Dear Pandit ji, Gobar Times improves the basics of environment education. We have a nature Club, and we do activities like campus cleaning, bird watching, planting trees and so on. So, I suggest making Gobar Times more descriptive about environment activities that can be included in our nature club. Shivani Kashyap Via e-mail Dear Pandit ji, I recently started reading Gobar Times on the web. I find it extremely informative. I never thought environmental topics can be explained in such an interesting and simple manner. I would love to subscribe to Gobar Times only. It is really, really good. Thanks for such an initiative. Akshat Malik Via e-mail

What is green building?

Abdullah
Via e-mail

Dear Abdullah ji,
Buildings have major impacts on the environment over their entire life cycle – beginning from their siting, design, construction, operation, and maintenance till their removal. Forests are cleared and resources like water and energy are used for their construction, landscaping and maintenance. On the other, these resources depleted to give way to buildings. Resource-intensive materials provide the skin to the building and landscaping adds beauty to it – in turn using up water and pesticides to maintain it. Moreover, several building processes and functions generate large amounts of waste. Hence arises the need for green building. Green building is the practice of increasing the efficiency of buildings and their use of resources. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Depletion of natural resources is minimum during the construction and operation of a green building. It minimises the demand for non-renewable resources, and maximises the use, reuse, recycling, and utilisation of renewable resources. It employs efficient building materials and construction practices, and optimises the use of on-site sources and sinks by bio-climatic architectural practices. It consumes minimum energy to power itself by using efficient equipment to meet its lighting, air-conditioning, and other needs. It uses renewable sources of energy, and efficient waste and water management practices; and provides comfortable and hygienic indoor working conditions. And everybody related to the building has a role to play – may it be the architect, the landscape designer or the electrical, plumbing, and energy consultants. Here are the main aspects of a green building design:

1. Site planning
2. Building envelope design
3. Building system design HVAC (heating ventilation and air conditioning), lighting, electrical, and water heating
4. Integration of renewable energy sources to generate energy onsite.
5. Water and waste management
6. Selection of ecologically sustain¬able materials (with high recycled content, rapidly renewable resources with low emission potential, etc.).
7. Indoor environmental quality (maintain indoor thermal and visual comfort, and air quality)

Green building can:

1. Reduce operating costs by increasing productivity and using less resources
2. Enhance public and occupant health by improving indoor air quality
3. Reduce environmental impacts

But, the costs of designing and constructing a green building are pretty high. However, it costs less to operate a green building that has great environmental benefits and provides a better place for the occupants to live and work in.

Dear Pandit ji,
I really like your magazine. It is very informative and easy for the starters in science.
I have two questions: how do eagles fly a long distance by flapping their wings only once or twice? And could you please give me some information about 'Peregrine Falcon'?

Siddhant Singh
Via e-mail

Dear Siddhant Singh ji,
Thank you for appreciating our work. Here are your answers.
Eagles flap their wings as little as possible to conserve energy. They exhibit one of the two ‘intermittent flight’ patterns – flap-gliding (the other pattern is flap-bounding). When an eagle glides, it flies the same way as an airplane. The wings are stretched out at a slight angle and do not flap. This deflects the air gently downward, building up air pressure beneath the wings, while reducing the pressure above the wings. The difference in pressure is lift, a force that acts roughly perpendicular to the wing surface and keeps the bird from falling. But there is a loss of speed due to air resistance (or drag) on its body and wings, and altitude. So, it needs to flap its wings once or twice, that is, use flap-gliding. In flap-gliding or intermittently powered flight, eagles use powered flight to increase height before gliding with open wings. While gliding, an eagle supports its weight with its wings and does no mechanical work. The Peregrine Falcon (Falco peregrinus) is a cosmopolitan (found almost everywhere around the world) bird of prey in the family Falconidae. It is also known as the Peregrine, and historically as Duck Hawk in North America. This medium to large-sized falcon has seventeen described subspecies, which vary in appearance and range. The females are larger than males, with a blue-gray back, barred white underside, and a black head and ‘mustache’. It feeds on medium sized birds, and may hunt small mammals. But it has become an endangered species due to the overuse of pesticides such as DDT.

The Indian Peregrine Falcon The Indian Peregrine Falcon or Falco peregrinus peregrinator, described by Sundevall in 1837, is found in many places in South Asia including India, Pakistan, Sri Lanka and Southeastern China. It is also known as the Black Shaheen and Indian Shaheen, and was formerly called Falco atriceps or Falco shaheen. It is non-migratory, and small and dark, with rufous underparts barred with lighter color.

Some facts:

1. The name ‘peregrine’ means wanderer.
2. It is one of the most widespread birds in the world. It is found on all continents (except Antarctica), and on many oceanic islands.
3. It is a very fast flier, averaging 40 to 55 km/h in travelling flight, and reaching speeds up to 112 km/h in direct pursuit of prey.
4. During its spectacular hunting stoop from heights of over one kilometre, the peregrine may reach speeds of 320 km/h.
5. The bird has one of the longest migrations of any North American bird.
6. People have trained falcons for hunting for over a thousand years, and the Peregrine Falcon was always one of the most prized birds.
7. The methods of handling captive falcons developed by falconers helped in the efforts to breed the Peregrine in captivity and reestablish populations depleted during the DDT years.

By the way, Peregrine Falcon is also an expert in flap-gliding.