Editorial 1 : The universe’s hum and an opportunity to explore
Recent Context:
- For the first time, physicists have detected strong evidence of the long-hypothesised background “hum” of nanohertz gravitational waves — omnipresent ultra-low frequency ripples in spacetime spreading throughout the universe from multiple sources all around us, continuously.
- The findings were made through a global collaboration, with unique contribution from Indo-Japanese Pulsar Timing Array (InPTA) teams through the Pune-based GMRT telescope.
Historical Context:
- The first detection of gravitational waves was announced on February 11, 2016. These had been predicted almost exactly a century ago by Albert Einstein as a natural consequence of his theory of gravity the Theory of General Relativity
- General Relativity implies that under certain circumstances, space itself would be stretched and compressed resulting in the production of gravitational waves, it is like throwing a stone in a placid pool of water.
Significance of Gravitational waves:
- Detection and study of gravitational waves has since opened a new window into our universe at the largest scales.
- As a consequence of it, astronomers’ part of different collaborative initiatives have announced the detection of ultra-low frequency gravitational waves which could expand this window to explore hitherto unexplored regions of the universe.
Detection of gravitational by LIGO (Laser Interferometry Gravitational-wave Observatory)
- LIGO, as the name suggests, is based on the principle of interference.
- A laser beam is split into two, each of which is sent down a pair of arms, each several kilometres long which are oriented perpendicular to each other. The beams are reflected back and then made to interfere.
- If there has been no disturbance, the beams cancel each other out exactly.
- However, occasionally when a gravitational wave passes through the interferometer arms, it would stretch and compress the arms by an incredibly small amount a million trillion times smaller than the proton.
- This will result in the beams not cancelling each other. The signal, after deep data analysis is to rule out other possibilities like seismic tremors, is then taken as a gravitational wave detection.
- Since gravitational waves were first detected by LIGO (Laser Interferometry Gravitational-wave Observatory), its detectors have observed dozens of short high-frequency gravitational wave bursts.
- These high-frequency waves are thought to be a result of collisions of black holes about as massive as our Sun as well as of neutron stars. Black holes and neutron stars are stellar remnants of stars which have exhausted their nuclear fuel.
LISA (Laser Interferometer Space Antenna), a step ahead of LIGO:
- The detections at LIGO and other detectors have all been of high-frequency waves, typically a few kilohertz. The sensitivity is determined by the length of the arms of the detector the lower the frequency of the waves, the longer the arms that are required to detect them.
- This is one of the motivations for LISA, the planned space-based detector by the European Space Agency. This detector would have arms which would be several million kilometres long.
- For the nanohertz (a billionth of a hertz) waves which have now been reported, one would have needed a galaxy-sized detector which is not possible to build.
Using radio pulses to detect the elusive waves:
- The basic idea is to use radio pulses from objects called millisecond pulsars to detect the elusive waves. Millisecond pulsars are rapidly spinning neutron stars which beam radio waves in regular pulses.
- These pulses arrive on the Earth with extremely regularity. If an ultra-low frequency gravitational wave distorts the intervening space between a pulsar and us, it can change the arrival time of these pulses
- It requires painstaking data collection of many millisecond pulsars over several years. For this, five multinational teams have been collecting data for over two decades on pulsar timings.
- These are the North American Nanohertz Observatory for Gravitational Waves, the European Pulsar Timing Array (PTA), Indo-Japanese PTA, Parkes PTA from Australia and the Chinese PTA. Each of these groups is a collaboration of several scientists from many institutions.
India-Japan coloration for detection of low frequency waves:
- The Indo-Japan PTA has researchers from the National Center for Radio Astrophysics (NCRA), Raman Research Institute and several other institutes. The upgraded Giant Meter wave Radio Telescope (µGMRT) at Narayangaon near Pune was used to collect data.
- This array of 30 radio antennae, each with a diameter of 45 metres, separated by a maximum distance of 25 kilometres, is amongst the most advanced radio telescopes in the world for low-frequency observations.
- Data from a particular class of millisecond pulsars were collected for over a decade to detect the effect of gravitational waves.
Current challenges related to detection of gravitational waves:
- There are several factors which might cause the pulsar timings to vary. All of these need to be individually accounted for and compensated for.
- The only way that such a tiny signal can be gleaned from the background is by doing a statistical analysis of dozens of pulsars over many years.
- This is one of the reasons why none of the collaborations is yet claiming a fool-proof discovery the five-sigma level in scientific jargon where the chance of it being a random event is one part in 3.5 million.
- Nonetheless, no one doubts that as more data is collected and analysed, the gold standard would be achieved.
Origination and detection of nanohertz waves:
- The origin of these nanohertz waves is not yet determined, though the most likely scenario is of supermassive black holes orbiting each other.
- Blackhole each with a mass millions of times of our Sun, are typically found at the centre of galaxies. When galaxies collide or merge, these could pair off and produce the waves which are detected
- The combined effect of mergers and collisions produce the constant background of these disturbances of space-time.
- Other possibilities are also being considered, including exotic objects like cosmic strings and even inflation — an event at the very beginning of the universe which resulted in an exponential increase in its size.
