Latest news with #Hoyle-Narlikar
Indian Express
21-05-2025
- Science
- Indian Express
Daily subject-wise quiz : Science and Technology MCQs on Polar Satellite Launch Vehicle, HeLa cells and more (Week 111)
UPSC Essentials brings to you its initiative of subject-wise quizzes. These quizzes are designed to help you revise some of the most important topics from the static part of the syllabus. Attempt today's subject quiz on Science and Technology to check your progress. 🚨 Click Here to read the UPSC Essentials magazine for May 2025. Share your views and suggestions in the comment box or at With reference to the Hoyle–Narlikar theory of gravity, consider the following statements: 1. Mach's principle states that the mass of every object in the universe is affected by its interaction with every other object was central to the Hoyle-Narlikar gravity theory. 2. Einstein was greatly inspired by the principle and incorporated it into his theory. 3. The Hoyle-Narlikar theory of gravity proposed a 'creation field' (C-field), a hypothetical negative-energy field responsible for the continuous creation of matter. Which of the statements given above is/are correct? (a) 1 and 2 only (b) 2 only (c) 2 and 3 only (d) 1, 2 and 3 Explanation — Jayant Narlikar, an eminent Indian astronomer, science communicator, and Padma Vibhushan recipient, died at the age of 87. — He was best known for proposing the Hoyle-Narlikar theory of gravity (also known as conformal gravity), which he developed in 1964 with English astronomer and professor Fred Hoyle. The hypothesis intended to improve upon Albert Einstein's General hypothesis of Relativity, which was published in 1915. — Mach's principle, which states that every object's mass is changed by its interaction with every other object, is central to the Hoyle-Narlikar gravity theory. The notion profoundly intrigued Einstein, but he was unable to incorporate it into his theories. Hence, statement 1 is correct and statement 2 is not correct. — The Hoyle-Narlikar gravity theory also proposed a 'creation field' (C-field), which is a hypothetical negative-energy field that is responsible for the continual formation of matter. This helps to explain the steady-state cosmology, which holds that the universe has no beginning and would exist indefinitely. Hence, statement 3 is correct. — The Hoyle-Narlikar theory of gravity was not widely accepted, particularly following the discovery of cosmic microwave background (CMB) radiation in 1965. The CMB, also known as an echo or shockwave of the Big Bang, is a cooled remnant of the first light to flow freely throughout the cosmos. Therefore, option (a) is the correct answer. Which of the following missions of the Polar Satellite Launch Vehicle (PSLV) have failed? 1. EOS-07 mission 2. Inaugural flight in 1993 3. C-39 mission Select the correct answer using the codes given below: (a) 1 only (b) 2 and 3 only (c) 1 and 3 only (d) 3 only Explanation — The Indian Space Research Organisation's (ISRO) 101st satellite launch failed. The Earth observation satellite EOS-09 was aboard the PSLV-C61 (Polar Satellite Launch Vehicle). — This was the 63rd PSLV launch. Since their introduction in the 1990s, PSLVs have only failed twice – the first during the inaugural flight in 1993 and in 2017, when the C-39 mission was unsuccessful. Here is why PSLVs have become reliable for India's Space agency and what happened during the two failed missions. — ISRO has three types of launchers: the PSLV, the Geosynchronous Satellite Launch Vehicle (GSLV), and the Geosynchronous Satellite Launch Vehicle Mk-III (LVM3). Variants are chosen based on the cargo weights and the orbit they will reach. — PSLV: Satellites used for navigation, mapping, or other functions must be transported into space by launch vehicles or rockets such as the PSLV. The rockets feature powerful propulsion systems that create massive amounts of energy, which is required to lift large things such as satellites into space while resisting the Earth's gravitational pull. Therefore, option (b) is the correct answer. With reference to the stars, consider the following statements: 1. Regardless of duration, all stars survive by maintaining a balance between two competing forces: the inward pull of gravity and the outward pressure produced by nuclear energy. 2. In the dense core of a star, nuclear fusion converts hydrogen into helium. 3. When a star's fuel is exhausted, gravity takes over — and then the nature of its death depends entirely on its mass. How many of the statements given above are correct? (a) Only one (b) Only two (c) All three (d) None Explanation — The stars in the sky seem to shine forever, but they too are subject to lifespans determined by their mass and internal physics. Some last for billions of years and others are transitory in comparison, with far shorter lifetimes. — Regardless of duration, all stars survive by maintaining a balance between two competing forces: the inward pull of gravity and the outward pressure produced by nuclear energy. Hence, statement 1 is correct. — In the dense core of a star, nuclear fusion converts hydrogen into helium. This process occurs when extremely high temperatures and pressures allow atomic nuclei, which are ordinarily repelled by positive charges, to collide and fuse, releasing massive energy. That energy heats the surrounding gas, resulting in thermal and radiation pressure that prevents gravitational collapse. Hence, statement 2 is correct. — This beautiful explanation of how stars glow was not previously known. Only in 1938, while taking a train to Ithaca, New York, did German-American physicist Hans Bethe scribble down the equations detailing how nuclear fusion powers stars, a breakthrough that earned him the Nobel Prize and resolved one of astrophysics' most pressing mysteries. — But even fusion has its limits. When a star's fuel is exhausted, gravity takes over — and then the nature of its death depends entirely on its mass. Hence, statement 3 is correct. Therefore, option (c) is the correct answer. Consider the following statements about HeLa cells: 1. They were the first successfully cloned human cells. 