Down Memory Lane – Summer (Institutes) of 65 at RIEM

A throwback to the past

The Regional Institute of Education Mysore Alumni Association [RIEMAA] is making its presence felt in several ways through Facebook as well as its own website, http://riemaa.com/, and has recently come out with its own charter.   As a former principal of this prestigious institution, I keep myself in touch with some of its active members through the enormously popular social networking portal.  Recently I came across a number of group photos posted in the portal, including the one reproduced below, which jolted my memory strongly.  On seeing it, I wrote by way of a comment; "This combined group photo was taken in the summer of 1965 when the Physics and Chemistry departments of both the University of Mysore and RIE Mysore held their first ever summer institutes for college teachers with active support from the USAID. It has opened up the flood gates of my memory and I intend to write about these events in some detail one of these days in my own blog."  As promised, I am travelling a long time down memory lane to narrate the story associated with this photo dating back to the summer of 1965.  While the associated events and people are deeply etched in my memory, it is astonishing that I couldn't even remember that such a photograph had ever been taken even though the RIE main building provides the backdrop for it.  So, one can imagine what a pleasant surprise I had in discovering it.  I don't know how this precious photo was unearthed, but am thankful to whoever did so, scanned it and posted it in the RIEMAA portal.  Three of us had been correctly tagged in the picture and I have identified as many others as I could recognize in the caption provided below the photo.

[Click to enlarge]

Seated from left: (5) Prof G Chaurasia, Principal, RCE; (6) Prof K L Shrimali, VC of Mysore University and former Union Minister for Education; (7) Prof Steve Cram of Kansas University, USA (Physics Consultant attached to RCE); (8) Prof Koelsche (Chemistry Consultant from USA attached to RCE); (9) Prof S Chandrasekhar FRS, HOD University Physics Dept; (11) Prof M Devadasan, Vice Principal and HoD Education of RCE.

Standing from left: (1) Mr N Ganesan (Administrative Officer, RCE); (3) Prof K N Srinivasa Rao (University Physics Dept); (6) Mr S Raghavendra Rao, RCE HoD in Chemistry; (7) Dr V Rajamadhav Rao, RCE HoD in Physics; (9) Self!; (11) Mr B N Singh, RCE Chemistry lecturer.

The Roots

The National Council of Educational Research & Training (NCERT) was founded as an apex body for school education in the country in 1961 and two years later its regional units, including the Regional College of Education (RCE) in Mysore, were set up.  Later upgraded as the Regional Institute of Education (RIE), I joined the RCE Mysore on my birthday in September 1964 and soon got busy with the developmental activities of the fledgling institution. Incidentally, the chairman of the committee at NCERT headquarters which selected me for the job of lecturer was, by a happy coincidence, Prof S Chandrasekhar, then Head of the Physics Department in the Mysore University who is seen prominently in the above photograph.  My association with this famous physicist was to continue in many ways as this narrative unfolds.

  

The main focus at the RCEs was on the four-year integrated in-service teacher education courses (BSc Ed, BA Ed and the short lived BTech Ed) which brought subject specialists like me and pedagogy experts like Prof P N Dave together for the first time in the country.  Dr V Rajamadhav Rao (seen in the photo) was my senior colleague in the Physics faculty and together we put in a lot of effort in designing the curriculum and course content for the BSc Ed programme.  We also had a modest role in the more traditional one year B Ed course.  Developing the Physics laboratories was a huge effort in which we were aided by a large consignment of excellent science teaching equipment and materials of Russian origin received through the Unesco.

 

The American Connection

Around the same time, the NCERT and the RCEs became beneficiaries under the academic assistance programme of the United States Agency for International Development (USAID) which provided the real stimulus for the RCEs embarking on the four-year integrated programmes, much on the lines prevailing in American institutions.  The RCEs came to be associated with the Ohio State University College of Education which organized advanced training for some of their academic staff in the USA.  I was to be a beneficiary of this in 1966-67.  But, before that came the summer institutes in several science subjects for college teachers in the country, organized with active support from the USAID through a number of American universities and institutions.  RCE Mysore was selected to host a six-week summer programme each in Physics and Chemistry for in-service teachers from colleges of education in the southern region, as was the University of Mysore for teachers from degree colleges. This was a rare distinction for an institution so new, young and inexperienced.  We had to prove ourselves worthy of the trust.  We needed to put in some very hard work.

New Science and Mathematics Curricula in USA

Stung by the shock treatment meted out by the Russians in the space race, the American administration challenged the education system in the country to come up with grass roots level reforms in Science and Mathematics curricula, particularly at the school level, to regain its dominance.  A number of new curricular programmes were hurriedly developed and implemented all over the country.  Hosted by the famous Massachusetts Institute of Technology (MIT), the Physical Science Study Committee (PSSC) came up with a radically new and innovative curriculum in Physics that came to be known as PSSC Physics.  It was designed to promote a sound understanding of the basic concepts of Physics through new text material supported by investigative laboratory activities centered on simple and inexpensive equipment, a very comprehensive teachers' guide, student manuals, a set of standardized achievement tests, supplementary reading materials and a large number of 16 mm films related to the curriculum content.  Similar curriculum projects were developed in Chemistry and Mathematics as well.  Some of the best known scientists and science educators in the country were associated with these projects, including a number of Nobel laureates in both Physics and Chemistry.  These projects erred on the side of over ambition and could not be sustained for long in the American system.  However, they were the forerunners of more pragmatic versions to come.  The PSSC made way later for a less demanding, more liberal and broad based Harvard Physics Project (HPP). 

 

The Indian Context

In those days India had come under the umbrella of the USA in many spheres, including secondary and tertiary education.  The Indian education system welcomed American initiatives in introducing the new science and mathematics curricular programmes for tryout in many institutions in the country, including the RCEs, through specially tailored summer training programmes for teachers and teacher educators.  All the curricular materials had been shipped to us in multiple sets sufficiently in advance.  We therefore had adequate time to study and familiarize ourselves with them.  For me and many others like me, it was a highly enriching experience doing this and thereby learning some really meaningful Physics for the first time in our lives.

For teaching Physics at collegiate level, USAID sources had identified a number of resources including laboratory equipment for advanced level experiments, some of which had been designed and prototyped in institutions like Caltech and MIT.  Apparently because of the four-year integrated science and technology programmes, the RCEs also received complete sets of these equipment and materials apart from selected institutions like the University of Mysore.  Though these were not intended for use specifically at the 1965 summer institutes, they were to be used extensively in the undergraduate and later postgraduate pre-service courses at RIEM.

