This traditional Indian toy demonstrates Centrifugal Force. It can be made by the poorest child. All you need is a broomstick, some thread and an eraser. Tie a big and small stick together and poke the rubber to make it heavy. Perch the toy on your index finger and spin it away to glory!
It is difficult for children to comprehend the abstract concepts like Centrifugal Force. This simple experiment will give children a “feel” for centrifugal force. As you spin the wire ring, the balls fly and stay up because of the force of spin.
At the heart of this Japanese lantern is a bulb in a cylindrical pivoted box. Hot air from the bulb while escaping pushes against the blades. This makes the box spin. As the box spins the pictures on it cast their beautiful shadows on the fixed cylinder. You will see a very beautiful shadow play of images.
The Talking Frog is a very dynamic paper toy and can be made with a paper square. The frog has a fixed jaw and a moving jaw which is operated by a stiff paper strip tucked in it. Make eyes and decorate the frog. Now gently hold the frog with one hand and push-pull the strip. The frog will move its jaw and will appear to be talking.
Children have made this toy for hundreds of years. Made from a paper square this dynamic rabbit flaps its ears as you move its tail. This instant toy takes less than a minute to make and always brings a smile on the faces of the children.
For this multiple generator you need 5 strong neodymium magnets, 5 insulated thin copper wire coils with 1000 turns and 5 LEDs. Place 5 modules with each coil attached to one LED on a wooden base. In the center is a vertical pivot. A CD with 5 strong magnets can spin on this pivot. The gap between the magnets and the coils is about 2-3mm. As you rotate the CD the moving magnetic field creates an EMF and all the LEDs light up brightly!
This toy is based on a double crank. On rotating the crank all the four legs of the lizard move in unison imitating the walk of a real lizard as if it was climbing a wall.
The cardinal principle of magnetism – like poles repel and unlike poles attract has been cleverly woven into this toy. Place ring magnets on a straw with similar poles facing each other. These magnets will repel each other. When pushed down the top magnets will bounce up.
Instead of a permanent magnet this motor has an electromagnet which is made by winding insulated copper wire on a sewing machine bobbin. Its spinning coil is made out a meter long insulated copper wire. On one end the entire insulation is scraped. On the other only 3-sides are scraped. The remaining insulation forms an ON/OFF switch. A 1.5-volt battery is sufficient to run this splendid motor.
For this experiment you will need a PVC pipe and a Bottle Brush that just fits into it. Hold the pipe vertically with left hand with half of the brush in it. Now repeatedly hit on top of pipe with the right hand. The brush will slowly climb up in the pipe.
This wonderful Bird of Peace has been designed by the famous Origamist Paul Jackson. This bird is a great symbol of peace. You can fold it from a card sheet and stand it on your table. It is a gift which your friends will deeply cherish.
The magnetic Dancing Dolls will keep very child enraptured for hours. The dolls are light make of wood, color wool and wire. In the base is a steel screw. Place the dolls on a card sheet and move a magnet from below. The dolls move left, then right and sometimes hold each others hands and dance a duo.
THIS PENCIL SPINS, LEVITATES AND WRITES !!!
This story more than 100 years old. In 1904 Sherlock Holmes the famous detective based in London investigates a murder. Next to the site of the murder are cycle tracks, on a muddy road from the school and the village. And only if they could figure out the direction of the cyclist based on the track, they can nab the culprit. Watson as usual is not sure. “This track, as you perceive, was made by a rider who was going from the direction of the school.” “Or towards it?” “No, no, my dear Watson… It was undoubtedly heading away…
This incident happened many years ago when I was finishing my high school in Meghalaya, a state in India’s northeast there are lush and dense forests everywhere. I used to walk to my school with my friend everyday through a narrow 2km long path. If I had taken the road the 2km walk would become a 20 km, 1hr bus ride. This was because the closest road-bridge was far away. Also the path to my school had an amazing tree bridge which is now famously called the living tree bridges of Meghalaya. These bridges are made from aerial roots…
And how does gas pressures determine effects when high voltage is applied across them? Watch the video that was important in the exploration of cathode rays that eventually led to the discovery of the electron by JJ Thomson
In part 2 of my MRI series, I discuss how an external magnetic field affects the magnetic moment of the hydrogen nucleus. In particular, how it aligns and precession. Both are explained at length in a non technical fashion
One of my students asked me to quickly review a bone scan with an X-ray image. Here is a quick video I produced
CAT or CT scans are used to achieve high resolution images inside the body. But how do they work? Watch the video to find out
Reviews how an A brightness (B) scan is produced in the context of ultrasound/sonograms