What an important rule that would be.
Thursday, July 11, 2013
Reactions
How can you get the golden-brown colour and fabulous aroma by cooking food?
Temperature is the trick.
And by temperature I really do mean high temperature. Chemically it's something called caramelisation reaction, which occurs when we heat food in an oven, grill or oiled frying pan up to around 160oC. That doesn't mean we get nothing below 160oC. By the time the temperature rises to 140oC, it will kick start another set of Maillard reaction. These reactions between proteins and sugars explain the secret of many cooks. Brushing a little egg white on the surface of flour, I was told, provides extra protein to react with carbohydrates, helping it brown and adding taste. Notice how much we love the freshly baked bread after these reactions in the oven.
So now I know why cooking food in a microwave oven doesn't work wonder. In the case of the microwaves, they are tuned to the vibration frequency of water molecules. The heat comes directly from the water in the food, whereas caramelisation and Maillard reactions only happen with dry heat. Alas, without these miraculous reactions, the tasty aroma molecules won't appear.
Take one more look at these reactions in the kitchen, and then outside. You'll see a similar thread of theory around us. There are similar reactions around, whatever your subject. Take final year medical students; once sitting in the library and reading lecture notes only, they now are mandated to go to the medical wards and work as part of a team - in the form of apprenticeship. One tried and tested method is to give them a quota. That means the students have to see a minimum number of new patients, and take blood from, say, no less than six patients. We'd like to aim high and let the students work hard, more or less like achieving the temperature of 140oC. That is really tough when you compare to spoonfeeding in the classroom (the microwave-equivalent in the kitchen). But, at the end, we hope it will give them a glimmer of golden-brown splendour.
How high should we raise the bar? I don't have the right answer but I remember another important rule in cooking: less desirable molecules can appear after too high a temperature. Go beyond 200oC, and be prepared to get the bitter-tasting carcinogenic stuff.
Temperature is the trick.
And by temperature I really do mean high temperature. Chemically it's something called caramelisation reaction, which occurs when we heat food in an oven, grill or oiled frying pan up to around 160oC. That doesn't mean we get nothing below 160oC. By the time the temperature rises to 140oC, it will kick start another set of Maillard reaction. These reactions between proteins and sugars explain the secret of many cooks. Brushing a little egg white on the surface of flour, I was told, provides extra protein to react with carbohydrates, helping it brown and adding taste. Notice how much we love the freshly baked bread after these reactions in the oven.
So now I know why cooking food in a microwave oven doesn't work wonder. In the case of the microwaves, they are tuned to the vibration frequency of water molecules. The heat comes directly from the water in the food, whereas caramelisation and Maillard reactions only happen with dry heat. Alas, without these miraculous reactions, the tasty aroma molecules won't appear.
Take one more look at these reactions in the kitchen, and then outside. You'll see a similar thread of theory around us. There are similar reactions around, whatever your subject. Take final year medical students; once sitting in the library and reading lecture notes only, they now are mandated to go to the medical wards and work as part of a team - in the form of apprenticeship. One tried and tested method is to give them a quota. That means the students have to see a minimum number of new patients, and take blood from, say, no less than six patients. We'd like to aim high and let the students work hard, more or less like achieving the temperature of 140oC. That is really tough when you compare to spoonfeeding in the classroom (the microwave-equivalent in the kitchen). But, at the end, we hope it will give them a glimmer of golden-brown splendour.
How high should we raise the bar? I don't have the right answer but I remember another important rule in cooking: less desirable molecules can appear after too high a temperature. Go beyond 200oC, and be prepared to get the bitter-tasting carcinogenic stuff.
Monday, July 1, 2013
Shoe Box
Some time in the summer, at the end of an academic year when Obama was 17 years old, a party was thrown in Hawaii. The old picture of Obama and his date in that party was recently taken out of his schoolmate's shoe box, and shown to the readers of Time magazine.
The years have gone by in the blink of an eye, and oh, photographs are no longer developed. Gone is the day of putting old photographs in an album or shoe box. For about as long as the Internet has existed, the photos of teenagers are more often stored on Facebook than in a shoe box. A few mouse clicks give them the digital footprints. Long lasting one, and easily retrievable. It's almost like a diary online for a myriad of stories, starting from the dish at a restaurant to the ceremony of tying the knot. Letters are giving way to electronic mails, and shoe boxes are giving way to Inbox.
When shoe boxes packed with old memories were as big a part of many old guys' treasure chests, we had to make sure the shoe box wasn't thrown away when we moved. Part of the challenge of maintaining the shoe box is the need to keep buying sachets of dehumidifier. Back in my home and office, I have been making use of boxes to keep track of history. Everything. Clinical photographs captured in slides (something you can't see without a slide projector), a handwritten letter written by my mentor (after I failed in a postgraduate professional examination), and hundreds of letters from my wife during my year of overseas training. Boxes are small, I know, when you think about the size of Dropbox nowadays. My boxes, however, capture far more things than Dropbox can hold.
The years have gone by in the blink of an eye, and oh, photographs are no longer developed. Gone is the day of putting old photographs in an album or shoe box. For about as long as the Internet has existed, the photos of teenagers are more often stored on Facebook than in a shoe box. A few mouse clicks give them the digital footprints. Long lasting one, and easily retrievable. It's almost like a diary online for a myriad of stories, starting from the dish at a restaurant to the ceremony of tying the knot. Letters are giving way to electronic mails, and shoe boxes are giving way to Inbox.
When shoe boxes packed with old memories were as big a part of many old guys' treasure chests, we had to make sure the shoe box wasn't thrown away when we moved. Part of the challenge of maintaining the shoe box is the need to keep buying sachets of dehumidifier. Back in my home and office, I have been making use of boxes to keep track of history. Everything. Clinical photographs captured in slides (something you can't see without a slide projector), a handwritten letter written by my mentor (after I failed in a postgraduate professional examination), and hundreds of letters from my wife during my year of overseas training. Boxes are small, I know, when you think about the size of Dropbox nowadays. My boxes, however, capture far more things than Dropbox can hold.
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