2. These cells contributed to the identification of the Bovine Papillomaviruses (BPV) as the primary cause of many types of cervical cancer. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2 Explanation — The HeLa cell line is one of the most important cell lines in the history of medical science and has been the foundation for some of the most significant advances in this field. — HeLa cells were the first successfully cloned human cells, and Jonas Salk used them to test the polio vaccine. Hence, statement 1 is correct. — Furthermore, they contributed to the identification of the human papillomavirus (HPV) as the primary cause of many types of cervical cancer, including the one that killed Lacks, and were instrumental in the development of the HPV vaccine, which earned its creator, Harald zur Hausen, the Nobel Prize in Medicine in 2008. Hence, statement 2 is not correct. Therefore, option (a) is the correct answer. With reference to the JN.1 variant of COVID, consider the following statements: 1. It is a sub-lineage of the Omicron variant. 2. This variant is distinguished by its heightened transmissibility and potential to evade immune responses, even in the vaccinated population. 3. JN.1 is most likely to affect the elderly individual and those with underlying health conditions. Which of the statements given above are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3 Explanation — The JN.1 variant is not entirely new, it is a sub-lineage of the Omicron variant that has been circulating globally for some time. — This version is distinguished by its heightened transmissibility and potential to evade immune responses, even in the vaccinated population, according to Dr Harish Chafle, senior consultant, intensivist chest physician, bronchoscopist, and sleep disorders expert at Gleneagles Hospital in Parel, Mumbai. Hence, statement 2 is correct. — JN.1 is a sublineage of the Omicron type that is currently being closely monitored by the World Health Organisation. Hence, statement 1 is correct. — JN.1 is most likely to impact people with low immune systems, the elderly, and those who have pre-existing health and healthy adults may also get the virus, but they are likely to recover without significant consequences. Hence, statement 3 is correct. Therefore, option (d) is the correct answer. Daily Subject-wise quiz — History, Culture, and Social Issues (Week 111) Daily subject-wise quiz — Polity and Governance (Week 111) Daily subject-wise quiz — Science and Technology (Week 110) Daily subject-wise quiz — Economy (Week 110) Daily subject-wise quiz — Environment and Geography (Week 110) Daily subject-wise quiz – International Relations (Week 110) Subscribe to our UPSC newsletter and stay updated with the news cues from the past week. Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X.
Indian Express
21-05-2025
- Science
- Indian Express
UPSC Key: Steady State Theory, Shirui Lily festival, and India-UK FTA
Important topics and their relevance in UPSC CSE exam for May 21, 2025. If you missed the May 20, 2025, UPSC CSE exam key from the Indian Express, read it here. Syllabus: Preliminary Examination: General Science Mains Examination: General Studies-III: Achievements of Indians in science & technology; indigenization of technology and developing new technology. What's the ongoing story: Jayant Narlikar, who had contributed immensely to the development of an alternative model of the universe along with his mentor Fred Hoyle, passed away Tuesday morning in Pune. He was 87. Ailing for some time, he had had a fall two weeks ago and had to be operated upon last week. Key Points to Ponder: — What is the Big Bang theory? — What is the steady-state theory of the universe? — What is cosmic microwave background (CMB) radiation? — What is the Hoyle–Narlikar theory of gravity (also known as conformal gravity)? — What are the various theories associated with the formation of the universe? — What are the challenges in the Big bang theory? Key Takeaways: — The Big Bang theory suggests that the universe has a definite beginning, and a possible end. In contrast, the steady state theory, which was the mainstream theory in the 1950s and 1960s, maintains that the universe has always been the way it is, without any beginning or an end. — The idea has become less popular over time, with mounting evidence that supports the Big Bang theory. But Narlikar remained unconvinced. — Acknowledging that he was in a small minority, he argued in his autobiography 'A Tale of Four Cities' that there was still enough evidence to 're-examine the situation'. — The Hoyle-Narlikar theory, as it came to be known, on the steady state universe was just one such idea. In the process of formulating their model, the two also came up with an alternative theory of gravity, by modifying Einstein's general relativity. — Then there was their work on cosmological red-shifts, the fact that light coming from far-away objects appears shifted towards longer wavelengths, corresponding to the red end of the visible spectrum. Narlikar questioned the accepted understanding that the red-shifting was caused mainly by the relative motion of the source. — Narlikar did, eventually, return to India after a few years, where he trained several generations of astrophysicists and built institutions like IUCAA. — He delved into science