science.inspire

Well-developed Answers to “Pack Light, Pack Smart”

2010-07-05T12:23:00.001+08:00

“I agree with some of you who said that the mass still remains the same because the amount of clothes remains the same. The only good thing if the clothes are compressed in the bag, it will not take up much space and therefore, we are able to use a smaller bag and eliminate the excess baggage in terms of mass of the bag.” - Anonymous

“Using the property of air occupies space and has mass in Science, we can vacuum the bag after putting in the clothes and seal it. In this way, there is minimal amount of air occupying space and contributing to the mass.

These clothes have a definite mass and definite volume. By packing light (vacuuming the bag) is just removing the air and lowering the mass of the whole bag, not compressing the clothes or make them lighter.”
- Oan Jia Xuan (6 Charity)

“Scientifically, it is impossible to lighten or compress our clothes as they are solids. However, clothes trap air which contributes to their weight. Thus, if we vacuum all the air from the clothes or bag we are "lightening" the clothes.”
- Adam Tan (6 Charity)

“When we pack light, the air inside the ziplock bag will be vacuumed out and thus, it leaves more space for other stuff.”
- Quinn Cheong (6 Charity)

“You can put the clothes in an air tight ziplock bag. Even though the clothes have a definite mass and cannot be compressed lighter, they have air in between them which has mass.”
- Scott Yap (6 Charity)

Well-developed Answers to “Wollen Sweater VS Windbreaker”

2010-07-05T12:20:00.001+08:00

“I will chose the woollen sweater because it traps hot air and keeps the person warm.”

- Xavier (6 Grace)

“The difference is the wollen sweater protects you from the cold winter and the snow while the windbreaker protects you from the strong cold wind.”
- Pearlyn Loon (6 Hope)

“The windbreaker can protect Alice from the wind while the woollen sweater can keep her warmer.”
- Ng Jin (6 Charity)

“If Alice is going somewhere wet or windy, she should use the windbreaker as it is waterproof and blocks off the wind. However, if she is going somewhere that is not wet, the woollen sweater is more suitable. The woollen jacket also tends to be warmer as it is a poorer conductor of heat than the wind breaker, and it will conduct away heat from the body at a slower rate.
Difference: The woollen jacket is made from a material that was once alive, but the wind breaker is made from a material that was never alive.”
- Jeremy Teo (6 Charity)

“The windbreaker is waterproof and is used to resist wind chill and rain. However, the woollen sweater traps more heat as wool absorbs the radiated heat and most of it is not re-radiated from the outside. In addition, the thicker material blocks air flow from reaching you, creating a warmer air layer between the sweater and the body.

The wollen sweater tends to be warmer as it is a poorer conductor of heat as compared to the windbreaker. Thus it will keep the person warmer for a longer time. The windbreaker is used to shield the wearer from wind, rather than to insulate, which the woollen sweater would do.”
- Olivia Tan (6 Charity)

Well-developed Answers to “Unbreakable Books”

2010-07-05T12:17:00.001+08:00

“There is friction as the pages are overlapping one another.”
- Ron (6 Hope)

“The friction between the pages of the thick book made it difficult to pull the two books apart.”
- Wong Yu Kee (6 Charity)

“Science concept - Frictional force

When the two people were pulling the books, the books were not separated because the frictional force between the pages is greater than that of the pulling force.”
- Jeremy Teo (6 Charity)

“When the pages overlap, it will be hard to pull out due to friction which is acting on the pages. To release the two books, just release tension and pull on the two ends very slightly.”
- Samuel Tay (6 Charity)

Well-developed Answers to “Wonder Flask?”

2010-07-05T12:13:00.002+08:00

“Rubber to seal the heat, metal because it is good conductor of heat to keep the liquid warm and plastic for the handle so that you do not get burnt.”
- Ferris (6 Hope)

“As they are insulators of heat, they slow down the hot/cold beverages to eventually become the same temperature as the surroundings.”
- Koh Kai Yit (6 Faith)

“A thermos flask has a narrow region between the inner and outer wall which does not allow any air flow, thus enabling the liquid to stay at the same temperature without losing too much heat.”
- Crystal Ng (6 Charity)

“It is a storage vessel which provides thermal insulation by interposing a partial vacuum between the contents and the ambient environment. It prevents heat from escaping and keeps any beverage that is put inside hot.”
- Lynn Yeo (6 Charity)

“Conduction of heat through the trapped air between the stopper and the hot beverage is minimal since air is a poor conductor of heat. Conduction through the sides of the flask is prevented by the vacuum between the double-glass walls of the flask.

To minimise heat loss through radiation, the walls of the glass are silvered so as to reflect the radiant heat back into the hot beverages.”
- Ng Jia Xin (6 Charity)

“Vacuum is a poor conductor of heat. The metal covering has a reflective surface to minimise heat loss.”
- Teo Chong Boon (6 Charity)

“It uses a vacuum to insulate the inside from the outside. The vacuum reduces the different ways heat can be dissipated - mainly conduction and convection.”
- Adam Tan (6 Charity)

“The vacuum contains no or very few atoms, which slow down or stop heat gain/heat loss. The liquid in the flask will gain heat or lose heat very slowly as the top is a cap and there is no vacuum there. The cap is also made of plastic but there is some rubber at the edges to prevent heat gain heat loss.”
- Lim Jin Feng (6 Charity)

Wonder Flask?

