Science Horizon ODISHA BIGYAN ACADEMY - What does Atomic Energy really mean to you ?
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4THYEAR 8THI
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Science Horizon
4TH YEAR 8TH ISSUE AUGUST, 2014
President, Odisha Bigyan Acade my Editorial Board
Prof. Uma Charan Mohanty
Prof. Gopendra Kishore Roy
Advisor
Prof. Sodananda T orasia Prof. GovindChandra Sahoo
Chie f Editor Prof. T ariniCharan Panda
Prof.Niranjan Barik Prof. Arun Chandra Sahu
Editor Prof. NirajKanti Tripathy
Prof. T araniCharan Kara
Prof. Satyaban Jena
Managing Editor
Dr Rekha Das Prof. Bijay Kumar Parida
Secretary, Odisha Bigyan Academy Prof. Madhumita Das
CONTENTS
Subject Author Page
1. Editorial:
Nuclear Technology with 'Atom for Peace' - Initiative Prof. Niranjan Barik 2
2. Atom for Peace, Not for War Prof. Manashi Goswami 3
3. Radioactive Waste :AHindrance to Nuclear Power Shri Kamala Kanta Jena 8
4. Ancient Indian Astronomy and itslast Modern Heir Prof. Sudhira Panda 14
5. Developmentsin Indian Satellite Technology Prof. N. K. Mahalik 23
and its Applications
6. Towards Sustainable Development with Nihar Ranjan Acharya 26
Vedic Principle of EcologicalHarmony
7. Why Sacred Groves areImportant from Prof. Madhab Chandra Dash 32
Socio-Ecological Point of View ?
8. Green Tea and its Benefits Mrs. Chitrotpala Devadarshini 37
Dr. Birendra Ku Prusty
9. A Brief History of RegionalScience Centre, Bhubaneswar Dr. Jayanta Sthanapati 39
10. Medical Quiz Dr. G. C. Sahoo 47
The Cover Pag e depicts : Atom for Pe ace . Cover Design : Sanatan Rout
EDITORIAL
NUCLEAR TECHNOLOGYWITH 'ATOM FOR PEACE' - INITIATIVE
Every year on 6th and 9th August, history In the field of agriculture, specialized radiation
reminds the World Community about the dreadful tec hniques have bee n used t o pr oduc e superior
power of the atom that devastated Hiroshima and species of crop s and man y other m utant varieties
Nagasaki of Japan on these days in 1945 during the calle d cultiv ars, which include grains such as rice,
last phase of Second World War. As an aftermath barley, wheat, bans lentils and peas; fr uit varieties
awakeningon thisshameful act of self-destruction of such a s ap ples, or an ge s, ban an as, gr ap ef ruit ,
humanity, the International Nuclear Community started po megr an at es, gr ap es; cr op s such as co tt on ,
the 'Atom for Peace' - initiative to develop appropriate sunflower, soybeans etc.; ornament al flowers such
Nuclear Technology for harnessingpower of the atom as ro ses, dah lias, bougainvilleas etc. Besides that,
asa toolfor the benefit of mankind.
foodirradiation involving carefully controlledamounts
Majo rity o f people are well aware of the of ionizing radiations such as beta particles or gamma
contribution of nuclear technology to the production rays to break the DNA-bonds of targeted pathogens
of electricity via commercial nuclear power plants. have improved the shelf -life of many foo d and
But most people are quite unaware about the greater
agricultural products.
im pact of this tec hnology thr ough non -power
applications. T here are many other ways, the peaceful In industrial sectors, radio-active isotopes are
at om h as e nter ed quietly into our lives, oft en used as tracers to study the mixing and flow-rates of
unannounced and in many cases unappreciated and wide range of materials, to locate leaks andto measure
yet serving us in providingfood, clothing, comfort as the rate of wear of engines and plant equipments. As
well as ensuring our health, happiness, safety and tracersisotopesalso play an important part in detecting
security. T his has been possible by harnessing the and analyzing pollutants in the environment. Radio-
power of the radio-isotopes and the radiations for active emissions a re highly p enet rat ive. On the
applications in health care, industry, agriculture and principle of their attenuation property in material
research as well. T hese newapplications continue to
medium, level gauges are used in industries where
make major humanitarian contributionsto the quality
levels of gases, liquids and solids must be checked.
of our lives.A few such applications out of the myriads
of others in practice can be cited here for general Radio-isotope thickness gauges are used in making of
awareness and appreciation. continuous sheets of materials such as paper, plastic
film, metal and glass sheets etc. Density gauges are
Radiation, mainly gamma radiation in high
also used in detergent manufacture. By appropriate
enough quantities, kills micro-organisms, for which
radiation treatment hasbeen the common practice now- exposure to radiation, changesin molecular structure
a-days to sterilize most of the medical equipments, ca n be cr eate d fo r n ew m ate rial dev elo pmen t.
surgical glov es, dr essin gs, ba ndages, syr in ge s, Radiation cross-linked poly-vinyl chloride used for wire
catheters, heart valvesand other devices routinely used andcable insulations, vulcanization of rubber for tyre
during medical procedures. Radiation being a cold production, heat-shrink polymers used for packaging,
processit also sterilizes a range of heat sensitive items wood-plastic composites cured by gamma radiation
such as powders, ointments, solutions, face-creams used as flooring materials are few such examples.
andbiological preparations like bone, nerve, skin etc. Some materials are also created by altering their
usedin tissue grafts. The imaging properties of radio- molecular struct ure to absorb huge amounts of liquid.
isotopes have proved superior to X-rays in nuclear Examples include air-refr esheners, tissue papers,
diagnostic techniques to determine anomalies in heart, sanitary napkins and diapers etc. Finally radiation is
brain, kidneys, lungs, liver, breast and thyroid glands. also used for publicsafety, including airport screening,
Bone and joint disorders along with spinal disorders smoke detectors, crime solving, archeology datingetc.
also benefit directly using radio-isotopes in modern T hus the list of applications of radio-isotopes and
imaging techniques such as Single Photon Emission radiations can literally go on and on which enhance
Com puted Tomo graph y (SPECT ) and Posit ron
our modern life stylethat we have taken for granted.
Emission Tomography (PET ). T herapeutic uses of
radio-isotopesand radiations in the treatment of cancer During the last fifty or more years the challenge to
is widely known, which is improving day by day by harnesspower of atom for humanitarian applications
targeting the canceroustissue only without killing or has been very impressively met which is nothingshort
impairing the healthy tissues. of a wonder.
Prof. Niranjan Barik
e-mail : dr.nbarik@gmail.com
AUGUST, 2014
ATOM FOR PEACE, NOT FOR WAR
Prof. Manashi Goswami
ComeAugust,thewhole world remembers Three other planes had left earlier in order to
two frightful days ofworld history,August 6th ascertain the weather condition over the
and 9th, 1945. The atomic bombings of the possible targets. On the hook in the ceiling of
cities of Hiroshima and Nagasaki in Japan the plane hung the ten- foot atomic bomb
were conducted on these days by theUnited "Little Boy". On 6th August,1945, the first
States during the finalstage of World War II. choice target Hiroshima, was having clear
These two bombings were thefirst and remain weather. At 8:15(am) local time, Enola Gay's
the only use of nuclear weapons in warfare. door sprang open and it dropped the little boy.