  

USAID also realized the need for competent and experienced human resources for a successful conduct of the summer institutes.  To ensure this, a senior professor from reputed American educational institutions was attached to each of the summer programmes in India as an academic consultant and adviser.  At RCEM we had the services of Professor Steve Cram (seen in the photo) of Kansas University who had a rich experience of the formative processes involved in the development of the PSSC Physics curriculum.  A very kind and fatherly figure, he was a major source of inspiration for my own activities in the summer institute.  We also had the part time services of Prof Lane Branson, a physicist-cum-electronics engineer to help us with the laboratory equipment and materials.  He liked Mysore city and the college so much that he returned to RCEM for a long-term association with our USAID supported Physics Resource Materials project in the late sixties.

Some dramatis personae in the photo

The group photo was taken presumably at the time of the joint inauguration at the RCEM campus of the four summer institute programmes, two each by the University of Mysore and RCEM, by Dr K L Shrimali, the then Vice-chancellor of the university to which RCEM was and still is affiliated.  Dr Shrimali was an eminent educationist of the country, a former minister for education in the central cabinet under Jawaharlal Nehru, a Padma Vibhushana awardee later in life and a worthy successor to the legendary Sardar K M Panikkar as the university's vice-chancellor.  He was a great friend of the college and evidenced special interest in its development.

Dr Chaurasia was the founder-principal of the college and the architect of its sprawling 130- acre campus which is one of the most picturesque sights today in the city.  Dr Devadasan was the vice-principal of the college and nominated as the joint director of the two summer institutes held in its campus.  As he had no science background he looked after only the administrative aspects.  He was assisted by Mr N Ganesan, the Administrative Officer of the college. Dr Rajamadhav Rao and I represented Physics while Mr S R Rao and Mr B N Singh looked after Chemistry.  Dr Koelsche was attached to the Chemistry institute as the visiting consultant.

Apart from Dr Shrimali, the most important person seen in the photograph is Prof S Chandrasekhar, the then HoD of the University Physics department and a nephew of the great Indian physicist and Noble Laureate, Prof C V Raman.  He should not be mistaken with his namesake the Indian-born astrophysicist Prof S Chandrasekhar, of the University of Chicago, but the two Chandrasekhars happened to be cousins. The astrophysicist Chandrasekhar was awarded a Nobel Prize in Physics in 1983 for his stellar work on stellar evolution done half a century earlier [see my blog post titled, "Chandrasekhar, Fermi-Dirac and White Dwarfs (Aug 11)"].  The Chandrasekhar seen in the photograph went on to become an outstanding Liquid Crystals physicist at the famous Raman Research Institute (RRI) in Bangalore, founded by his great uncle.  His achievements merited the fellowship of the Royal Society of England, an honor often regarded as only one rung below that of the Nobel Prize.  I had the great good fortune of working for my doctorate degree in Physics under him during 1977-81 as a UGC Fellow at RRI.  I had assisted him in several ways while he was at Mysore and he rewarded me for this by sponsoring me for a UGC fellowship when the scheme was first introduced in 1977.  Under this scheme I was attached to RRI on study leave even while remaining in the college service on full pay and other benefits.  The four year span I spent in the Liquid Crystals Labs of RRI was some of the most memorable in my life since it exposed me to frontline research in the field as well as bringing me in touch with some of the very eminent physicists of the day. A particularly memorable event of this period was an international seminar on Raman Spectroscopy organized in Bangalore by RRI to commemorate the fiftieth anniversary of the discovery of the famous Raman Effect in 1928. I was one of the active volunteers in its organizing committee.

Another person seen in the photograph that I remember very fondly is Prof K N Srinivasa Rao, an outstanding Mathematical Physicist who was earlier my teacher at the Central College, Bangalore during 1956-59.  With a wry sense of humor and wit, he was an exceptionally gifted and inspiring teacher who came to his classes with just a few pieces of chalk and could work out even the most complex derivations and problems of mathematical physics in a spontaneous and beautifully organized handwriting on the black boards, without reference to any written notes or books.  Curiously, he had only four fingers in his writing hand and I had seen him play some decent tennis as well using it.  The tennis I myself learnt and played later was a closer imitation of his prowess in the game than I was ever able to manage in measuring up to the mastery of Physics he displayed!

Finally, let me shift the glare of attention in the photo to myself.  People who have known me over the last two or three decades may find it impossible to believe that the funny looking skinny little figure in the ill fitting coat and very ill at ease as well, with part of the lower left side of the anatomy appearing to be missing, is really me as I was the year after I had joined the college!  Perhaps the saving grace in the photo is that I was obviously the youngest of the lot!  When I first saw the photo in the Facebook, I too couldn't believe the sight, but then I found to my chagrin an old photo of mine at home from the same period mocking at me in the face, dispelling any doubts whatever.  So, I have to own up to my identity.  Fortunately, the face doesn't betray my hard work and exertions during those days when day and night as well as home and work-place had merged into a continuum to make the enterprise a success.

A look back

Enough planning and organizational effort had gone in to make the Summer Institutes of 1965 a success and a landmark in the history of the institution.  The traditional lectures made way for interactive discussion sessions with liberal use of teaching aids, supported strongly by laboratory exercises built around the PSSC equipment and materials. The films also played a very useful role.  Some sessions were devoted exclusively to the role of teacher educators in promoting science education.  I was as much a participant in the programme as a resource person and, in purely academic terms, ended up receiving much more than I could give; such was the impact of the new PSSC curriculum materials at our disposal. The participant enthusiasm and feedback were both encouraging.  The institute laid the foundation for more such efforts in the future, on a regular annual basis, for well over a decade from then on.  They added significantly to RIEM's reputation and status as a premier institution for teacher education in the country, something that is sadly on the decline in the recent past.  RIEMAA should contemplate how it can contribute to arresting this trend and even reversing it if possible.

Nature's Bounty in God's own Country, Wayanad – Personal Photo Album Part 12

Background

In my last travelogue on the sights of Kumarakom in Kerala I had made a passing reference to my recent visit to Wayanad, the hilly and scenic district in the northern part of Kerala, indicating my intention to blog about it someday.  I feel I should do so forthwith while the visit is still fresh in my memory.

 

It was early one morning a little over a month ago when my daughter in Bangalore rang me up to announce that she and her family were embarking on a three day visit to some scenic places in Wayanad and invited her mother and me to join them on their way through Mysore.  My immediate reaction was to decline the invitation on the rather unconvincing plea that I had no special interest in Wayanad that justified spending two nights away from home.  When I mentioned this to my young confidant Chiranjeevi later that day, he flew into a paroxysm of disbelief that I of all people should be thinking so.  He narrated his own experience of Wayanad, particularly the famed Edakkal Caves, and prevailed upon me to reconsider my decision.  I sheepishly conveyed this to my daughter who had just about started doubting the adventurous spirit that I had demonstrated on numerous occasions in the past, particularly during my visit all by myself to China two years ago.  My momentarily tarnished image was swiftly restored and our team of six, spanning three generations and nearly seven decades, was happily on its way two days later, with the prospect of great weather beckoning us everywhere.  As it turned out, it was a delightful and memorable experience for all of us.