2010-06-01T22:51:00.001+08:00

Have you ever used or seen someone use a flask like the one on the picture?

They are called thermos flasks and people use them to contain either hot or cold beverages.

List the materials used and explain how they help in making this item useful?

In what ways do such flasks keep hot beverages warm and cold beverages cool?

Unbreakable Books

2010-06-01T22:41:00.004+08:00

Enjoy the short clip :)

You can try this out with our very own yellow pages and see if this trick works!

What Science concepts do you think keep the books together?
Compare this trick to an experience you have where you prevented two things from slipping from each other.
Explain clearly why the books cannot be pulled apart.

Wollen Sweater VS Windbreaker

2010-06-01T22:39:00.001+08:00

A wollen sweater

A windbreaker

Alice is planning to go Country X at the end of the year. The temperature there ranges from about 13 degree Celsius to 22 degree Celsius.

What are the similarities between the choices above?
What are the differences between the two choices above?
Which of the above, a wollen sweater or a windbreaker, should she choose to bring along for her trip?
Give reason(s) for your choice.

Pack Light, Pack Smart

2010-06-01T22:21:00.007+08:00

Why are people often being advised to pack light when they travel?

What do you know about Science that helps in packing light?

Explain how this is achieved.

Do you think that in Science, the packaged clothes are truly lighter?

Share your thoughts.

Not-so attractive flower after all!

2010-03-31T19:07:00.002+08:00

Insects are attracted to brightly coloured flowers.

But, how can they tell colours when they are colourblind?

More Stone Cooking

2010-03-20T23:45:00.007+08:00

Watch Stone Cooking

I applaud your participation in this discussion - quite similar to the Chestnuts question in CA1.

"Stones can transfer the heat from the fire to the bread and will cook it." Jin Feng

"Metal pans conduct heat more quickly." Chong Boon and "conducts heat better than stones." (Quinn)

But all participants to this question state that "Stones are good conductors of heat".

But from the question on stones used in the sauna, Farid said, "Stones are bad conductors of heat, thus trap the heat and does not allow it to escape quickly."

How can we decide who is right?
Can you describe what makes a good heat conductor? That will guide us in this discussion. I await your responses.

Teh Tarik Trick

2010-03-20T23:08:00.010+08:00

First and foremost, I thought you expressed your thoughts clearly and logically.

"Metal containers are good conductors of heat and allow heat from the tea to escape to the surrounding easily" (Uda)

Pulling it up and down is "to further allow heat to escape to the surrounding air and entertain customers while waiting for their tea" (Jeremy)
and "to mix the tea well and make it bubbly!" (Scott)
Using 'Science' to entertain is an idea worth considering when doing business!

Plastic mugs are rarely used as "when the teh tarik is poured inside, the plastic may melt ... and let out harmful chemicals"(Quinn)

Possible but plastic bowls are used to serve hot soup and Teh Tarik is 'packed home' in plastic bags. Relating to other situations is helpful.

"I think porcelain will not crack." (Scott) Do you agree?

Glass mugs crack "as glass is a poor conductor of heat and thus conduct heat away at a slow(er) rate " (Jeremy)

Adam added, "The inner surface of the cup will expand more (faster) than the outer surface." He asks, "Could a 'thinner cup' where 'the inner and outer surfaces of the cup will gain the same amount of heat because they are closer' be used instead?

Making suggestions require a higher level of thinking and when justified is even richer. Thank you!

And Jia Xuan suggests that we "put the glass mug into a metal container. Heat from the hot water ... will quickly be conducted away by the metal" Observe how tea in glass mugs are served with a metal spoon in it! Exactly for the reason Jia Xuan shared with us. See the video again and spot the spoon!

The World of Shadows!

2010-03-14T22:44:00.011+08:00

Click on the words below to view this video:
Shadow Puppets
How do you think the shadows are formed?
What could cause the shadows to become blurred?
How did the 'man' at the beginning of the shadow grow larger suddenly?
Explain what tricks can be used to achieve bigger and smaller shadows.

All About Stones

2010-03-14T22:35:00.003+08:00

In Finland, people go to saunas (hot houses) as they believe it's a healthy way to relax. Stones are heated up inside a well ventilated (air can move in and out) room.

When the stones are ready after 2-3 hours reaching temperatures higher than 100C, water is poured on the stones.

Imagine what happens as soon as water touches the stones!

Explain what you think happens. (Remember steam can't be seen.)

How does this process help the occupants feel warm?

Why do people pour water on the stones instead of just warming the room up with a heater?

Why Stones?

2010-03-14T22:14:00.000+08:00

Nomadic tribes (people who move from one place to another) use stones to cook their food. Here bread is being cooked on stones that are placed on fire.

Explain how you think the stone helps the bread to cook.

How is the process different from using a metal wok for example?

