The program started with a film titled ‘Man’ by Steve Cutts. Is available on Youtube. Was an interesting way of portraying how we have converted everything in our path to garbage today. What is important is not the clean-up, but the steps that will lead to garbage not being created.

The first talk was by Samir Dhurde on Astronomy. He started by giving a brief history of IUCAA. The founder director is Jayant Narlikar. He is also an author of a few sci-fi and fiction books. The buildings were designed by Charles Correa. Every 28-Feb is open day at IUCAA – National Science Day. Must plan a visit if I am in town.

We started with a small discussion about Telescopes. A binocular is actually a telescope. The tripod / telescope mount is basically to ensure that the hand shake does not affect the image. What do telescopes do? They make distant objects –

• Bigger
• Brighter
• Sharper

Types of Telescopes –

• Refractor – double concave lens – converges
• Reflector – uses mirrors instead of lenses
• Compound – uses both

These are some of the bigger telescopes in India and globally.

• Vaina Bappu Telescope, Kavalur run by IIA
• Hanle, Ladakh – 2.01 m focus
• Girawali Observatory, Pune – Optical and IR, spectroscopy of faint objects
• SALT, SA – 11 m dia telescope
• Astrosat – UV imaging telescope, made in Pune
• NCRA, which is next door to IUCAA operates GMRT – which has 30 towers with dishes on them. These are spread over a 50 sq km area near Narayangaon, about 80 km from Pune.
• Coming up, 30 m telescope coming up at Mauna Kea, Hawaii

Sailors – did not watch Star TV, they only watched stars. If a scientist finds something interesting, she pauses. Samir made us pause for more than 30 minutes on this single picture. He asked us what did we observe – and there were discussions on each of the observations. Opened my eyes – literally..

• How many stars are there in the picture? (Can be applied for bacteria counts also)
• Where in the sky does the aurora happen? Why does it happen?
• Yellow glow is city lights. Why is light being wasted by sending it upwards?
• Lack of light can also be information
• Milky way – Akash Ganga – Is a flat galaxy – we are at the corners
• Patches of more stars, those with less stars.
• The clouds are other galaxies – Magellanic cloud
• Line is a man made satellite passing through the frame – one orbit in 90 minutes. Long click required – so long exposure.. Blur happens. How long was the camera open – based on the length of the line?
• The blue line are phyto-planktons, they create their own light.

Ashok took us through some fast paced demos. Will talk about some of the stuff that I was seeing/hearing for the first time:

• Straw wave toy, when made using cycle spokes – is more fun.
• If you want to reverse straw horn – then suck air in
• Pitch – is related to the length of vibrating column. The long one is your sir’s voice – the small one is your Madam’s.
• 6 holes in a flute – sapta sur. Because the seventh hole is at the bottom of the flute. Though in Ashok’s humourously self-critical way it is not Bansuri, it is Be-suri!
• You need to take care of your nose when you are cutting – you can’t see clearly if an object is less than 25 cm from the eye
• Corrugated pipe wash basin – just rotate it – you can get sound when we rotate it.
• Javelin throw – or cricket bat – if you want to hit a six with minimum effort, use 45 degree
• Chana wala – how they cheat – use more height – looks big – but less volume
• Pipe + Paper cone. Use it along with paper in order to make archery practice
• Static electricity – works best in winter. Blow balloon – and rub. Then it sticks to hand – static electricity

• Total internal reflection using laser pointer and dettol bottle.
• Refraction – using agarbatti at the top of the bottle

• Duster powder – dark room – laser pointer – you can see ray of light and angle of reflection
• Then we use a CD 3 reflections – because of 3 layers or 5 layers
• 3 LED colors RGB shown in dark room. Colorful shadow. Square hole in newspaper – you can see Venn diagram of Cyan Magenta

We ended with a film by an NID student – Ganguly.  Was an ‘out’standing student in class – always punished. Read Danger School – and made a film out of that. Ironically, he is a teacher now. Teaches at NID. The film is Do Flowers Fly.

Visit to the Muktangan Exploratory

The Muktangan exploratory was started by Prof VG Bhide, ex Vice Chancellor of Pune university, in 1992 in the campus of BVB School, Pune. It shifted to its independent premises in 2006. His son has left his job abroad to join as the Director of the exploratory a few months ago. Classes are held for students of Class 5 to 10. Students come in once a week – or for a week-long workshop in summer. They have developed their own activity syllabus – after studying CBSE / ICSE and SSC board syllabi. There are 7 labs in the exploratory: Physics, Chemistry, Biology, Math, Computer, Earth Sciences and Electronics. They also have a balloon planetarium made by Duckback. Being the silver jubilee year, they are organizing ‘Meet a Scientist’ talks – where scientists from different fields come in and talk to students about the work that they are doing.

