Monday, 16 May 2022


Black Holes in Space


The Milky Way Galaxy's Central Black Hole called "Sagittarius A," has finally been imaged !
Eventhough it is in excess of 4 million solar masses, it is nothing compared to the colossal 6.5 billion solar masses of that supergiant elliptical external galaxy designated M87, that was imaged in 2019, in the constellation Virgo.
Black Holes were predicted to exist by the theory of general relativity propounded by the great theoretical physicist of all time, Albert Einstein, in 1915.
When the end product of a massive star breathes its last nuclear breath, it either ends up as a White Dwarf star (upto 1.4 solar masses, as derived by the nobel laureate Subramaniyan Chandrasekhar) or a Neutron star (upto 3 solar masses) or a Black Hole (> 3 solar masses), only depending on its final end mass.
A Black Hole is the end product of a massive star which got exhausted of its core nuclear fuel. What happens is, when a massive star dies, it collapses due to its inwardly acting gravitational field.
Stars are burning balls of emanating electromagnetic radiation, generated in their cores by nuclear fusion reactions. In its prime life time called the "main sequence time," a star is balanced by the inwardly acting gravitational force countering its enormous radiation pressure, escaping outward from its millions of degrees hot centre.
With the passage of time (i mean, cosmic time scales - of millions and billions), stars get exhausted of its hydrogen nuclear fuel, and succumb to the inwardly acting gravitational force as the outwardly acting counter-balancing radiation pressure gets depleted. Now, a star collapses on itself and gets reduced in radius.
The collapse is of such magnitude that the stars atoms get closely packed to one another. It gets into a state of electron degeneracy where the atomic electrons resist further collapse. A star like the Sun, shrinks to a radius of a planet like Earth. It becomes a high density star called a "White Dwarf star." This as the name suggests is a dwarf in terms of its size and incandescent white in terms of its surface temperature. It burns by a process called "triple-alpha process," in its core, and is supposed to live for a few million years, till it reduces itself further into many stages towards a final state of becoming a blown-out brown dead stuff.
Suppose, if the end product of a post main sequence star, is more than 1.4 solar masses, as defined by the chandrasekhar limit, it turns out into a Neutron star. How ?
As I said, the white dwarf star is in a state of electron degeneracy. In a massive body of > 1.4 solar masses, the orbital electrons are forced to break down. The atom ceases to exist and becomes only nuclear matter. The electrons fuse with the protons and become neutrons. It is called a state of neutron degeneracy.
The entire star is composed of only neutrons. Its radius is enormously reduced. It's just like, if the planet Earth, all of a sudden, became a small island ! A spoon-full of its matter now, weighs billions of tons !
These neutron stars, that rotate super-fast are also called "pulsars," and these radio-pulsars, are picked-up by radio telescopes on Earth. The famous Crab pulsar, is located within the crab nebula supernova remnant.
Super-Novae, are gigantic explosions of the end products of massive stars, before their core collapses into a neutron star.
And don't forget, our Sun is a star, but, its not likely to explode into a supernova. It will slowly swell up to gigantic proportions to the extent of gobbling up the inner planets, becoming into a red giant star and even becoming a red-supergiant star with a luminosity of ten thousand suns, only to finally expel it's extended atmospheres, to leave a remnant nebulae. After these stages, it will end up finally, into a white dwarf star, in another five billion years. These are theoretical astrophysical predictions, from well-established models of observational studies of
"stellar evolution."
Well then, what is a Black Hole ?
When the end product of a massive star is more than three solar masses, a star remnant collapses into a Black Hole. Even light with its fabulous velocity of 300,000 kms/s, can't escape from the gravitational field of a Black Hole. How can we see it ? Simply, we can't see it exist in any part of the EM spectrum, other than by its attractive gravitational field. They were predicted to exist indirectly by the behaviour of its nearby stars. But, now with advanced imaging methods and technology, scientists have been able to image its location negatively, by imaging the infalling surrounding gas that emits EM rays before its final disappearance into the Black Hole, all around it circumferentially.
The Black Hole is simply a space-time region of a finite mass of the end product of a massive star that turned into a point of singularity a mathematical proposition, which has an infinite density, infinite temperature and infinite pressure.
It's gravitational boundary is called event horizon. Any thing including light that enters it is doomed to be ever within it. Its gobbled up for good. Actually, there is only empty space between the event horizon and singularity.
Black Holes are regions of collapsed space-time itself due to the presence of not only mass, but singularities. They are supposed to be of many kinds. Stellar black holes, relic primordial black holes of the big bang and supermassive black holes at the galactic centres.
M87 and Sagittarius-A are SMBHs.
- to be continued....
...this writeup is not a forward or cut copy paste. It was written spontaneously.

