Silence is reigning in the campuses for the past two decades; there has been no student movement over real issues. What is the reason behind this exception? We must try to seek truth from the facts. Before we jump to any conclusion, let’s cast a glance upon the facts related to higher education in our country.

In India only 7% of the eligible population reaches higher education, for the past two decades as per the government’s policy, seats have continuously been decreased and fees have been increased. The deduction in seats is not absolute but is relative in comparison to the number of applicants. Government has itself accepted that traditional higher education (B.A., B.Sc., etc) has lost its ‘signaling effect’ or is no longer job-oriented, whereas professional courses like engineering and medical have become the belongings of higher middle and higher class. Management courses are not even affordable for the higher middle class, only the higher class can reach there. After the period of liberalization and globalization, India’s education policies changed a lot and the government is spending less on higher education and students are made to pay from their pockets. Till 1970, the government was spending 1% of GNP which was reduced to 0.35% during the 1990s. In 1983, before the implementation of new education policy, the government had been paying 80% of higher education’s expenditure but in 1999 it was reduced to 67%. On the other side also, in engineering and medical education, the government is withdrawing its hands. Till 1960 there were only 15% private seats in engineering, but till 2004 this figure increased to 86.4%, in medical education also it has increased from 6.8% in 1960 to 40.9% in 2004. In management institutes, this number is 90%.

The motive of all such policies must also be seen. If a student from a humble background reaches higher education, he/she will soon comprehend the reality of this “competitive society”, his/her anger towards the system will be much greater and this feeling might prove to be very dangerous. So it is better to make these very dreams themselves so costly that common students cannot afford them.

The commodification of education is also the reason behind the changing class character of the students’ population; issues of the common masses do not concern them. That is why the social law of resistance fails to apply within the boundaries of campus. That law will become functional only when the sensitive students within the campus will associate themselves with the struggles of the 93% eligible population who do not reach the campus. Only then, one can imagine any change.

With time the understanding of the idea grew and with verification of its other predictions, like bending of light due to a massive object, this theory gained the acceptance of brains all over the world. There was yet to be an observation that would verify the ‘Gravitational Waves’.

It was not until 1974, that this prediction would be attested by Taylor and Hulse after their observation of a binary pulsar, which lead them to an indirect proof of gravitational waves and a Nobel Prize in 1993. A first direct detection of these waves was first announced on 11th February, 2016, at Washington, and was done using the Advanced LIGO (LASER Interferometer Gravitational-Wave Observatory) which consists of two interferometers: one in Hanford, Washington and other in Livingstone Louisiana, operating in unison to detect gravitational waves.

It was for this, that the Nobel Prize in Physics, for the year 2017 was awarded to Reiner Weiss, Barry C. Barish and Kip Thorne for their ‘decisive contribution to the LIGO detector and observation of Gravitational Waves’. The Nobel can be awarded to a maximum of three laureates and they were the pioneers of the idea but it is important to acknowledge the cumulative effort of thousands of scientists and engineers from all over the world which were also a part of this game changing experiment, that opens new windows to observational astronomy and cosmology, leaving us with enormous amounts of ideas to explore.

But first things first: What exactly are Gravitational waves?

Let’s draw out an analogy between electromagnetism and gravity. We are aware that when an electric charge is in an accelerated motion it emits electromagnetic waves: ripples of distortion in the electromagnetic field travelling through space and time transversely, carrying an associated energy with them, and interacting with matter in its path. Similarly, the source of gravitational interactions is mass. Thus, when a mass accelerates it loses its gravitational energy in form of ripples of distortion in the gravitational field travelling, pushing and pulling matter on their way, through space-time, carrying energy transversely, travelling at the speed of light in vacuum. Now, the gravitational interaction, as we know is much weaker than the electromagnetic interaction (approximately 1038 times weaker), so consequently the energy carried by the g-waves is negligible in comparison to the electromagnetic waves, making them extremely difficult to observe. For instance, as the Earth travels around the Sun in its curved trajectory, it emits gravitational waves. But for the entire Earth, that gravitational wave output amounts to a few hundred watts, not enough to ever be detected. Our sun also emits gravitational waves just as it emits electromagnetic waves, but in comparison to roughly 400 million trillion megawatts it emits as heat and light, it only emits about 79 megawatts in gravitational waves; again the amount is too low to be detected.