The Journey

We started our journey on the Mysore-Calicut road rather late in the morning and, on the way, made a detour to visit the Gopalaswamy Temple and surroundings on a hill inside Karnataka.  It is a very quiet and peaceful place dominated by the temple and often known to be enveloped by low lying clouds and mist early in the morning; but we had reached there well past the time to experience any of it.  Yet, the place held out a peculiar charm and was well worth the detour.  Here is a picture of the temple seen behind a fascinating tree which held centre stage for me.  Discerning readers may have noticed this type of tree appearing in several of my earlier photo albums as well.

 

[As in my previous albums, all pictures are in high resolution and can be blown up to their full size by clicking on a picture and opening it in a separate window] 

As we drove through the fairly long stretch of Bandipur forest between Karnataka and Kerala (my son-in-law doing all the driving all the time), the two children were eagerly looking forward to spotting any wild life they had been taught to expect, but were very disappointed to see only the all too familiar monkeys on the way. This was the case on our return journey too.  How sad they had to be content with the wild life they had seen only outside their natural habitat, mostly in the Mysore Zoo!

Sultan Bathery

It was lunch time when we reached our destination, Sultan Bathery, the most prominent town in the district, where we checked into Hotel Mint Flower, a spacious and comfortable hotel right on the main road.  It was to act as the base for our visits to different places during the next two days.  The name Sultan Bathery is a localized version of the older English name, Sultan Battery, named after Tippu Sultan, the famous former ruler of Mysore who had used the abandoned local Jain Temple to house his armory.

We had a quick lunch and set out on our first visit, to Pookot Lake, about 50 km away, most of the distance on the highway leading to Calicut.

Pookot Lake

The Pookot Lake is a fairly large water body, surrounded by rich greenery adding to the scenic beauty.  Boating is very popular, with boats of a variety of types available for hire.  We hired a row boat large enough for the six of us and spent most of the evening on the lake, enjoying the soothing experience on the calm waters.  We also visited a rather poorly maintained small aquarium within the lake complex, with the fish definitely more interesting than their neighborhood which was indeed an insult to the natural beauty of the lake and its surroundings.  There was also a small park for the children to play before dusk set in and we had to leave the place.

Here are two pictures of the lake and its surroundings.  The first is a panoramic view of most of the lake, with the boarding area for the boats in the foreground. In the second picture I rather unintentionally captured a more serious fellow photographer at work on one of the banks of the lake.

Early next morning, anticipating a very long day with visits to as many places as possible in unfamiliar and difficult terrain, we decided to leave our car parked at the hotel and hired a wide bodied jeep with the driver doubling up as our guide as well.  My son-in-law got full reprieve for the day from his arduous driving duties. After a sumptuous breakfast, we started with visits to two nearby places, both very close to the town.

Jain Temple

Our first visit was to the remains of the once famous Jain Temple that Tippu Sultan is said to have used to house his armory. Located close to a main road down a short sloped approach, lined on both sides with beautiful flower beds and lush greenery, the stone edifice stood out in a sunken quadrangle. It was in obvious disuse, but otherwise well maintained by the archaeology department of the government of India. The bare and drab stone structure was in sharp contrast to the strikingly rich greenery surrounding it on all sides.  Here is a picture taken from inside the structure and overlooking the entrance, with the identities of the three people caught unawares quite easy to guess.

On our way back, I couldn't help being attracted to the flower beds as strongly as the two children.  Some of the flowers were in full fresh bloom and I took a number of pictures of these magnificent gifts of nature to humankind in their natural habitat.  I am presenting one of them here as a strikingly appropriate symbol of peace and tranquility, in stark contrast to the symbol of conflict and intolerance that the place itself once appears to have been.

Heritage Museum

Our next visit was to the Wayanad Heritage Museum located very close to the town.  This small museum is appropriately housed in an ancient building, surrounded by rich greenery and a children's park.  It was only natural to expect the two children to rush into the park and start playing on the swings so thoughtfully provided, leaving the museum for the elders to explore.  However, after some time they were persuaded to join us and look at the varied exhibits, mostly of stone implements, hand tools, sculptures, terra cotta objects and other artifacts belonging to the tribes that had populated the district many centuries ago.

Here are two pictures of the heritage museum building and the park:

Tea Gardens

Our next destination was the Kanthanpara waterfalls on the way to which we passed through some of the most beautiful tea gardens in the state.  We got down at one particularly attractive place, walked up a large sloped tea plantation, soaked in the serene atmosphere and spent a good bit of time wandering around aimlessly.  Here are two pictures of this lovely place:

Waterfalls

The Kanthapara waterfalls are not as well known as two others (Meenmutty and Soochippara) in the district which we had to miss for want of time.  More difficult to reach and for this reason less frequented, the place and the winding road leading up to it are surrounded by some of the most spectacular and picturesque greenery in God's own country, including the tea plantations pictured above.  When we reached the falls, under the protection of the state forest department, there were no other visitors and the place was all ours to explore, guided thoughtfully by a departmental official in uniform.

 

The following picture shows the rather shallow first stage of the three-stage falls seen at the end of the lead up road.  Incidentally, it also captures the whole of my daughter's family.

When we first saw this we were rather disappointed by the very short depth of the water fall though the surrounding sight was very impressive.  But our guide quickly assured us there were two more, progressively deeper, stages to follow and led us downhill to the first of them. It is captured in the following picture from such a close vantage point that he became rather nervous and breathed a sigh of relief when I moved away after I had clicked my pictures.

We had to gingerly walk further downhill and a fair distance as well before we came face to face with the last and the deepest stage of the falls shown in the following picture.

The sight was quite breathtaking, particularly because of the large volume of water flowing down from a height of about 25 meters.  Our guide explained that the large flow was because of the copious river water following a good monsoon season that had just ended.  After a decent time spent immersed in the scene, we walked back to the starting point where the guide encouraged the children to take off their dress and give each other a wild bashing in the shallow and safe waters a short distance away.  Their unabashed merriment went on for so long that they had to be dragged out from the place with the promise that more was in store for them later in the afternoon.

