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| SCIENCE TRIBUNE | Thursday, November 8, 2001, Chandigarh, India |
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Birth anniversary on
Nov 8 Exoplanets
galore SCIENCE
QUIZ |
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How was
the moon born? For many generations, men and women have looked at the moon and have been inspired to love by its cold presence. We use it to make up our calendar and are afraid when the sun eclipses it. But how was it born? Hindu legends have it that the moon came out of the celestial churning by the gods and demons. In China, Taoist myths says that the Great Lord of the Universe, P’ and Ku’ created the sun and moon. European children, however, believe it is made of green cheese.
One suggestion is that the moon was formed somewhere else in the universe but that it drifted into the solar system. By a stroke of luck for the lovers of the future, the gravitational attraction of the earth captured it. Others say that the moon and the earth condensed together from the original nebula that formed the solar system. Another theory is that some celestial object came close to the earth and pulled the moon out from the Pacific Ocean. Yet another group believes that massive rock like objects that originally circled the sun and one of these hit the earth and the moon was thrown out. Most favoured at the moment is a model that is based on a sophisticated three-dimensional computer simulation of colliding objects. This new model takes into account in three dimensions both the thermodynamic effects of another planet hitting the earth and the gravitational interactions between all the pieces that were dislodged. This indicates that a Mars-sized body hit the almost fully formed earth around 4.5 billion years ago, ejecting debris. This junk which circled the earth slowly condensed into the moon. Results from this simulation fit observations more closely than the other theories and indicate that moon is younger than previously thought. An older moon would have more iron than is found in moon rocks that have been analysed. The new model also explains the current orbits and compositions of the earth and its satellite better. However, many discrepancies remain and the birth of the moon is not completely known. The main objection is that if the moon was pulled out the earth, rock samples from the moon and the earth should be somewhat similar in composition. But the abundance of elements in moon rocks is sufficiently different from rocks found on earth that it is unlikely that the moon taken out of the earth. There are other difficulties. The moon circles round the earth in an orbit that is inclined by about 5 degrees to the equator. But calculations that take into account the attraction of the earth, the sun and other planets show that in the distant past, the moon orbit was tilted far more, about 10 to 12 degrees and that the moon has been moving away from us. Four and a half billion years ago it was 22,530 kilometres away but it is now 450,000 kilometres distant. Perhaps one day we shall have to make do without moonlit night! If a large object had hit the earth, some astronomers state, a moon would not have come out, but should have resulted in a disk of debris orbiting above the equator before freezing into a satellite that would have stayed in this position. Other planets like Saturn have such debris going round the planet in the equatorial plane. Scientists agree with this theory but they now say that the traffic of debris tilted the moon’s orbit. The attraction of the newly created moon and the debris created huge tidal waves in the debris and forced the moon into a more inclined orbit. But what was this massive body that
hit the earth? It was possibly an asteroid large hunks of matter that
populate the universes and ranging in size from less than 1 to more
than 1000 kilometres in diameter, though some objects could be very
much larger. Asteroids are material left over from the formation of
the solar system. Though they are never visible with the unaided eye,
many asteroids are visible with binoculars or small telescopes. One
theory suggests that they are the remains of a planet that was
destroyed in a massive collision long ago. Some have orbits that cross
earth’s path and some have even hit the earth in times past. In
January 1801, Giuseppe Piazzi discovered an object, later named Ceres
after the Sicilian goddess of grain, that he first thought was a new
comet. Later, it became clear that it was more like a small planet.
Several hundred thousand asteroids have since been discovered and
thousands more are discovered each year. Most of them go round the sun
in a region called the asteroid belt, located between Mars and Jupiter.
Some asteroids strayed out and were captured by planets, such as
Deimos and Phobos, the tiny moons of mars, the outer eight moons of Jupiter
and Saturn outermost moon. One such and very large asteroid struck the
earth that was more or less a liquid drop and blew out the junk out of
which the moon was born. PTI |
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Birth anniversary on
Nov 8 Dr Christiaan Neethling Barnard, who performed the world’s first human heart transplant in 1967 was a researcher of varied interests and wide-ranging tastes. The world was startled on December 3, 1967, when the South African surgeon, then 45 removed a patient’s dying heart and replaced it with a healthy one taken from an accident victim at Groote Schuur Hospital in Cape Town (South Africa). Though the recipient died after 18 days but Dr Barnard’s work won him the acclaim of every medical authority, as well as creating international acclaim for South Africa. Dr Barnard, born on November 8, 1922, was the son of an improverished farmer near the township of Beaufort West in Karoo of Cape Province. His father served as a missionary to racially mixed people earning a meagre salary of $ 750 a year. Dr Barnard had three brothers. He was so poor that young Barnard ran a record mile in his bare feet; he won a school tennis championship with a borrowed recquet and cardboard covering the holes in his sneakers, he studied by rural firelight and was at the top of his class. Dr Barnard always gave credit to his mother, who instilled in him and his brothers the belief that they could do anything they set their minds to and do it well. He was personable and bright, earning a coveted place at the University of Cape Town, where he studied medicine. After receiving a medical degree