Dr Rajiv Desai
An Educational Blog
HOLOGRAM
HOLOGRAM: _____ Typical laser-lit transmission hologram ____ Prologue: Suppose you want to take a photograph of an apple. You hold a camera in front of it and, when you press the shutter button to take your picture, the camera lens opens briefly and lets light through to hit the film (in an old-fashioned camera) or the light-sensitive CCD chip (in a digital camera). All the light traveling from the apple comes from a single direction and enters a single lens, so the camera can record only a two-dimensional pattern of light, dark, and color. To be more accurate camera records wave length (color) and intensity (amplitude) of light waves. If you move your head slightly, the photograph remains same i.e. it is two dimensional. The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) […]
Closed-Circuit Television (CCTV)
Closed-Circuit Television (CCTV): ________ CCTV pictures showing Al Qaeda’s terrorists Mohamed Atta and Abdulaziz Alomari boarding a 6:00 a.m. flight from Portland to Boston’s Logan International Airport on September 11, 2001. _____ CCTV footages of 2015: _______ Prologue: In the past people didn’t misbehave because they thought God was watching them. Today we’ve replaced an all-seeing God with the glassy eye of the CCTV camera. A CCTV camera can operate 24 hours a day, seven days a week, and 365 days a year without a toilet break or lunch. It does not need a holiday, maternity leave and rarely goes sick. There were 25 million CCTV cameras in operation worldwide, with 2.5 million in the UK in 2002 but today the figure is doubled. Practically every major city now boasts a CCTV system aimed at, among other things, preventing, detecting and reducing crime. Increasingly these developments are mirrored in villages, […]
SCIENCE OF LANGUAGE
_ SCIENCE OF LANGUAGE: _ The figure above shows English to Gujarati mappings for consonants: _________ Prologue: Human life in its present form would be impossible and inconceivable without the use of language. To the question: “Who is speaking?” Mallarme, the French poet, answered, “Language is speaking.” The traditional conception of language is that it is, in Aristotle’s phrase, sound with meaning. Everybody uses language, but nobody knows quite how to define it. Language is arguably the defining characteristic of the human species, yet the biological basis of our ability to speak, listen and comprehend remains largely mysterious; about its evolution, we know even less. The origin of language is a widely-discussed topic. Whole doctorates have been based on it, thousands of books have been written on it, and scholars continue to argue about how and why it first emerged. Many animals can communicate effectively with one another but humans […]
THE SLEEP
_ THE SLEEP _ Prologue: When I was working as a medical specialist in Saudi Arabia, my duty time was 7.30 am to 5 pm and additional calls at night. If I woke up at 2 am to treat a serious patient and finished work at 3 am, technically speaking I worked 1 hour extra. My Saudi boss used to say that I can come 1 hour late next day at 8.30 am as I worked previous night for 1 hour extra. It is stupid to say the least and cruel to say the most. The issue is not 1 hour night disturbance but you do not get good sleep after being woken up at midnight and your next day is spoiled due to day-time sleepiness. I am sure that medical professionals, police, military, fire brigade etc will agree with me. Even today, I am the only physician in the […]
DUALITY OF EXISTENCE
DUALITY OF EXISTENCE _ Prologue: I had posted this comments on face book on 1/1/2010 as my website was not ready but the matter is so important for students that I decided to post it on my website to educate students. _ POSTULATE: Everything in universe that exists, living or non-living, has a dual mode of existence with each mode following a different set of logic/rationale to explain phenomena associated with such existence and the duality is spontaneous ,simultaneous and consistent with the existence of dual universe. _ The universe allegedly came into existence with big bang 13.7 billion years ago with the creation of matter, energy, space and time ; along with laws to regulate them. The Earth, a planet on which we live being a part of solar system with the Sun being the star; and the Sun being a part of our galaxy the Milky Way; and […]