Before our next visit we made a detour to nearby Kalpeta, another large town in the district, and had a barely tolerable lunch in a vegetarian hotel which our driver had rated as the best in the town.

Banasura  Reservoir

Not far from Kalpeta is the Banasusra Sagar, a large reservoir formed by the largest earthen dam in India.  With enchanting scenery all around and located far from the madding crowd, it is an excellent picnic spot.    At the protected entrance to the site we had to buy a group ticket for a jeep to drive us through a devious path to the picnic spot.  The reservoir was nearly full, the sky gloriously blue, the weather quite windy and the waters far from calm. They all seemed to add to the beauty of the place.

 

Speed boating on the lake is a major attraction.  But with only two boats plying at that time there was a considerable wait for our turn; we were in no hurry whatsoever. The children were a bit apprehensive while boarding their boat but returned from the fifteen minute trip with an excitement and thrill only they are capable of experiencing.  After this they had a long stint in the nearby park while I went around exploring the place with my camera.  Here are two pictures from my collection, both showing the lake in all its splendor.

Banasura Island Retreat

While we were at the Banasura dam site, we came to know about a well isolated small island resort located near the other end of the lake and wanted to visit it on our way back.  Our driver had a hard time finding it and an even harder time driving up to it over a narrow gravel road that could have been designed as a test for both the vehicle and the driver. He was not too pleased with our request to change our original plan and visit this place which even he had not heard about. 

When we finally ended up at this resort it was worth all the trouble we had taken.  As advertized, it was indeed a place where one could experience a 'life of silence... stung with the beauty of nature' [See http://www.banasuraisland.com/images/banasura.pdf].   Commanding a wonderful view of the lake and the lush greenery all around, it is the ideal sort of place for anyone seeking to move far away from the madding crowd.

We were greeted by the manager of the resort who took us round and showed us all its features and facilities, including two luxury cottages directly facing the lake and providing a spectacular view as can be made out from the following two pictures:

The next picture taken from the top of the resort's main building shows a particularly enchanting sit out under a thatched roof in the foreground and a building housing the restaurant and recreation facilities in the background, both blending nicely with the surroundings.  We learnt that the resort was a very popular weekend retreat for harassed senior executives from the corporate sector.

It was getting dark by the time we had some refreshments and tea in the resort's restaurant.  So we decided to call it a day and asked our driver to take us back to our hotel in Sultan Bathery for an early dinner and a well deserved night's rest.  We were well aware that the hardest part of our trip was due next morning.

Edakkal Caves

We had an early breakfast, checked out of our hotel and headed for the famous Edakkal Caves nearby about which we had heard a great deal in advance.  Everybody had warned us that reaching the prehistoric caves at the top of a steep hill after a considerable walk from the parking lot would be a herculean task and had strongly advised the two septuagenarians among us to keep off and let the younger ones indulge in the adventure.  I had absolutely no intention of heeding such advice, especially in the light of my experience of climbing up the Great Wall of China near Beijing on a summer day in 2009 and the less strenuous Rock Fort in Trichy just last year, both after I had acquired my age tag. 

Edakkal consists of two caves, the larger one straddling on top of the much smaller one, both formed out of very large boulders just below a steep hilltop. To reach the lower cave one has to walk along a man-made pathway, sloping up rather steeply most of the way, a distance of about one and a half kilometers from the parking lot.  It is relatively easy to reach, but the way to the upper cave, which can be reached only through the lower one, is very steep, rough and rocky and would have been even dangerous had it not been for the erection of staircases with iron railings and wooden steps in strategic locations leading up to each of the caves.  They have been identified as a habitat of the prehistoric Neolithic people (of the late Stone Age dating back six to eight thousand years) on the basis of the hieroglyphic like carvings on the cave walls that have survived to this day. This was a historic discovery made by an English archaeologist around 1890.

It was hot and sunny when we started on foot from the car park, went past the entry gate where a system of traffic control was being enforced to ensure no abnormal build up of the crowd uphill or downhill and reached the foot of the first cave after giving ourselves frequent rests on the way.  The children didn't need any such rest and it was more like a walk in the park for them.

While climbing up through the first cave with quite a crowd around me, I irretrievably lost one of my slippers which slipped away between two of the wooden steps.  I had been utterly careless about proper footwear for at least this part of my trip and had to put up with considerable discomfort thereafter until I was back in the car.  It was not without difficulty that I managed to reach the top, climb down a flight of steps and step inside the upper cave, with a feeling of accomplishment not unlike the one I had experienced on the Great Wall of China.  Here is proof that I had indeed made it to the enthralling Edakkal Caves.

After the five of us had spent a long time resting and relaxing, looking at the strange wall carvings and taking plenty of pictures from all vantage points, it was time to retrace our journey.  Strangely, we were pretty much alone and not a soul could be seen on the staircase leading down to the lower cave which had been bristling and bursting with people barely half an hour earlier.  My next picture has captured this rather extraordinary sight.  The only explanation I could think of was that the upward traffic had been blocked at the entry point for some unknown reason.  We didn't investigate this any further, but the picture of the entry gate I clicked on my return journey and presented below lends some support to my assumption.

Epilogue

After the excitement of the Edakkal Caves, we bade goodbye to Wayanad which we could not explore fully and hope to revisit someday to fill in the gaps. On reaching Mysore late that evening, I called up Chiranjeevi to thank him for his persistence with me and told him about my Edakkal experience in particular.  After quizzing me he said that we had not in fact seen all of it.  He distinctly remembered having been able to climb up the hill behind and above the upper cave.  Then I remembered reading a signboard at the top to the effect that entry beyond that point was forbidden; there were also two guards to enforce this diktat.  I have asked myself if I would have ventured further and higher if there had been no such restriction.  In all fairness I should say the answer is an emphatic yes.

Dark Matter, Dark Energy and the Runaway Universe

In a spiral galaxy, the ratio of dark-to-light matter is about a factor of ten. That's probably a good number for the ratio of our ignorance-to-knowledge.  We're out of kindergarten, but only in about third grade.

Vera Rubin (1975)

Prologue

When the Nobel Prizes in Physics for 2011 were announced earlier this month, I just happened to be reading a book titled "The 4% Universe – Dark Matter, Dark Energy and The Race to Discover the Rest of Reality" written by Richard Panek. Also by a strange coincidence, I happened to be reading the particular section of the book describing the works of the three cosmologists, Saul Perlmutter, Brian Schmidt and Adam Riess, who ended up sharing the award for their mind boggling and remarkably unexpected discovery concerning the ultimate fate of the Universe, made at the turn of the last millennium.  I wonder if I was subconsciously anticipating the award.