Observations showed that the pulsar orbit was shrinking at exactly the rate that general relativity predicted it would, if gravity waves existed and were carrying away the expected amount of energy. It was this result that lead the astrophysicists to be secure about the Gravitational Waves and provided them with the confidence required to go forward with direct measurement with large detectors as LIGO.

LIGO Begins: The Origin Story!

Starting in 1960’s American and Soviet scientists conceived the basic ideas of LASER interferometry for detection of gravitational waves. In 1967, Rainer Weiss published his analysis of interferometer use, and in the next year Kip Thorne initiated theoretical development at Caltech. Many prototype interferometers were proposed in next two decades, but they failed to acquire funding or to make any further progress technically. Meanwhile, in 1980’s the National Science Foundation (NSF) funded a study in large interferometry lead by MIT, and Caltech constructed a forty meter prototype. Under pressure from NSF, these premier institutes came together to lead the LIGO initiative. In 1994, when Barry Barish took over as laboratory director, LIGO was told that it was its last shot at attaining funding, but a revised theoretical, budget, and project plan was successful in obtaining the green signal and funding. The project, at 395 million USD, broke first ground in late 1994 and the construction neared completion in 1997.

Initial run of LIGO from 2002 to 2010 detected no such gravitational waves. So, it was closed for further advancements in the equipment, increasing its sensitivity by a certain orders of magnitude. It was not until September 2015 that LIGO/a LIGO would begin the second phase.

Simultaneously, an Italy based Laser Interferometer, VIRGO also started working in 2015, actively to detect gravitational waves. To the delight of involved scientists, it detected its first signal on 14th September 2015, emerging due to a merger of two massive black holes having 29 and 36 times the Solar Mass, which merged into a super massive black hole having 62x Solar Mass, which happened in a corner of the universe 1.3 Billion light years away. This lead to dissipation of gravitational energy, form the merger, equivalent to 3 solar masses. These results were published on 11th February 2016, in which LIGO Scientific Collaboration along with VIRGO collaborationconfirmed the first direct detection of Gravitational Waves. As of now, till November 2017, LIGO has announced four more detection of similar signals.

The Anatomy of LIGO/aLIGO

The LIGO consists of two large interferometers: one in Hanford, Washington and another in Livingstone, Louisiana separated by 10 milliseconds of light travel time (approx. 2400 miles). Each primary interferometer consists of two 4 km beam lines orthogonal to each other carrying a test mass to form a power recycled Michelson Interferometer. A pre-stabilized Nd:YAG laser source emits a beam of 20 W power of wavelength 1064 nm, which through a beam splitter sends the beam to the two arms. By the use of partially reflecting mirrors,Fabry-Perot resonance cavities are formed in both the arms, increasing the effective length of the path travelled by light beam. After approximately 280 trips down the 4km arms the light beams recombine at the beam splitter. The equipment is kept such that, these two beams are out of phase and interfere destructively and no light arrives at the photo-diode.

Now, when a gravitational wave passes through the interferometer, it disturbs the test masses in both the arms, shortening and lengthening the arms by a very small distance causing the beams to become slightly less out of phase, causing resonance and some light is detected at the photodiode. The results from both the interferometers were compared and analyzed to be found similar, hence proving that the movement in the test masses were due to a common distortion, not due to any seismic or human activity.

Each of these test masses had an extremely sensitive sensors to monitor any form of motion up to one attometer(10-18 -10-19 m). The sensors could measure a displacement of a 10000th of a proton. This is equal to measuring the distance to Alpha Centauri with a precision of a hair strand. With this extreme sensitivity, came a drawback: the signal could be disturbed by smallest of seismic activity or even traffic! To nullify the effect, the test masses are equipped with active and passive damping measures. Active damping works similarly to the noise cancelling headphones; a sensor is attached to measure the surrounding noise, and the computer informs the device to move in form so as to cancel the noise. Secondly, the system prevents any motion that is not countered by the active system from reaching the test mass. The test mass (the mirrors) are suspended by a 4 stage pendulum called as the Quad. They are held by a 0.4 mm think fused silica glass fibers. Four vibration damping masses are present in the pendulum which absorb the vibration. The “Main Chain” side faces the laser beam, while the “Reaction mass” side helps to keep the test mass steady from noise not associated with astrophysical sources. Thanks to Inertia, the sheer weight of these masses also contribute to damp the vibration.