fiction, writing short and long stories in Marathi and English, many of which became part of the school curriculum. He pursued science popularisation, and campaigned against superstition and pseudo-science. Do You Know: From Explained: Narliakar's challenge to the Big Bang — The Hoyle-Narlikar theory produced evidence to support what is known as the steady-state theory of the universe. It is an alternative theory of the universe. — Unlike the Big Bang theory that suggests a definite beginning, and possibly an end, to the universe, the steady-state theory maintains that the universe has always been, and would continue to be, the way it is — infinite in extent, without a beginning or an end. It acknowledged an expanding universe, which was experimentally verifiable, but proposed that the universe was able to maintain a constant density by continuously creating new matter. — Born in 1938 in Kolhapur, Maharashtra, Narlikar was a young PhD student at Cambridge University in the early 1960s, when he produced a series of influential works in cosmology. He did so under the guidance of Hoyle, who had come up with the steady-state theory of the universe in collaboration with Hermann Bondi and Thomas Gold. — Incidentally, Hoyle is also the one who coined the term 'Big Bang', referring to that theory in a rather dismissive manner in a radio interview in 1948. — Hoyle and Narlikar instead worked to explain the steady-state theory. One of their key ideas in their hypotheses was the constant creation of new matter in the universe. This was important for the model of the universe that they proposed. — Despite the elegant mathematics that Narlikar had produced, the steady-state theory slowly lost out, with the emergence of new observations that fit the Big Bang model better. One of the most prominent discoveries in this regard was that of cosmic microwave background (CMB) radiation in 1965. — Narlikar, while acknowledging the growing evidence in favour of the Big Bang, maintained that the evidence was still not unambiguous, and was based on several unproven assumptions that were open for challenge. He considered himself amongst the minority that believed that sufficient evidence existed to re-examine the situation. Other Important Articles Covering the same topic: 📍How renowned cosmologist Jayant Narlikar helped build the steady-state theory of the universe 📍Astrophysicist Jayant Narlikar passes away: What is the Hoyle–Narlikar theory of gravity? Previous year UPSC Prelims Question Covering similar theme: (1) Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of universe? (2012) 1. Detection of microwaves in space 2. Observation of redshift phenomenon in space 3. Movement of asteroids in space 4. Occurrence of supernova explosions in space Select the correct answer using the codes given below: (a) 1 and 2 (b) 2 only (c) 1, 3 and 4 (d) None of the above can be cited as evidence Syllabus: Preliminary Examination: Current events of national and international importance Mains Examination: General Studies-III: Role of external state and non-state actors in creating challenges to internal security. What's the ongoing story: Moving to rally global support for India's war against terror emanating from Pakistan, members of the all-party delegations – three teams start their foreign visits Wednesday – will seek to dispel Pakistani misinformation on Operation Sindoor, expose Islamabad's duplicity on countering terror, explain India's stand on the Indus Waters Treaty and underline the country's 'new normal' in response to cross-border terrorism. Key Points to Ponder: — What is the purpose of sending delegations to other countries? — How important is international cooperation in fighting against terrorism? — India's retaliatory response demonstrates a credible shift from passive restraint to active deterrence. — What do you understand by this statement? — What is hyphenation and dehyphenation in international politics? — This is not a clash of equals but of a rules-based state and a revisionist actor. What does this mean? Key Takeaways: — Three delegations, headed by JDU's Sanjay Kumar Jha, Shiv Sena's Shrikant Shinde and DMK's Kanimozhi, were briefed by Foreign Secretary Vikram Misri Tuesday. They were told that they will have back-to-back meetings with people from the government (Ministers, MPs and other lawmakers), think tanks, academics, journalists, civil society and others. — 'Our ambassadors and missions abroad have already started working on lining up the meetings,' a delegation member said. — JDU's Jha, who is heading the team visiting Japan, South Korea, Indonesia, Malaysia and Singapore, said the key message to be conveyed to these countries is that 'India has had enough'. Editorial Nirupama Rao writes: What makes this face-off with Pak structurally different is China's embedded role — The recent bout of hostilities between India and Pakistan has once again exposed the fragility of deterrence in South Asia. This time, however, the conflict cannot be framed solely as a bilateral flashpoint. — The United States, returning to its well-worn role of crisis manager, has momentarily revived the India-Pakistan hyphenation that New Delhi has long worked to dismantle. More consequential, though, is the increasingly visible footprint of China in Pakistan's military posture. — The conflict may have started on the Line of Control, but it now plays out in a strategic triangle, with each vertex holding different stakes and tactics. — India's retaliatory response has delivered tactical benefits. It demonstrates a credible shift from passive restraint to active deterrence. — The reappearance of hyphenation in global discourse, particularly through American statements seeking to 'own the ceasefire', is a