I devote this post to a description, as far as possible in nontechnical language, of the key astrophysical and cosmological concepts leading up to this discovery, some of the more important related discoveries leading up to it and their implications to an understanding of the nature of the Universe.  In doing so I will naturally be indulging in oversimplification, sacrificing much of the rigor associated with such advanced concepts in a frontier discipline like Cosmology.  Interestingly, the whole story is less than a century old.

Unlikely as it may sound, some of the basic concepts of contemporary physics and astrophysics central to this story have been touched upon in my two previous blog posts titled "Bose and Einstein – A Historic Collaboration (Jul 11)" and "Chandrasekhar – Fermi-Dirac and White Dwarfs (Aug 11)", respectively.  Readers without a background of collegiate physics may find it helpful to read them first before continuing with the present one.  Even if they don't understand all of what I am trying to convey, my purpose will be served if I am successful in generating a little bit of the excitement that is sweeping the scientific community today. Incidentally, the whole story is intricately woven around the edifice of Einstein's General Theory of Relativity.

Beyond the Milky Way

Less than a century ago, our view of the Universe did not stretch beyond the familiar Milky Way and numerous objects presenting a fuzzy appearance were classified as nebulae and believed to be part of the Milky Way.  However, bigger and better instruments like the 100" Mount Wilson telescope in California and vast refinements in techniques of spectroscopic and photometric analysis, showed that most of these nebulae were actually far away galaxies much like our own Milky Way, a discovery we owe principally to the great Edwin Hubble.  A typical galaxy has about as many stars in it as there are galaxies in the Universe (this number is about a hundred billion).  For example, the naked-eye fuzzy object in Andromeda constellation, formerly thought of as a nebula, was shown to be a galaxy much like our own Milky Way and situated about 2.2 million light years away.  A light year is the distance travelled by light through free space in one year, travelling at the constant speed of 300 000 km/sec, and is equal to 9.46 trillion kilometers.  This may be an unimaginably large distance by earthly standards, but quite puny on the cosmic scale.  The Andromeda galaxy is indeed our nearest galactic neighbor among a galactic population of hundreds of billions (I am ignoring two satellite galaxies called the Large and Small Magellanic Clouds, which are much closer and can be seen in the southern skies).  Our Sun is an insignificant star in an equally insignificant part of the Milky Way; and the Earth is, but for the intelligent life it harbors, a rather insignificant part of the solar family.

Measuring Galactic Distances

The world of astronomy and astrophysics boasts of some great female personalities, one of them being Henrietta Swan Leavitt of the USA, whose painstaking and pioneering work in 1908 led to the development of what is called the 'standard candle' for the measurement of distances on the galactic scale.  She discovered a remarkable class of stars of periodically varying brightness, known as cepheid variables, which exhibit a precisely predictable relationship between their intrinsic brightness and periodicity.   This means, if we measure its variation in brightness from one peak value to the next (this is easy to do with a photometer), we can work out how bright it actually is.  If the light from it is bright enough to measure (as can often be achieved through powerful telescopes), we get its apparent brightness. A measurement of its periodicity yields its actual brightness. Using the inverse square law of variation of brightness with distance, it is then possible to work out its actual distance.

If we want to know how far away a particular galaxy is, we need to discover at least one cepheid variable star within it and apply this technique. This has been done successfully with almost all nearby galaxies.  However, if a galaxy is too far away (typically billions of light years away) the technique won't work because the individual stars cannot be resolved sufficiently to look for variable ones.  As we shall see later, the three cosmologists winning this year's Nobel Prize for Physics solved this naughty problem by studying another class of stellar objects called supernovae, which can be discovered even within such far off galaxies, and developed another 'standard candle' for the measurement of very large inter galactic distances.

   

Measuring Galactic Speeds

All objects in the Universe are in constant motion, with different speeds and in different directions with respect to each other at any instant of time.  These parameters associated with any stellar object are as important as its distance from any observer.  A simple and well known principle of physics, called the Doppler Effect, enables us to determine them through some straightforward observations.

To understand the Doppler Effect, let us recall a common experience most of us would have had.  This is the distinct difference in the pitch (frequency) of the sound emanating from a railway engine hooting as it is passing by us at a fair speed near a railway track.  As it is approaching us the pitch sounds distinctly higher than as it recedes from us.   When compared to the pitch from a stationary engine, the pitch from the receding engine is reduced and the one from the approaching engine increased.  In other words, the wavelength (which is the inverse of the frequency or pitch) of the sound note from the object moving away from us increases and that from any object approaching us decreases.  The magnitude of the change is related to the speed of the object; by measuring it we can also measure the speed of the object.

 

The Doppler Effect is also applicable to the light (or any electromagnetic radiation) emitted by any stellar object.  By using the Doppler formula one can determine the speed of the object by measuring the change in wavelength of a suitable spectral line in the radiation emitted by the object using a spectroscope attached to the viewing end of a telescope.   The change is of course with reference to the same spectral line from a suitable terrestrial source which is at rest with reference to the measuring equipment.

Most Doppler measurements of the speeds of stars and even nearby galaxies in the early phase of such experiments were consistent with the expectation of a random distribution of such speeds.  However, as bigger and better telescopes came into use and measurements could be attempted on the more distant galaxies, a discernible pattern started emerging, mainly through the efforts of Edwin Hubble who did his measurements with what was at that time the world's largest telescope, the 100" Hooker Telescope on Mount Wilson in California.   He observed that most of these distant galaxies showed a 'red shift', meaning that their spectral lines systematically showed an increase in their wavelengths.  Clearly, they were moving away from us at speeds that could be determined from the measured shifts.  This finding was highly unexpected and sensational by itself.  However, an even greater sensation was to follow when it was noticed that the farther away a galaxy was the greater its red shift, i.e. its speed away from us.  The effect was readily quantifiable.  The speed was directly proportional to the distance!  For some reason, the whole Universe appeared to be expanding in a rather simple way, at least when looked at on a sufficiently large scale.

The Big Bang Universe

Hubble's discovery of distant galaxies speeding away from us, and from each other, at ever increasing speeds, could be interpreted only one away – that they must have started off on their journeys close together once upon a time in the distant past.  Arguing on this line, the Belgian astronomer-cum-catholic priest Georges Lemaitre, who had worked with Arthur Eddington in Cambridge, suggested that all the galaxies and by implication all the matter in the Universe must have originated from a 'primordial atom', marking the very birth of the Universe. Significantly, he was not envisaging the 'creation' of the Universe in the biblical sense, but purely as a theoretical construct to fit the observations.  As the idea developed further, principally by Alexander Friedmann, Ralph Alpher and the charismatic George Gamow, the entire Universe was visualized as an incredibly dense, super hot and compact primordial entity which, for some as yet unclear reason, blew up in a gargantuan explosion, started expanding very rapidly and in due course ended up in the form that we find today. On the basis of the measured speeds of the receding galaxies the process was estimated to have started about twenty billion years ago. Details of all that happened from time zero till to date needed to be worked out, but the basic idea sank in and attracted attention as an alternative to the prevailing 'steady state' theory which visualized the Universe as without a beginning or an end and without any mad rush among its inhabitants to run away from each other.  Fred Hoyle, who had championed the steady state theory and was unimpressed by the new idea of an expanding Universe with a definite beginning in time, called the latter disdainfully as the Big Bang and the name has stuck ever since.