I had got in touch with Bharati Bakshi, and she was a great host. She took us around all the labs – and at each lab the coordinators spent good time with us – in explaining the experiments that the kids worked on over there. At the end of the visit we were invited by the Director for a chat. Bharati has invited our 3 / 4 class to visit the Exploratory. I in turn invited the Muktangan team to visit our school. Hopefully should get this done in Feb / Mar. Was speaking to Arvind about Muktangan, and he rued the fact that though they have such great infrastructure and building, the utilization is not good. Also they don’t like inviting ‘competitors’. Was also not very happy about their instructions to us of not taking photos.

Of all the coordinators, I found the one in the Chemistry lab the best. He had high energy levels and was amazingly helpful. Wish I had one like him when I was in school – where Chemistry was my most feared subject. He mentioned that the place to start learning chemistry is the kitchen. I loved the crystal flowers he had made from supersaturated solutions.

I think any reaction where there is a color change or a blast would serve to ignite the interest of students in chemistry. They had an interesting periodic table made up wooden blocks. I suggested adding objects made of those material to this 3d table, so that students can appreciate where these elements are used. My other idea was that each child should learn about adulteration – especially if they can learn how to adulterate food themselves. One interesting idea would be for them to make ‘artificial’ milk using urea and detergent J. The only danger is that some of them may be tempted to take this up as a vocation!

The Earth lab’s most interesting display was on eco-systems. As Bharti explained to us, that the earth is an isolated eco-system where the only external input that comes is the sun’s energy. She had on display 4 sealed jars: Desert, Tropical, Pond and Marine eco-systems. The oldest jar had been sealed 9 years ago! Unfortunately in the extreme heat of the last summer, that eco-system had collapsed. One more interesting experiment that this lab does is to show students how much bacteria we have on our bodies. An agar semi-solid culture is created – and students put their hands to leave the prints behind. After a week one can start seeing bacterial growth in the hand-print! Students also do chromatography – a basic one, where they learn to separate chlorophyll. There is an interesting contraption to measure lung volume. A bell jar full of water – students have to blow a lungful of air in it at the top, and water gets pushed out. The height of the air column is proportional to the lung volume. Bharti informed me of in interesting discovery with this apparatus. Students of a deaf-dumb school were visiting – and she found that most of these students had much smaller lung capacities than normal students. (Lung volume ranges from 2 to 4 liters.) Her hypothesis is that a lot of the air that we inhale is used to power our sound boxes. Worth investigating!

We then moved on to the Math Lab. This is where carpentry and probably clay modeling can work well together to make models. There was the interesting 2d model of (a + b)² which looked something like this.

What was more interesting was the model for (a + b)³. Would be an interesting mental exercise for you to be able to tell me how many pieces would go into making this model!

One more interesting one was of a wooden circle that had been sliced into 15 small sectors. You could rearrange them into a sort of rectangle with alternate pieces up and down – and then measure the width of this rectangle. What do you think the answer would be? There was also a contraption with a lot of parallel boards in which you could roll in balls. They hit a parabola shaped board at the end of an incline and there was a hole at the focus which took away these balls. What do you think the apparatus featured below is demonstrating?

Next stop was the electronics lab – which made me nostalgic – as I was a member of the electronics club in my school days. The first experiments kids work on is to discover which materials conduct electricity – and which ones don’t. Actually, a better starting experiment could be one where we use the cement sack filaments and rub them together to see them repelling each other. The concept of static electricity – and free electrons. What is done is a circuit is made using a battery and an LED. The material is placed between two contact points and the brightness of the LED tells you how good a conductor that material is. Materials usually used in the experiments are – Alloys, Mercury, Gold. (With gold you have to be careful as there is a chance of it blackening at contact points.) The simple concept of conductors can also be used to develop games like steady-hand.

Interestingly the concept of one way flow is illustrated very well by reversing the polarity of the LED and demonstrating that there is no electricity flow – blocked. So it is like a one way valve. As students progress, they are asked to make solderless circuits using breadboards. My thinking is that each of these components and meters needs to be made into boxes which can be built up like Lego blocks. Another idea is to teach basics of logic gates using simple switches. Any devices which play on light and sound would be of interest to students – so apart from LED one can use things like LDR. And it would be fun to create speakers using old mineral water bottles.

The physics lab had an interesting chair which was mounted on a truck wheel rim and bearing, You had to sit on it and the chair is made to rotate. You have some dumbbells with you which you can hold outwards by stretching your hands. Your rotational speed immediately reduces. Why? There is a company that was promoting its science kits over there – mystemlab.com – must check up the site sometime…

There was some interesting work with mirrors. You basically fix one mirror at the base of a protractor – and the second one is hinged and can be rotated. As you change angle you can see the number of images changes. What do you think would be the image count when the angle is 45 degree?