Would the cooking time be different if several smaller stones were used instead of one large piece?

A Refreshing Teh Tarik!

2010-03-14T21:50:00.010+08:00

Have you ever watched someone "make" a Teh Tarik?

Watch this by clicking on the words below:

F1 Teh Tarik Surprise

It is quite a show!

Why do you think metal containers are used?

Why is the tea 'pulled up and down' in the process?

Why do you think glass mugs are used instead of plastic mugs at hawker centers?
One problem encountered is that the glass will crack when hot tea is poured into it.
Why does cracking occur in the above case?
When is the glass container most likely to crack?
Suggest ways to prevent it from cracking and explain why you think your trick might work!

Jumping in the Pool

2009-10-18T22:07:00.006+08:00

During his holiday at Sentosa, Jason woke up at 6 a.m, jumped into the swimming pool and yelped,
"Wow! It's sooooo cold!"
He quickly got out and went back to the hotel room and jumped into his bed with his wet swimming trunks.
"OOH, this is so warm and toasty!"

What made Jason feel cold in the pool? (Remember, always connect to Science concepts).
What made Jason feel warm in bed?
Explain clearly why.(You can try to connect to a similar experience you had!)

Variegated Leaves

2009-10-18T21:58:00.000+08:00

How does this plant grow?

How is it different from other plants?

How is it similar to other living organisms?

What's In A Material?

2009-10-18T21:48:00.002+08:00

Picture From 3M

Explain clearly how clothes/gear with reflective material can help a person cycling at night?

Whenever you are unsure about how to answer a question, you can compare the situation to a reverse situation: here - wearing clothes with no reflective material.

Stunning Passion Fruit

2009-10-18T21:40:00.001+08:00

Did you know that the Passion fruit plant needs support to climb up. The fruits are truly stunning as the plant itself seems very fragile and unable to produce such a heavy fruit.

What processes enabled this Passion fruit grow?

What is still attached to the Passion fruit?

In what ways is this fruit similar to a child?

Last Wise Words

2009-10-09T23:03:00.004+08:00

Interact with complex questions / graphs / pictures to pick up valuable clues (don't highlight - just use your pen to underline words or scribble notes)
Start with Booklet A and do it meticulously with full focus - explore all 4 distractors before making final choice
MANAGE your TIME - to score well, you need to try to finish ALL questions
Specific answers = answers that are relevant to question
When confused, choose any of the following strategies:

Infer what Science concept is being used in question
Pose other questions to clarify your thoughts
COMPARE to another set-up
COMPARE to a reverse situation
Connect to your knowledge in life (yes, you do have lots of prior / other knowledge)
Break down your answer in steps before crafting final answer

Common problems with wrong answers:
Answers are generic/vague and do not connect to that specific question
Answers are not scientific and do not explain in terms of Science concepts
Answers do not make use of data provided when asked
Answers did not make comparisons - use words like more/most etc..when asked

Ice Cubes in Drink

2009-10-09T22:41:00.003+08:00

Remember that you can either say:
Higher temperature or hotter (not hotter temperature)
Lower temperature or colder (not colder temperature)

Connect to Science Concepts - most of you did this well:
There is a difference between ice cubes and water - Xin Yi
Water loses heat to the ice cubes causing the temperature of water to decrease - Umar

But JJ gave a very different answer:
With more ice cubes, the temperature of water will be able to remain lower for a longer period. Ice would still lose heat to the surrounding as the temperature around (in Singapore) would most likely be higher - JJ

Most of you found it tricky to explain clearly why. Therefore when this type of specific answer is needed, you need to plan out the steps:

I will use the procedure spelt out by Zoen but break it down further.

Since difference in temperature dictates loss/gain of heat, imagine the following:
Measure the difference in temperature of water and a beaker of ice cubes?(say it's 30 degrees)
Put 1 ice cube in water
What is the actual temp of water after 5 mins? (let's say now it's 20 degrees)
Add another ice cube.
What is the actual temp of water after 5 mins? (Let's say it's 10 degrees)
What can you tell me about the difference in temp between this water and a beaker of ice cubes?
Temperature difference is getting lesser and lesser as you add the ice cubes 1 by 1.

Since temperature difference is important for loss/gain of heat, as difference of temperature is minimal now (but still losing to the surrounding), the ice cubes will not melt as quickly as before and therefore drink remains colder longer.