 

Einstein's Blunder

The concept of an expanding Universe with a definite beginning had been an unwelcome consequence of the General Theory of Relativity. Einstein had derived an equation for the behavior of the four dimensional space-time continuum in which gravitation was interpreted as a geometrical property of the continuum, with matter producing a distortion or curvature of it to enable objects to move in it the way they are observed to move.  An expanding Universe was a logical consequence of such an exercise. However, Einstein's belief in a static, steady state Universe was so strong that he tweaked his equation to conform to the concept by arbitrarily introducing an extra term called the cosmological constant into his result. Later, when Einstein realized that the theoretical foundation for the expanding Universe had been staring at his face all the time and that he had lost out on what was perhaps the most important discovery in cosmology up to that time, he termed the introduction of the cosmological constant as the biggest blunder of his life.

Cosmic Microwave Background (CMB)

The observed accelerations of far away galaxies did provide a very sound argument for the Big Bang theory but more was needed before it could supplant the steady state theory and take root as the definitive theory of formation and evolution of the Universe.  Such a 'smoking gun' was provided serendipitously in 1965 by two Bell Telephone Labs researchers in the USA who were using a horn antenna for detection of annoying radio interferences from nearby sources.  A systematic observation led the two, Arno Penzias and Robert Wilson, to the totally unexpected and puzzling discovery of a uniform but faint microwave background radiation coming from everywhere in space.  The radiation was interpreted by Robert Dicke, David Wilkinson and others at the nearby Princeton University as left over from an early stage in the evolution of the Universe, and its discovery was considered a crucial test of the Big Bang theory of the Universe. From the measured wavelength and energy distribution of this cosmic microwave background (CMB) radiation and using Planck's radiation formula which links them to temperature, they could determine the temperature of the material emitting the radiation to be around 3K (three degrees on the Kelvin scale, which corresponds to about minus 270 degrees on the familiar Celsius scale).  This could be interpreted as the mean temperature to which the Universe has cooled today starting from an extremely hot and dense phase around 20 billion years ago.  With some assumptions it was possible to estimate the temperature at which the whole process should have started and the rate at which the cooling has proceeded since then.  The starting temperature should have been so enormously high that the 'primeval atom' should have consisted only of pure energy, with particles materializing from the energy at a slightly later, cooler epoch.  From then on the formation of nuclear matter, synthesis of higher elements, atoms, molecules, etc., should have all followed according to the laws of physics which are now well understood.

The highly uniform temperature of the CMB radiation over the entire sky strongly supports the Cosmological Principle according to which the Universe is homogeneous and isotropic when averaged over very large scales.

The discovery of the cosmic microwave background radiation proved such an important cog in the wheel of the Big Bang and the subsequent expansion of the Universe that it won a Nobel Prize for Physics in 1978 for Penzias and Wilson.  The Big Bang theory found its footing and the intellectually satisfying steady state theory began to fade away into oblivion, unable to withstand the assault from observational evidence, much to the annoyance of people like the flamboyant Fred Hoyle and his Indian associate Jayant Narlikar.

The Evolving Universe

Our present-day understanding of the evolving Universe based on the Big Bang model rests on a rock solid foundation of observational evidence provided by telescopes and accessories of ever increasing sophistication, ranging from the now defunct Hooker telescope used by Hubble to NASA's immensely useful space telescope appropriately named after Hubble himself, still very much in use.  In between, we have had a number of progressively larger and more advanced ground based telescopes in different parts of the world. Tools and techniques of Information and Communication Technology have played a crucial role in the process.  For example, the CCD camera which is so ubiquitous in hand held electronic devices today has revolutionized astronomical imaging techniques beyond belief.

  

Without pausing to address the crucial question of how, let me summarize what we know about our Universe today.  However bizarre the ideas may appear, they are all backed by strong observational evidence.  Incidentally, when we talk of an expanding Universe we mean that space itself is expanding, carrying with it the galaxies like spots on the surface of an inflating balloon, in a manner consistent with Einstein's General Relativity.  Also, a question like what is it expanding into is meaningless since by definition there can be nothing outside the Universe.

The Big Bang event is now reliably determined to be 13.7 billion years old, not 20 billion as initial estimates indicated.  It all began in a blinding flash lasting the tiniest fraction of a second, smaller than any time duration encountered in any physical process, during which the primordial atom underwent an incredibly large and exponential expansion to set the whole evolutionary process in motion.  This has come to be called the inflationary phase of the Universe and the concept was propounded by Alan Guth of Stanford University to account for the extremely uniform distribution of the CMB radiation and several other puzzling observations.

When inflation stopped, the Universe consisted of what is called a quark-gluon plasma from which elementary particles were formed. At the prevailing extremely high temperatures, and the predominance of radiation over matter, particle-antiparticle pairs of all kinds were being continuously created and destroyed in collisions. At some point in time a certain imbalance (the precise nature and reason for which is yet to be understood) set in, giving rise to a very small excess of matter particles over antimatter particles.  This resulted in the predominance of matter over antimatter in the present Universe. As the Universe continued to grow in size and drop in temperature, the particle energies decreased to a level at which protons and neutrons could be synthesized.  At this time the energy density of the Universe was dominated by photons.

A few minutes into the expansion, when the temperature was about a billion degrees Kelvin, neutrons combined with protons to form deuterium and helium nuclei in a process called Big Bang Nucleosynthesis.  However, about 75% of protons remained as hydrogen nuclei. As the Universe cooled further, the effects of matter began to dominate those of radiation and gravitation came into the picture very prominently.  After about 380,000 years, the electrons and nuclei combined into hydrogen atoms, which became the dominant form of matter at that time.  Radiation got decoupled from matter and spread out through space uniformly, largely unimpeded. This left-over radiation is what constitutes the CMB today.