Then there is another apparatus which is an infinite well. It is basically made using a blackened box with a mirror fitted below. There is a glass fitted at the top and there is a tube of LED lights which is spiraled on the sides. You peer in and you can see images of the LED lamps going all the way down to infinity. I looked around the contraption and could find only one mirror at the bottom. So how do you think this infinite well worked?

There was a variety of pendulums on display. There was a Yo-yo kind of disc pendulum, which you had to roll up a metallic disc – and it would keep on going up and down. There was also a marble pendulum line – where I had expected to see the usual experiment of swinging in one marble – and seeing the other one swing out. But what was interesting to note that you could do that with two marbles also – and see two marbles shoot out! Another interesting pendulum was the Focault’s pendulum – which is basically a 5 m long pendulum which is used to demonstrate Earth’s rotation. You start swinging it – and come back an hour later to see that it is now centered at a different spot! Finally the piece-de-resistance were the spark generators – the Van De Graaf and the Whimsurt. It really looks awesome to see the sparks fly across the electrodes as you start your rotations.

Learning with Vidula Mhaiskar

Science is the movement from qualitative to quantitative – through experiments. And in the teaching of science, story telling is important. Tell kids stories of how things were discovered. All you needed was to have been in the right place at the right time. One of you, had you been born in the seventeenth century in Europe – would have as good a chance of discovering the laws of gravity. The laws of physics would have been in your name instead of Newton’s!

Most schools can afford to do pure activity based work till 8^th grade. After that the board mania has to take over. In toy-making encourage students to do controlled experiments. This can be done if the entire class ends up making a single toy. We can then compare performances of individual students – and then try to see what for example makes one of the fishes rotate faster than others – or which airplane flies for a longer time. Students are then able to see that for example in a helicopter-fan you need to have the right angles. Too much of an angle means no rotation. Small blades means faster rotation. What do you think would happen if one of the blades is made shorter? When a teacher’s tumbling toy did not tumble, Vidula explained that her fold at the bottom was not too tight – the concept of center of gravity becomes very clear once you have made a toy that does not tumble..

Or how we normally associate oil with slipperiness – but too much of oil can also cause adhesion. So we are looking at a variety of forces that act on an object! Another interesting experiment she makes kids do, is to have them exert 1 N of force. This is quite interesting – and it takes time for students to realize that it is quite a small unit – equivalent to the lifting of just 100 g. Putting on a button takes 5 N of force.

In the falling fish experiment, what happens if the fish is flatter. Some of the students then start comparing the fish to the ones they eat – the pomfret vs the Bangda. Whenever Vidula does the fish, she also asks the class to make an Origami crow. The crow helps pick up the fish – and put different colored fish into different baskets. She also makes the crows pick up the fish on a small paper stick – and carry them from one lake to another – enacting the story of the cheating crow.

We looked at the straw wave generator. It is created by laying an insulation tape – and putting straws across it. You then put another tape on top to complete the sandwich. You need to hold it tight – and you can then see what happens as we send little energy bursts through twists across from one end. How the tightness determines the speed of the energy transfer. How it reflects – and loses energy as it travels back and forth. She then demonstrated the same principle through a balloon piece that she attached to a Colgate tube.

If you stretch the tube, the pitch of the sound changes. She called the lower pitch – the Amitabh Bachchan one, and the higher pitch the Lata Mangeshkar one. She demonstrated it through wavelength by getting us to wind the straw wave more and showing that the length between crests reduces – but the number of crests goes up – the inverse relationship between frequency and wavelength.

One of our teachers told us of an experiment she did: she asks her students to repeat the same word – but each time a wee bit faster. She hypothesized that the pitch changes as the speed changes. We tried it ourselves, but it did not work. The pitch frequencies work at much smaller ranges than the repetition frequencies.

Another interesting experiment Vidula does, which we need to try is to switch on a song on a speaker – and start walking away. The first sound to disappear is the tabla, then the male singer – and finally the female singer. Great way to demonstrate the link between frequency and propagation.

Vidula had an interesting device to measure lung volume. A flexible plastic tube – the kind that you would find in Form Fill Seal machines. She tied up one end of the tube – which was approximately 5 m long. She then asked one of the teachers to cup the tube around her lips – and blow in one lungful of air. The blowing end of the tube was then pushed in till the time the air was compressed into a cylinder. By simple geometry, now the volume could be calculated. Relative comparisons of lung capacities was done by comparing the lengths of the tubes filled in.