 

Thursday, 7 April 2022

The Milky Way

 The Milky Way 

Many years ago, from Mahabalipuram, when I pointed out to my friends who were the pioneers of Astrophotography in India, and said, look...the Milky Way, they said, no clouds ! I persisted, and said, no its the Milky Way, the centre of our Galaxy, in the constellation Sagittarius. I kept gazing at it ! They looked at it now, only more intensely than before and ever since have been remembering this incident when we all meet. This fabulous spectacle became an ever lasting intriguing memory of natural  power and splendour revealing itself as bright and dark patches of great fire power. Astrophotographers, simply are in love with it !

To the left of the photograph is East and top is North, approximately. The bright fuzzy cloud like nebulosity is the dense central region of the Milky Way Galaxy, just at the north-western edge of the constellation Sagittarius. The whole region shows extensive thick and thin nebulous clouds with intervening dark rift of dust that curves and divides as it spreads outwards from the galactic centre. It is seen all the way to the constellation Cygnus with its associated rift system, to the north, within the constellation Cygnus.

The right half of the photographs's middle and upward curvature of stars represent  the constellation Scorpius. The brightest is designated Alpha Scorpii a red giant star called popularly Antaras, at the top of the photograph. It lies at a distance of 550 light years and is called the rival of Mars, as it is often difficult to distinguish it from the planet Mars that mimics it in colour and brightness, when it happens to lie near Antaras, in its trip around the Sun. In the middle is the star Shaula (lambda Scorpii) to the left of which can be seen the star open cluster Messier 7.

The Milky Way, can be better seen with simply the unaided eye. All that is required is a dark site and clear transparent skies. It is an awe inspiring spectacle to watch the curves of dusty dark lanes of intricate divisions with its varying opacity and thickness, that spread across the night sky, especially when the whole region is high up and culminating - the north south line the prime meridian, a great circle.

Binoculars are an advantage in revealing the intricate details of the Milky Way Galaxy, but with higher powers the field of view gets narrowed down and restricted. The wider the field of view (FOV) the better is our appreciation of the entire spectacle. The Milky Way Galaxy has anywhere between 100 to 400 billion stars. Our Sun together with the Solar System, travels around its centre taking about 240 million years to complete one full revolution around it, at the speed of 220 kilometres per second. The Solar System is located at a radius of about 27,000 light-years from the Galactic centre, on the inner edge of the Orion Arm, one of the spiral-shaped concentrations of gas and dust. The galactic center is an intense radio source known as Sagittarius A, a supermassive black hole of ~4 million solar masses

This photograph was obtained with just a samsung mobile phone placed on a support over a water tank and giving an exposure of a few seconds with a high ISO. The images were later aligned and stacked in a computer and software enhanced with photoshop. The digital era has revolutionised astronomy in a magnificienat way. Amateur Astronomers all over the world have been narrowing down the division between the professional observatories doing research work at the world's largest leading observatories with the help of recent advancement of ever more sophistication in electronics and computers and sensitive equipment that has come their way.

Look Above


Vainu Bappu Observatory

 

Photograph & digital enhancement by: Aravind Anand.
Place: VBO, Indian Institute of Astrophysics, Kavalur.
12°34′29″N 78°49′14″E.
700 meters (2,297 feet).
<https://en.wikipedia.org/wiki/Vainu_Bappu_Observatory>
<https://www.iiap.res.in/?q=vbo_vbt>
Date: 4th April, 2022.
Time: 10.30 UTC (3 AM IST).
Constellation: Sagittarius - Scorpius region.
Sky condition: No clouds, Still and hazy. Dew condensing by 1 am. 
Messier objects seen: thru Binoculars:  M42, Omega Centauri, M4, M13, 
Constellations traced out: Orion, Canis Major, Canis Minor, Auriga, Gemini, Leo, Virgo, Coma Berenices, Scorpius, Sagittarius, Lyra, Ursa Major, Ursa Minor, 
Early evening sky : Hazy.



