Weak Stems

2009-10-09T22:06:00.007+08:00

Observe with All your senses - Connect to Science Concepts:

Unlike other plants, their stem isn't strong enough to support the plant. These plants need the help of other plants or trees to get sunlight - Juan Pang
Crawlers cling onto stems and thin items with their tendrils - Calvin
Tendrils and their support (other plant stems or thin trellis) are like the skeletal system and the muscular system of our body - they work together - Yi Lin
In the second plant, we observed holes in the leaves and clasping roots - so they do not 'climb' up on supporting trees or plants in the same way. As plants climb onto others, sunlight passes through the holes and gives the leaves below some sunlight - Yun Na / Carlo

Pose other Questions that might help you find answers:
How do they get the other necessities to survive - water and nutrients? Yun Na and Carlo asked.
Compare the weak stems to the strong stems:
We believe weak stems plants will never become trees and therefore do not need as much water and nutrients - water is needed to keep strong stems firm. - Yun Na / Carlo

BTW, in our Wizard project, we have also tried to grow weak stem plants (Monstera and Money plant) without any soil after concluding that they might not need as much nutrients as other plants. You would like to know that they are growing well and even developed quick adaptations like growing extra roots / hairs in their roots to absorb more water.
Yun Na / Audrey / Xin Yi/Shanice

Carnivorous Plants

2009-10-09T17:02:00.003+08:00

Research before answering:
Carnivorous plants grow in nutrient poor soil - Benjamin
They live in wetlands and have to depend on other sources of nutrients for its survival - Nicholas King

Connect to Science Concepts - use scienctific language
These plants are different from usual food producers. I think it is beause the food producers are like 'prey' and the carnivorous plants are like 'predators'. Food producers produce food (through photosynthesis) for herbivores and omnivores and carnivorous plants make food for themselves and 'eat' insects for nutrients. I think they can still make food as after all, they still have leaves - Yi Lin

And add interesting bits that make sense to you:
I feel this adaptation can be helpful if there is a massive volcanic eruption and ashes block the sunlight (like Mount Pinatubo).

Chestnuts

2009-10-09T14:10:00.016+08:00

Extra Q1: Is sand really a good conductor of heat?
Please note that it is very important when discussing conductivity to analyse in comparison to what else.

Compare Sand to just Air:
Is Air a good conductor of heat compared to Sand? (Zoen asked)
Air is not a good conductor of heat - Syafiqah

Compare Sand to Metal:
Sand on the beach absorb the heat from the Sun - but if you dig deep inside beyond the upper layers of sand, you will find that the bottom layers remain cooler than the top layer.
Imagine (excellent strategy advocated by Yi Lin) layers of metal under the sun. What do you expect to happen?

Extra Q2: Is cooking time shorter or longer?Compare Cooking with Sand and Cooking without Sand - the answer will be clearer to You
The sand might be like a temperature control. If the chestnuts went straight into the wok on the fire, they moght get 'incinerated'. If there was a slow fire, the chestnuts might take a long time to roast. Chetsnuts can be cooked over a big fire without getting burnt thanks to the 'temperature control' - Timothy

Sand helps to bring the temperature gradually to the desired heat then keep heat constant so as not to dry up / overcook the nuts - Nicholas king

Compare Top layer to Bottom layer of chestnuts
Another reason might be that the chestnuts at the bottom of the vat might cook faster than the ones on top and end up overcooked - Benjamin

What could have happened then:

Sand particles close the gaps between the chestnuts (Yu Ling)
Sand will not let the heat be lost to the surrounding (Syafiqah)
Smaller particles of Sand helped to retain heat whereas larger particles might cause heat to escape - Nicholas King
When sand particles get heated up, they heat up the neighbours' - conduct/transfer heat to the chestnuts - Zoen
So it seems that distributing heat evenly to the chestnuts is important just as keeping them warm while cooking them slowly.

Cranberries

2009-10-09T13:43:00.004+08:00

Here are some of the answers:

(Relate to process of cooking and preservation connected to Science )
The purpose of cooking the jam is to kill bacteria in the cranberries - Si Jia
The canned food we have are also heated before being put into cans to be sent off to supermarkets - Ong Yan Quan
Foods are also preserved through other methods such as: Salting (eggs), pickling (vegetables) - Nicholas King

(Relate to Fungi and environment that are conducive to their growth)
The main reason for the fungi to grow inside is due to its exposure to either oxygen or warmth. Si Jia
The jam is also moist - Rae Ann
Fungi are Decomposers and they need warmth, air and moisture - Abraham

(Connect to other knowledge - finding plausible reasons using Science concepts)
My grandmother shared with me that one must also heat up the empty glass jar as there might be organisms living inside the jar itself - Yun Na
The 'machines' that were used to make the jam were not clean and could have contained spores - Benjamin
After the cap is open, air can go in and maybe fungi and bacteria went in - LiPing

Science Inspire Day FeedBack

2009-09-26T13:22:00.005+08:00

Share your thoughts with us

What did you enjoy the most?
How is it different from learning in class?
What other skills did you develop when planning for Science Inspire?
What was your favourite exhibit or Wizard presentation?

What would you recommend for Science Inspire 2010?

POST-IT notes - Science Magic

2009-09-06T20:49:00.000+08:00

What enables Post It notes to stay up on any surface?
Explain how that helps to keep the note up.

(When in doubt, ask other questions that can help you clarify how to answer the question)

Roasting Chestnuts in China Town

2009-09-06T20:18:00.007+08:00

Chestnuts are mixed with sandlike particles for roasting.

What is the purpose of using that?

(When in doubt about a question - always ask this: As compared to what?)

Therefore why should he use the particles instead of just placing the chestnuts straight on the fire?

How would changing the size of the particles affect the cooking?

Explain why.