Alright, so Einstein was correct; but why are Gravitational waves so important?

Gravitational waves will usher in a new era in astronomy. Most of the astronomy done in the past has relied on different forms of electromagnetic radiation (visible light, radio waves, X-rays, etc.), but electromagnetic waves are easily reflected and absorbed by any matter that may be between their source and us. Even when light from the universe is observed, it is often transformed during its journey through the universe. For example, when light passes through gas clouds or the Earth’s atmosphere, certain components of the light will be absorbed and cannot then be observed.

Gravitational waves will change astronomy because the universe is nearly transparent to them: intervening matter and gravitational fields neither absorb nor reflect the gravitational waves to any significant degree. Humans will be able to observe astrophysical objects that would have otherwise been obscured, as well as the inner mechanisms of phenomena that do not produce light. For example, if stochastic gravitational waves are truly from the first moments after the Big Bang, then not only will we observe farther back into the history of the universe than we ever have before, but we will also be seeing these signals as they were when they were originally produced. The physics that went into the creation of a gravitational wave is encoded in the wave itself. To extract this information, gravitational wave detectors will act very much like radios—just as radios extract the music that is encoded on the radio waves they receive, LIGO will receive gravitational waves that will then be decoded to extract information on their physical origin. It is in this sense that LIGO truly is an observatory, even though it houses no traditional telescopes.

However, the data analysis that is required to search for gravitational waves is much greater than that associated with traditional optical telescopes, so real -time detection of gravitational waves will usually not be possible. Therefore, LIGO creates a recorded history of the detector data. This provides an advantage when cooperating with traditional observatories, because LIGO has a ‘rewind’ feature that telescopes do not. Consider a supernova that is only observed after the initial onset of the explosion. LIGO researchers can go back through the data to search for gravitational waves around the start time of the supernova.

– Arnav Pushkar

Today every student of science is acquainted with the name of Stephen Hawking, whose full name was Stephen William Hawking. The world knows Hawking as a great Physicist, Cosmologist, Writer and Science Interpreter. He was a materialist scientist (Philosophers are divided into two great camps according to their answer to the question, which is primary, mind or nature. 

Those who assert the primacy of mind over nature form the camp of the idealists and consider the material world as the reflection of the idea, and the others who consider nature as primary and idea as a reflection of material reality form the camp of the materialists) who continuously endeavored to expand the horizon of science, to take science to new horizons. This year on 14th March, the famous man on the wheelchair, bid adieu to the world, his brain remained active, sharp and sound till the end when all the organs finally failed. By sheer coincidence, it’s the same 14th march which is the date of birth of another great among the greatest scientists, Albert Einstein. So history named one of its days after two such great and humanitarian scientists who lived their lives in the pursuit of gaining new grounds for science and advocated for employing the scientific knowledge that mankind gained over the centuries into the service of the whole of mankind.

Stephen Hawking was born in Oxford on the 8th day of January 1942, a time when scientists were trying to see the essence of matter and the evolution of the universe through the dialectics of determinism and agnosticism. The school of determinism sees the universe and nature as knowable and its ultimate aim is the unification of thinking with being, to get to the theory of everything, agnosticism is the philosophy that challenges the possibility of an exhaustive knowledge of the world. It believes that the thing in itself or in other words, the essence of a thing is ungraspable. Albert Einstein, Erwin Schrodinger belonged to the school of determinism while Niels Bohr, Heisenberg subscribed to the school of agnosticism. It was the era of great debate in the academic circles, and it was also the era of an insatiable thirst for profit and imperialistic wars, that led to the annihilation of Hiroshima and Nagasaki, and the doom of nuclear holocaust loomed large over the world. Meanwhile, Hawking, like other general students completed his school education and graduated from Oxford University. It was there where his interest in science and the origin of the universe started deepening. Thereafter he entered Cambridge University for his doctoral.