Saturday, 22 January 2022

Father

30/09/1939 to 17/01/2022

January 2022 Mon 17th by 7 pm, my good great father Dr PD Venkatakrishnan, MBBS., DPH., MF Hom (Lond)., expired. He was 82 years of age. He was born in Cuddalore (Thirupadiripuliyur) to Pudukottai Venkataswamy Devaraja Mudaliar and Nagaratinam Ammal. His paternal grandmother was Papathi Ammal and maternal grandmother Dhanabagyam Ammal. He was named Venkatakrishnan after combining his paternal grandfather Venkataswamy Mudaliar and maternal grandfather Krishnaswamy Mudaliar names.

His father practiced Siddha Medicine, at Cuddalore, Thirupadiripuliyur, a scholar of Tamil Literature who spent his time with friends discussing Indian religio-philosophy and Shaiva Siddhanta. He was fondly called 'Thirumandira mani,' by his elite scholar friends. He had a reputation for unworldliness and he was a seeker who had been wandering the banks of the Godavari in search of divine  truth for 14 years, after his early marriage, as was customary in those days of the early 20th century. He learned the art of Siddha Medicine from a mystic there. After the family came to know his whereabouts, they begged him back home and my father was born when he was 47 only preceded by his now late elder sister at his 45th year. He died at the age of 64 years when father was a second year student at the Stanley Medical College in 1962. 

My father got married to Ms Meera the first daughter of Sri Sivarama Mudaliar and Rajalakshmi Ammal of Sowcarpet, Chennai. She was a devoted and simple woman who took great care of him. Unfortunately, she died of a chronic illness at the age of fifty three on April 3rd, 2000.

Dr Venkatakrishnan, who was fondly called 'PDV' by his close friends, (particularly, Professor Dr Thiruvengadam Kannan, MD., DM (Medical Oncology), had been his close associate, friend and well wisher for nearly four decades) was from Stanley Medical College. He started his career as a lecturer in general surgery, at the Homeopathic Medical College at Kilpauk in the 70s. He worked as Municipal Health Officer in Vaniyambadi for four years and then in Gudiyattam for almost an equal period of time. Later, he also worked as District Health Officer of Tanjore District, in the 80s. 

From Tanjore, he moved to Stanley Medical College and later to Madras Medical College as Assistant Professor of Community Medicine (then SPM). He finally became the Controller of Examinations at the TN Dr MGR Medical University, the post of which he held for 5 years before his voluntary retirement from government service. 

He practiced homoeopathic medicine as a duly qualified consultant homeopathic physician for half a dozen years in Anna Nagar, Chennai. His clinic name was "Sai Holistic Clinic." He had obtained his MF Hom, at the Royal London Homeopathic Hospital, London, where he stayed and studied homeopathy, in the early 90s. A serious homeopath, he practiced with compassion and care and with scientific honesty. He helped his patients who came to him for nearly three decades and maintained their case sheets in his handwritten diaries. A soft spoken person, but, I found his voice loud and clear particularly when he dealt with his patients. 

He also held various teaching and  administrative positions at some of the private medical institutions like Vinayaka Missions Medical College & Hospital, Salem, Meenakshi Medical College Hospital & Research Institute, Kanchipuram, SRM Medical College & Hospital, Kattankulathur, Adhi Parasakthi Medical College and Hospital, Melmaruvathur and finally Chettinad Medical College & Hospital, Kelambakkam.

He was a passionate and great teacher who loved teaching, all that he had learned. He studied continually all his life and often talked at great length explaining even small things, to who ever listened. 

