Monday 15 August, 2011

London Force

London Force(also known as London Dispersion Force) is a weak Intermolecular force and is a part of van-der-Waals Force.It is a force acting between atoms and molecules.The LDF is named after the German-American physicist Fritz London.The LDF is a weak intermolecular force arising from quantum induced instantaneous polarization multipoles in molecules. They can therefore act between molecules without permanent multipole moments.London forces are exhibited by nonpolar molecules because of the correlated movements of the electrons in interacting molecules. Because the electrons from different molecules start "feeling" and avoiding each other, Electron density in a molecule becomes redistributed in proximity to another molecule. This is frequently described as formation of "instantaneous dipoles" that attract each other. London forces are present between all chemical groups and usually represent the main part of the total interaction force in condensed matter, even though they are generally weaker than ionic bonds and hydrogen bonds.
This is the only attractive intermolecular force present between neutral atoms (e.g., a noble gas). Without London forces, there would be no attractive force between noble gas atoms, and they wouldn't exist in liquid form.London forces become stronger as the atom or molecule in question becomes larger. This is due to the increased polarizability of molecules with larger, more dispersed electron clouds. This trend is exemplified by the halogens (from smallest to largest: F2, Cl2, Br2, I2). Fluorine and chlorine are gases at room temperature, bromine is a liquid, and iodine is a solid. The London forces also become stronger with larger amounts of surface contact. Greater surface area means closer interaction between different molecules.

Saturday 25 June, 2011

Dr.Subhash Mukhopadhyay-The Second Man to create Test Tube Baby

He was born on January 16, 1931 in Hazaribag, Bihar (now in jharkhand), India. He studied and graduated (in 1955) with an honours degree in physiology from the Calcutta National Medical College, which was then affiliated with the prestigious University of Calcutta.He created history when he became the first physician in India (and second in the world after British physicians Patrick Steptoe and Robert Edwards) to perform the In vitro fertilization resulting in a test tube baby "Durga" (alias Kanupriya Agarwal) on October 3, 1978.Facing social ostracization, bureaucratic negligence, reprimand and insult instead of recognition from the West Bengal government and refusal of the Government of India to allow him to attend international conferences, he committed suicide in his Calcutta residence on 19 June 1981.His feat has been given belated recognition as the Indian physician who in 1986 was "officially" regarded as being the first doctor to perform in-vitro fertilization in India.
18 November 1978. An ‘expert committee’ was appointed by the Government of West Bengal under the medical association to decide over the fate of a convict named Dr. Subhas Mukhopahyay. His charges are, one, he claims to be the architect of first human test tube baby named Durga (3 October 1978). Secondly, he denounced the report to the media before being cleared off by the Government bureaucrats. Thirdly, he made this impossible possible with few general apparatus and a refrigerator in his small southern avenue flat while others cannot even think of it, although, having all the expensive resources in their hand. (in this research Mukhopadhyay was assisted by Sumit Mukherjee and S.K. Bhattacharya.). Fourth and most important allegation, he never let his head down by the Government Bureaucrats and his straightforwardness always attracted jealousy out of his peers. The committee was presided over by a Radio physicist and it was composed of a gynecologist, a psychologist, a physicist and a neurologist. None of them were having any knowledge about modern reproductive technology. “Where did you keep these embryos?” Mukhopahdhyay said “in sealed ampules.” Then he asked again “How did you seal an ampule?” Speechless Mukhopadhyay could only utter “pardon?” From here started a questioning and counter questioning session which need not to be mentioned was utterly meaningless. “Oh! Embryos do not die while sealing?” there were people who never saw embryos in the entire span of their lifetime.
The Committee put forward its final verdict, “Everything that Dr. Mukhopadhyay claims is bogus.”
Only 67 days earlier, on 25 July 1978, world’s first human test tube baby Louise Joy Brown was born at Oldham General Hospital in England. Architects were Robert Edward and Patrick Steptoe. In their procedure they collected Ovum By using Laparoscope. At first they observed the evolution and development of the Ovum for a long span of time and then collected it through a small incision. Ovum thus collected is then fertilized by sperm on a small disc. When it forms into an embryo scientists placed it into the womb. But Mukhopadhyay without using laparoscope collected ovum by performing a small operation in the vagina. He increased the number of ovum collected by using a hormone and developed embryo. Lastly, he placed it in the womb.
Thanks to his peers and Government bureaucrats he ultimately handed with a punishment. He had been transferred to ophthalmic department which sealed his prospect to work on hormones.What is more ridiculous is that after his death, in 1983, one by one three scientists Howard Jones, Gleichar and Trounson (Australia) in three separate research claimed the invention of Human test tube baby. All these three research were already successfully accomplished by Mukhopadhyay long before their time. One of these scientists even found his research published in famous Journal “Nature”.
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Wednesday 22 June, 2011