Over a long period of time, the slightly denser regions of the nearly uniformly distributed matter attracted other nearby matter gravitationally and thus grew even denser.  This clumping of matter should have produced small irregularities in the otherwise uniform distribution of matter on a cosmic scale. They have in fact been discovered through correspondingly minute, local anisotropies (typically about one part in a hundred thousand) seen in the intensity of the CMB radiation, most prominently and conclusively by the path breaking WMAP (Wilkinson Microwave Anisotropy Probe) satellite.  The process resulted in the eventual formation of gas clouds, stars, galaxies, and the other stellar objects, including clusters and super-clusters of galaxies, populating the Universe today. The details of this process depend on the amount and type of matter in the Universe and are only now beginning to be understood. However, the type of matter with which we are familiar at both the atomic and cosmic scales is grossly, in fact hopelessly, inadequate for the purpose.  Observational evidence, including the one provided by WMAP, supports only a little over 4% of the Universe as consisting of this 'normal' matter; we are literally in the dark as regards the rest of it.

Dark Matter

Almost everything we understand about normal matter is through an analysis of the electromagnetic radiation we receive from such matter.  For matter on a cosmic scale, this is strongly complimented by a study of the gravitational forces among its constituents. This is how we know the behavior and physical properties of stars, stellar systems, interstellar matter, galaxies, inter galactic matter, galactic clusters and super clusters, etc.  As we shall now see, a large part of the matter on the galactic and super galactic scale behaves in a manner consistent fully with the existence of gravitational forces among its constituents, but without any electromagnetic interaction and therefore invisible in the normal sense, giving rise to the concept of dark matter.

It is time to bring in another great female astronomer, Vera Rubin, to whom we owe the earliest recognition of dark matter. Rubin and her colleague Kent Ford analyzed a large number of galaxies to study the radial distribution of matter in them using the Doppler principle outlined earlier. The stars in the disk of a galaxy move in roughly circular orbits around the center. If the disk is inclined to our line of sight, the stars on one side are approaching us while those on the other side are moving away. The wavelength shift is proportional to the speed of the light source relative to us.  Rubin and Ford made careful measurements of Doppler shifts and then calculated the orbital speeds of the stars in different parts of those galaxies.

Because the core region of a spiral galaxy has the highest concentration of visible stars, astronomers assumed that most of the mass and hence gravity of a galaxy would also be concentrated towards its center. In that case, the farther a star is from the center, the slower its expected orbital speed. Similarly, in our solar system, the outer planets move more slowly around the Sun than the inner ones. By observing how the orbital speed of stars depended on their distance from the center of a galaxy, one could calculate how the mass is distributed throughout the galaxy.  To their great surprise, Rubin and Ford discovered that the stars from the sparsely populated outer parts of the galaxy were moving just as fast as those in the interior.  This was very odd, because the visible mass of a galaxy does not have enough gravity to hold such rapidly moving stars in orbit. It followed that there had to be a tremendous amount of unseen matter in the outer regions of galaxies where the visible stars are relatively few.

Independent evidence for the existence of such dark matter on the galactic scale has also been discovered through a technique called gravitational lensing. A gravitational lens is formed when the light from a very distant, bright source, such as a quasar, is 'bent' around a massive object (such as a cluster of galaxies) between the light source and the observer.  The bending attributable to virtually invisible objects in the foreground indicates the presence of dark matter on a vast scale.

While there is ample evidence for dark matter on the cosmic scale, there is as yet no evidence for it at the local level.  We have no idea about what dark matter is made up of, in sharp contrast to our understanding of ordinary matter through a wide range of inter particle interactions and the interactions between material particles and electromagnetic radiation.  Whatever entities dark matter may be made up of, they don't interact with ordinary matter, at least to a directly observable degree.  They appear to be as elusive as the neutrinos, which have been incidentally ruled out as possible dark matter candidates since they are virtually massless.  Dark matter particles need to be quite massive even if very illusive.  All efforts to detect such particles in laboratory conditions all over the world have so far proved futile; but they are continuing, actually on an expanded scale.  In anticipation of its eventual discovery the name WIMP (Weakly Interacting Massive Particle) is already in use for the hypothetical dark matter particle.  The objects identified as consisting of dark matter in galaxies and galactic clusters are being described as MACHOS (Massive Astrophysical Compact Halo Objects).

Structure and Properties of the Universe

As the observational evidence piled up in favor of the Big Bang and the expanding Universe, the obvious question in everyone's mind was what would happen to it in a sufficiently distant future.  Would the expansion continue indefinitely into the future, with the Universe ending up in a big whimper or would it slow down, come to a halt and eventually fall back on itself under the influence of gravity, leading to a big crunch?  The answer depends on the dynamic properties of space-time itself, determined by the interplay between matter and gravitation. It also depends on the topological (geometrical) properties of space itself as could be determined by general relativity, supported by observations.

The outward expansion of the Universe is countered by an inward pull of gravity on the expanding matter and this in turn depends on the density and pressure of the matter in the Universe.  If the density of the Universe exceeds a certain critical value, then the geometry of space is closed and positively curved like the surface of a sphere.  If the density is less than the critical value, then the geometry of space is open (infinite) and negatively curved like the surface of the saddle placed on a horseback.  If the density of the Universe is nearly equal to the critical density, then the geometry of the Universe is flat, like a sheet of paper.  Based on WMAP measurements, we now know that the Universe is flat with only a 0.5% margin of error.   This is a very significant finding, with a bearing on the eventual fate of the Universe.

Do we have a good estimate of the critical density of the Universe?  Yes, we do and the value is the equivalent of there being just about six protons (hydrogen nuclei) in one cubic meter of space!  Remember, only a little over 4% of this is our familiar normal matter! This is so incredibly small that it is impossible to produce a vacuum of this magnitude on Earth no matter how we try.

 

Evolution Scenarios

The diagram below depicts different scenarios for the eventual fate of the Universe in the tug-of-war between the outward momentum of expansion and the inward gravitational pull.

If the density of the Universe is greater than the critical density, then gravity will eventually win and the Universe will fall back on itself, giving rise to the hypothetical 'Big Crunch' as indicated by curve A.  If the density of the Universe is less than the critical density, then the Universe will expand for ever as indicated by curves B and C.  Gravity might slow the expansion rate, but there isn't enough gravitational pull from the material in the Universe to stop or reverse the outward expansion.  This is described as the 'Big Chill' or the 'Big Freeze' because the temperature continually decreases with the passage of time.  However, available evidence actually supports an accelerated expansion scenario as depicted in curve D for reasons soon to be discussed.