At the MMC Chennai, he was dealing with History of Medicine. He was guided in this direction by Prof B Ramamurthy (eminent neurosurgeon). He use to discuss these matters everyday at home, and made quite a number of projection 'slides' scanned from text books and other rare sources, spending a lot of his personal money from his salary. In those days, there were no computers. It was only then coming into use in India. They came up first at the banks, railway station ticket counters, etc., and invaded slowly to all other areas. Nowadays, its easy to make PowerPoint presentations and preserve it for eternity in our hard disks and Google cloud memory. And it was three decades ago. Unfortunately, father had to discard all those slides later as they got badly damaged due to time. He did indeed have a lot of literature concerning medical history which has long been missing.

As much as he had admirable students, he also was so reverential to his superiors and teachers. He interacted and infact inherited a lot of books from his seniors which he donated at a later date, due to want of space, to ardent adherents of the homoeopathic tradition.

Long after his retirement from government service, he developed a decade long association with his then Professor (in his student days) at Stanley Medical College and Hospital, who had long since retired, the late Dr Ramanathan, MS., General Surgeon, Biochemist, Homeopath and Ayurvedic expert. He was an octogenarian at that time, passionate with homeopathy and ayurveda which he discussed with my father almost every week ends. He taught me too, once on the subject of nosodes (I am no expert)  and on the late discovery of H pylori, asking me to spare the evening for him. Father called him a genius.

Father was a scholar of tamil language, and was equally good in English literature. He understood tamil poetry as well as Shakespeare with ease. He always edited and looked for grammatical and spelling mistakes, which we imbibed from him and still developing. 

Ofcourse, he pricked and scolded people for their insincerity, ignorance and lack of insights, into the nature of things. He was a scientific minded rational thinker who showed interest in science, philosophy and dry humour. 

He was a city bird who liked roaming around the busy streets of Sowcarpet and Mylapore areas. He liked tasting Basandhi, Poori, and Coffee at the busy hotels of Sowcarpet, where he had the blessing of being in the early and middle stages of his life. 

He was a free thinker and did a great deal of talking on all manner of things. He walked a great deal - window shopping, and every year, we visited the exhibition with family, at the island grounds, and never missed that train round-up. He took me to the 'circus' which use to be held those days near the old zoo and my lady's garden, behind the moore market, at choolai. 

He was a tolerant individual who never distinguished people based on religion, caste, creed or nationality. He was fond of Sri Ramakrishna Paramahamsa and Swami Vivekananda, his only great modern Gnani. He loved visiting the mylapore Sri Ramakrishna Mutt, and prayed to Shirdi Sai Baba and visited many of his temples. He also paid his respects to thirukovilur Gnanananda Swami and his Mutt and his being and philosophy. 

He liked the Ramayana written by C Rajagopalachari and Shiridi Sai Satcharitam. He quoted the Thirukural often. He enjoyed Adi Shankarachariyar's Bajagovindam, and Rajaji's Kurai Ondrum Illai song. 

His favourite deity was Lord Muruga, Lord Rama and Lord Sri Krishna. In his city days in Sowcarpet in the 80s, he visited in turns the Kandswamy temple, Ekambaranathar temple and Kaligambal temple to which my mother accompanied him, often staying for late night Kutcheries. But, he never was dualistic than advaitic in his spirit. He never worshiped much but never intervened with others too. And he greatly admired the Buddha. He knew all too well that, 'desire is the root cause of human sufferring' but never much understood fear, let alone love. 

He was fond of Ramana Maharishi of Thiruvanamalai, and has many books which are a collection of his teachings. He also studied the book Autobiography of a Yogi, by Paramahamsa Yogananda, and often wondered in private with me, what it all means ! Why people choose different paths ? Is there anything at all ? He wondered if there is any meaning for life ? Why this creation ? Why Carnivores exist in nature ? Why manifestation is puzzling and enigmatic ? What is it that is living in us ? And what is it that is dying ? Is this a test for us...like questions ? 

He studied Jiddu Krishnamurti whom he admired and was equally amazed with his teachings. He presented me, his "commentaries on living," telling me, 'this will clear all your doubts, fears and confusions.' But he called him the elite-polite  philosopher. And he quoted him too, within certain limits, never allowing  me to jolt him out of his orbit. 

He loved the belly laughter talks of the spiritual master Dada JP Vaswani, of Meera Movement, Pune. Whenever, dadaji visited chennai he took us to his hilarious spiritual discourses. We sought his blessings too. 

