Science & Tech. for IAS Main’s 2017-18
Updates 
By- TRILOK SINGH & Dr. Ravi P. Agrahari (Scientist in IIT Delhi)
Q.1 What are Neutrinos? How Neutrinos will help understand the various processes of Earth? What are its other significances?
Ans. Neutrinos, first proposed by Swiss scientist Wolfgang Pauli in 1930, are the second most widely occurring particle in the universe, only second to photons, the particle which makes up light. In fact, neutrinos are so abundant among us that every second, there are more than 100 trillion of them passing right through each of us — we never even notice them. This is the reason why INO needs to be built deep into the earth — 1,300 metres into the earth. At this depth, it would be able to keep itself away from all the trillions of neutrinos produced in the atmosphere and which would otherwise choke an over-the-ground neutrino detector. Neutrinos have been in the universe literally since forever, being almost 14 billion years old — as much as the universe itself. Neutrinos occur in three different types, or
flavours – ve, vì and vô. These are separated in terms of different masses. From experiments so far, we know that neutrinos have a tiny mass, but the ordering of the neutrino mass states is not known and is one of the key questions that remain unanswered till today. This is a major challenge INO will set to resolve, thus completing our picture of the neutrino. Neutrinos are very important for our scientific progress and technological growth for three reasons. First, they are abundant. Second, they have very feeble mass and no charge and hence can travel through planets, stars, rocks and human bodies without any interaction. In fact, a beam of trillions of neutrinos can travel thousands of kilometres through a rock before an interaction with a single atom of the rock and the neutrino occurs. Third, they hide within them a vast pool of knowledge and could open up new vistas in the fields of astronomy and astrophysics, communication and even in medical imaging, through the detector spin-offs. Further, they have many more significance such as- First, neutrinos may have a role to play in nuclear non-proliferation through the remote monitoring of nuclear reactors. The plutonium-239 which is made via nuclear transmutation in the reactor from uranium-238 can potentially be used in nuclear devices by terrorist groups.
Using appropriate neutrino detectors, the plutonium content can be monitored remotely and used to detect any pilferage. Neutrino research can be our answer to ensure that no terror group ever acquires nuclear weapons. Second, understanding neutrinos can help us detect mineral and oil deposits deep in the earth. Neutrinos tend to change their “flavour” depending on how far they have travelled and how much matter they have passed through in the way. Far more importantly, we believe that this same property might help us detect early geological defects deep within the earth, and thereby might be our answer to an early warning system against earthquakes. This is where an area of Geoneutrinos is applicable. First found in 2005, they are produced by the radioactive decay of uranium, thorium and potassium in the Earth’s crust and just below it. Rapid analysis of these Geoneutrinos by neutrino monitoring stations — a process called Neutrino Tomography — could provide us vital seismological data which can detect early disturbances and vibrations produced by earthquakes.
Third, as we now know, neutrinos can pass right through the earth. They may open up a faster way to send data than the current ‘around the earth’ model, using towers, cables or satellites. Such a communication system using neutrinos will be free of transmission losses as neutrinos rarely react with the atoms in their path. This can open up new vistas for telecom and Internet services. Some scientists further believe that if there is any extraterrestrial form of life, neutrinos will also be the fastest and most trusted way to communicate with them. Fourth, neutrinos are the information bearers of the universe — which are almost never lost in their path. India’s effort in studying neutrinos at INO may help us unravel the deepest mystery of the universe — why there is more matter than antimatter in the universe. Some scientists believe that formidable neutrino research can help us understand dark matter. Dark matter and dark energy make up 95 per cent of the universe, far more predominant than ordinary matter in the universe — but we hardly understand it. Neutrinos are the only way to detect this great mystery which may completely alter our understanding of the universe and physics. Searches for this dark matter can only be carried out in INO. We believe that the neutrino is our mode of access to some of the most unimaginable technologies, and therefore, with INO, India is poised to take its rightful place at the helm of neutrino research.
Q.2 What is INO? What are its objectives? Discuss its benefits for India?