diplomatic regression. For over two decades, India has sought to decouple its international positioning from Pakistan, leveraging its economic scale, democratic governance, and global partnerships. — India must engage diplomatically but reject frameworks that reduce its global profile to regional conflict management. The message must remain clear: This is not a clash of equals but of a rules-based state and a revisionist actor. — What makes this confrontation structurally different is China's embedded role. Beijing is not merely a diplomatic shield for Pakistan but a material enabler. Pakistan's current air capabilities are heavily influenced by Chinese platforms. Strategic planners must absorb this reality: Pakistan no longer acts alone, and China no longer stays outside. — Ultimately, this is not a moment of collapse but one of recalibration. India is confronting a new strategic geometry: Crises are triangular, platforms are shared, and narratives are contested as much as borders. The US will remain a tempering actor, but not an arbiter of truth. China will remain a silent catalyst. Pakistan, emboldened by both, will remain a spoiler. — India's task is to respond when needed, restrain when possible, and reinforce its role as a power whose stability is not defined by others' volatility. In conflict, as in diplomacy, maturity lies not in escalation, but in the control of the terms of engagement. Do You Know: — Hyphenation refers to this tendency to link the two countries together in policy decisions and treat them as a single entity. The hyphenation of India and Pakistan-often written as 'India-Pakistan' is premised on several factors, including shared history, similar geography, and conflict over Kashmir, among others: both nations 'share the federal parliamentary republic government system, along with a mixed economy. India and Pakistan's natural resources are also comparable. — De-hyphenation is a form of foreign policy where a country keeps diplomatic ties with two or more countries with conflicting interests, without letting the conflicts prioritize one country over another. The policy allows countries to hold independent relations with countries otherwise distrustful or hostile towards each other while treating each country as a single entity rather than as a part of a conflict with the other countries. Other Important Articles Covering the same topic: 📍Mediation, Kashmir & trade: Delhi rebuts Trump claims point by point Syllabus: Preliminary Examination: Current events of national and international importance Mains Examination: General Studies-I: Indian culture will cover the salient aspects of Art Forms, literature and Architecture from ancient to modern times What's the ongoing story: The Shirui Lily festival returns to Manipur on Tuesday (May 20) after a two-year pause because of the long-drawn conflict in the state. This will be the first major tourism festival to be hosted by the state since the start of the conflict in May 2023, making safety concerns and elaborate security arrangements an integral part of the preparations this year. Key Points to Ponder: — Learn about the conflict in Manipur — What are the important cultural festivals celebrated in northeast India? — Which is the state flower of Manipur? — Which are the main tribal communities in Manipur? — What are the special characteristics of the Shirui Lily? Key Takeaways: — The Shirui Lily Festival is organised by the Manipur government's Department of Tourism. First held in 2017, it is one of two major tourism festivals organised by the state government. — While it is named after the Shirui Lily, or the Lilium mackliniae, recognised as the state flower of Manipur, the other major festival is named after the Sangai, or the Manipur brow-antlered deer, recognised as its state animal. — The Shirui Lily festival coincides with the blooming season of this rare flower. Held in Manipur's Ukhrul district, which is home to the Tangkhul Naga community, the event is designed as an eco-tourism festival to raise awareness about the Shirui Lily and to promote tourism to the hills of Ukhrul. — The Shirui Lily is endemic to the upper reaches of the Shirui Hill range in Ukhrul district at an elevation of 2,673 m above sea level. While locals had long been familiar with the plant — calling it the 'Kashsong Timrawon' after Timrawon, the daughter of mythical goddess Philava who resides and protects the hills of Shirui — in 1946, botanist Frank Kingdon-Ward identified it and gave it its scientific name. The name, Lilium mackliniae, draws from his wife Jean Macklin's name. — Over the years, this already endangered species has faced further threats to its habitat. Do You Know: — The five-day-long Yaoshang festival, Manipur's version of Holi, is celebrated every year on the full moon of Lamta (February-March) of the Meitei lunar calendar. — Yaoshang begins just after sunset followed by Yaosang Mei thaba, also known as Burning of the Straw Hut. Children visit neighbours to ask for monetary donations, called nakatheng. — Yaoshang, unlike Holi, is celebrated with a traditional twist in Manipur. During these five days Manipur comes alive with sporting events during the day and traditional 'thabal chongba' dance in the night. — The thabal chongba is a traditional dance of the Meitei, where boys and girls gathered in an open ground and dance in a circle. But these days thabal chongba is performed throughout the month of Lamta. Other Important Articles Covering the same topic: 📍Yaoshang festival begins in Manipur 📍Hornbill Festival 2024 Previous year UPSC Prelims Question Covering similar theme: (2) Consider the following pairs: (UPSC CSE 2018) Tradition State Chapchar Kut festival Mizoram Khongjom Parba ballad Manipur Thang-Ta