Sea Bean Marvel

2009-09-06T20:09:00.010+08:00

What is in a seed? How do you think it is dispersed?

Although the Sea Bean is in a pod, it drops off one seed in one section at a time.

How different is it from other legumes? Why has it developed this adaptation?

How Much Ice?

2009-09-06T19:56:00.006+08:00

What is the effect of putting ice cubes in a glass water? How does the number of ice cubes affect the time taken to melt in the liquid?

Sunny Sunflowers

2009-09-06T19:29:00.001+08:00

What are the differences in the two flowers?

One seed or Many seeds? Explain how you came to your conclusion.

Creepy Creepers

2009-09-06T19:21:00.000+08:00

What are the similarities and differences in the two plants below.

How do they overcome the problem of their weak stems?

Carnivorous Plants

2009-09-06T19:04:00.001+08:00

The following plants are found in the wilderness in marshes and bogs.
Such plants feed on insects.

Compare these carnivorous plants to the ususal food producers.

What could be the cause of their physical and behavioural adaptation?

What are the consequences of their adaptation?

Cranberry Jam in a Jar

2009-09-06T18:53:00.001+08:00

This jam was cooked with sugar before being placed in a jar.
What was the purpose of cooking the cranberries first?
How did the fungi grow inside the jar?

Why?

2009-08-31T16:44:00.000+08:00

If water is a lubricant, why by putting some water on your hands, it is easier to grip paper?

The Way of the Gentle Force 柔道

2009-07-23T16:07:00.004+08:00

This picture was taken during a Judo match in the 2008 Beijing Olympics. Which simple machine is at work here? Can you think of other body movements which show simple machines at work? Mr John Lim

Cosy NEST

2009-07-17T14:19:00.005+08:00

How does this nest differ from nests usually found on trees? What does it teach us about the birds who built it?

Airplanes and Simple Machines

2009-07-03T20:03:00.011+08:00

Planes have an inclined plane on their wings but what actually enables them to fly?

Why can some planes with no engine to propel forward, still can fly if they are towed in the air like gliders?

Click on the following to view the flight of a real glider plane:
http://www.maniacworld.com/Auto-Pilot-Glider.html

Life Without Simple Machines?

2009-07-03T09:54:00.009+08:00

Imagine lifting this up?

Of all the simple machines you have learnt about, which one of them do you think Man cannot do without in everyday life?

Explain clearly why.

Simple Machines in a Construction Site

2009-07-03T09:49:00.003+08:00

The above picture shows a construction site. The crane is used to lift heavy objects from a lower surface to a higher one using a pulley system.

If pulleys had not been invented, how can heavy materials used to construct buildings be moved to higher surfaces using other simple machines?

Tools and Simple Machines

2009-07-03T09:37:00.004+08:00

The picture above shows 2 tools (ring spanner on left and spanner on right end).
What simple machines are used here? Explain using 'science language'.

Why is it necessary to produce various sizes of such a tool? Explain clearly by supporting your answer with valid reasons.

Simple Machines

2009-07-03T09:30:00.007+08:00

The above toy used the concept of Simple Machines.

What simple machine is used here? Explain clearly how this toy can remain balanced.

Second Question of the Series

2009-06-08T11:19:00.003+08:00

How Can an Igloo actually works, its made of Ice right?
Than why do you wrap cotton wool around a piece of Ice, it melts slower? Whan you wrap a cotton wool around you, you got warmer, right?

Plants

2009-06-06T16:26:00.004+08:00

I found this SAM entry from Park Ser Yun very refreshing. She was interested to find out more about plants and the subject of pollination and fertilisation.
Here are two of her intriguing questions.

Do all flowers produce nectar?
Why do male and female reprocuctive parts exist in one flower?

Please comment and share Your thoughts.

GM Food - Food for Your Thoughts

2009-06-06T15:15:00.001+08:00

I wonder if GM food has a negative impact on human health?

I only know that GM food harms monarch butterfly caterpillars.
However,I do know that GM food can be useful for pest resistance,etc.

Please comment!

Let's Take a Break from Hatchet

2009-06-06T15:11:00.001+08:00

Hello Everyone,

I hope you enjoyed the June holidays. I have decided to post a blog on something that we can commonly see but really do not understand on how it works. This will be the first question of many in this new topic. Hopefully Mrs Chien will understand.

1a) Why is it that a ping pong ball can actually stay afloat?

b) What Forces are actually keeping it afloat?

c) Newton's third law states that "Every force has an equal and opposite reaction". How can we relate it to this situation?

Science in Hatchet

2009-06-06T15:06:00.002+08:00

The questions below are based on your literature text Hatchet. Find the excerpts in your book before answering them.

It is important to follow these instructions if you wish to maximise your thinking:
1) Connect your answers to Science concepts - these are NOT questions about literature
2) Do not restate the facts as we can all read the text - we are interested in your thinking process!
3) Learn from your friends

More on Q5 and Q6

2009-06-04T13:15:00.003+08:00

The four items were:
Bank notes, bark, twigs and grass. Many of you talked about the Chemical potential energy in all the items and as you can see this fact also applies to the bank notes.