Indian Pioneer of Space-Vikram Ambalal Sarabhai


A distinguished cosmic ray physicist, who fathered and piloted India’s
eminently successful space programmes, Dr. Vikram Ambalal Sarabhai
was born on August 12, 1919 in Ahmedabad, Gujarat. After passing the
Intermediate from the Gujarat College, Vikram joined the St. John’s College
under Cambridge University and graduated with Tripos in physics and
mathematics. He was then only 20. When World War II started in 1939, he
returned to India and worked as a research scholar on cosmic rays under
Dr. C. V. Raman at the Indian Institute of Science, Bangalore. (Cosmic rays
travel at speeds close to the speed of light and collide with atmospheric
particles while entering the earth’s upper atmosphere.) Sarabhai carried out
investigations on cosmic rays at Bangalore, Pune and the Himalayas, in
tropical latitudes and high altitudes, and studied their daily variations; he found that they were
related to the sun’s activity. The studies opened up before him the possibility of intense research in solar and interplanetary physics. He returned to Cambridge on the cessation of war in 1945 and pursued further research at the Cavendish Laboratory; after he got his Ph.D., he came back to India in 1947.Vikram Sarabhai was a Man with a Mission. A visionary, he had set before him exemplary goals; to achieve them, he worked unceasingly with dedicated zeal and determination. His basic goal in life was to use science and technology as instruments for his country’s socio-economic development and make them play crucial roles for the welfare of the common people of India.
               Sarabhai founded several institutions, among them the Physical Research Laboratory in
Ahmedabad, which has now grown into a world renowned centre of scientific excellence. In 1962,he was awarded the prestigious S. S. Bhatnagar Medal for research in physics.
He took up the reins of the country’s space research and rocket and satellite launching
programmes on his appointment as Chairman of the Indian National Committee for Space Research (INCOSPAR) in 1962. Next year the Thumba Equatorial Rocket Launching Station (TERLS) was set up in Thumba, near Thiruvananthapuram, it being near the geomagnetic equator. The same year, on November 21, the first rocket, was launched from there. He was also instrumental in setting up the Space Science and Technology Centre, later named after him.
               Following the premature death of H.J.Bhabha, Sarabhai was made the Chairman of the Atomic Energy Commission in May 1966. In 1969, the Government of India constituted the Indian Space Research Organisation (ISRO), with Sarabhai as its Chairman.
Sarabhai passed away in his sleep on December 30, 1971. The International Astronomical
Union decided to call the Crater Bessel in the moon’s Sea of Serenity as the Sarabhai Crater.

