Monday, November 15, 2010

Growing crystals and the cloud chamber




This picture was taken last year when Zilfi, Hafiz and Jaya posed with the crystals grown by 4 Gigih 2009. It took them about 6 weeks to grow the copper sulphate crystals from 3 mm size seed to this size. Every now and then they had to change the solution so that the seed remained immersed in a super saturated copper sulphate solution.

I told them they were the parents of the baby seed and they had to make sure their babies got fed ( the milk was the super saturated solution ) and then the babies would grow big. It was great to see the delight on their faces when they watched their babies grow beautiful and big!
Translate this principle to cloud seeding. Ever wonder why when a plane flies, it leaves cloud like tracks behind it?
That's because the ions in the exhaust gas of the plane acts as seeds for the super saturated water vapour to condense upon.
Now connect this to the Wilson Cloud chamber to detect radioactve sources.
The pic shows a cloud chamber diagram. The radioactive source creates ions which acts as the seeds for the super saturated water vapour to condense on and mini cloud tracks are created
Hope this creates some connection and understanding.









Sunday, October 17, 2010

How electricity create magnet

This video is taken from the neok-12 program I posted earlier courtesy Unesco. For those of you who missed the opportunity of doing the experiments on magnetism, you can catch up via this video.

I an also testing out how to put videos on the blog.

Saturday, October 16, 2010

Eggsperiment

The eggesperiment(experiment) story started with Prethini. She was from SMK Padang Tembak and she had been assigned a project on pressure. I had shown them a video of Dr. David Wheeler in Mahanakorn University, Bangkok where Dr Wheeler slept on a bed of nails but was not injured.
The video prompted Prethini to think and so she came to discuss her idea with me. Once I said yes and said her idea could be carried out and her concept was correct in Physics - Prethini took over and literally hatched it all.
She brought a tray of eggs to school, I only provided my camera and moral support. Two girls hoisted our slim Prethini (40kg) on to the tray of eggs and we took the photos. Our real challenge came when we showed the photos but people did not believed it was real so Prethini and her friends demonstrated this by standing live on a tray of eggs in front of a crowd of about 100+ Physics students. One guy in the crowd said that the eggs did not break because they had already been prehardboiled so Prethini challenged him to choose any egg in the tray to break it and he did break it and it was still as raw as from the mother hen.
Some years later after Prethini in SMK Seksyen 5 Wangsa Maju, I encountered Haikal. He found Physics difficult and somewhat boring. So I gave him Prethini egg's assignment and he learnt how to hoist himself and placed both feet on the egg tray together without breaking any eggs. No one could lift him up as Haikal was a good 70kg.
I inserted the photo of Haikal in the Form 4 Physics test paper and asked all the students to explain why Haikal and all 70kg of him could stand on the eggs tray without breaking any eggs using a Physics concept. From that moment - Haikal became famous in Form 4.
Furthermore he could explain why the eggs didn't break. His morale enjoyed a great boost when he was able to explain correctly in front of other students. After that I no longer had much problems with Haikal finding Physics boring.
We conduct another fun activity in the series of eggsperiments. Here a hard boiled egg with the shell peeled off is made to enter a conical flask using newspapers and matchsticks. Obviously physics is applied but I shall not post the answer here but merely post the picture here to intrigue the readers.The students have become so successful at doing this that they graduated first from using quail eggs to later on using the much larger chicken eggs. Also they have improved the speed by which the egg enters the conical flask so much so we included this in an event called the Science Explorace which is an race in conducting science activities between 6 classes of students outdoors in the school field.

Thursday, October 14, 2010

The simple joys of being a teacher.


I am in the midst of marking Physics Trial SPM exam scripts. For some mysterious reasons, Physics has papers has been held only on the last 2 days of the Trial exam for two years running! Immediately after the exam was over, I was called out of school for 2 days of meetings and will be out for another 3 days of meetings next week. And the due date for the marks is next week! Help!
Every single teacher knows well the agony and labour involved in marking exam scripts and especially in this sort of situation when we have to complete marking scripts so very quickly!
But I have great reason for joy! 5 Dynamic 2010 has given me reason to sing!!! You see one student has given me a perfect score for her essay script 20/20!! Oh Wow! And another student who used to get miserly scores for her essay has now scored 15/20!!! I shall not mention names here but tomorrow when I give back Paper 2 to 5 Dynamic, they shall know of my joy and pride in them! Oh, it is so worthwhile to teach 5 Dynamic 2010! Also several students in 5 Dynamic achieved more than 40/50 for Paper 1.
This brings home a succinct truth for Physics! The underdog shall not remain forever the underdog! If the underdog is willing to learn from his/her mistakes, be willing to focus, be willing to change the style of learning, the underdog can literally fly! Hence my picture of flying dogs! Of course sometimes in the process of learning to fly, we suffer bruises and some painful cuts in strategic places like some of the flying dogs in this picture but don't ever let that stop you from attempting to fly!
Haha! the joys of being a teacher! Discovering and knowing for a certainity that underdogs can fly! I recieved a plaque gift from a beloved teacher. I immediately nailed that plaque on my office door because I believed in it. It said "Children are born with wings but teachers help them fly!"