By Au gust 1945, the allied Manh attan
project had successfully t ested an atomic
deviceand had produced weapons based on
two alternate designs. A u ranium gun type
atomic bomb (Little Boy) was dropp ed on
Hirosh ima on Aug ust 6,1945, followed by a
Pluto nium implo sion-type bomb (Fat Man)
on the city of Nagasaki on August 9. Within
the first two to four month s of the bo mbing,
The Mushroom Cloud
acute effect killed 90,000 - 166,000 people
Thebomb exploded 1,900feet abovethe
in Hiros h ima and 60,000 - 80,000 in
cit y. The mu shro om cloud itself was a
Nagasaki. During the following months large
number of people died various radiation spectacularsight.A bubbling mass of purple-
effect s and inju ries. gray smoke with a hot red burning core
estimated to have reached a height of 40,000
On the Day
feet. Such was the description of dreadful
At 2.45 amon Monday,August 6,1945 a devastation that tookplaceon 6th August 1945
B -29 bomber plane, the Enola Gay took off at Hiroshima city.
from Tinian, a north pacific island in the
Why Hiroshima
Marinianas ,1500 miles sou th of Japan.
Colonel Paul Tibbets, the pilot nick named TheU.S.A. began in spring 1945studying
B-29 as "Enola Gay"after his mother. Just targets for dropping of the atomic bomb.To
before the take-off the plane's nick name was observe accurately the effect of at omic
painted on its sides. The Enola Gay was bombing, the potential cities required to have
escorted by two other bombers that carried an urban area of at least 5 kmin diameter. On
cameras and avariety of measuring instruments. July 25,1945, an order was issued calling for
Science Horizon 3
AUGUST, 2014
thefirst atomic bomb to be dropped on one of tre mendou s amo unt of energ y. Fo r example
the four cities Hiroshima,Kokura,Niigata & splitting of one atom of uran ium p rodu ces
Nagasaki. The name Hiroshima as the prime aro und 220 M eV o f ene rgy. The fiss ion
target was issued on August 2 . One reason is process becomes self-sustaining as neutrons
that Hiroshima was the only city thought to pro duce d by the splittin g of atom strike
have no Allied-prisoner-of -war camps. On 6th nea rby nuclei a nd produc e mo re fission.
August,the sky over Hiroshima city was clear This is known as chain reaction which causes
hence Hiroshima's fate was destined for nuc lear e xplosion.
destruction.
The Science Behind Atom Bomb
A nuclear explosion is an explosion that
occurs as a result of the rapid release of
energy from high speed nuclear fission or
fusion reaction. The driving reaction may be
nuclearfission,nuclearfusion or a multistage
cascading combination oftwo.
The immens e dest ructiv e power of
atomic weapons is derived from a sudden
release of energy produced by splitting the
nuclei of the fissile elements making up the
bomb's core. TheU.S.developed two types of
fission based atomic bombs during the second
world war.The first "Little Boy" was agun type
weapon with a uranium core. The second
weapon dropped on Nagasaki was called "Fat
Nuclear Chain Reaction
Man" and was an implosion -type device with
a plutonium core. Natural uranium contains very less
amount (0.7%) of fissionable U-235 isotopes
Fiss ion
and rest is U-238 isotopes. When a uranium-
The iso t op es Uran iu m- 235 an d 235 atomabsorbs a neutron and splits into two
Plut onium-239 rea dily un de rgo fiss io n. newatoms , it releases three new neutrons and
Fission occurs when a thermal neutron strikes the sum total of mass lost in the process
the nucleus of either isotope splitting the appears in the form of energy according to
isotope s into fragme nts and rele asing a Einstein's famous Mass-Energy equivalence
4 Science Horizon
AUGUST, 2014
formula E = mc2.Two neutrons do not continue U-238, the isotope often captures the neutron
the chain reaction because they are lost or to become U-239,failing to fission,and thus
absorbed by U-238 atom. However, on an failing to instigate a chain reaction that would
average one neutron does collide with a detonate a bomb. Hencethe first challenge of
neighbouring atomof U-235, which then splits theproject was to determinethe most efficient
and releases again neutrons and someenergy. way to separate and purify U-235 from the
This causes a nuclear chain reaction. overly abundant U-238.
Criticality
In order to detonatean atomic weapon, a
critical mass of fissionablematerial is needed.
This means enough uranium-235 or plutonium-
239 is required to ensurethat neutrons released
by fission will strike another nucleus, thus
prod ucing a ch ain reaction. The mo re
fissionable material is available the more is
thechancethat such an event will occur. Critical
mass is defined as the amount of material at
which a neutron produced by a fission process
will,on an averagecreateanother fission event.
Difference between Little Boy & Fat Man
Little Boy
Little Boy and Fat Man utilized different
Once enough Uranium-235 was obtained
elements and completely separatemethods of
to power the bomb, the bomb was assembled
construction in order to function as nuclear
with agun type design.In this specialdesign an
weapons. Little Boy detonated due to a fission
amount of U-235 is fired at another to combine
chain reaction involving the isotope U-235of
the two masses. This combination created a
uranium, while Fat Man used Pu-239 isotope
critical mass that sets off a fission chain
of plutonium.
reaction to eventually detonate a bomb. The
Little Boy two masses of U-235 had to combine quickly
LittleBoy was powered by theUranium to avoid the spontaneous decay of the atom
isotope U-235.Most Uraniumfound naturally which would cause thebomb to fizzle and thus
in the world exist as U-238, leaving only fail to explode. Little Boy was carrying around
0.7%of naturally existing Uranium as the 64 kg of pure U-235 of which only 0.6 kg was
U-235 isotope. When a neutron bombards on detonated during the explosion.