Ans. The India-based Neutrino Observatory (INO) Project is a multi-institutional effort aimed at building a world-class underground laboratory with a rock cover. The underground laboratory, consisting of a large cavern of and several smaller caverns, will be accessed by a tunnel. INO project is jointly supported by Department of Atomic Energy (DAE) and Department of Science & Technology (DST) with DAE acting as the nodal agency. The observatory will be located underground so as to provide adequate shielding to the neutrino detector from cosmic background radiation. Tunnel construction is very common and will not have any impact on environment, water sources or dams in the region. The operation of INO will have no release of radioactive or toxic substances. It is not a weapons laboratory and will have no strategic or defense applications. The objective of INO is to conduct basic research on the elementary particle called neutrino. Presently 21 research institutes, Universities and IITs from all over the country are involved in this project. INO is expected to galvanise interest in basic science research in the whole country and particularly in and around Theni and Madurai districts of Tamil Nadu. Science students across the country will have opportunity to pursue cutting edge research in the field of particle physics while being located in India. This project for experiment on neutrinos is very important for our scientific progress and technological growth for three reasons. First, they are abundant.
Second, they have very feeble mass and no charge and hence can travel through planets, stars, rocks and human bodies without any interaction. In fact, a beam of trillions of neutrinos can travel thousands of kilometres through a rock before an interaction with a single atom of the rock and the neutrino occurs. Third, they hide within them a vast pool of knowledge and could open up new vistas in the fields of astronomy and astrophysics, communication and even in medical imaging, through the detector spin-offs. The experiment has potentials to benefit us largely by playing a role in nuclear non- proliferation through the remote monitoring of nuclear reactors, understanding neutrinos can help us detect mineral and oil deposits deep in the earth, They may open up a faster way to send data than the current ‘around the earth’ model, using towers, cables or satellites and neutrinos are the information bearers of the universe and neutrino research can help us understand dark matter which is a great mystery yet to solve. In this way the INO project experiment on Neutrinos is our mode of access to some of the most unimaginable technologies, and therefore, with INO, India is poised to take its rightful place at the helm of neutrino research.
Q.3 What is Mitochondrial gene therapy? Explain the process of Three Parent Embryo developments?
Ans. Mitochondrial Replacement Therapy, a ground-breaking technique that uses genetic material from three different people to prevent certain inherited — and hitherto untreatable — genetic diseases from passing from the mother to her offspring, received a resounding mandate on Tursday in the House of Commons. Britain thus becomes the first country in the world to approve such a procedure, considered the only hope for women who carry defective mitochondria to have healthy children. Mitochondrial gene therapy, the technique, would allow women who have mutations in the DNA of their mitochondria, the organelles that provide chemical energy for cells, to have genetically related children who don’t carry the mutations. It is controversial, however, because it would modify the DNA of an embryo in a way that could be passed on to future generations. People who have faulty mitochondria can experience a variety of symptoms, including heart problems, seizures, and blindness. The Symptoms are variable, however, and the condition can be difficult to diagnose. Some babies born with defective mitochondria die within months. Other people don’t show any symptoms until much later in life. The process of three parent baby involves following steps-
• It will treat women with mitochondrial disease (a range of inherited diseases caused by defective mitochondria, the elements in the cell that generate energy).
• The healthy nuclear DNA will be removed by patient’s egg cell leaving behind faulty mitochondrial DNA.
• Patient’s Nuclear DNA will be transplanted to donor’s egg with healthy mitochondrial DNA
. • Therefore, by replacing the dysfunctional mitochondria carried by a woman who wishes to conceive with the healthy mitochondria of a donor. The egg is then fertilised with the partner’s sperm through IVF.
• The embryo thus created is one technically cleansed of the mutated mitochondrial DNA that the mother originally carried.
• The reconstructed egg cell fertilsed with sperm in the lab and implanted into patient, and thus the resulted embryo will have three genetic parents.
Q.4 Explain Big Bang theory? Recently scientists have discovered a Big Black Hole, what are the implications of this discovery on Big Bang theory?
Ans. The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment. According to the standard theory, our universe sprang into existence as “singularity” around 13.7 billion years ago. What is a “singularity” and where does it come from? We don’t know for sure. Singularities are zones which defy our current understanding of physics. They are thought to exist at the core of “black holes.”
Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density (a mathematical concept which truly boggles the mind). These zones of infinite density are called “singularities.” Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something – a singularity. Where did it come from? Why did it appear? We don’t know. After its initial appearance, it apparently inflated (the “Big Bang”), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe.
It continues to expand and cool to this day and we are inside of it: incredible creatures living on a unique planet, circling a beautiful star clustered together with several hundred billion other stars in a galaxy soaring through the cosmos, all of which is inside of an expanding universe that began as an infinitesimal singularity which appeared out of nowhere for reasons unknown. This is the Big Bang theory. Recently, Scientists say they have discovered a black hole so big that it challenges the theory about how they grow. Scientists said this black hole was formed about 900 million years after the Big Bang. But with measurements indicating it is 12 billion times the size of the Sun, the black hole challenges a widely accepted hypothesis of growth rates.
“Based on previous research, this is the largest black hole found for that period of time. Current theory is for a limit to how fast a black hole can grow, but this black hole is too large for that theory. The creation of super massive black holes remains an open topic of research. However, many scientists have long believed the growth rate of black holes was limited. Black holes grow, scientific theory suggests, as they absorb mass. However, as mass is absorbed, it will be heated creating radiation pressure, which pushes the mass away from the black hole. Basically, we have two forces balanced together which set up a limit for growth, which is much smaller than what has been found. Discovery is still going on further and scientists expects more black holes to be observed as the project advances.
Q.5 What is spectroscopy or Raman Spectroscopy? How it helped finding the reason behind changing colour by chameleons?
Ans. Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, by a prism. Later the concept was expanded greatly to comprise any interaction with radiative energy as a function of its wavelength or frequency. Spectroscopic data is often represented by a spectrum, a plot of the response of interest as a function of wavelength or frequency. Raman Spectroscopy is a vibrational spectroscopy technique used to collect a unique chemical fingerprint of molecules. Each molecule has a different set of vibrational energy levels, and the photons emitted have unique wavelength shifts.
Vibrational spectroscopy involves collecting and examining these wavelength shifts and using them to identify what is in a sample. Different peaks in the spectrum correspond to different Raman excitations. Raman Spectroscopy produces information about a cell. It tells you about the state of the cell, and possibly whether or not it is virally infected and whether or not it is cancerous, precancerous, or not cancerous. It can be used to study HIV and malaria. A laser is shone at the cell and the information needed is extracted from the spectra obtained. Raman spectroscopy relies on the scattering of light, and with a little help from Raman Spectroscopy, Swiss scientists have found out the answer to an endlessly intriguing evolutionary poser.
It turns out that chameleons have a mobile lattice of Nanocrystals on the surface of their skin, which come together and disperse there by shifting the wavelength of light reflected by the reptile. These nanocrystals of different shapes, sizes and organizations are distributed in two layers of skin cells called iridophores (iridescent light-reflecting cells).
While the upper layer of iridophores is responsible for rapid colour change achieved by a shift in spacing of Nanocrystals in a triangular lattice, the deeper layer of cells broadly reflects light, especially in the near-infrared range. With an increase in distance between Nanocrystals in excited male panther chameleons, iridophores shift their selective reflectivity from short (blue) to long (red or infrared) wavelengths, causing the corresponding shift from green to yellow/orange skin
Q.6 Why there is a larger interest of astronomers in study of Pluto and Kuiper belt? How can Pluto help studying the history of the Earth?
Ans. The fact that space is an ideal laboratory for scientists, its vastness enables fundamental experiments, orders of magnitude more accurate than on Earth, eliminating the influence of gravity, atmosphere, seismic noise and other interactions. These astronomical observations help us learn about the microscopic and macroscopic structure of the universe. Lunar and planetary missions, over the years, have provided extremely valuable scientific data on the formation and evolution of planets and their moons.