After this, she worked out some magic. She kept some distance between the mouth of the tube and her mouth – and she blew in some air into the tube. Then she compressed the end – and we found that the entire tube was full. She then explained that this was the result of Bernoulli’s pressure drop. The velocity of air causes pressure to drop in the tube – and the surrounding air rushes in. Hence the super-lung-woman effect.

The tetrahedron is the building block of nature. This was demonstrated through the match-stick toys. About how flexible hexagons and squares are – but not triangles. Hence we find triangles used all over in construction structures – for they are stable. The tetrahedron is the 3d Bhai of the triangle. An interesting assignment she gave us was to build a tetrahedron out of an envelope. We need to make a central fold. Make two folds such that the side of the envelope reaches the center line. Then cut at that point – leaving a small space for a flap. And then join.

We discussed the challenge of group work in these projects. One of the ideas is that all the kids should make the same project, so that variance and results and correlations can be discussed by the class. If the project is too complicated – or the resource material is scarce, then it can be something like make one fold and pass it on to the next person in the group.

One interesting idea that Vidula shared was to have toys as visiting cards. There is a folding spinning top, which she created using a tetrahedron tikli from Tulsi Baug, the trinket shopping area of Pune. Another design for the same can also be made using a dimple made into the paper.

Some interesting puzzles she made us think of:

• How do we teach students about projectile angles? We get the entire class to make straw sprinklers. For each student the range of the sprinkler is measured. We make students discover what the upward angle of the sprinkler straw should be for range to be maximum. And what is this range?
• A rectangular paper is given to a student – saying that this is a plot of land which is 2 2/3 acres. Your task is to mark out 1 acre which has to be given to one of his sons. How would you do this?
• Let students guess what it the maximum number of times that they can fold a newspaper. Another interesting experiment was finding out the thickness of a newspaper. You do repeated folds – and then measure the thickness. And once you have found the thicknessm let them calculate how many times will you need to fold the newspaper to reach the moon?
• I am giving you a rectangular paper out of which you have to make a storage for sugar. Should we have a taller cylinder or a squatter one?

Students don’t want knowledgeable teachers, they want happy teachers. Same applies to students also – so how do we make them happy? So in building toys, first is to let them have fun. The science can always come later..

Notes on Science Center Visit, University of Pune, Mar 2018

We reached late – should have started at 1015. Ended up starting at 1030 hrs. Takes time to load kids into the car – next time need to build travel buffer. Thankfully, no vomiting in cars this time. Met with the Director – who had arranged for 3 volunteers to be around. The class moved in a single group.

Virus Model

We were first told about the Great Indian Bustard – it seems that there is only one of these birds left in Maharashtra. The class was quizzed about why they think this has happened.. We could have continued the discussion about the extinction of species – but there was more to see..

Monocotyledon seed trunk 

Dicotyledon seed trunk

For me the visit was good for my study of anatomy. Had never figured out which is bigger – the liver, the pancreas or the gall bladder. Found out why life is futile without the liver – it is also the largest internal organ. It kinda wraps over the stomach. And the pancreas and gall bladder are hidden away somewhere between the liver and the stomach. No wonder they are always in trouble with the stony stuff. The heart is smaller – fist sized. We always imagine it as much bigger.

Our Compact Insides – Note the kidneys at the back

Although the lung is made totally of muscular tissue, it requires external muscles of the diaphragm to fill it up with air. I wonder what the body’s internal pressure dynamic are!

Air Sacs for exchange, inside the lung

We then moved on to physics. I loved the shock wave demo. A drum was beaten in front of a pyramid of paper cups. The waves just knocked them over. A good demo of the compression waves that comprise sound.

Paper cup pyramid demolition with sound attack

Another interesting way of making sound visible was to tape a small reflective surface on a speaker – and project a Laser light on to it. This laser is reflected on a curtain. As we speak the speaker diaphragm vibrates and the reflected laser produces patterns on the curtain.

Making sound visible

The instructor made all of us sense our spoken vibrations by asking us to place a finger on our vocal sound box and speak. Another simple experiment with sound was to put a buzzer on a string and rotate it. We could hear the frequency change – this was the Doppler effect. Btw, this also works when you rotate a flexible pipe in the horizontal plane.

Lightning generator, using static electricity

The next simple experiment involved putting a radio in a metal cage – to find that it stops working. When touched with a metal scale, it magically starts working again. Good concept of earthing of radio signals.

Trapped Radio

Lever

The last experiment was rolling down two balls on two inclines. One was a straight incline – the other was a cycloid curve. The ball on the cycloid sped faster – and reached earlier than the straight incline. Need to do some research to find out why.

Balloon Mirror

The interesting part was also the outdoor exhibits. Students did not really become curious about the square wheel buggy – and most of them did not appreciate the rotating chair demonstrating the law of conservation of angular momentum. Maybe we need more science in our classroom for the appreciation to happen!