Science Horizon 5
AUGUST, 2014
Fat Man
Powered by Plutonium, Fat Man could
not use thesamegun-typedesign that allowed
Little Boy to explode effectively. Th e form
of Plutoniumcollected was containing traces
of Pu-240 isotope, as opposed to the desired
Pu-239. Pu-240's higher d ecay rate would
causespontaneous decay beforethe gun type Fat Man
design could bring two masses of plutonium Atom for Peace
toget her. This process lowers the energy It was unfortunate that the atomic energy
involved in theactual detonation of the bomb. beforebeing utilized forthebenefit of mankind
Hence, a new design was constructed at Los was used for destruction of mankind. In 1950s
Alamos laboratory of U.S.A. The newdesign the attention was shifted to harnessing the
used conventionalexplosives around a central power of the atom in a controlled manner to
Plutonium mass to q uickly squeeze and apply the steady heat yield for generating
consolidate Plutonium, increasing pressure electricity through nuclear reactors.However,
and density of the substance. An increased by 1942 the first artificial nuclear reactor,
density allowed the Plutonium to reach its Chicago Pile -1 had been already constructed
critical mass, firing neutrons and allowing at the University of Chicago by a team led by
fissio n chain react ion to proceed. To Enrico Fermi. But theprimary purpose ofthose
det onat e the bomb the exp losiv es were reactors was themass production of Plutonium
ign ited, releasin g a s ho ck wav e t hat isotopes for nuclear weapons. Besides the
compres sed the inner Plu tonium core and military use of nuclear power, there were
led to its explosio n. Fat M an was carry ing politicalreasons to pursue civilian use ofatomic
6.2kg of plut onium, of which only 20% was energy.U.S.A. president Dwight Eisenhower
detonated during explosion. madehis famous ATOM FOR PEACEspeech
to the UN general assembly on December 8,
1953. This diplomacy led to the dissemination
of reactor techn ology to all institu tions
worldwide including those in U.S.A.
Before 1950s, radiation from Radium
was the only source for treatment of cancer.
Nownuclear reactorhas opened up possibilities
for making other elements radioactive. These
6 Science Horizon
AUGUST, 2014
radioactiveisotopes are nowused extensively At present 30 countries worldwide are
in medicine, agricultu re an d in du st ry. operating 435 nuclear reactors providing12.3%
Radioactiveisotopes have helped in diagnosis of the world's electricity. The use of nuclear
and prevention of many critical diseases. They power in domestic and commercial purpose
are of immense use in the field of agriculture has become a reality in France since 1976.
for better production of crops, high yielding France has been still dominating the world in
variety of seeds, pest control and fertilisers. nuclear power with 73.3% share of its total
Radiation alternated vaccine has immunised powerconsumption.After Kudankulamreactor
sheep fromlungwormdiseases. In India under of India being fully operational with almost
UNDP (Un ited Nat io n Dev elo p men t
Programme) collaboration such vaccines are
going to be produced commercially in a
laboratory located in Kashmir Valley. Bhabha
Atomic Research Centre at Trombay is well
known in the world for production of many
useful radioisotopes.It produces near about
325 radioisotopes.
Kudankullan Reactor Centre
1000MW power output,thenumber ofreactors
in India has been raised to 21,with nuclear
power capacity of 5308 MW and nuclear
powersharehas enhanced to 3.5%. Thewhole
BhabhaAtomic Research Centre (Trombay).
world has now realised that nuclear energy is
Perishable food stuffs, if exposed to the ultimate sourceofenergy which can reduce
radiation, are found to remain fresh beyond thegreenhouse gases and save our earth from
their normal time. Hence radiation is used for global warming, which is pushing it to a big
canning of food and preservation. In a tropical catastrophe. So it is well justified that atom
country like India, self- life of fruits and only can bring peace to the world in truesense,
vegetables are short.Small dose of radiation if immensely available energy from its core
prevents sprouting ofpotato and onion while can be judiciously harnessed and utilised for
higherdose can delay the ripening ofmango, the well being of the entire mankind.
apple,banana etc. BARC, Trombay has a semi
Regional Institute of Education,Bhubaneswar- 22
commercial food processing plant. Mob.- 9439615558
Science Horizon 7
AUGUST, 2014
RADIOACTIVE WASTE :
A HINDRANCE TO NUCLEAR POWER
S hri Kamala Kanta Jena
Matt er is made u p of molecules . nuclear reactors in nuclear power plants. A
Molecule is composed of atoms. A water nuclear reactor is a power-generating device
molecule represented by H2O consists of two in which heat is derived froma controlled nuclear
Hydrogen atoms and oneOxygen atom.Atoms reaction.The heat is used to convert water into
are so small that a row of one lakh atoms can its vapour which rotates turbine that produces
accommodate within the thickness of a hair. electricity. We deal with fission reactors to
Atomcarries protons, neutrons and electrons. extract heat in power stations. Electricity
Protons and neutrons are concentrated within generated by nuclear power constitutes 75%
a tinier nucleus, whereas electron cloud makes of the total power generated in France, 50% in
up therest of theatom's overall size. Keeping Switzerland, 30% in Germany, 20% in the
protons and neutrons within such a squashed United States and only 3% in India.
space is possible for the strongest nuclear Radioactive Nuclear Waste
force, which is 1038 (one followed by 38 zeros)
Thermal power plants use coal. Nuclear
times the gravitational force.
power plants use nuclear materials like
Uranium. The leftovers fromtheuse ofnuclear
materials are known as nuclear wastes,which
areradioactive. Uraniumobtained fromnature
contain s only 0.7% of Uranium-235, the
element practically needed for reactors. The
ore undergoes various steps to act as enriched
fuel containing 3% Uranium-235. The fuel
Fig 1 : Nuclear Fissi on and Nuclear Fusion once loaded in a reactor runs for 6 months at
A bigger nucleus can split up into smaller a stretch. When discharged,it is cooled under
nuclei. Splitting up of a bigger nucleus into water at the reactor site for a year or two and
smaller ones as in case of atom bomb is then shipped in shielded barrels either to
known as nuclear fission. Two or morelighter permanent storage facilities or to a chemical
nuclei can combineto create heavier nucleus. reprocessing plant. Nuclear power plants do
Format io n of heav ier n u cleu s d ue t o not pollute the environment by discharging
combination of two ormore lighter nuclei as smoke/ash as fossil fuel plants do, but the
in case of Sun is known as nuclear fusion. radioactive isotopes stillcontained in thespent
Huge amount of energy is released in both the fuelof the nuclear reactors areat stake.Spent
processes.The energy so obtained is known as fuels are highly radioactive, because a large
atomic energy.Atomicenergy is produced by number of radio-isotopes are present in it.
8 Science HorizonAUGUST, 2014
substantial shielding. Gamma rays are the main
hazard to peopledealing with sealed radioactive
materials us ed in in dustrial gauges and
radiotherapy machines.Radiation dose badges
are worn by workers in exposed situations to
detect them and hencemonitor exposure.All
of us receive about 1mSv per year of gamma
radiation from cosmic rays and from rocks.