Friday 17 June, 2011

Louis Pasteur-The Vaccine Man


The greatest name in man’s victorious fight against diseases, Louis
Pasteur, was born on December 27, 1822 in the French town of Dole.
He was the only son of Jean-Joseph Pasteur, a poor tanner. Before Louis
was three years old, the family moved to the town of Arbois. As a child, his
interest lay in painting and he wanted to be an artist; but inspired by his
parents, he became devoted to his studies in school and college and
graduated from the Royal College in Besancon. Then, in 1843, his success
in an entrance exmination enabled him to join the famous Ecole Normal
Superieure in Paris. After four years he passed from there with distinction in
physics and chemistry.
He developed keen interest in chemical research and diligently pursued it.
When he was only 26, he made an exciting discovery: about crystal structure. He
found two different— asymmetric – forms of tartaric crystals — mirror images of
each other; he could separate them and show that both rotated polarized light in equal but opposite
directions. Pasteur thus became the father of a new science, stereochemistry.
In 1854, he was made Professor of Chemistry in the new University of Lille. It was here that he
did his first major work on fermentation, which became the origin of microbiology. Lille, a centre of
wine- and beer-making, was facing the problem of the liquids getting sour and putrified during
fermentation. Pasteur showed that it was microbes that caused them to be spoilt, and by moderately
heating them for a few minutes, the microbes would be eliminated. By pasteurisation (now used all
over the world in the case of milk), Pasteur saved the industry from collapse.
The silk industry in France was being crippled by a similar crisis, when millions of silk worms
perished by an unknown disease. Pasteur found that the worms had two killer diseases, both
caused by microbes.His immunization method to eliminate them helped the industry to survive utter
ruin. He now turned his attention to medicine. Exhorted by him, surgeons started disinfecting their
instruments by boiling and steaming before performing an operation.
His great discovery, which saved millions of human lives and won for him world-wide gratitude,
was his cure for rabies caused by a mad dog’s bite. Despite grave danger, he sucked a mad dog’s
saliva into a tube and made a vaccine of weakened rabies’ germs out of it. He now faced a
dilemma : how to try it on humans. It was then that a boy named Joseph Meister, bitten by a dog in
14 places, was brought to him(see box on facing page). Pasteur Institutes, on the model of the
Institute in Paris established as per his wish, have been set up in many countries, including one at
Coonoor in India. Pasteur died (at the height of his glory) on September 28, 1895 at Saint-Cloud near
Paris. Craters on Mars and the moon have been named after him.

Thursday 16 June, 2011








Friends yesterday the world viewed the longest lunar eclipse in the century.It lasted for about 100 minutes.These are some fascinating photos of lunar eclipse