You mostly agreed that it was important for the items to be dry to light up with the sparks. Si Jia wrote, "The bark of the tree was dryer and harder than both the twigs and grass."

Is that the only reason why it caught fire more quickly. Find out what type of tinder is used to start a fire. Tobias Lee added that the bark was thinner than the rest. Explore more about tinder and let me know.

Also how come no one talked about the bank notes? Why did they not catch fire?

As always Yea Won's connections to real-life examples are refreshing. So what would you say was the method of cooking the duck?

Since we are on the topic of Heat

2009-06-01T09:52:00.002+08:00

Q1: Why does heat always flow from a hotter place to a colder one?

Q2: Can you blow hot and cold?
Do it like you are checking your breath, it's hot right then try to blow a candle out, your breath is cool right.
Why?

Perspiration

2009-05-31T18:47:00.007+08:00

Ever wonder if water makes a person lose heat, then why is it that when we run and perspire, our temperature increases instead?

Chapter 4, pg 33

2009-05-28T22:20:00.004+08:00

"His clothes were wet and clammy and there was a faint chill. He pulled the remains of his windbreaker, pieces really around his shoulder and tried to hold what heat his body could find."

Q1) Explain clearly the chill that Brian felt.

Q2) Describe fully how Brian managed to 'hold what heat his body could find' despite the winndbreaker being in pieces.

Chapter 4, pg 32

2009-05-28T22:15:00.005+08:00

"The darkness of the night was thick and for a moment, he began to panic again. To see, he thought. to see is everything."

Q3) Explain clearly why Brian couldn't see where he was?

Chapter 8, pg 75

2009-05-28T22:12:00.007+08:00

"... he kicked out and threw the hatchet at the sound, a noise coming from his throat. But the hatchet missed, sailed into the wall where it hit the rocks with a shower of sparks..."

Q4) Explain clearly how the sparks were created?

Chapter 9, pg 84-85

2009-05-28T21:58:00.005+08:00

"A cloud of sparks rained down, most of them missing the nest, but some ... hit the depression and of those six or seven found fuel and grew and cused the bark to take on a red glow."

Q5) In his attempt to make the fire, Brian selected four different items. How are these items similar?

Q6) Why was Brian able to light up the bark of the tree and not the twigs and grass he had used earlier?

Chapter 15, pg 130

2009-05-28T21:53:00.008+08:00

"The birds were everywhere, five and six in a flock, and their camouflage was so perfect that it was possible for Brian to sit and rest...."

Q7) Describe two behavioural adaptations the foolbird displayed in order to escape from predators.

Q8) In what other way could one of these above behavioural adaptations help the foolbird?

Chapter 15, pg 133

2009-05-28T21:46:00.006+08:00

"they were little more than sticks that flopped out of the bow, sometimes going sideways. Even when a bird was seven or eight feet away the arrow would turn without feathers to stabliise it..."

Q9) Explain clearly how feathers can help to stabilise the arrows?

Questions to Ponder

2009-03-31T22:12:00.005+08:00

Is it true that went you want to heat something, you actually put in more mass .
Is it true that when you speed something up, it has more mass?
How can you tell Einstien's Equation was even right?
Why can't you travel beyond the speed of light?
How do you make sure your thinking is the right one?
Can you tell wheter people are telling the right facts?
How can you tell the Earth is round?
How can you tell green is green, you may take what I call brown as green and being taught its green, can you tell the differents at all?
How do you tell one another out, can you even remember their voice, Why?
A fish and a fungi, a protist and an animal, a plant and a amphibians, how do you group them all?

Try these questions out, ymay look simple but do try them, remember don't stop asking questions in science question it! Thats how science actually works!

Posted by Pek Yu-Xuan Sean

New Taxonomy?

2009-03-26T14:34:00.003+08:00

Taxonomy is the art of classifying things. A few centuries back, a naturalist, Carl Linnaeus use a binomial system of classifying living things.

This system makes use of the animal characterisitics, for example:
Aves (Birds)
Pisces (Fishes)
Mammalia (Mammals)
Amphibia (Amphibians)
Phanerogamia (Plants with conspiciuous flowers)
This system make use of a binominal representation like for humans, Homo Sapiens , with Homo as the genus (Family) and Sapiens as the species.

While, Aristotle use thier movements of the animal to classify it - For example fish is classified as the swim for movement while birds are classified as Flying animals.

1)The Linnaeus system is now prefered over most system like the Aristotle one, what distinct advantage does it have over the latter?
2)The system has it flaws too! Can you name a few?

Posted by Pek Yu-Xuan Sean

Steam or Water Vapour

2009-03-24T20:25:00.004+08:00

Before I go on the last post on the water rockets in Think and Talk Science1, if you are keen on finding out more about the question, please check the following before our last discussion:

How are steam and water vapour (in Science) similar and different
Are they visible?
How are they produced?

Last Post on BBQ Char Cool

2009-03-20T17:23:00.005+08:00

Let me sumarise what "BBQ Char Cool" have said and let' s work from there.