Conclusion:
- it is clear that these nanohertz waves would, in future, allow us to explore the earliest universe.
- As to whether the “hum” is the primordial “aum” as one commentator seemed to think, we can only wait and watch. Or hear.
Editorial 2 : How India can leverage its biggest strength
Recent Context:
- India’s biggest strength is its manpower. The next 25 years could be the golden years for the country provided we make the best use of the favourable demographic composition.
- To reap the demographic dividend, we need to improve our labour force participation by improving the employability of our labour force through large-scale skilling.
- At the same time, we need to create employment opportunities for the youth who enter the job market every year.
Demographic dividend of India: A favorable young population for nation building
- India is the youngest among the most populous countries in the world.
- India’s average age is 29 years, whereas the average age in US, China, France, Germany and Japan is 38, 38, 42, 45 and 48 years, respectively.
- India, with its huge population, is now in a phase in which its working-age population is rising and the old-age dependency ratio coming down.
- The world, in contrast, is ageing with an increase in the population of the aged and a drastic reduction in fertility rates.
- For example, India’s old-age dependency ratio will reach 37 per cent in 2075, whereas the same will be 55.8 per cent in France, 75.3 per cent in Japan, 49.3 per cent in the US, 53 per cent in the UK and 63.1 per cent in Germany.
- Most countries are experiencing record low fertility rates for example, 6.77 births per 1,000 people in the case of China and a shrinking labour force.
Making using of human capital for higher growth and standard of living:
- Most developed countries today have been able to make use of their phase of favourable demographics for higher growth and standard of living.
- In Asia, China has already set an example of being a superpower by harnessing its demographic dividend from the early Eighties till 2008-2009.
- China’s early focus on labour-intensive manufacturing and subsequent structural transformation resulted in an almost 10 per cent annual average growth rate over four decades, which is unprecedented.
- There is a need to create opportunities for the existing labour force and the new entrants into the labour market by improving their productivity.
- Promoting labour intensive sectors:
- There is a need to shift a major chunk of the 45.5 per cent of the labour force engaged in agriculture with low and negligible labour productivity.
- As most of the labour force has limited education and skillsets, they can only be used in labour-intensive manufacturing such as textiles, toys, footwear, auto components, sports goods and agricultural processing
- Sectors like restaurants, hotels, mining and construction, healthcare and caregiving services have huge potential
- Investing and encouraging Manufacturing sector:
- For the manufacturing sector to grow, there is need for an accelerated focus on
- infrastructure development to reduce trade and transaction costs,
- trade facilitation measures
- a better IPR ecosystem
- ease of doing business on the ground and
- further rationalisation of labour laws and the taxation system.
- For the manufacturing sector to grow, there is need for an accelerated focus on
- Supporting MSME:
- MSMEs are the backbone of Indian manufacturing. They need support in improving competitiveness, achieving scale, digital infrastructure, technology up-grade and branding to be part of a larger supply chain and the global value chains
Steps taken to reap benefit of demographic dividend
- India can oreap the demographic dividend and be a source of labour supply for the world if we make our labour force more productive and efficient through skilling, re-skilling and up-skilling.
- Further, we have to focus on quality education and health facilities. Simply having the largest labour force is not enough in an environment of fast-changing production processes.
- Skill development programmes of government:
- Skill development programmes such as the Jan Shikshan Sansthan, the Pradhan Mantri Kaushal Vikas Yojana and the National Apprenticeship Promotion Scheme are government’s skill development initiate for skilled human capital development.
- The skill development programmes have succeeded in many parts and have increased human resources supply in various sectors during 2017-22. However, 93 per cent of the employment in India is absorbed by the unorganised sector, where workers are employed in underpaid jobs.
- The skill mission has the MSDE Vision 2025 in sight which is set to improve linkages between education and skill, catalyse demand for formal skills and create a high-skilled ecosystem
- Qualitative health for healthy human capital:
- With wide-ranging reforms such as Ayushman Bharat and Swachh Bharat Mission, the Centre has ensured health equity to a great extent.
- Though India is a pharmaceutical giant with a $50 billion industry and is a global leader in vaccines, accounting for about 60 per cent of DPT, BCG and measles vaccines, there is need to scale up access and quality health services for the majority of the population.
- In order to make Drug price affordable, Pradhan Mantri Bhartiya Janaushadhi Pariyojana is a welcome step.
- A qualitative education system for knowledgeable human capital:
- The National Education Policy 2020 gives importance to updating knowledge. It also aims at ensuring productive employment opportunities and decent/dignified work as listed in the United Nations Sustainable Development Goals 2030.
- In 2018, the government launched the Samagra Shiksha programme to provide inclusive, equitable and quality education at all levels of school education.
- However, there are several instances of schools being non-functional, authorities being reluctant to drive change and students suffering. The delivery of quality education up to higher secondary education to all is imperative for making a productive labour force.
Conclusion:
- The next 30 years belong to India provided we accelerate our reforms and achieve the desired results of flagship programmes of Skill India, Make in India, Start-up India, and others.
- It’s time to focus on labour-intensive manufacturing and human capital. India can be the source of the labour force for the rest of the world.