(d) Neutrons : Neutrons may be emitted
Fig2: Dangerous RadioactiveWastes within Shielded Barrels
from n uclear fis sion and fusion. They are
Types of Nuclear Radiation mostly released by nuclear fission. They are
(a) Alpha particles : Alpha particles are also found from radioactiv e decay, cosmic
helium nuclei consisting of two protons and rays o r particle accelerato rs. Large n eutron
two neutrons. They are emitted fromnaturally- sources are rare, and are u sually limited to
occurring heavy elements such as uraniumand large-sized devices like nuclear reactors and
radium. They are also emitted from some part icle accelerat ors. Th ey are seld om
man-madetransuranicelements and radioactive encoun tered outs ide the co re of a nu clear
wastes.They cannot penetrate theskin, but are reactor. Thus normally they do not make any
dangerous only if emitted inside the body. problem outside the nuclear plants. Fast
(b) Beta particles : Beta particles are fast- neutro ns can be very destructive to human
moving electrons emitted by many radioactive tissue.Neutrons are the only type of radiation
elements including radioactive wastes. They which can transform non-radioactive materials
are more penetrating than alpha particles, but into radioactive mat erials.
easily shielded. The most energetic Beta
particles can be stopped by a few millimetres Dangers of Nuclear Radiations
of wood or aluminum. They can penetrate a When atoms are split, a lot of energy is
little deep into human flesh but are generally released.It sounds innocent enough, but nuclear
less dangerous to human beings than gamma processes produce dangerous radioactive
radiation.Exposure to Beta radiations produces materials having serious long termbiological
an effect like sunburn,but which is slower to effects. They emit penetrating radiations that
heal.The weakest ofthem,such as fromtritium,
can cause damage to the molecules of living
can be stopped by skin or cellophane.
cells. The radiat ions d issociate complex
(c) Gamma rays : Gamma rays are high- molecules ofliving tissues through ionization.
energy beams much the same as X-rays. They Cellular function(s) may be temporarily or
areemitted in many radioactivedecays and may permanently impaired and the cell may be
be highly penetrating. So they require more killed by the effect of nuclearradiations.They
Science Horizon 9AUGUST, 2014
measurement takes into account biological
effects of different types of radiation. Since
the sievert is a relatively large value, dose to
humans is normally measured in millisieverts
(mSv),which is one-thousandth of a sievert.
One gray ofbeta or gamma radiation has
Fig 3 : Effect of Nuclear Radiatio ns on Fish,
Butterfly and Frog one sievert (1 Sv) of biological effect.
induce cancerous growth, cause severe skin One gray of alpha particles has 20Sv of
bu rn s, leu kaemia and d iso rders in t he biological effect.
reproductive, immune, cardiovascular and One gray of neutrons is equivalent to
endocrine systems ofthehuman body.Exposure around 10 Sv.
to radiation has been linked to gen etic
Dose of more than 40 grays severely
mutations and birth defects even upto five
damages the human vascularsystemand causes
gen erat ions . Harmfu l radiations can kill
death. A dose of 1.5 to 10 grays causes
vegetation,fishes and animals.
destruction of human bone marrow, leading to
Radiation-Doses infection and hemorrhage. The injury may
The severity of theinjury depends on the include degeneration or destruction of the
type of radiation, the dose, the rate at which irradiated tissue and the initiation of cancer.
thedose was absorbed,and theradio-sensitivity A human body exposed to nuclear radiations
ofthe tissues involved.In orderto quantify the may have late effects. Themost important late
radiation exposure in our daily lives and to effect of radiation exposure is an increased
assess its potential health impacts, it is incidence of leu kemia and/o r other ty pes of
necessary to establish a unit of measurement. cancers. Statistically significant increases in
The basic unit of radiation dose absorbed in leukemia and can cers of th e thyroid, lung,
living tissue is known as gray (Gy). Onegray and the female breast have been demonstrated
in pop ulations exposed to radiation doses
represents the deposition of one joule of
greater than 1 gray. Currently only the lower
energy per kilogram of tissue.
doses of radiation are effectively used in the
Doses are also measured in rad, 100 medical pract ices.
rads being equal to 1 gray. Rad is defined as
the dose when 1 kg of matter absorbs 0.01
joule of radiation energy. However,neutrons
and alpha particles cause more damage per
gray than gamma or beta radiation. Therefore
another unit, the sievert (Sv)is used in setting
Fig 4 : Effect of Nu clear Radiation s on
radiologicalprotection standards. This unit of Human Child and Fruit
10 Science HorizonAUGUST, 2014
Radiation Doses (mSv/yr) and Effects
(Source : World Nuclear Association)
mSv/yr Effects
2.4 Typicalbackground radiation experienced by everyone
1.5 to 2.5 Average dose to Australian uraniumminers and US nuclear industry workers
Up to 5 Typical incremental dose foraircrew in middle latitudes.
9 Exposure by airline crew flying the New York - Tokyo polar route.
10 Maximumactual dose to Australian uraniumminers.
10 Effective dose fromoneabdomen & pelvis CT scan.
20 Current limit (averaged) for nuclear industry employees and uraniumminers.
50 Former routine limit for nuclear industry employees, now maximum allowable
for a single year (average to be 20 mSv/yr max). It is also the dose rate which
arises fromnatural background levels in several places in Iran, India and Europe.
50 Allowable short-term dose for emergency workers
100 Lowest annual level at which increase in cancerrisk is evident
Allowableshort-termdoseforemergency workers taking vitalremedialactions (IAEA).
130 Long-term safe level for public after radiological incident
170 7-day provisionally safe level for public after radiological incident
250 Allowableshort-termdose for workers controlling the 2011 Fukushimaaccident.
250 Natural background level at Ramsar in Iran, with no identified health effects
350 Criterion for relocating people after Chernobyl accident (for lifetime).
500 Allowable short-termdose for emergency workers taking life-saving actions
680 Tolerance dose level allowable to 1955
700 Suggested minimumdose for maintaining evacuation after nuclear accident
800 Highest level of natural background radiation recorded, on a Brazilian beach.
1000 Short-termexposure may causeafatal cancer many years later in about 5%people
5000 Short-term exposurewould kill about half those receiving it within a month.
10000 Short-term exposure is fatal within a few weeks
Radioactive Waste Management (LLW)generated fromhospitals and industry
Nuclear wastebeing radioactive cannot is suitable for shallowland burial.Intermediate-
be disposed anywhere unlikeother industrial level waste (ILW) contains higher amounts of
wastes.Very lowlevel waste (VLLW) contains radioactivity and requires shielding.High level
radioactive materials at a level which is not waste (HLW) arising from the burning of
con s id ered h armful t o p eo p le or th e uraniumfuel in a reactor is highly radioactive
surrounding environment. Low level waste and hot. It requires cooling and shielding.
Science Horizon 11AUGUST, 2014
Germany,India,Japan, Russia,Switzerland and
UKusually disposethewastes afterreprocessing.