dance Sikkim Which of the pairs given above is/are correct? (a) 1 only (b) 1 and 2 (c) 3 only (d) 2 and 3 Syllabus: Preliminary Examination: General issues on Environmental Ecology, Biodiversity and Climate Change – that do not require subject specialisation Mains Examination: General Studies-III: Conservation, environmental pollution and degradation, environmental impact assessment What's the ongoing story: Saurabh Rathore, Abhijit Abhyankar, Somnath Baidya Roy, and Ankit Singhal write: Everybody has their favorite way of travelling. Usually, the choice of the mode of transport is driven by convenience, comfort, and cost. But things are changing around the world for a completely different reason. There is growing interest in what experts call a 'modal shift' — moving people and goods from roads and flights to railways — that could have a big impact on the environment, traffic, and even the economy. Key Points to Ponder: — What is the contribution of road transport to the emission of greenhouse gases? — What are the major greenhouse gases emitted by road transport? — Understand the pros and cons of road transport and rail transport — What is the national rail plan? — What is a carbon credit? — How can rail transport help in reducing carbon emissions? — A modal shift from road to rail is crucial for India, which is one of the world's largest GHG emitters. Analyse. Key Takeaways: — This matters because cars, buses, and trucks are significant sources of CO2 and other greenhouse gases (GHG) that cause global warming. In fact, transport causes nearly a quarter of the world's energy-related carbon emissions. — Road transport is the biggest culprit, whereas rains are much cleaner. For example, trains produce only about 19 grams of carbon dioxide for each passenger per kilometre — compared to 63 grams for buses, 123 grams for aeroplanes, and 148 grams for cars. Freight carried by train is also much more efficient. — Despite the environmental benefits, rail use is going down worldwide. Between 2007 and 2021, the share of freight moved by train fell from 51 per cent to 40 per cent globally. For passengers, the share dropped from 12 per cent to 8 per cent. — This loss is mainly because road transport is growing fast, especially in countries like India and China. If this trend continues, emissions from the transport sector in lower-income countries could cause a 16 per cent rise in GHG emissions. — The European Union is setting an example with policies to move freight from roads to rail or ships. It aims to shift 30 per cent of road freight to rail or ship transport by 2030 and over 50 per cent by 2050. China is trying to shift freight transport to rail and has already seen less road traffic and a cleaner environment as a result. — India has one of the largest railway networks in the world, and many people and goods already travel by train. However, the shift toward road transport is also happening here because improvements in infrastructure have made it easier to travel by road. — The National Rail Plan aims to boost the freight modal share of railways to 45 per cent by 2030 with significant investments in Dedicated Freight Corridors. A similar plan is needed to increase the passenger modal share of rail. — The Delhi Metro alone is claimed to have removed over five lakh vehicles from the road daily in 2021, cutting CO2 emissions by at least 23.82 grams per km traveled. In Mumbai, the metro and monorail modal share is projected to rise from 2 per cent to 36 per cent, reducing motor vehicle use from 35 per cent to 24 per cent. — A modal shift from road to rail is crucial for India, which is one of the world's largest GHG emitters, with 14 per cent coming from the transport sector alone. India plans to attain net zero status by 2070, which will require drastic cuts in GHG emissions from all sectors, including transport. — India can also earn carbon credits by proving that the modal shift is reducing emissions through more rail use. These credits can be sold internationally to help fund more green projects. — Shifting transportation from roads to rail is not just about trains but about building a cleaner, safer, and sustainable future. India has a huge opportunity to lead this change, reducing emissions while boosting its economy and improving daily life. Do You Know: — Carbon dioxide emissions from India's transport sector could be reduced up to 71 per cent by 2050 if high-ambition strategies are adopted on three key parameters – electrification, improving fuel economy standards, and switching to cleaner modes of transport and mobility, said a new study by World Resources Institute (WRI) India. — The transport sector accounted for 14 per cent of total energy-related CO2 emissions in 2020, 90 per cent of which was driven by road transport, which remains the most carbon-intensive. — Out of this 90 per cent, two-wheelers contributed about 16 per cent, cars about 25 per cent, buses 9 per cent, freight light-duty vehicles (LDVs) 8 per cent, and freight heavy-duty vehicles (HDVs) 45 per cent (the highest). Other Important Articles Covering the same topic: 📍With high targets, CO2 emissions from transport sector could be slashed up to 71% by 2050: Study UPSC Prelims Question Covering similar theme: (3) Which of the following statements are correct about the deposits of 'methane hydrate? (2019) 1. Global warming might trigger the release of methane gas from these deposits. 2. Large deposits of 'methane hydrate' are found in Arctic Tundra and under the seafloor. 