Supernovae as Standard Candles

As they reach the end of their life cycles, super massive stars may use up their nuclear fuel and collapse under their own weight.  The collapse leads to an incredibly gigantic explosion, sends out a shock wave through space followed by a shell of material ejected at great speeds from the star's atmosphere.  This is accompanied by the release of enormous amounts of radiation in a blinding flash that lasts a very short period, followed by rapidly decreasing brightness over a period of just a few weeks.  Called a supernova, this is a relatively rare event within any galaxy, on the average only one in a hundred years or more.  At its peak, a supernova can outshine the entire galaxy within which it occurs.  For this reason it is relatively easy to detect and study a supernova even within the most distant galaxies.

   

Depending on the details of the mechanism of energy production and release, supernovae come in two categories – Type I and Type II.  Within each type there are subdivisions. Our story is centered round Type Ia supernovae whose brightness variations show a regularity that makes them uniquely suitable as yardsticks for measurement of distances to the farthest galaxies known.  They can be used as 'standard candles' much like the cepheid variable stars for much shorter distances.  This is the technique largely pioneered, perfected and employed extensively with startling consequences by Perlmutter, Schmidt and Riess who have been awarded this year's Nobel Prize in Physics. Besides using a number of some of the largest earth based telescopes, they also made substantial use of the Hubble Space Telescope which provided some major advantages for the purpose.  Indeed, their discovery is recognized as one of the many outstanding achievements of the Hubble telescope itself.

A Type Ia supernova results from having a white dwarf star in a binary system.  Because of the huge gravitational force of the dwarf star, matter is sucked in continuously from the normal star to the white dwarf until the latter attains a critical mass (the Chandrasekhar limit) and undergoes a thermonuclear explosion.  Because all white dwarfs achieve the same mass before exploding, they all achieve the same luminosity and can be used as standard candles.  By observing their apparent brightness, the actual distance can be determined by using the inverse square law for brightness variation with distance. By knowing the distance to the supernova, we know how long ago it occurred. By measuring the red shift from the spectrum of the supernova, we can determine its speed of recession and hence how much the Universe has expanded since the explosion using Hubble's law.

 

Despite the rarity of the supernova event in any galaxy, potentially a good number of supernovae can be studied at any one time because of the enormous number of galaxies existing in the Universe.  By doing so, we can piece together an authentic history of the expanding Universe extending to the very edge of space.

Dark Energy

In the 1990's two teams of astronomers, working independently but in frequent touch with each other, the Supernova Cosmology Project (CSP) based at the Lawrence Berkeley National Laboratory led by Perlmutter and the (international) High-Z Supernova Search Team led by Schmidt in Australia, investigated a large number of distant Type Ia supernovae in order to measure the expansion rate of the Universe. Consistent with wide-spread belief, they expected that the expansion would be slowing down (according to one of the scenarios A, B or C indicated in the previous diagram).   They expected the supernovae to be actually brighter than indicated by their measured reds shifts.  Instead, to their utter surprise, bordering on consternation, they found the supernovae to be actually fainter than expected. The brightness of the supernovae decreased with distance significantly more rapidly than anticipated.  There could only be one interpretation of this. The expansion of the Universe was accelerating, as in scenario D of the diagram!

As outlined earlier, measurements of the CMB radiation indicate that the Universe has a flat geometry on a large scale. The amount of matter in the Universe, either normal or dark or taken together, is very much less than what is required to produce this flatness. The difference must therefore be attributed to some hitherto unknown cause, which came to be called dark energy for want of a better description. It is this dark energy which is seen to be causing the observed accelerated expansion of the Universe by countering the effects of gravity; in other words acting like anti-gravity.

Evidence for the existence of dark matter is now clear-cut though its nature is still very elusive.  By contrast, dark energy remains a complete mystery. The name dark energy implies that some kind of 'stuff' must fill the vast reaches of mostly empty space in the Universe in order to produce an accelerated expansion. In this sense, it is a 'field' just like an electric field or a magnetic field, both of which are produced by electromagnetic energy and very well understood. But this analogy breaks down completely when it comes to dark energy.

Some astronomers now tend to identify dark energy with Einstein's discarded cosmological constant which he had originally introduced when he saw that his theory was predicting, embarrassingly at that time, an expanding Universe.  If successful, this idea may provide a backdoor vindication of Einstein's action, but for entirely unforeseen reasons.

While bright ideas to account for dark energy and its effects are not wanting, for the present at least its nature is a mystery waiting to be unraveled as in any good detective story.

The 4% Universe

Just half a century ago we were blissfully ignorant of the fact that the Universe we were then familiar with was only about four percent of the 'real' one that we have just begun to recognize.  The rest of it was, and still is, hidden from our direct experience. Vera Rubin's observations about our level of ignorance quoted at the beginning are perhaps as valid today as they were when she made them.

It is now reliably estimated that the Universe consists of about 23% dark matter besides the 4% normal matter.  This leaves out a huge 73% of it to be accounted for by dark energy which is as elusive today as when first recognized.  Unraveling the nature of dark matter and dark energy, which are so overwhelmingly pervasive in the Universe, is easily the greatest challenge facing astrophysics and cosmology today.

   

The Runaway Universe

It is now evident that we are part of a Universe that is behaving like a wildly galloping horse, running away from everything aimlessly and without any tangible purpose, though governed by all known laws of physics.

 

The following illustration from a NASA website depicts in a nutshell the evolution of the Universe from the Big Bang to the present.  The accelerated expansion started about 7.5 billion years ago; until then the expansion was nearly in conformity with our earlier expectation.  This is because gravity was still a dominant force up to that epoch.

The Ultimate Fate

The Earth is an insignificant part of the solar family which occupies an equally insignificant place in the Milky Way galaxy.  Less than a century ago we discovered that this is itself an utterly insignificant part of the Universe as we came to know.  Now we know that the Universe we have been able to understand so far is only an insignificant part of the one that we are yet to understand.  This sums up not only the level of our ignorance but also the degree of our insignificance. The vast Universe is still waiting to be understood.  But we do seem to have at this time a plausible answer to one of the ultimate questions bothering humankind for centuries – what is the ultimate fate of the Universe?  Cosmology is no longer an infant discipline depending on philosophy and metaphysics to provide the answers. It is now a full blown science that can face this question head on.

All available observational evidence today points to a runaway Universe in a state of wildly accelerating expansion, with its hidden dark energy tearing it apart at the seams. If the process continues, the galaxies should move so far away as to eventually become invisible to us by any means and we might at best be able to see our nearest neighbors.  Worse still, the galaxies should be torn into shreds like confetti, even the matter inside them being ripped apart into its constituent particles, perhaps into a quark-gluon plasma of the primordial Universe, but spread over incredibly vast distances.  We can however take solace in the comforting thought that this is all far off in the future, hundreds of billions of years away!