That Pluto was discovered in 1930 as the ninth planet of the Solar system is well-known. Twenty years after its discovery, astronomers postulated the presence of the Kuiper Belt, comprising a vast collection of icy objects beyond the orbit of Neptune, in which Pluto itself was a member. The first Kuiper Belt Object (KBO) was discovered in 1992 — throwing doubt over Pluto’s status as planet — and since then observers have found more than 1,000 KBOs, with diameters ranging from 50 kms to almost 2,400 kms. The International Astronomical Union in 2006 chose to classify Pluto and the recently discovered large Kuiper Belt Objects as dwarf planets.
The Kuiper Belt contains a sizable supply of ancient, icy and organic material that are held in deep freeze, and that were left over from the birth pangs of the planets, containing evidences of the distant past. Because of this, planetary scientists are keen to learn more about Pluto and its moons, Charon (the largest), Styx, Nix, Kerberos and Hydra, and other objects in the Kuiper Belt. Scientists believe that Pluto’s atmosphere loses a lot of mass into space. The thermal energy of typical molecules in the upper atmosphere is sufficient to escape Pluto’s gravitational hold, a process called hydrodynamic escape.
The same may have been responsible for the rapid loss of hydrogen from Earth’s atmosphere early in our planet’s history, making Earth suitable for life. Pluto is the only place in the solar system where we can study hydrodynamic escape on a planetary scale today. Another important connection between Pluto and life on Earth is the likely presence of organic compounds more complex than the frozen methane on Pluto’s surface and water ice inside the dwarf planet. Recent observations of smaller KBOs show that they are also most likely to harbour large amounts of ice and organic substances.
Such objects are considered to have routinely strayed into the inner part of the solar system billions of years ago, collided with Earth, and helped to seed the young Earth with the building blocks of life. Given all these scientific motivations, it is understandable why there is increased scientific interest in Pluto and the Kuiper Belt. The first dedicated spacecraft platform to explore Pluto at close quarters was NASA’s New Horizons. Valuable insights into the origin of the outer solar system and that of planet and satellite systems are expected to be discovered from the data sent by NASA’s New Horizons. This will raise scientific fervour all around.
Q.7 What do you mean by encryption? Do you think the provisions of recent draft encryption policy of government were against freedom of speech and expression or it was necessary to curb cyber crime? Give your opinion.
Ans. Encryption, a process in which digital messages are scrambled so they can’t be accessed by anyone other than those they are meant for, is a means to ensure freedom of expression and to keep information secure in the digital world. The thing to appreciate most about the government’s draft encryption policy, brought forth with the ostensible goal of ensuring privacy and promoting Internet security, was the speed with which it was withdrawn. There was little in the draft that was true to the goal; the provisions, instead, had enough in them to harm the cause. The aliases one uses in the social media environment can be a fun way to keep casual users from identifying you.
But that isn’t enough. The digital world also comprises criminals and terrorists, and repressive regimes. Some of them would not only want to know who you are and hack into your information and messages but also have the means to do so. Encryption keeps intruders at bay. When the draft was released, experts and netizens could quickly figure out that the provisions had the real potential to undermine encryption. One of the provisions sought to give the government access to encrypted data that rest with government departments (save the sensitive ones), corporates and individuals. Another provision required users to store all encrypted communications for a period of 90 days.
The backlash had its effect; the draft was withdrawn the very next day. Although the draft was withdrawn soon, but while the draft goes back to the drawing board, it is important to realise that any debate on encryption isn’t going to be easy and straightforward. Bigger battles await us. The world over, administrations have sought weaker encryption standards or backdoor access to Internet products. This is a public safety vs privacy issue. So it needs to be tackle very carefully. Administrations cite public safety as the reason for asking for encryption access but Granting governments the power to tap into every message and item of information and store them, will have the potential to make the system extremely vulnerable.
On the other hand for the freedom of speech and expression, it is a seemingly universal position among technologists that there is no special access that can be made available only to government authorities, even ones that, in principle, have the public interest in mind. Therefore, Access to encrypted data should, be provided as an exception, not as a rule, there should be proper policy to tackle both the issues of internal security and public privacy.
Q.8 What is Astrosat? What is its significance for India?