Radioactive wastes remain biologically
hazardous for thousands ofyears, beyond the
span of any human institution.The wastes need
along-term safe storage.Thus thetechnology
Fig 5 : Dispos al of Radioactive Waste in Repository
for waste management should be adequate
enough for thepresent and the futuregenerations
Nuclear power is t he fourth-largest
as well. Permanent but potentially retrievable
source of electricity in India after thermal,
storage in deep stable geologic formations is
hyd roelectric and renewable so urces of
the best solution.The wastes should be stored
electricity. India has 20 nuclear power plants
in well shielded,guarded repositories for later
in operation with 6 nuclear power plants
disposition or may beconverted to very stable
generating 4780 MW electricity. With this
compoun ds, fixed in ceramics or glass,
numberof reactors Indiaproduces 5,000 cubic
encapsulated in stainless steel canisters, and
metres of HLW every year, in addition to
buried far underground in very stablegeologic
thousands of cubicmeters of intermediateand
formations. The life span of radiation may be
low-level nuclear wastes. As on 1st January
reduced using laser.Some nations likeSweden
2014, th ere were 430 n uclear react ors
have started burying wastecontaining ceramic
considered to be in operation in the world
cylinders under sea for better result.
co nt ribu ting 16% o f th e wo rld's to tal
electricity production. With this statistics,the Public Opposition
hugeness of the nuclear waste generated No country in the world has found a
globally every year can be understood. Each permanent solution for proper disposal ofthe
year, nuclear power generation facilities nuclear wastes. Building newplants means the
worldwide produce about 2,00,000 cubic production of more waste with nowhere for it
metres of low-level and intermediate-level t o go . St o ring rad ioact iv e was tes far
radioactive waste, and about 10,000 cubic underground may not put thedangers to an end.
metres of high-level waste including used fuel The phenomenalike earthquakeand volcanic
designated as waste. Used fuel still contains eruptions could jeopardize the safety of a
someof theoriginal Uranium-235 and various nuclear waste repository. The safety of such
plut onium is ot opes. Th is uran ium and rep o sit o ries is t he s ub ject o f pu b lic
plutoniumfromthe wastes can be separated by controversy, especially in the geographic
processing and recycled for re-use in a nuclear region in which the repository is located or is
reactor. It lessens the risk of wastes. Major proposed to be built. For example, opposition
commercial reprocessing plants operate in fromstate residents and questions about the
France,UK, and Russia.Belgium, China,France, geologicstability of the proposed repository
12 Science HorizonAUGUST, 2014
at Yucca Mountain site have helped prolong committed to phase out nuclear power very
govern ment studies. Similarly, a $2 b illion soo n. France cancelled s everal plan ned
repository built in underground salt caverns reactors and was considering the replacement
near Carlsbad, New Mexico, is design ed to of aging nuclear plants with environmentally
storeradioactivewaste fromthe manufacture saferplants. Germany announced plans in 1998
ofnuclear weapons during theCold War. This to phase out nuclear energy. No orders for
repository, located 655 meters underground, nuclear plants have been placed in the U.S.
is designed to slowly collapse and encapsulate since1978. The number of operating reactors
the plutonium-contaminated waste in the salt worldwide has been reduced to 430 this year
beds. For the time being, the dispos al is from 439 in the last five years.
within our control. But this may put us in hot
Conclusion
water in future, if the world would primarily
depend upon nuclear power. Our Kudankulam Global warming and energy insecurity
nuclear power plant in Tamil Nadu has faced promote nuclearpower as aclean and safe way
local opposition for a quart er of the century to curb emissions of greenhouse gases and
and witnessed violent protests in 2012 by the redu ce dependence o n foreign en ergy
local villag ers. resources. But nuclear power generation
pro cess reveals nuclear p ower to b e a
Phasing Out Nuclear Power
dangerous and expensive formof energy that
In 1950's when people were thinking to poses serious risks to human health and national
reduce air pollution, nuclear energy was security. We have double-crossed the nature.
perceived as acheap,plentifuland clean energy Often we forget that nature could support our
ofthe future. Even theutility industry believed need but not our greed and do injustice with
th at nu clear p ower wo uld rep lace t h e
nature.We have polluted our abodewe livein,
increasingly scarce fossil fuels and lower the because of o ur impatience and lack of
cost of electricity. People also favoured the
env iron ment al co ns ciou s nes s b efore
mission hoping at leastthetransition ofnuclear
implementing a new technology. Even today,if
power from the field of war to peaceful uses.
we stop all the emissions completely, it will
But the calculations went wro ng. High
take not less than 1000years to get a pollution
construction costs,strict building and operating
free environment back. Therefore, we should
regulations, and heavy expenditure towards
look ten times before we leap a step forward.
permanent and safewastedisposal makenuclear
Wemust think often feasiblesafe methods for
power plants much more expensive than the
sustainabledisposalof radioactivewastebefore
powerplants that burn fossilfuels. Thenuclear
setting up anuclear power plant. Otherwise,we
power industry has come under growing
may hoist with our own petard one day.
pressureto cut operating expenses and become
moreeffective. Many countries have planned OES(A), Lecturerin P hysics,
Bhadrak Autonomous College, Bhadrak, Odisha- 756100
to phase out nuclear powercompletely.Sweden Email: kkjena1@gmail.com
Science Horizon 13AUGUST, 2014
ANCIENT INDIAN ASTRONOMYAND ITS LAST MODERN HEIR
Prof.S udhira Panda
Our beautiful Earth and unending blue Sid dhan ta was written by Brahma and
sky are always with us, since birth till death, pu blis hed b y Narad a. Similarly "S oma
and surprisingly we neverget fed up with them. Siddhanta" was written by Soma (Moon)and
Ratherthey remain with us as source ofmystery published by some unknown ancient sage.
and wonderment forever. Fromthe beginning However, Lomasha Siddhanta was written and
of the civilization people tried to unveil this published by the great sage Lomasha himself
mystery ofthe Earth, the sky and the heavenly and Arya Siddhanta was written and published
bodies including Sun. Inheriting the oldest by thegreat astronomerAryabhatta.
civilization of the Earth, many ancient great Aryabhattathe inhabitant of Pataliputra
souls of Indiaresearched on them and passed (formerly Kusumapur and presently Patna in
their knowledge to the common people. The Bihar) wrote Arya Siddhanta at the age of 23
h all o f fame includ es lu min aries like in 476 A.D. For t he first t ime he discovered
Aryabhatta, Barahamihir, Bhaskaracharya, that theday and night takes place as the effect
Brahmagupta, Ganesh, Sudhakar Dwibedi, of the earth's ro tation aro und its own axis.
Satananda,Kamalakar Bhatta, Kutanacharya, However, he couldn't prove it with s trong
Ellacharya,Bapudev Sastri and Madhab Mishra. logic. As a resu lt he was insulted b y the
They had their own Siddhants. Besides those commo n people. He could establis h his
man y mo re migh t h ave con trib u ted equat ion throug h experiment and th eory.
significantly to astronomy whose names were Howev er, he is recogn ized as t he first
not record ed in t he his tory, s ince t heir astro nomical experimentalist in India.
Siddhantas were not published.