'It is because of high chemical potential energy that enables it to burn for so long.'
Posted by Yu Ling

' The most common types of charcoal used are lump charcoal and briquettes. Briquettes are convenient, inexpensive source of fuel. It can burn more consistenly and longer then lump charcoal but not quite as hot. Charcoal can be burnt in power stations to turn generators to produce electricity. It can also be used to cook.

The porosity of activated charcoal accounts for its ability to readily absorb gases and liquids; charcoal is often used to filter water or absorb odors. Charcoal was also consumed in the past as dietary supplement for gastric problems in the form of charcoal biscuits.'
Posted by Xin Yi

'Disadvantages of using charcoal are that it is not a clean fuel. Charcoal transport generates more ash than LPG, Kerosene and Gelfuel.'
Posted by Pauline

'From what I researched, charcoal is a blackish residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances. The resulting soft, brittle, lightweight, black, porous material resembles coal and is 85% to 98% carbon with the remainder consisting of volatile chemicals and ash.'
Posted by Renise

Let' s stick to the instructions and give better awnswers!

Last Post on Porcupin

2009-03-19T14:39:00.006+08:00

Debate on Porcupin - up to its chosen name was very animated! In particular, the observations made were objective and spot on. Answers on its physical and possible behavioural adaptations were relevant:

'When threatened, it will puff out its hairy thorns.' Posted by Nicholas King (6C)

We do know that puffing up makes organisms look larger and less vulnerable.

'The caterpillar has a fake eye on its back - the black dot - to mislead its prey that (the dot) is its eye ...' Posted by Kay Kiat

Question is "Why fake eyes?"

Finally, this comment by Marcus Chionh triggers other thoughts: 'MAYBE they do not have any spikes underside of it because they need to crawl, not curl up'

Many felt though that the absence of spikes underneath may help both actions of crawling and curling up.

We also know from our reading that caterpillars like to crawl underneath leaves as an extra precaution. Where do its usual predators come from? Mull over this as that was part of a PSLE question in 2008.

Last Post on Pollen - Welcome or not!

2009-03-19T14:09:00.007+08:00

This question was fairly well debated with pupils making connections with what you have learnt, research and supported points made with examples from life around you.

The discussion on the pollination process was rich and I liked the comment by Sean Pek (6C) that flowers do know how to attract pollinators.

'I wish to explain how plants can 'lure' animals to pollinate them to the same plant, like being close to other plant so that the pollinator do not have to travel far to get more nectar, making the pollen land on the plant.'

I also think that Samuel Tay and Sean Pek below made some good points:

'Wind dispersed pollen must land on the same species of flowers to ... (fertilise the flower). Insect pollinated plants needs the help of insects to transfer the pollen grains from the anther to the stigma. For some species, if they do not land on the same type of plants, the pollen tube will not (grow). Some, however can cross breed.' Posted by Samuel Tay

'It is rare to crossbreed flowers of different genus ... if they have the chromosomes that are interchangeable, it may mix and the microgametophytes will mix with the ovum to form a seed. Finally, it seriously depends on its genus. If they are the same , most likely, there will be a baby (or egg).' Posted by Sean Pek

When we look around us, we do not see a large variety of cross-bred flowers for example. So maybe we should ask a different question: Do ovules accept all types of pollen?

Finally we thank all the curious pupils who gave us a good list of cross-bred animals - longest list went to Marcus Chionh (6G) - so my question is, "What do they have in common?'

I liked the heated argument by Ellia (6C) and comapny about cross-pollination and self-pollination. Maybe we can discuss during the next holidays!

Last Post for Mooncakes on the Moon

2009-03-19T13:54:00.005+08:00

Some of you vaguely discussed the variety of mooncakes on the market - but did not delve deep enough into the facts.

There are two main types sold in Singapore, notably the brown skin classic with yolks or not and the ones covered with a soft skin called 'snowskin'.

The boxes both came from upmarket hotels and the styrofoam one came with 'snowskin' mooncakes. The elaborately decorated one is made of medium-thin cardboard and came with brown skin mooncakes and a sachet of dessicant.

Last question is therefore what is the purpose of the two types of insulators. There is a reason for the styrofoam which if compared to cardboard is a far more effective insulator. Part of the answer might lie in this statement made by Rachel Neo (6F) - 'Some of the boxes are airtight,while others are not'.

It will be good to think of the mooncakes and their 'skin' mentioned above when thinking of an explanation.

BBQ Char Cool 2

2009-03-17T23:42:00.004+08:00

It is important to differentiate coal and charcoal - fossil fuel v/s just trees that have been treated. Please also read the comments from Pauline who clearly states some of the benefits of charcoal. Also Xin Yi and Renise gave some relevant information on charcoal.

Maybe some of you can elaborate and make the differentiation clearer to the confused ones.

The comment by Yu Ling on the chemical potential energy of charcoal is well connected to the current P6 topic.

Also I agree that it's so much preferable to write in your own words to show what you understand. Short, concise comments do a better job than long explanations.

Pollen - welcome or not?

2009-03-17T14:24:00.006+08:00

A jaglion(offspring between a male jaguar and a female lion.)