Tuesday, September 28, 2010

Science movies

This website has all kinds of science movies from video on using the micrometer and all sorts of measuring instruments to videos on magnets and forces. Have fun surfing and learning using videos. Change your mindset!


http://www.neok12.com/

Tuesday, September 21, 2010

Thomas Young's experiment

Wave theory of light
In Young's own judgment, of his many achievements the most important was to establish the wave theory of light.

To do so, he had to overcome the century-old view, expressed in the venerable Isaac Newton's "Optics", that light is a particle. Nevertheless, in the early 1800s Young put forth a number of theoretical reasons supporting the wave theory of light, and he developed two enduring demonstrations to support this viewpoint. With the ripple tank he demonstrated the idea of interference in the context of water waves. With the two-slit, or double-slit experiment, he demonstrated interference in the context of light as a wave. He used reflection off thin films of soap and oil.

The picture ( which was an animation before I uploaded it ) shows a double slit source in front. If the particle theory alone was correct, what would be seen would be only two bright light lines on the screen. But what is seen actually are many bright( and dark) fringes which meant the 2 light sources had been diffracted and then experienced interference. which meant light was also a wave and not just a particle.

An earlier posting on my blog about the giant soap bubble showed colourful fringes in the soap bubbles which were a result of interference from two sources of light, one source from the upper skin of the bubble and the 2nd source - one reflected off the lower thin skin of the soap bubble

Never be afraid to think differently from the venerable authorithies eg Newton! You could prove them wrong. And thinking differently is innovation!

Tuesday, September 14, 2010

Dispute of two camps


In the early eighteenth century, the argument about the nature of light had turned the scientific community into divided camps that fought vigorously over the validity of their favorite theories.


One group of scientists, who subscribed to the wave theory, centered their arguments on the discoveries of Dutchman Christiaan Huygens. The opposing camp cited Sir Isaac Newton's prism experiments as proof that light traveled as a shower of particles, each proceeding in a straight line until it was refracted, absorbed, reflected, diffracted or disturbed in some other manner.
The above paragraph is taken from molecular expressions micro.magnet.fsu.edu/primer/lightandcolor/particleorwave...

Use some of the info and pics on my previous blogs on light and waves to help you decide. Who do you think is correct? Which camp are you on?

Monday, September 6, 2010

soap bubbles


What connections does soap bubbles have with Physics? Any wise guys out there?
The picture shows a giant soap bubble with happy children chasing after it at a beach.
I remember taking my three children when they were young to the National Science Centre back then near Lake Gardens to play with soap bubbles by dipping sticks with certain shapes into special soap solution and our delight as bubbles of various sizes and shapes emerged and mesmerized us with their dance before they burst.
Catch the video Giant Stinson Beach Bubbles (Canon 550D) on Youtube and be enthralled by the delight of the children at the beach.
Don't forget to think about the connection in Physics with these giant soap bubbles.

Thursday, September 2, 2010

Bicheno, Tasmania 11th Sept 2002


I shall forever label Tasmania - the land of rainbows. We saw rainbows for five consecutive days!
Here at Bicheno, we saw end to end double rainbows appear, dissapear and then re-appear at least three times. in the space of one hour. Wow!
From the physics point of view, can you tell me 3 differences between the primary rainbow at the bottom and the secondary rainbow at the top?
Bicheno is also good for watching the wild fairy penguins for free unlike in Philip Island, where you have pay to enter the Penguin Parade place.

Cradle Mountain, Tasmania, 9 Sept 2002

I spy, I spy something down there Do you see what I see?

When I caught a fleeting glimpse of what I suspected - I was not too sure if it was true cos' my techo brain said otherwise.

But as we descended from the mountain to cross the bridge (I think this should be the Ford River) what I suspected was actually true - a beautiful rainbow over the river. Do you see it?

This rainbow was kinda unusual; it is very low and also the time was about mid noon. That's whyI didn't quite trust my eyes when I first saw it cos' my technical physics brain told me the objective data - that usually rainbows are formed during early morning or evening and in high places - not low places.

This rainbow was formed by the spray of the river water. That's why it could be so low since it didn't depend on raindrops - which was also why it could be formed even at about mid noon.

I snapped this picture in excitement. I was absolutely delighted when the rainbow showed clearly in the picture! Each time I look at this picture, it reminds me - it is wiser to trust my eyes , my heart and my gut feelings and not my techo brain. And it also reminds me that God can esaily re-arrange the time ( from evening to noon) and position ( high place to low place) as He wish and I was simply privileged to catch Him being sovereign!