Barahamihira was on e amo ng t he
Hindu astronomy is as old as the Vedas. nabaratna(nine Gems) in thecourt of the Great
The name of the great astronomers and their King Bikramaditya. In 505 A.D. he published
Siddhants are mentioned in history. Mainly his works Brihat Sanhita, Pancha Sidhantika
five Siddhants arewell-known in India, namely, etc. He was respected as a writer and unique
Surya Siddhanta, Brahma Siddhanta, Soma collector. In Brihat Sanhita he compared
Siddhanta, Lomasha Siddhanta and Arya Siddhantas with his own observation regarding
Siddhanta. There is a myth about Surya Sun's movement in ecliptic. He for the first
Siddhanta,which says that theSiddhantaswere time fab ricat ed in struments for celest ial
the advices of the Surya vanshi to the demon observation. He also gave a mathematical
Maya. So also the myth goes that Brahma interpretation to thoseobservations.
14 Science HorizonAUGUST, 2014
Brahmaguptaof Rewarin 628 A.D. wrote just a supporting workto "Surya Siddhanta".
Brahmasphuta Siddhanta at the age of 30. In It rejects th e idea of Bhaskarachary in
this bookhe made some corrections to theold "Siddhanta Siromoni". Because of many
Siddhantas.The Hindu astronomy only came complicacies this scripture didn't become
fromBrahmasphuta Siddhanta.Brahmagupta popular. However, among allscriptures in the
was also a famous algebraist and algebra was history only Surya Siddhanta, Siddhanta
spread to Europe through Arabic countries Siromoni and Bra hma Sidd hant a were
later on. referred to for the astronomical calculations.
Pandit SudhakarDwibedi wrote Ganak Thenext 400 years
Tarangini or Manjala Grantha in t enth was the dark age of
century. Satananda, the great mathematician Indian astronomy. The
from (Jagannath) Puri, wrote the scripture vacuum was filled by a
Vaswati in 1099 A.D.. He for the first time person fromthe remote
introduced decimals in his as tronomical corner of Odisha who
calculation. The advent of Bhaskara from for a long time was not
Sahyadri (some place in Western mountain known even in his own
range), marks an watershade in the history of nativestate. Khandapada,
ancient astronomy.His great work, Siddhanta his birth place was a backward hilly feudal
Siromoni is one of the standard treatises of s tate in th e th en Od is h a p rov in ce.
the Differential Calculus. Karnakutuhala is Mahamahopdhaya Samanta Chandrasekhar
ano ther imp ortant work of Bhaskara in Singha Harichandan Mohapatra was born in
astronomy. With the death of Bhaskara, the 1835A.D. of Lunar Pousa Krushnaastami.
living breath of mathematical science and The Political Background of Odisha
astronomy parted fromIndia.
Before 1947 A.D. Odisha was under
In seventeenth century King Jayasingh Britis h Ru le. It was d iv id ed into two
of Jayporeestablished many observatories in catego ries, namely Khasmah al and Gad ajat.
north India by taking the help of Euclid Khasmahal consis ted of the coastal region
Geometry and it is he who translated Euclid while Gadajat, consisted of 24 feudal states.
Geometry into Sanskrit. Khasmahals were directly ruled by the British
KamalakarBhatta, the grandson ofPandit while Gadajat regions were ruled by the local
Srikrushna Daibabit a courtier of Samrat chieftains directly res ponsible to the British
Jahangirhailed in thesixteenth century.However, government. Kh andapada was one among
his scripture "Siddhanta -Tatwa-Bibeka" is those 24 Gadajats.
Science Horizon 15AUGUST, 2014
Chandrasekhar was the only son of Samanta was observing the stars and
Shyamabandhu Singha, the youngest son of planets of clear autumn night sky, sometimes
seventh king Narasingha MardarajaBhramarbara from his courtyard or by making holes and
Ray. As a member of the royal family he was setting bamboo pipes in the thatched roof.
known as Samanta. He was named Chandra While observing the position and movement
Sekharas his parents got theson by worshiping of pole star, Ursha measures, Cashiyopia,
Lord Siva after the death of their two daughters Constellions, Venus,Jupiter, Mars, Mercury
and a son.As per superstition his parents sold and their respective rising and setting times,
him to a Muslim (pathan) priest to save him henoticed that there wereerrors in calculations
fromdeath for which he is popularly known as in old sidhantas. He decided to make the
PathaniSamanta. correction, for which he worked from age
The interest in the sky was almost an fifteen to twenty-three. In those days, he used
inborn quality with Pathani Samanta. In his to observethe heavenly bodies in the night sky
childhood days hewas interested in observing and were recording his findings on palmleaves
the vultures flying and hovering in the sky. in the daytime. He also verified the statement
With passage of time, his interest shifted to in Atharva Veda that the distance fromsun to
the astronomical observation of stars and earth is one hundred fifty four times more than
planets.He got the preliminary knowledge of the distance frommoon to earth.
astronomy fromhis father Syamabandhu Singh
Samanta's findings contradict those old
Samanta. The astrono mical scriptures he
geocentric planetary models followed by all
referred to were mostly written in Sanskrit.
Indian astronomers, the models given by
ThereforeChandrasekhar learnt Sanskrit from
Ptolemy and the Helicentricmodern planetary
his guru Ananda Khadenga and studied the
mo del of Newton -Kepler. Acco rding to
works on algebra, trigonometry and lilabati
Samanta, all the planets except Earth are
(one chapter on algebra in the scripture
revolving around the Sun and the Sun with
Siddhanta Siromoni of Bhaskara) written by
otherplanets revolves around stationary Earth.
the ancient mathematicians.At the age of 15,
he could master all the theories behind the The model is smilar to that of Tycho Brahe.
calculation of the movement of the heavenly Surprisingly all thefindings are almost similar,
bodies.Hestarted calculations to predetermine since all of themused the relative co-ordinates
the time of sunrise, sunset, solar eclipse and in their respective calculations.
lunar eclipse and its time span. For these He has recorded his findings in his
observations he mostly used his self-made scripture Sidhanta Darpan. The important
instrument Gola Yantra (Armilary Sphere). corrections are mentioned in Tables 1 & 2.
16 Science HorizonAUGUST, 2014
Table - 1 : Sidereal Periods in mean Solar Days
Eurpoean Surya-Siddhanta Siddhatna-S iromani S idhantaDarpan
Astronomy Difference Difference Difference
Sun 365.25637 356.25875+.00238 365.254843+.000206 365.25875+.00238
Moon 27.32166 27.32114+.00001 27.32114-.00052 27.32167+.00001
Mars 686.9794 689.9975+.0181 686.9979+.0185 686.9857.0063
Mercury 87.9692 87.9585+.0107 87.9699+.0007 87.9701+.0009
Jupiter 4332.5848 4332.3206-.2642 4332.2408-.3440 4333.6278+.0430
Venus 224.7007 224.6985-.0022 224.9679-.0028 224.7023+.0016
Saturn 10759.2197 10765.7730+6.5533 10765.8152+6.5955 10759.7605+.5408
Table - 2 : Comparison of the Mean Inclinations of the Orbits of the Planets to the Ecliptic
Eng. Ast. Surya-5 Siromani Darpana
Mercury 7 0' 8" 5 25 6 55 72
Venus 3 53 35 2 46 36 3 23
Mars 1 51 2 1 30 1 50 1 51
Jupiter 1 18 41 10 1 16 1 18
Saturn 2 29 40 20 2 40 2 29
Moon 5 8 48 4 30 4 30 59
Oliquity of the Ecliptic 23 27 24 0 24 0 23 30
Samanta discovered three irregularities Planet Venus moves over the solar disk
in Moon's motion.Hehad mademeasurements seen as small pebble during a transit . Last
and made threecorrections to the old siddhants transit of venus was in 1882 which was not
as regards the motion of the Moon. He named vis ible to India. Acco rding to saman t's
those irregularities as (i) Tungantar(Eviction), prediction next transit ofVenus was due on 8th
(ii) Paksh ika (Variat io n) , (iii) Dig amsa June 2004.