I found him to be neither a theist nor an atheist but simply a scientist, sometimes clear, sometimes unclear. And we did have a lot of dialogue, in which he always had a say, fearing my jolting him out of orbit, and regular routine of his life. Practical man of experience and knowledge and insight to allow too much doubt and questioning. I should have learnt my lessons !!

He admired hindustani and carnatic music and was fond of the bhajans sung by Sri Sathya Sai Baba himself. He once maintained a collection of cassettes of KJ Yesudas, MS Subbulakshmi, Lalgudi Jayaraman, Kunnakudi Vaidyanathan, Veenai Chittibabu, Purasai Arunagiri, Sirgazhi Govindarajan, Sai Bhajans, and others. He got me a violin and encouraged me to learn music, and study astronomy, medicine and philosophy. 

He has a daughter by name Aruna who is married to KS Sasikumar, an Engineer working in the USA. Mr Sasikumar, ME., (S/o late Thiru Konavattam Shanmugam, Retd from TN Secretariat), works in the software, a rational thinker and self-made person. Aruna was encouraged by my mother to learn Bharathanatyam, which she continued for many years. Father never objected to it but he insisted on her basic education. They have two girl children who are studious and also have been learning music.

I fondly remember with nostalgia his great admiration and enjoyment of the Jugslbandi by the maestro Zakir Hussain, at the Madras Music Academy. He loved it all. Unfortunately in his later years, he developed hearing loss and as a result was so frustrated to talk with people. He didn't much like the dependence of hearing aid gadgets eventhough he used them.

In the 1980, there was the Total Solar Eclipse. We were in Vaniyambadi, at that time, and I was ten years old, and in the 5th standard. We used mirrors to project the indirect image of the sun into our room to observe the eclipse. There were lots of unscientific  information and superstitions which frightened us. But the scientific curiosity to know, culminated in 1986-87, by ordering a newtonian reflector telescope from Devadas Telescoptics, Guindy, Chennai. 

After a period of six months at MMC, Chennai, where he did his Diploma in Public Health, and again four years as Municipal Health Officer at Gudiyattam, father got transferred as District Health Officer, of Thanjavur district. Since all the members of our family, having read before, the  romantic and thrilling, mostly fictious, but historical novel "Ponniyin Selvan" by Kalki Krishnamurthy, we all greatly enjoyed the time period of two years at the ancient capital of the Cholas. It was the time of the apparition of comet Halley in 1986. I was in the 10th standard. We couldn't succeed much with Comet Halley, but the ordered telescope was ready at Chennai. In the mean time,  we moved to Chennai and father joined as an Assistant Professor at Stanley Medical College. 

Here began my journey of an intellectually stimulating and spiritual, decade long relationship and a journeying together, with the famous writer-editor of the Indian Express and Hindu paper fame, Mr Harry Miller, MBE, AIBPP, ARPS, FZS (Lond).  It was my father who taught me how to write by dictating and editing my letters to him, in the initial days. Subsequently, as it happened latter, Harry Miller himself wrote me 35 long letters, editing my English language and enormously encouraging me in my astrononical pursuits, in the understanding of the nature of this cosmos. He was a force indeed ! A simple unassuming personality, who lived in the Boat Club Road, Adyar, in the later days of his life, before he breathed his last breath in 1998. 

He greatly admired the late amateur astronomer, Prof P Devadas, FRAS., telescope maker, observational astronomer and selenologist. He was so amazed when we first observed planet saturn for the first time, distinctly showing its ring. He directed me to learn from Devadas, the nuances of the science of observational astronomy and telescope making. And for his part, Professor P Devadas, took great care in explaining my doubts in astronomy and even paid his last respects to my departed mother enquiring dearly to my father, whose interest in astronomy, scientific outlook and encouragement, he valued and appreciated much.

Father got me the Cambridge Atlas of Astronomy, an authoritative source book, when we visited the book exhibition held in those times, at Arts College grounds, Mount Road, Chennai. Much before that, and in the days before, he regularly visited the British and American libraries, indeed dozens of times, as he was a voracious reader of all manner of things. It was in those periods, that he got me the books of the celebrated British Amateur Astronomer, Sir Patrick Moore, CBE, FRAS. That was how, I got introduced to amateur astronomy and I became an amateur astronomer. 