Young Stephen Hawking

When he was just 22 years old and was working on the theory of relativity, there was a severe motorneuron-disease that got him under its claw and that was going to paralyze all his limbs one by one. Due to this, he suffered from depression for a little while. But his passion for science overwhelmed his depression and very soon he returned to the world of science.

In the field of Cosmology, this period was marked by an ongoing great debate on two extant theories about the origin of universe. One was the steady state theory and the other was the big bang theory. According to the steady state theory, the density of matter remains steady despite the expansions of the universe and the universe maintains its homogeneity. While according to the big bang theory, the universe originated from a state of infinite density and temperature, and thereafter the universe has been expanding continuously. In the year 1965, at the age of 23, Stephen Hawking collaborated with Roger Penrose and proposed the theory of space time singularity (Fig-1). In 1970, Taking his work forward he proved that if the universe functions in accordance with the general theory of relativity then it must also obey the singularity theorem and Alexander Friedman’s theory of Physical Cosmology.

Space-Time Singularity

The year 1973 took Hawking on a journey to Russia where he had discussiosn with two scientists, Yakov Borisovich Zeldorich and Elesy Starobinsky, which motivated him to work on quantum mechanics and quantum gravity. During this period Hawking made the conjecture of radio emissions by black hole, which is since known as Hawking Radiation. To understand the origin and dynamics of the Universe, Hawking strived to conjoin the two contradictory ends of theoretical physics: Quantum Mechanics and the Theory of Relativity, so as to establish the single equation, which he called the Theory of Everything. Hawking’s contributions were not limited to solving mathematical equations neither his interest remained academic only. In his opinion knowledge, science and philosophy are not the sole prerogatives of a privileged few but are the common inheritance and are things to be understood and discussed by every individual. In his world acclaimed book ‘A Brief History of Time’, he says –

This is one of the reasons that Hawking had been taking science and specifically astronomy among lay persons to the possible threshold of simplicity and clarity of language. He authored quite a number of books that includes half a dozen books of fiction specially dedicated to children. At the same time, Hawking countered the philosophical attacks on reason and science. Theoretical and mathematical formulations were reached at but the interpretations of these formulations were being made in an idealist or in a metaphysical way, setting aside scientific reasoning, and talking in terms of the mind of God and the absoluteness of truth. Hawking all along disproved these ideas by giving materialistic explanations. In the year 1983 Hawking collaborated with Jim Hartley and proposed the Hartley-Hawking model. The model proposed that before Planck’s time the universe had no boundary on space-time. Before the big bang time did not exist and so it is meaningless to talk in terms of the beginning of the universe or absolute truth.

The proposal brought in change in the classical idea of singularity and gave a determined blow to ideological explanations. Hawking played the role of a science interpreter over a large portion of the period after 1990. Politically Hawking was a justice loving person. Hawking, like quite a few scientists, was a strong opponent of the imperialistic wars, arms proliferation and genocides. Be it the mass-killings in Vietnam or the war of aggression against Iraq or nuclear arm stockpiling.

Hawking made his protests known on a number of occasions. Hawking in his essay published in ‘The Guardian’ strongly criticised the mass-killing in Syria. Although no one can target his greatness and his one hundred percent participation in the service of humanity, he has his own philosophical limits. He was not consciously aware of the approach and method of dialectical materialism. This was the main reason why he could not reach an alternative to this rotting system. However, at the twilight of his life, he could see capitalism as the root of all ills and said in the year 2015 –

Together with it, Stephen Hawking in his last years strongly opposed those adherents of this capitalist system, who propagate the fear of fantasies like, artificial intelligence and alien attack amongst the masses, in order to prolong their regime, by saying that Capitalism holds a greater threat to humanity than the machines. Summing up one can say that Stephen Hawking stood till the end of his life against the exploiting system. He vociferously criticized the consequences of this profit oriented system. In the field of Physics, also when the neo-Kantists and idealist thinkers and scientists led physics to the ditches of agnosticism and idealism, he carried forward the materialistic way of thinking, that also in the era when illogical claims and paragons were coming from all quarters. Even as equations were interpreted subjectively he indulged in debates all along. His death comes to every justice loving persons and to the whole human society at large as an irreplenishable loss. We will consider his contributions to science in the coming issues of The Spark.

– Akash Anand

इस लेख को हिंदी में पढ़ें।