(Annualequation).
It is int eresting t o know that t he
Saman ta reco mmen ded variou s instruments which Samanta Chandrasekharwas
corrections to be incorporated as to themean using to observe the heavenly bodies or to
position of planets for obtaining their true measurethe height and distance of thedistant
positions and accordingly had prescribed for objects, were improvis ed using cheaply
thecomputations of astronomical predictions available natural materials such as bamboo
which are supposed to remain valid for chipsand woodensticks.They were sodisarmingly
thousands of years. simple in construction that the modern man
Science Horizon 17AUGUST, 2014
can hardly accept those as instruments.Those aredrawn across celestial sphere to determine
instruments are locally known asMana Yantra, position, motion and their respective rising
Golayantra, Dhanuryantra, Shanku, Surya and setting times ofheavenly bodies throughout
Gh adi , C ha payant ra, Go lardh aya ntra, the year.
Chakrayantra and Swayangwaha Yantra. Dhanuryantra: It is an instrument which
These instruments are briefly introduced below. was fabricated by SamantaChandraSekhar in a
Mana Yantra: It is aT-shaped instrument few minutes by the help of coconut strings.He
made of two sticks, one standing vertical to improvised it impromptu to prove his point in
the other. Former way of an answerto the question "What's the
one got holes or angular distance between Mars and Venus ?"
marks in each unit. The gentleman (Prof Roy), well- versed in
The observer can astronomy, was actually testing him. Pat came
d et ermin e t h e the reply from Samanta, "6°".
height and distance
of a distant object
simultaneously by
observing the object insidethose holes taking
two readings fromdifferent positions. This is
the instrument which made Samanta popular
among the common people ofOdisha sinceits
working principle is very simple based on
rudimentary geometry.
Golayantra : It is a replica of earth
surrounded by the sky. In other words it
represents a globesurrounded by the celestial
s ph ere. As we
knowthe globe is Sanku: It is difficult to believe in this
used to locate a age of highly sophisticated machines and
place on the earth instruments, that this is an instrument. It is a
through imaginary single stick standing vertically upward on the
lat it ud e an d plane ground. Fromtheposition and length of
longitudelines on its shadow wecan determinethe exact directions
it. Similarly oftheplace, latitudeoftheplace and declination
imag in ary lin es and longitude of Sun throughout the year.
18 Science HorizonAUGUST, 2014
Surya Ghadi: It was fab ricated by Chakrayantra: It is also
Samanta Chandra Sekhar and established by aSundialfabricated bySamanta
Prof, Jogesh Chandra Roy in Ravenshaw following the similar principle
College (now Ravenshaw University). It has of parallel axis to axis of
been showing correct local time since 1902. rotation of earth and plane
parallelto the equatorial plane.
Swayambahayantra : It is an instrument
consisting of a container
filled with water and an
indicatorplate connecting
Surya Ghadi with apot floating on the
Chapayantra: It gives informations on wat er. Co nt in uo u s
time,date and month with equal accuracy like evacuation of water with
the highly complex and expensive Jantarmantar a constant rate indicates
observatory located at New Delhi. constant time interval in
t he ind icat o r p late.
Samanta was keeping this instrument all the
time with him, since it can work in both day
and night time independent of sky conditions
(whether cloudy or clear, sunny or night).
Pathani Samanta, the rare genius would
have been lost to the world had he not been
discovered by Radhanath Roy.Radhanath Roy
was then a school inspector. He was visiting
Golardhayantra : It was designed by theschools ofKhandapada. In passing it may
Saman ta by usin g the b e ment io ned t hat Radh anath Roy is
lower part of the circular considered as the founder of modern odia
water pot and a stick of literature.Before his discussion with Samanta,
length equivalent to the likethe localpeople,Roy mistook Samanta as
radius of the pot inserted a mere ast rolo ger. After retu rnin g from
vertically upward at its Kh an dap ad a Rad han ath Roy talked to
center.This shows equally Madhu sudan Rao (another precurs or of
accuratetimeas the other modernism in Odia literature), and they
sundials. together wroteto Mahesh Chandra Nyaratna
Science Horizon 19AUGUST, 2014
theprincipal ofSanskrit College, Calcuttaand
invited himto Odisha to test the knowledgeof
Pathani Samanta. After long discussion with
Pathani Samanta at Cuttack M. C. Nayaratna
was co nvin ced abou t Saman ta's sou nd
knowledge in Sanskrit. He assigned Prof.
Jogesh Chandra Roy 'the professor of science'
in Ravenshaw College, Cuttack the task of
testing thescientific authenticity of Samanta's
work. Prof. Roy not only tested Samanta's
knowledgebut hebecame adisciple ofSamanta
to learn astronomy. SamantaChandra Sekhar's
achievements written in palm leaf scripture
took the form of a book by the combined
effort of Radhanath Roy, Madhusudan Rao,
Siddhanta Darpan
Mahesh Chandra Nyaratna and Prof. Jogesh
ChandraRoy. It was published with the financial Siddhanta Darpana contains 24 chapters
support from the kin g of Athamallik Sri with 2506 slokas , out of which 2290 verses
MahendraDeo and theking of Mayurbhanj Sri composed by Samanta and 216 citations from
Ramachandra Deva in 1894 A.D. All total Rs earlier authors. It contains 55 tables, each
1250/- had been spent to get 5000 copies of tables contains morethan 50 numberssometimes
SidhantaDarpan printed in Debanagari script. given up to five places in sexagesimal system.
The introduction to the Siddhanta Darpan Allthis shows his amazing computational skill
running into 61 pages was written in English and ability to carry out enormous calculations
by Prof. Jogesh ChandraRoy. The copies were using largenumbers without any aid.
distributed in England (700 copies), France Two articles were published in the
(300 copies), Germany (1000 copies) and international journals, Nature Vol-59, March
America (800 copies) in 1899 A.D. The title 1899,No.l532, pp. 436-437 and Knowledge
Mahamahopdhyawas conferred upon himby Vol-XXII, January-December 1899, pp. 256-
the British Government on 28th Sept. 1993 258 regarding Samanta Chandra Sekhar and
A.D. in aDarabar specially arranged at Cuttack Siddhanta Darpan . Excerpts from Nature and
(thethen state capitalof Odisha)as Samantaan Kno wled g e (abo v e men tion ed is su es )
orthodoxHindu refused on religious ground respectively are given in following tables and
to travel to Calcutta to receive the award. paragraphs.