Mooncakes on the Moon 2

2009-03-16T20:51:00.007+08:00

That was a great debate on mooncakes - errr but there is severe digression. It is important to know when to control our thoughts and get back to the focus.

Great input:

1) Insulators
2) Warm or cold moncakes
3) Material

All else is detracting from the main focus which is Science here.

No one has adressed the similarity stated by many of you: Both are insulators. Then how does one insulator differentiate form the other? Is the purpose of the insulator in both cases different?

Many discussed material used - does that have an importance besides aesthetics - please move away from that point because you are missing important Science facts here!

But most importantly, did anyone ask around or think about the main types of mooncakes available in Singapore? Please note the word "MAIN". Do they affect the types of boxes used? The long discussion of eating cold or warm mooncakes should have been such a good clue.

Finally, to say that styrofoam is probably not from an expensive restaurant is a subjective comment because it is impossible to tell just by looking at a picture. I will divulge more later.

I enjoy the chatter as only through free Talk can we clarify our own thoughts. We must be willing to change our thoughts after "listening" to others when they make sense. It is not a case of "Hear me. I'm right!' Comments that make sense have been researched and are well suported by facts and examples.

Let's focus on making our chatter productive and fun at the same time.

UFO - Unravel For Own understanding

2009-03-16T17:47:00.004+08:00

Are there really UFO's or are they just a Fake scam?

Pollen - Welcome or Not?

2009-03-12T17:27:00.002+08:00

How does pollen know where to land?
Are all types of pollen accepted guests on all types of stigmas?

How about animals? What happens when a male of one species mates with the female of another species? Do we have a baby?

BBQ Char Cool!!

2009-03-12T17:22:00.004+08:00

Who doesn't love a juicy chicken wing grilled to perfection above charcoal?
What is charcoal and why is it possible for it to burn for such a long time?
What is/are the difference/s between charcoal and its original state?
I hear charcoal has many other benefits.
Tell me about some of them.
But of course there are disadvantages to using charcoal.
Suggest some possible ways of harnessing the goodness of charcoal while minimising harmful effects.

Comment on THINK SCIENCE TALK SCIENCE 1

2009-03-11T20:26:00.001+08:00

The pupils were at the Mindfest at the Science Centre.
What do you think caused the bottles to shoot up?
What do you think is coming out of the bottle?
How do you think it was formed?

Comment on THINK SCIENCE TALK SCIENCE 2

2009-03-11T20:20:00.000+08:00

Observe Porcupin.
Porcupin is a caterpillar found in the school carpark.
What physical adaptations help Porcupin in evading predators?
Besides physical adaptations, how else do caterpillars behave in order to survive?

MOONCAKES on the MOON?

2009-03-11T20:05:00.003+08:00

In Singapore, different types of mooncakes are sold in different types of containers.
In what ways are the containers similar and in what ways are they different? What is the reason for choosing different types of containers?

science.inspire

Well-developed Answers to “Pack Light, Pack Smart”

Well-developed Answers to “Wollen Sweater VS Windbreaker”

Well-developed Answers to “Unbreakable Books”

Well-developed Answers to “Wonder Flask?”

Wonder Flask?

Unbreakable Books

Wollen Sweater VS Windbreaker

Pack Light, Pack Smart

Not-so attractive flower after all!

More Stone Cooking

Teh Tarik Trick

The World of Shadows!

All About Stones

Why Stones?

A Refreshing Teh Tarik!

Jumping in the Pool

Variegated Leaves

What's In A Material?

Stunning Passion Fruit

Last Wise Words

Ice Cubes in Drink

Weak Stems

Carnivorous Plants

Chestnuts

Cranberries

Science Inspire Day FeedBack

POST-IT notes - Science Magic

Roasting Chestnuts in China Town

Sea Bean Marvel

How Much Ice?

Sunny Sunflowers

Creepy Creepers

Carnivorous Plants

Cranberry Jam in a Jar

Why?

The Way of the Gentle Force 柔道

Cosy NEST

Airplanes and Simple Machines

Life Without Simple Machines?

Simple Machines in a Construction Site

Tools and Simple Machines

Simple Machines

Second Question of the Series

Plants

GM Food - Food for Your Thoughts

Let's Take a Break from Hatchet

Science in Hatchet

More on Q5 and Q6

More Questions on Q4

Since we are on the topic of Heat

Perspiration

Chapter 4, pg 33

Chapter 4, pg 32

Chapter 8, pg 75

Chapter 9, pg 84-85

Chapter 15, pg 130

Chapter 15, pg 133

Questions to Ponder

New Taxonomy?

Steam or Water Vapour

Last Post on BBQ Char Cool

Last Post on Porcupin

Last Post on Pollen - Welcome or not!

Last Post for Mooncakes on the Moon

BBQ Char Cool 2

Pollen - welcome or not?

Mooncakes on the Moon 2

UFO - Unravel For Own understanding

Pollen - Welcome or Not?

BBQ Char Cool!!

Comment on THINK SCIENCE TALK SCIENCE 1

Comment on THINK SCIENCE TALK SCIENCE 2

MOONCAKES on the MOON?