3. Methane in atmosphere oxidizes to carbon dioxide after a decade or two. Select the correct answer using the code given below. (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3 Syllabus: Preliminary Examination: General Science Mains Examination: General Studies-III: Achievements of Indians in science & technology; indigenization of technology and developing new technology. What's the ongoing story: At 95, he was fit and active enough to be re-inducted as member of Atomic Energy Commission (AEC) earlier this year. But age finally caught up with M R Srinivasan on Tuesday. Key Points to Ponder: — What is India's nuclear program? — What are Pressurised Heavy Water Reactors? — Which was India's first research reactor? — What is the status of India's nuclear program? — What is the contribution of M R Srinivasan to India's Nuclear program? Key Takeaways: — Among the first generation of nuclear technologists in India, Srinivasan was one of the key people who built the country's nuclear power programme. — Joining the Department of Atomic Energy (DAE) in 1955 at the age of 25, Srinivasan rose to become its Chairman in 1987 and also headed the AEC. A mechanical engineer, his most important contribution was in the refinement and adaptation of Pressurised Heavy Water Reactors, which went on to become the backbone of nuclear power in India. — Srinivasan was part of the team that built Apsara, India's first research reactor in the 1950s, and was involved with every nuclear power plant built thereafter. — Srinivasan had become the head of the Nuclear Energy Board in 1984. The Board managed and operated all nuclear power plants before it was transformed into the Nuclear Power Corporation of India Limited (NPCIL) in 1987. Srinivasan was the obvious choice for the position of its founder-director. — 'Picked by Homi Bhabha himself, he played a pivotal role in the setting up of India's very first nuclear power plant at Tarapur in the late 60s. Later he led the team that established India's extensive nuclear power complex at Kalpakkam.' Do You Know: Three-stage nuclear programme → STAGE 1: Pressurised Heavy Water Reactors (PHWRs) use natural uranium-based fuels to generate electricity, while producing fissile plutonium (Pu239), which can be extracted by reprocessing the spent fuel. It uses heavy water (deuterium oxide) both as a coolant and moderator. The programme has been supplemented by the construction of imported Light Water Reactors (LWRs). → STAGE 2: It involves setting up Fast Breeder Reactors (FBRs) of the kind at Kalpakkam, using plutonium-based fuels, which can enhance nuclear power capacity, and convert fertile thorium into fissile uranium (U233). Reprocessing of the spent fuel is vital for efficient utilisation of the plutonium inventory. → STAGE 3: The third stage will be based on the ThU233 cycle. U233 produced in the second stage can be used for the third stage of the power programme, which consists of advanced thermal and fast breeder reactors, for long-term energy security. The Advanced Heavy Water Reactor (AHWR) is proposed for this. Now, the use of molten salt reactors is also seen as an option. Other Important Articles Covering the same topic: 📍Knowledge Nugget: India's three-stage nuclear programme — A must-know for UPSC exams 📍India is taking the nuclear energy leap Previous year UPSC Prelims Question Covering similar theme: (4) Consider the following statements: 1. Fast Breeder Reactors (FBRs) are envisioned as the third stage of India's three-stage nuclear programme. 2. Pressurised Heavy Water Reactors (PHWRs) use heavy water (deuterium oxide) as a coolant. 3. Thorium-bearing monazite is an example of fissile material. How many of the above statements is/are incorrect? (a) Only one (b) Only two (c) All three (d) None Previous year UPSC Mains Question Covering similar theme: With growing energy needs should India keep on expanding its nuclear energy programme? Discuss the facts and fears associated with nuclear energy. (UPSC CSE 2018) Syllabus: Preliminary Examination: Economic and Social Development – Sustainable Development, Poverty, Inclusion, Demographics, Social Sector Initiatives, etc. Mains Examination: General Studies-I: Role of women and women's organisation, population and associated issues, poverty and developmental issues, urbanisation, their problems and their remedies. What's the ongoing story: Stating that agriculture is important 'not only for growth, but also inclusive growth', NITI Aayog member Prof Ramesh Chand Tuesday said growth in the farm sector was more impactful in reducing poverty than manufacturing. Key Points to Ponder: — What do you understand by inclusive growth? — How do you define poverty? — What are the poverty alleviation programme in India? — What is the potential of agriculture in bringing inclusive growth? Key Takeaways: — 'There are studies which show the power of 1% growth in agriculture to reduce poverty is four times the power of manufacturing to reduce poverty,' Chand said at a symposium on 'Innovation and Sustainability in India's Root and Tuber Crop Sector'. — Emphasising 'agriculture focused inclusive development', he said, 'I prepared a case for agriculture focused inclusive development, that agriculture is important, not only for growth, but also important for inclusive growth.' — The symposium was organised by the Peru-based International Potato Center (CIP) in collaboration with the Central Potato Research Institute (CPRI), Indian Council of Agricultural Research (ICAR). It was held as part of the CIP's board meeting. — The CIP, which commenced its work in India in 1975, plans to establish its South Asia Regional Centre at Singana in Agra, one of the top potato producing districts of the country — India is today the second largest producer of potato in the world, and perhaps it will be the largest in near future. That's an excellent foundation for future growth,' Heck added. — With production of 93 million metric tonnes, China