Monday 13 June, 2011

Atoms Dance To Death

The surrender of Germany and Italy in 1945 marked a milestone in the pursuit of peace by the Allied powers. The Second World War had ended, at least for the people of Europe. But that did not truly signal the return of world peace. The other Axis power, Japan, held on, tenaciously, and continued the war. They did not then know of the atom bomb, which the United States of America had acquired. It is ironic that the man who acted as the catalytic agent for paving the way for the atom bomb, Albert Einstein, was a man of peace. He was a pacifist in every sense of the word. He could not have foreseen, in 1905, when he defined the relationship between mass, energy and the speed of
light (energy = mass multiplied by the square of the
speed of light), that his discovery would be the
forerunner of the atom bomb.
When Hitler gained power in Germany, Einstein
was working at the Kaiser Wilhelm Institute. He found
the anti-Judaism of the new regime repugnant to
full freedom to pursue his special interests. Scientists
from all around the globe kept in touch with him.
His contacts informed him about the work
undertaken by German scientists to split the atom
and to release the immense energy it held. In 1939,
Einstein knew for sure that German scientists were
trying to develop an atom bomb by creating a chain
reaction to produce immense energy and power to
the bomb and lend to it terrific destructive power.
Einstein rued the fact that by defining the link
between mass and energy, he had laid open
possibilities of a bomb the like of which the world
had never seen. He could guess that the bomb
would give a tremendous advantage to Germany.
Einstein decided to nip the trouble in the bud.
In 1939, he wrote to President Roosevelt of the USA
about the danger latent in Germany gaining a lead
in developing the atom bomb: “Some recent work
by E. Fermi and L. Szilard, which has been
communicated to me in manuscript, leads me to
expect that the element Uranium may be turned
into a new and important source of energy in the
immediate future. It may become possible to set
up a nuclear chain reaction in a large mass of Uranium
. . . . This new phenomenon would also lead to the
construction of bombs, and it is conceivable - - -
though much less certain - - - that extremely powerful
bombs of a new type may thus be constructed. A
single bomb of this type, carried by a boat and
exploded in a port, might very well destroy the whole
or together with some of the surrounding
territory.. .”
The scientist urged the President to take
immediate steps to promote research on Uranium in
order to be ready to check Germany if the danger
became real. The President took immediate action.
The work on developing the bomb set off the ground,
under cover of the code name Manhattan Project.
After five years, the first prototype of the atom
bomb, developed by splitting Uranium 235, was
tested in the desert region around Los Angeles. The
devastation it caused was far beyond the wildest
expectations of the scientists, who reported the
results to the President.
President Roosevelt, who was elected for the
fourth term and assumed office in January 1945 (the
rule restricts the tenure to two terms) died within
August 2005 52 Chandamama
three months, on April 12. Vice-President Truman
(see photo) stepped into the high office.
The war in the South East had not ended. Should
the bomb be used to bring Japan down on its heels?
President Truman, unwilling to wait indefinitely for
the defeat of Japan through normal warfare, decided
to use the bomb.
Hiroshima was a prosperous city of Japan. Its
economy rested mainly on shipbuilding. It was 8.15
a.m. on August 6,1945. The roads bustled with
workers heading for the shipyard. The drone of an
aircraft added to the rustle of people hurrying to
their work spots. The people looked up, fear in their
eyes, to check if it was an enemy aircraft on a
bombing mission. The sound of the siren confirmed
their fears and they ran seeking suitable shelters.
Some of the people, while they ran for safety noticed
a small parachute descending with a bomb attached
to it. Within seconds the bomb freed itself from the
parachute, hit the ground and exploded. In less than
one-tenth of a second the temperature rose to
300,000 degrees centigrade. In one second of
detonation all the buildings around came down like
houses of cards. One hundred thousand people died
almost instantly. But that was only part of the
tragedy. Millions of people, who were beyond the
zone of the strike, faced the risk of radiation and
slow death. Observers reported that the explosion,
while it lasted, was “brighter than the sun”.
The pilot of the aircraft, Enola Gay, named after
his mother, turned back to the airbase, having
completed his mission. Soon the whole world was
shocked by the devastation. Panic gripped
Japan, but Emperor Hirohito and his
advisers still felt that they could stand
up to the assault by America. However,
when on August 9, 1945, another atom
bomb was dropped on Nagasaki, a
flourishing trade centre, Japan woke up
to the fact that no useful purpose could
be achieved by continued resistance. The
Emperor and his advisers, too, realized
that they could never match the new arsenal of the U.S.A. Japan
surrendered. Thus ended the
Second World War. Gen.
MacArthur assumed total control over Japan.
At that time, no reporter was allowed access to
the devastated cities. Yet George Weller, an American
journalist, managed to sneak into “the wasteland of
war”. His first reports spoke of the radiation fallout.
Thousands of people were reporting sick and doctors
categorized it as a mysterious “Disease X”. It was
only much later that the true cause of the disease
became known. Radiation was playing havoc with
the lives of millions of people.
It took Japan decades to free itself from the
lingering effect of radiation, let loose by the tragic
bombings of August 1945.

Thursday 9 June, 2011

Think of a Small Biological Computer

Scientists of the Weizmann Institute of Science in Israel have programmed
the world’s smallest computer to detect cancer of the prostrate and
lung. The team of scientists guided by Prof. Ehud Shapiro (photo) used a
computer they had designed and made entirely of biological molecules. An
idea of the size of the computer can be imagined by pointing out that a
drop of water can hold about a trillion (one million million) of such
computers!The biological molecules constituting the computer consist of three units:
input, computation and output. The input unit is made up of short strands
of deoxyribonucleic acid (DNA). These DNA molecules contain all the vital
information about the genes in living cells and formulae for all life processes.
These molecules check for the presence of a single-strand substance called messenger ribonucleic  acid (mRNA). The mRNA is controlled by four chosen genes. If cancer has set in, the four genes in the cell would have become under-active or over-active.
The computation unit, consisting of a long hairpin-shaped DNA strand, then checks each input
in turn. Only if all the four genes point to cancer will the computation unit give a diagnosis of
cancer. The computation unit also contains the third unit or component of the bio-computer which is again a single strand DNA known to have the potential to fight cancer. If the diagnosis by the computation unit reveals cancer in all the four genes, the third unit DNA activates its fighting
potential. There is thus a possibility that in the not-too-distant future, cancer can be diagnosed and treated even without looking for the appearance of symptoms.