Thanks to father and his scientific upbringing, I somehow learnt to manage medical science, astronomy, philosophy, religion, music, art & culture, in a balanced way in my life.  And I am still learning. 

He loved cowboy movies of John Wayne and James Bond movies. He was too fond of Laural and Hardy movies and Tom & Jerry shows. He was fond of Gregory Peck and Guns of Navarone and the movies like Mackenna's gold, and Magnificent Seven, etc., 

He equally enjoyed old tamil movies like Thayagaraja Bhagavathar's Haridas, NS Krishnan's  meaningful comedies, and Sivaji Ganesan and Padmini movie  Thilana Mohanambal with Balaiyah and Nagesh comedy. He liked the movie Malaikallan particularly the character Abdul Rahim Sahib played by MGR and Enga Veetu Pillai.  Sivaji and MR Radha in Balapandiya, the movie Kathalika Neeramillai, and a few later period movies like Kamalhasans Michael Madana Kama Rajan etc., These  were my observations, spanning decades  long period. Generally, for most part, he was a silent man, studious and reserved and composed, rarely loosing his temper. 

He was a great admirer of Sir Arthur Conon Doyle and his great character the detective Sherlock Holmes and Dr Watson. He quoted passages from the novel. He loved watching the serial by Jeremy Bret playing Sherlock Holmes. He was greatly fond of the Scandal in Bohemia adventure and the novel Hound of the Baskervilles. He talked in length about the rival of Holmes, Professor Moriarty and the death of Moriarty and Return of Sherlock Holmes.

Eventhough he was not a sportsman he liked sports particularly Tennis. He encouraged body building and muscular exercises. He liked the all time great, the legendary Bruce Lee. He use to like and mention often the names of  Sir Garfield Sobers, Colin Croft and Wesley Hall. He was fond of Clive Lloyd, Vivian Richards, Joel Garner and the other west Indian pace bowlers like Patrick Patterson and Curtly Ambrose bowling. He often talked about Tony Greig lifting Gundappa Viswanath after viswanath hit him for a boundary. He liked Graham Gooch, Ian Botham, David Boon,  Sunil Gavaskar, Kapil Dev, Imran Khan. More than cricket he liked tennis, and encouraged me and my son to play that game, and be sportsmen. He encouraged us to exercise and be muscular and stay strong and fit. He was good at playing carrom himself and had won a few games too. He walked a great deal. 

He told us world war stories. He admired General Sam Maneckshaw. He watched the Republic Day Military Parade and never missed "Beating the Retreat" parade held three days after the Republic Day. He greatly enjoyed the lighting up of the Rashtrapati Bhavan and Parliament Buildings at the end of the parade and the return of the band singing Sare Jahan Se Acha...Hindustan Hamaraa.

He always studied books, taking meticulous notes with carefully drawn lines and markings. Of late,  and with much difficulty, he managed to learn to use the smart phone, internet and social media. 

He loved talking about Robert Hutchison, Samuel Hahnemann the founder of homeopathy, Albert Einstein, Thomas Alva Edison, MK Gandhi, Jawaharlal Nehru, Dr S Radhakrishnan, Swami Vivekananda, Bharathiyar, Mark Twain, Adolf Hitler, Gengiz Khan, John F Kennedy, C Rajagopalachari, Kalki Krishnamurthy, CN Annadurai and other intellectual philosopher-scientists and educationists.
He told me stories of how he escaped from the tear gas and huge crowds that gathered to the funeral procession of the first CM of TN state  CN Annadurai. He maintained objectivity and never took sides. He viewed people with equanimity and was non-judgemental. His disagreements and misunderstandings were short-lived and he always reflected with empathy unshown. 

He admired my capacities but always pointed to my not taking it to its fullest potential. He was fond of his grandson Aravind whom he loved dearly and greatly admires his physical and intellectual capacities. He dearly protected his daughter-in-law Mrs Meena whom he understood with empathy. He always instructively educated people strictly adhering to rationality and science, and encouraged them to prempt and prevent sufferring and diseases. 

His passing away has created a void in our minds which can never be filled. Only memories remain. 
May there be love and peace.