tops potato production globally followed by India (60 million metric tonnes). In a statement, the CIP said India is on course to overtake China in potato production Do You Know: — Ram Singh writes: Inclusive growth is critical for us to become a developed nation by 2047. A leading indicator is improvements in the living standards of those at the bottom of the economic pyramid. Another is the direction of changes in income inequality. — Apart from being a moral issue, distribution of national income determines the composition of aggregate demand and hence, the allocation of resources to different production processes, which, in turn, will affect the pace towards Viksit Bharat. — In 1971, V N Dandekar and N Rath defined the poverty line based on calorie consumption (2,250 calories per person per day, based on National Sample Survey data of 1960-61), setting it at Rs 15 for rural and Rs 22.5 for urban areas. — In 1979, the Y K Alagh Task Force set poverty lines based on calorie needs of 2,400 calories (rural) and 2,100 calories (urban), which remained the official method until the 1990s. However, this methodology for estimating poverty at the national and state levels has been critiqued by many for giving an inappropriate picture of poverty in the country. — In 1989, the Planning Commission formed the Lakdawala Expert Group to 'look into the methodology of estimating poverty and to redefine the poverty line, if necessary'. The Lakdawala Committee in 1993 introduced state-specific poverty lines, adjusting for regional price differences, but faced criticism for not maintaining the original calorie norms. — In 2009, the Tendulkar Committee submitted its report of estimated poverty lines for rural and urban areas in all states. It concluded that the all India poverty line in 2004-05 was Rs 446.68 and Rs 578.80 per capita per month in rural and urban areas respectively. Other Important Articles Covering the same topic: 📍Poverty debates in India 📍Claims about India's rising inequality don't tell the full story UPSC Prelims Question Covering similar theme: (5) In a given year in India, official poverty lines are higher in some States than in others because (UPSC CSE 2019) (a) poverty rates vary from State to State (b) price levels vary from State to State (c) Gross State Product varies from State to State (d) quality of public distribution varies from State to State UPSC Mains Question Covering similar theme: Explain various types of revolutions, took place in Agriculture after Independence in India. How these revolutions have helped in poverty alleviation and food security in India? (2017) Syllabus: Preliminary Examination: Current events of national and international importance Mains Examination: General Studies-II: Bilateral, regional and global groupings and agreements involving India and/or affecting India's interests. What's the ongoing story: Harsh Vardhan Agarwal writes: The India-UK Free Trade Agreement (FTA) marks not just a high point in India's trade negotiations but a transformative opportunity for Indian industry. It is a signpost of India's maturing global presence — no longer content to participate in trade from the sidelines, but ready to lead, partner and shape the next wave of global economic growth. Key Points to Ponder: — Learn about the India-UK Free Trade Agreement (FTA) — What is the significance of FTA? — What is zero-duty? — What is the India-UK Double Contribution Convention? — Which sectors will be impacted by the India-UK FTA? — What is the status of India-EU and India-USA FTA? — What is the difference between FTA and the Comprehensive Economic Partnership Agreement (CEPA)? Key Takeaways: — Historically, Indian exporters — particularly in sectors like textiles, apparel, marine products, leather, and toys — have been at a tariff disadvantage in developed markets like the UK. That changes now. With zero-duty access for nearly 99 per cent of Indian tariff lines, Indian firms finally enjoy a level playing field against competitors from the EU, Bangladesh and CPTPP countries. — India's approach to the FTA reflects a calibrated strategy. While offering duty-free access to 85 per cent of UK products over a phased 10-year period, India has protected sensitive sectors such as dairy, apples, edible oils, smartphones and medical devices. — This balance of openness with strategic autonomy ensures Make in India and employment-intensive sectors are not disrupted. This should serve as a blueprint for future trade deals. — The FTA's most ambitious provisions lie in the services sector, a domain where India has a global edge… The landmark Double Contribution Convention, which waives UK social security contributions for Indian professionals on temporary assignments, is not just a cost-saving tool. It will make Indian service exports even more competitive. — The FTA provides a platform for deep bilateral cooperation in investment, innovation, and research. With the UK's strength in design, R&D and advanced manufacturing, and India's strength in scale, talent, and execution, this agreement paves the way for joint IP creation, technology transfer, and co-manufacturing. — For the first time, an Indian FTA includes chapters on labour rights, environmental protection, consumer welfare, gender equity and anti-corruption. — India's long-term economic vision — Viksit Bharat — demands that we expand our share of global trade, move up the value chain, and create large-scale employment. The India-UK FTA is a major leap toward that vision. Do You Know: — The Ministry of Commerce said in an FAQ that 'FTAs are arrangements between two or more countries or trading blocs that primarily agree to reduce or eliminate customs tariff and non tariff barriers on substantial trade between