Rainbows on shirts

I always had a penchant for rainbows. And when rainbows are that close to us - on the shirt (and near the heart) of my students in Seksyen 5- even nicer!
This rainbow spectrum was part of the Hodson Light Box Kit experiments where we conducted light experiments on thick and thin convex and concave lenses, plane and curved mirrors and lastly prisms.
The spectrum is formed by light dispersion when white light meet the prism.
I am updating this post many years later on 27th Aug 2022. The rainbow spectrum shown below is photographed by my 5+ years grand daughter Emma as I sprayed my garden hose onto the white wall of my car porch. The evening sun is behind me and the sunrays create a nice spectrum on the wall.
The most spectacular rainbows I and some friends have ever experienced was in August 1997. We were descending from the peak of Mount Kinabalu. The intense sun rays were behind us and in front of us was a lot of mist. We saw two circular double rainbows ( circular because we were at a very high place and could see the bottom bow of the rainbow as well as the usual top bow). We saw figures in the middle of the rainbows and when we moved our hands, the figures in the middle of the rainbow moved their hands too! That's when we all realized the figures in the middle of the rainbows were actually our shadows cast by the intense sun rays. The sunrays and the mist at this high point formed the two circular rainbows. We all recognized it was a holy moment, orchestrated perfectly by God Almighty in terms of location and weather conditions. Someone did take a photo but back then, photography technology is nothing like now (August 2022) and the photos showed donly the faintest rainbows. However in our memories of the entire group that descended from Mount Kinabalu, that moment is clearly etched in our memories and hearts. God is ever leading us in time and space, whether we are aware of Him or not.
Today 6th September 2022,( 25 years later from the phenomena we experienced together ) I found out the name of the above phonomena that happened to us while we were descending Mout Kinabalu. It is called the Brocken Spectre. No wonder we could see what our shadow silhouttes were doing clearly- the Brocken Spectre explaind the shadows were amplified and it is named a type of glory! Yes! The photo above is credits to https://panoramicireland.com/blog-ireland-guide/croagh-patrick-pilgrimage-brocken-spectre-ringed-glory-irish-mountain

Wednesday, September 1, 2010

Chan Meng Kit diffraction photo


This photo was taken by Chan Meng Kit - a beloved ex-student in SMK Seksyen 5, Wangsa Maju. I think he snapped it near the school cos' I can see KLCC and KL tower in the background. Again it looks like another pretty picture but the Physics of diffraction is shown so clearly here.
See how the sun light rays spread out after going through the obstacle of the thick clouds.
Take heart - if you are going through some obstacles - you will definitely spread out and grow to have more influence by the time you pass through the obstacles.

Diffraction of white light through the tree leaves

We often see this sort of pic and just enjoy its beauty without realizing this is a picture showing a scientific process called light diffraction.

When light passes through an obstacle like the leaves of the trees here, it will spread out ie the rays near the bottom are much wider than the rays near the top.

Similarly in life, when you face an obstacle - don't be discouraged - if you go through the obstacle - you will experience diffraction and spread out ie become much bigger than before you went through the obstacle.

White light from candle after going through diffraction grating


This is one of the prettiest experiments in Physics forcing white light from a candle or a bulb to go through a little obstacle called a diffraction grating.
What the viewer see now is two rainbow spectrums - one on the left and one on the right side of the white light source - called first order spectrums.
The violet colur is always nearer the centre white light. In the lab we see as many as 16 rainbow spectrums on the left and another 16 rainbow spectrum on the right. Cool right?

Tuesday, August 31, 2010

Aerial view of wavelength


In this aerial view photo of the waves, note the yellow arrow lines ( not the yellow circles) near the bottom of the picture.
You can see the yellow line with double arrows further out at sea is much further apart tha the one near the shore cos' the water is much deeper further out at sea.
The yellow arrows show the distance between one white wave crest to the next wave crest and this distance is called the wavelength

Wavelength and depth

Hopefully this 2nd picture can help explain more clearly to my dear friend Bee Leng.
As the waves get closer to the shore ( which is shallower) the distance between successive white crests ( called wavelength) become smaller.
When the waves are further from shore as in the deeper waters, the wavelength is much bigger.
I am updating this post 12 years later with some lovely photos of Kiama Bay near Sydney, courtesy my friend Wee Lai who stays near there.( 27th August 2022)
Can you see the wavelengths changing as the waves approach the shore?
Can you see the surfers riding the crest of the waves? The distance from one crest to the next crest is the wavelength. The bigger the wavelength, the deeper the water and the higher the velocity of the waves.

Physics and life


What's the colour of nearby hills and faraway hills?
Why do they appear to have different colours even though they are all the same hills and viewed by the same observer?
Well, the red component of white light is more esaily absorbed when it travels through long distances and so farawary hills appear less red ( also less orange, yellow, green) and more blue.

Physics and life


Students often find Physics meaningless (and a tad difficult) because they can't see the connection between Physics and life. I have been teaching Physics for almost 30 years and I can see the joy in my students' faces and eyes when they see the connections and find Physics fun.
.... So if you have issues with Physics, come follow us on this blog.
Look at the distance between each white wave crest (the wavelength). If that distance is bigger, it simply indicates the water is deeper.