20 Science HorizonAUGUST, 2014
Summary of contents of Siddhanta Darpan
Chapter Name of the section Contents No. of
No. slokas
1 Madhyamadhikara Description of time 55
2 Description of Bhaganaetc. 25
3 Mean planet position 77
4 Various corrections 57
5 Spastadhikara True planet position 221
6 Finer corrections 161
7 Triprasnadhikara Gnomos etc. 95
8 Lunar eclipse 87
9 Solar eclipse 78
10 Parilekhadescription 137
11 Transit of planets 111
12 Alignments of planets 93
13 Rising and setting of planets 85
14 Phases of Moon 68
15 Description of Mahapata 71
16 Goladhikara A set of question on Sun and Earth 80
17 Description of earth 160
18 Description of earth (contd.) 176
19 The celestial sphere 124
20 Description of instruments 112
21 Some deeper questions 251
22 Kaladhikara Description of year etc. 77
23 Prayer to Purusottam(Lord Jagannath of Puri) 5 6
24 Conclusion 154
25 Additions Transit of venus 5
Anyone who reads the very interesting fashion himself and where the time honored
introduction of sixty one pages that Prof.Roy clepsydra supplied the place of the sidereal
has attached to this Sanskrit work will regret clock. The only assistance he seems to have
very much his inability to fathomthe work that had were the similar rough observations of
follows.For therein is contained the results of Bhaskara (born 1114 A.D.) and some still
the patient and industrious inquiry of one who olderobservers. Prof.Roy compares the author
unaided by the accumulated knowledge of very properly to Tycho.But we should imagine
western astronomers, resolutely set himself himto be greater than Tycho, for without same
to solve the problems of celestial mechanics assistance, without encouragement of king and
by the aid of such instruments as he could the applause of his fellows, he has advanced
Science Horizon 21AUGUST, 2014
his favorite sciencequite as effectively as did fromhis equals in positions,because he shock
theDanish astronomer. It is especially curious off the aristocratic prejudice against star gazers
to note that thesystemat which Chandrasekhar and fortune-tellers. He had no one to encourage
ultimately arrived, and the explanations he himin his pursuit, and no notice was taken of
offers of it, bears a v ery con sid erab le his work. Our Government could only confer
resemblanceto that Tycho taught. The author upon him an empty title which he had never
has never been able to convince himself that coveted. Geniuses are like delicate plants,
the Earth turns on its axis, or that goes round never plentiful anywhere, and depend upon
the Sun, but to the planet, he assigned tender care for growth and development and
heliocentric motion, much as Tycho did. fertility. Let me therefore hope that the past
Knowledg e: " Th e eph emerid es neg lect of his c ount rymen may yet be
computed from his elements are seldommore compensated and that betterday may yet down
than a few minutes of arc in error, whilst the upon our old dandy crippled observer of
Bengali almanac may be in error as much as heavenly body.{KATAK, 1889}"
four degrees. To Hindus, for whom their However, Prof. Roy's wish and effort
re ligious obs erva nces are re gula ted by was agreed by the Government to give pension
astronomical configurations,this work,by none Rs . 50/- p er mo nt h to Chan dras ekha r.
of themselves, a strict follower of the secret Unfortunately the first and the last instalment
la ws o f th eir re ligion , an d co nd uc te d ofthe pension was spent for his funeralat Puri
th roug hout so lely by trad itional Hin du on 11th June 1904.
methods, is of the highest importance, as it Acknowledgement:
removes the confusions which had crept into
The author is thankful to Sri Sailaj Rabi
theirsystem, without in the least drawing upon
for the critical reading of the manuscript and
the sources of western science. But the work
is of importance and interest to us and to the valuablesuggestions.
westerners as well. It demonstrates the degree References:
ofaccuracy which was possible in astronomical 1. P. C. Naik, Pathani Samanta Instrument Kiits, The
Book Point, Bhubaneswar, (2008).
observa tion before t he invention of the
2. Pandit C. S . Mishra, Samanta Chandra Sekhar
telescope,and it enables us to watch ,as it were (Jibani), {Odia}, Pravati Press, Cuttack (1932)
one of the astronomers of hoary, forgotten 3. Mahamohopdhaya Samant Chandra Sekhar
Singha Harichandan Mohapatra, Siddhanta Darpan,
antiquity actually as his work before us today. Girish Bidyaratna Press, Calcutta, (1899).
It will not be out of context to mention 4. J. C. Roy, IntroductiontoSiddhanta Darpan, Siddhanta
Darpan, Giris h Bidyaratna press, Calcutta (1899).
the opinion of Prof. Jogesh Chandra Roy in 5. Orissa Bigyan Academy, Poster set on Life and
the last paragraph of his introduction to work ofPathani Samanta, Bhubaneswar, (2004).
Siddhanta Darpan . That is " And what did our
Department of Mathematics,
Indian Tycho receive ? He met with sneers Ravenshaw University, Cuttack-751003
22 Science HorizonAUGUST, 2014
DEVELOPMENTS IN INDIAN SATELLITE TECHNOLOGY
AND ITS APPLICATIONS
Prof N. K. Mahalik
Introduction of all these? He has threesensors, the eyes to
Twent y-firs t cent ury is an age of see, the ears to hear and the skin to feel the
satellites. All modern activities depend on heat or cold. For seeing things he needs some
satellites of one typeor other. They provide light such as solar energy or some artificial
information on earth resources (forests, water, light.Thus some sort of radiation is necessary.
agricu lt u re, min eral reso urces , t errain Human eyes can see the objects within the
condition etc) at the shortest possible time visible range of the spectral band of the
and at a lower cost.They give informations on electromagnetic radiation i.e. within the wave
weatherconditions,natural and other hazards. lengths of 0.04 micron to 0.07 micron. In
Anything happening on Earth and beyond the satellite remote sensing the same model is
Earth are quickly transmitted to the human followed where the electromagnetic radiation
society by communication satellites. Most of (EMR) in all the spectral bands are used by
the human activities are now conducted on- artificial eyes (sensors , radio meters and
line. With the development of satellite the transponders) placed aboard the satellite
Earth has become a small place and easily
accessible to all. With a computer at hand,
most things can be done, sitting at home.
What is Remote Sensing
In a broader sense it is sensing natural
resources, meteorological events and human
and other events and activities froma distance
without going to the place where the actual Fig.1
things occur or happen. The simplest modelof
remote sensing is observation of things by
human beings shown in Fig.1.
The figure shows how a human being
senses everything before him.He sees forests,
water bodies, human settlements,cloud cover,
rainfall,congregation of people, theiractivities,
and temperature effects, though his vision is
limited to a smallarea. What is the mechanism Fig.2
Science Horizon 23You can also read
