Dear Pandit ji,
How can cats survive a fall from a height, while human beings or other animals cannot (if they fall from same height)?
Manoj K. Sharma
Human Genetics Laboratory, Dept. Of Zoology,
Kurukshetra University, Haryana
Dear Manoj K. Sharma ji,
Cats love to settle in high places, or perch. However, this fondness for high spaces often leads them to trouble. But, a cat “always lands on its feet”. Because of its ‘righting reflex’. During a fall, a cat can reflexively twist its body and right its position using its acute sense of balance and flexibility. It first determines its position visually or by using its vestibular apparatus (in the inner ear).
Then, it rotates its upper body to face downwards and the lower body follows. Once righted, it may spread out its body to increase drag and slow the fall to some extent. This art begins to appear at 3-4 weeks of age, and is perfected at 7 weeks. But, it needs time to bring the reflex into action during a fall.
The height required for the righting reflex to happen in most cats (safely) is around 3 feet (90cm). In addition to the righting reflex, cats have a number of other features that reduces the risk. Their small size, light bone structure with extremelyflexible backbone and no collarbone, thick fur, and padded paws decrease their terminal velocity (the speed at which a falling object ceases to accelerate downwards and falls at constant speed).
At terminal velocity they also relax as they fall, which protects them to some extent on impact. A falling cat's terminal velocity is 60mph (100 km/h). Whereas, that of a falling man ina free-fall position is 130mph (210 km/h). And that too without the remarkable features of a cat. Thus, human beings and other animals cannot survive a fall from the same height as a cat.
Dear Pandit ji,
What are Ground and Neutral electrical connections?
Dear Abdullah ji,
Ground or earth electrical connection (more aptly, wiring system) is a conductor that exists to help protect against faults. It does not carry current in normal operation. On the other hand, Neutral is a circuit conductor that may carry current in normal operation. It is usually connected to earth. In a polyphase or three-wire Alternate Current system, the neutral conductor has similar voltages as each of the other circuit conductors, and similar phase spacing. By this definition, a circuit must have at least three wires for one to serve as a neutral. In the electrical trade, the conductor of a 2-wire circuit that is connected to the supply neutral point is also referred to as the Neutral.
This is formally described in the US and Canadian electrical codes as the ‘identified’ circuit conductor. If the entire system is only single phase then the current carrying conductor that is tied to earth is still a neutral by this definition. Combining the ground and the neutral (grounding to the neutral) provides some protection to thecase against live shorts. But if the neutral connection is broken, it will produce a dangerous live case. It is commonly used in the wiring of electricity supply companies, for fixed wiring in buildings, and for some specialist applications like railways and trams.
"Dear Pandit ji"
Dear Pandit ji,
I teach children about water and its necessity in the germination of a seed through practicals. Gobar Times gives eye-catching examples.
Dear Pandit ji,
Gobar Times broadens the mental outlook of its readers and makes them aware of causes of ecosystem destruction. They get to know the importance of many resources such as water and coal. And they also get to know the importance of gobar gas and from where does it come. I have also visited the Gobar Times website. We have done a lot of environment activities in our school. We have formed a team of eco-club members and had recently organised a visit to a forest nearby.
We selected a particular area in the forest and carried out a census of the species of trees, flowers, plants and mushrooms found there. We have also done surveys on common energy conservation methods in day-to-day life, and on land use pattern. We are going to hold an awareness programme on the hazards of plastic bags.
Thank you for your valuable feedback. But please do not forget to mention your names. I want to know all of you (…as much as you want to know the answers).
Pandit Gobar Ganesh
Dear Pandit ji,
Sorry for not writing any mails to you for so long. I just saw the new Gobar Times issue. It's spectacular and so beautiful! I have two questions for you: Were there any other observatories established by East India Co. apart from the ones you have written? And, how will KVIC use the soiled currency notes?
Dear Saira Khan ji,
Thank you for appreciating our work. Let me now answer your questions. Apart from the ones mentioned in our cover story, the East India Company established few more observatories. Such as:
Travancore Observatory In 1836-1837, the Raja of Travancore built observatory in Trivandrum. John Caldecott, director of the observatory, collected enormous amount of astronomical data, which included the observations and computations of the orbital elements of the comets of 1843 and 1845.
Observatory at St. Xavier’s College In 1875, Father Lafont set up a spectroscopic laboratory in St. Xavier's College, Kolkata, to carry out solar and stellar spectroscopic work. The observatory is now used for teaching purposes.
Observatory at Presidency College In 1900, another observatory was constructed in Presidency College, Kolkata, through a grant from the Maharaja of Tipperah. In 1922, the Astronomical Society of India gifted an 8-inch telescope to the observatory. Other observatories such as the Hennessy and Haig Observatories at Dehra Dun (1884, 1886), and Poona Observatory (1842) were set up during 18 -19th centuries.
The use of 100 per cent cotton in the making of currency notes in India has attracted the Khadi and Village Industries Commission (KVIC) to use old, soiled currency notes to make paper. They would be shredded and mixed with water, and used as raw material (or source of paper fiber) for hand-made paper.