in 1946, Dr Barnard worked for two years as a general practitioner in a small farming village and then returned to the Cape Town medical school to study birth defects and diseases affecting the bowel. There he won a scholarship to Minnesota University to work under two distinguished heart surgeons. In his first few weeks there, he was so short of funds that he had to mow lawns, wash cars and do other odd jobs to earn meal money. He returned to Cape Town where, with the help of a heart-lung machine donated by America, he developed one of the best heart surgery units in the world. After the first heart transplant of 1967, he went on to perform some more heart transplants more successful than the first. On January 2, 1968, Dr Barnard caused another sensation by transplanting the heart of a young man of mixed race into a retired white dentist, Philip Blaiberg. He survived for 19 months and 15 days. 1n 1970, he transplanted a heart onto a dog. In 1974, he was the first to do "piggyback" transplants in which he grafted a second human heart to the patient’s damaged heart with the aim of giving it time to heal. He also performed heart-lung transplants. Off the heart transplants he once remarked: "For me, the goal of medicine is not the prolongation of life; it is improvement in the quality of life that is important." He was also an enthusiastic supporter of euthanasia. Thanks to Dr Barnard’s pioneering work, today the heart transplant technique has been standardised. It has been performed an estimated 100,000 times around the world. The transplants are carried out in 160 hospitals in the USA alone, with one year success rate of 85 to 90 per cent and five year success rate of 75 per cent. Dr Barnard continued operating until 1983, when his fingers became gnarled by the rheumatoid arthritis. In 1984, he became scientist in residence at Baptist Medical Cantre in Oklahoma city. In 1986, Dr Barnard endorsed Glycel — an antiageing skin cream, but its questionable effectiveness tarnished his reputation. Barnard was not averse to publicity or recognition. "Any man who says he doesn’t like applause and recognition is either a fool or a liar," Dr Barnard once said in an interview. "You learn from mistakes, but success gives you the courage to go on and do even more." He toured the world extensively, not only lecturing on heart surgery but to talk and give interviews about subjects he knew nothing about from global politics to jogging. He was received by the Pope, many Heads of State, the United State Congress, chatted with Diana-Princess of Wales and featured several times in TIME magazine. He married thrice. He divorced his first wife of 22 years when he was 48 and married the teenage daughter of a multimillionaire. His third marriage to Karin Barnard ended earlier this year. He was awarded numerous prizes, fellowships and honorary degrees but alas! not the Nobel Prize. In the later years, Dr Barnard turned to writing, producing an autobiography and several novels. His scientific publications included — "Surgery of Common Congenital Cardiac Malformation (1968), "Heart Attack: You don’t have to die (1971), "The Arthritis handbook" (1984), papers in scholary journals. His favourite book was, "Gone with the Wind." Dr Barnard breathed his last after
suffering a fatal asthma attack in the morning of September 2, 2001 in
Cyprus while reading one of his own books. He is survived by five of
his six children: Diedre, Christiaan, Fredrick, Armin and Lara and a
brother Marius. |
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Exoplanets galore Apparently, they are all over the place as if on a factory production line, astronomers are finding new planets well outside our own solar system. Just recently an international research group discovered eight "exoplanets" all at once. Last spring, another team of planet-hunters reported finding 11 which were circling far-distant stars. By now, nearly 80 planets outside our solar system are known. "Every few weeks, there are a few more," notes Prof Joachim Wambsganss of the Astrophysics Institute of Potsdam University. Some scientists, reporting to the recent fifth Leibniz colloquium in Potsdam on their research, even believe that there are planets out there on which life has evolved. Wambsganss said that planets have been found at around 5 per cent of those stars studied so far. "But this points to the conclusion that there are many more planets," he added, noting that those located very far away are difficult to discover. So far, not a single planet outside the solar system has been directly observed. The main problem is stellar light which floods out any and all more weak sources of light in its vicinity. Exoplanets only give themselves away if they are large enough that their gravitational fields produce observable deviations in the movements of the stars they are orbiting around. This means that smaller planets remain undetected. "Perhaps even every star has a planet," Wambsganss said. Those planets discovered so far are often larger than the giant of our solar system, Jupiter, which itself has more than 300 times the mass of planet earth. Astronomers can also only indirectly measure that slight, rhythmic back-and-forth wobbling of distant stars in that they precisely observe its colours. For planet researchers, the regular changes in
a distant star’s colours help them to determine its trajectory, orbital
period and distance as well as the mass of the planets. DPA |
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SCIENCE
QUIZ
10. India launched recently from the Sriharikota Range PSLV C-3 which
carried Answers: 1. Itching at the site of
exposure in case of skin infection and low-grade fever, dry cough and
weakness in case of inhalation ; cholera and typhoid 2. By Bacterium
Bacillus Anthracis ; some plant eating wild and domestic animals 3.
Amaltas 4. Reva 5. Gallium; its melting point is 29.8 degree celsius
whereas human body temperature is 37 degree celsius 6. Cheetah; about
100 kilometre per hour; approximately 20 metre per second squared 7.
Ethylene glycol 8. Translatory motion 9. Refactoring 10. India’s TES,
Belgian’s PROBA and Germany’s BIRD. |
Latter
day astronomers have more realistic theories about the birth of the
moon. When the sun emerged as a new star, it attracted the millions of
huge and small rocks and debris that were floating around in the
universe as liquid blobs and these came together and solidified into
the planets to form the solar system. The moon, however, seems to have
a different origin.