Ans. Astrosat, is India’s first space observatory, recently the Indian Space Research Organisation (ISRO) has launched its first dedicated multi wavelength space observatory into space. Though there have been scientific missions in the past by ISRO – Aryabhata, SROSS, Youthsat, IRS-P3, GSAT-2, Chandrayaan-1 and Mars Orbiter Mission, this is the first time ISRO is launching a space observatory into space. Though ASTROSAT may be similar to the NASA’s Hubble Space Telescope, the former is about 10 times smaller and cannot be compared to the Hubble, which is versatile.
Besides NASA, space agencies of the European Union, Japan and Russia have launched similar facilities into the space. The 1,513 kg-weighing cuboid-shaped satellite would be eventually fine-tuned into 650 km above the Earth’s surface. The satellite can perform simultaneous multi- wavelength observations of various astronomical objects. The sun and star sensors, besides the gyroscopes, would provide orientation reference to the satellite, which has a mission life of five years.
ASTROSAT aims at understanding the high energy processes in binary star systems containing neutron stars and black holes, to estimate magnetic fields of neutron stars, to study star birth regions and high energy processes in star systems lying beyond the Milky Way galaxy. The mission also intends to detect new briefly bright X-ray sources in the sky, to perform a limited deep field survey of the Universe in the ultraviolet region. The capability to cover the full spectrum of wavelength simultaneously is the unique feature of ASTROSAT.
Hence, a space-based observatory like ASTROSAT will be of immense value to researchers based in India. Ground-based telescopes and the space observatory will complement each other. Further, with the successful launch of the space observatory, Astrosat, the Indian Space Research Organisation has put India in a select group of countries that have a space telescope to study celestial objects and processes. Besides providing an opportunity to build world-class instruments, Astrosat will present an ideal platform for researchers in these institutions.
Q.9 Discuss the IRNSS project of India? On what principle it is being developed? What are its implications?
Ans. IRNSS (Indian regional navigation satellite system) is similar to the global positioning system (GPS) of the US (24 satellites), Glonass of Russia (24 satellites), Galileo of Europe (27 satellites) and China’s Beidou (35 satellites). While GPS and Glonass are fully functional global systems, the Chinese and the Japanese systems are offering regional coverage and Europe’s Galileo is yet to become operational. India successfully put its fourth navigation satellite, IRNSS-1D, into orbit, bringing the country a step closer to having its own satellite navigation system. It’s a GPS-like regional satellite-based navigation system being developed by India.
But unlike the US-operated Global Positioning System (GPS), or the Russian GLONASS, which have global coverage, IRNSS will focus on the region — up to 1,500 km beyond India’s boundaries. IRNSS is planned as a constellation of seven satellites. Three will be placed in geostationary orbit; the other four in geosynchronous orbit. The three geostationary satellites will appear fixed in the sky, while the four geosynchronous satellites will appear to move in the figure of ‘8’ when observed from the ground. The IRNSS will provide two types of services – standard positioning service and restricted service. The former is provided to all users and the latter is an encrypted service for authorised users. With this success, India moved closer towards joining a select group of nations possessing their own satellite navigation system.
Named the Indian Regional Navigation Satellite System (IRNSS), the system consists of a constellation of seven satellites of which four – IRNSS-1A, IRNSS-1B, IRNSS-1C and IRNSS-1D – have been put into orbit till now. The IRNSS system is unique as it consists of only seven satellites while other systems have more than 20 satellites. It is claimed that India can replace the US GPS with the Indian system when full fledged operations begin. The fully operational system is expected to provide accurate position information service to users across the country and the region, extending up to an area of 1,500 km. The navigation systems strategic application is clear that IRNSS will be used for defense purposes as well.
Further, IRNSS will be used for terrestrial, aerial and marine navigation, disaster management, vehicle tracking and fleet management, integrated applications in mobile phones, mapping and geodetic data capture, etc. Also, it will be used in terrestrial navigation aid for hikers and visual and voice navigation for drivers. But the crucial use will be for Indian armed forces, which can rely on assured positional data during hostilities. Most modern weapon systems like guided missiles and bombs use navigation systems for targeting. An indigenous system like the IRNSS will ensure reliable development and execution of such capabilities.