them.' They can cover both goods and services. — The UK's Department of International Trade noted, 'Trade and investment barriers can make it more difficult and costly to trade or invest overseas. By removing or reducing them, FTAs can make it easier for businesses to export, import and invest. They can also benefit consumers by providing a more diverse and affordable range of imported products.' — Total UK exports to India amounted to £17.1 billion, while total UK imports from India amounted to £25.5 billion in 2024. India was Britain's 11th-largest trading partner last year. Britain said the deal was the 'biggest and most economically significant' bilateral trade agreement it had signed since leaving the European Union in 2020 (what was dubbed 'Brexit'). Other Important Articles Covering the same topic: 📍UK-India Free Trade Agreement (FTA) signed: the key goods included, what it means 📍Four ways in which India gains from an FTA with the UK Previous year UPSC Mains Question Covering similar theme: How would the recent phenomena of protectionism and currency manipulations in world trade affect macroeconomic stability of India? (2018) Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X. 🚨 Click Here to read the UPSC Essentials magazine for May 2025. Share your views and suggestions in the comment box or at
India Today
20-05-2025
- Science
- India Today
Indian astrophysicist Jayant Narlikar dies, PM Modi calls it monumental loss
Dr. Jayant Vishnu Narlikar, a towering figure in astrophysics and co-creator of the renowned Hoyle-Narlikar theory passed away at the age of leaves behind a legacy that has profoundly shaped modern cosmology and inspired generations of Minister Narendra Modi expressed his condolences, 'The passing of Dr. Jayant Narlikar is a monumental loss to the scientific community. He was a luminary, especially in the field of astrophysics. His pioneering works, especially key theoretical frameworks, will be valued by generations of researchers. He made a mark as an institution builder, grooming centres of learning and innovation for young minds. His writings have also gone a long way in making science accessible to common citizens. Condolences to his family and friends in this hour of grief.'advertisement Dr. Narlikar's most celebrated contribution is the Hoyle-Narlikar theory, developed in collaboration with British astrophysicist Sir Fred Hoyle in the passing of Dr. Jayant Narlikar is a monumental loss to the scientific community. He was a luminary, especially in the field of astrophysics. His pioneering works, especially key theoretical frameworks will be valued by generations of researchers. He made a mark as an— Narendra Modi (@narendramodi) May 20, 2025This groundbreaking theory offered an alternative to the Big Bang model, proposing instead a steady-state universe where matter is continuously Hoyle-Narlikar theory introduced the concept of 'Mach's Principle' into cosmology, suggesting that the inertia of any particle is influenced by the presence of all other masses in the elegant framework challenged prevailing notions and sparked vigorous debate, significantly advancing the field of theoretical his research, Dr. Narlikar was a passionate educator and institution builder. He played a pivotal role in founding the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, nurturing a generation of Indian astrophysicists and fostering international collaborations.A prolific writer, Dr. Narlikar authored numerous books and articles, making complex scientific ideas accessible to the public and inspiring countless young minds to pursue Isro chief Dr S Somanath expressed grief and said, "He was a visionary astrophysicist and science communicator who inspired my generation with his popular works such as 'The lighter side of gravity' and 'Seven wonders of the cosmos."Dr. Narlikar's legacy endures—in the equations he formulated, the institutions he built, and the curiosity he ignited in millions.
Scroll.in
20-05-2025
- Science
- Scroll.in
Jayant Narlikar, astrophysicist and writer, dies at 86
Astrophysicist and writer Jayant Narlikar died in Pune on Tuesday, said the Inter-University Centre for Astronomy and Astrophysics. He was 86. He had recently undergone a hip surgery, The Hindu reported. Born in Kolhapur in Maharashtra, Narlikar studied science at the Banaras Hindu University before completing his Mathematics Tripos at the University of Cambridge. He was a professor at the Tata Institute of Fundamental Research in Mumbai, where he was in charge of the theoretical astrophysics group. He is credited for developing the Hoyle-Narlikar theory of gravity along with British astronomer Sir Fred Hoyle. Narlikar became the founder-director of Pune's Inter-University Centre for Astronomy and Astrophysics in 1988. He remained a director at the IUCAA till his retirement in 2003 and was the emeritus professor at the institute. Narlikar also wrote science fiction stories and books in English, Marathi and Hindi. In 2004, he was awarded the Padma Vibhushan, India's second-highest civilian honour. He was awarded the Maharashtra Bhushan in 2010 and the Sahitya Akademi Award in 2014. Narlikar is survived by daughters Geeta, Girija and Leelavati. Maharashtra Chief Minister Devendra Fadnavis said that Narlikar had 'played a very valuable role in spreading science by creating literature in scientific subjects'. 'We have lost a great scientist and an equally great writer,' the chief minister said on social media, adding that the last rites will be conducted with state honours. S Somanath, the former chairman of the Indian Space Research Organisation, said that Narlikar was a visionary astrophysicist and science communicator 'who inspired my generation with his popular works'.
