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Year : 2019  |  Volume : 67  |  Issue : 8  |  Page : 227-

Emerging knowledge of gravity


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. Emerging knowledge of gravity.Neurol India 2019;67:227-227

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. Emerging knowledge of gravity. Neurol India [serial online] 2019 [cited 2022 Jun 28 ];67:227-227
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This picture has been contributed by Dr. R. Raghavendran, Professor of Neurosurgery, Institute of Neurosurgery, Madras Medical College, Chennai.

Known as ‘Vaan Irai Kal’ in Tamil, meaning ‘Stone of Sky God’, this natural monument located in the ancient heritage port town of Mamallapuram, 60 kms south of Chennai, Tamil Nadu, is a true wonder of nature. A 250 tonne, 6 metres high, 5 metres wide, gigantic granite boulder rests on a 4 feet base on a slippery slope of a hillock. The boulder is bigger and heavier than the monolithic stones of Ollataytambo and Machu Picchu in Peru. The giant boulder appears to be frozen in its descent down the hill it sits on, and defies gravity. The celebrated Pallava king, Narasimhavarman, and in another era, the then Governor, Arthur Havelock, made several failed attempts to move it from this state due to safety concerns. The delicately poised centre of gravity and the massive weight of this huge boulder allows it to balance on a small contact area; friction between the surfaces further enhances its stability. It is also possible that with the erosion of the surrounding soft rock, a small area of hard rock forms the unifying bridge between the boulder and its base. This natural wonder exemplifies gravity, the fundamental force of the universe by which objects are attracted towards one another. The gravitational web between various planets and stars maintains them in their defined positions relative to one another. The mass of each large object in space exerts its own gravitational force that leads to distortions around the object in this all-pervading gravitational field. A cataclysmic event far out in space may cause perturbation in gravitational waves making them observable on Earth with sophisticated detectors. These evolution in concepts represent the frontiers of human thought, fortified by mathematical interpretation, and their precision validated by a subsequent minute observation of a phenomenon of nature.

This photograph was taken in a wide-angle lens Nikon P600 with manual settings of exposure time 1/60 sec, aperture 3.4 and focal length 24 mm. The picture was taken in the early morning during the sunrise.