Pondicherry Reprise

We wandered to the pleasant town of Pondicherry again for a weekend, making the usual excuse, viz. out of town guests. The itinerary followed the good old routine, viz. leave in the morning, shore temple and Arjuna's penance and a good Mahabalipuram lunch, and trickle down to Pondi by evening. The guests got fascinated by all the Mahabs bric a brac, despite reassuarances that Pondi bric a brac was far better (but of course far more expensive!).


Pondicherry delivered as promised. The French quarter was elegant and well maintained. The ashram was serene and beautiful. The samadhi had a peaceful and meditative atmosphere, and a large collection of worshippers, even in the late evening. The ashram had its beautiful champa trees, now supplemented by a spectacular rock garden. The beach was cool at night, but a couple of sights were disturbing, is every kind of tourism a good thing?

 The next morning was a new experience, the Matrimandir at Auroville, with prior permission acquired due to the enterprise of the visitors and the presence of gracious Pondicherry hosts. The Matrimandir is a beautiful place of meditation, where the contemplative vision of the Mother has been encapsulated by the architectural vision of Roger Angier, in a remarkable piece of modern architecture. The Matrimandir is a squashed Cosmic egg, or to the less philosophical, a golden geodesic dome. The interiors are white marble, impeccably maintained, thanks to watchful guardians, all French on the day we visited. A spiral staircase leads to the central dome, with twelve pillars which represent the verities. The pillars are not structurally necessary, the French construction engineer who was our principal guide told us, but were a part of the Mother's vision. Natural light from a skylight falls on a crystal globe, and goes down to a meditation area below, with another receptacle at the centre of a beautiful marble lotus. The meditatively inclined felt the vibrations of the place (guess whose theta waves would not budge?).  The Matrimandir is encircled by twelve small meditation rooms, and is meant to be surrounded by twelve gardens, of which three are presently developed. There's an old banyan tree outside, and green lawns enveloped by a fledgling forest, a far cry from the sea of red mud that we saw when we visited last. Auroville originates in a dream, a dream of world unity, that seems to be developing slowly but surely, an oasis in the chaos and cacophony of the external world. It is a place to see, at least once!


This blog post by Neelima Gupte and Sumathi Rao.
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Piṟanta Nāḷ Vāḻttukkaḷ

Madras, that is Chennai, turned 374 today. In 1639, on this day, the British administrators Francis Day and Andrew Cogan, acquired a stretch of land from the Vijaynagar empire which went on to progress from the villages of Madraspattinam and Channapattinam to become Madras, nowadays known as Chennai. While 374 sounds like a respectable age for a city, strictly speaking Madras is much older than that. The temples of Triplicane, Mylapore and Thiruvanmiyur (the Parthasarathy, and Kapaleeswar and Marundeeswar temples) all date from the 8th century. Fort St. George, which was named in 1640 is a spring chicken in comparison.  Either way, good wishes are in order. So happy birthday, Chennai (that is what the header says, thanks Google translator, and we hope it got it  right). We hope to greet you again next year, when you turn 375, when you will hopefully be in better shape (don't start us off on the topic of the current potholes).

This blog post is by Neelima Gupte and Sumathi Rao.

The Pensieve

Aficionados of the Harry Potter series of books will recall the pensieve, the physical receptacle of memories, that sits in Professor Dumbledore's office, with silvery memories darting around on a smoky background, like koi fish in a pond, ready to be plucked out at will, or locked away. However, in our every day unmagical Muggle world, neuroscientists have long grappled with the question of the existence of a physical location of memories, and even more intriguingly with the basis of false memory, viz. the remembrance of incidents that never occurred. In a series of important papers, the most recent of which was published in the 25th July issue of Science, a group of scientists at the RIKEN-MIT Center for Neural Circuit Genetics, have established the existence of networks of neurons that form memory traces (or emgrams) for each experience we have, succeeded in activating them via optical techniques, and also in implanting memory associations of incidents that never occurred.

Early research in neuroscience in the 1940-s suggested that episodic memories were stored in the hippocampus, an area of the temporal lobe of the brain. Electrical stimulation of the hippocampus, undertaken in the treatment of epileptic seizures, succeeded in triggering episodic memories. However, it was not established that the memory traces were stored in specific cells of the brain. To establish this required new techniques, called optogenetic techniques. In a study carried out by Susumu Tonegawa and coworkers at MIT, mouse hippocampal cells were engineered to express the gene for channelrhodopsin, a protein that activates neurons when simulated by light.  They also modified the gene so that channelrhodopsin would be produced whenever the c-fos gene, necessary for memory formation, was turned on. Last year, the researchers conditioned these mice to fear a particular chamber by delivering a mild electric shock (yes, the cells were in live mice. Neuroscience experiments aren't pretty!). As the memory was formed both the c-fos gene and the engineered channelrhodopsin gene was switched on. Thus, the cells encoding the memory (located in an area called the Dentate Gyrus of the hippocampus) were tagged with the light sensitive protein. When the mice were put in a different chamber, they behaved normally. However, when a light pulse was delivered to the hippocampus, stimulating the optically tagged memory cells, the mice froze in fear as the memory of the shock was activated. Thus a direct contact was established between the memory trace and its storage location.

This was remarkable  in itself, but then the researchers went further. They tried to implant false memories in the mices' brains. First, the mice were allowed to explore a chamber, chamber A where no shocks were given. However, their memory cells were labelled with the optically sensitive gene. The next day, the mice were put in chamber B, where a mild shock was delivered, and simultaneously, the cells encoding the memory trace of chamber A were switched on optically. The third day, the mice were put in chamber A, where they froze in fear, even though they had never been shocked in chamber A. A false memory had been implanted (`incepted'). The mice feared chamber A, because when they were given the shock in chamber B, they were reliving the memory of being in chamber A. The mice also retained the fear of chamber B, where the real shock was given. However, they were not as fearful as those mice who had recieved a shock in chamber B, without having a memory of chamber A activated. A similar result had been achieved by Mark Mayford and coworkers at the Scripps Institute in San Diego, last year, using drug induced stimuli.

Now that we have seen the inception of false memories, what next? Steve Ramirez, who is one of the authors of the Science paper, said, `Now that we can reactivate and change the contents of memories in the brain, we can begin asking questions that were once the realm of philosophy. Are there multiple conditions that lead to the formation of false memories? Can false memories for both pleasurable and aversive events be artificially created? What about false memories for more than just contexts — false memories for objects, food or other mice? These are the once seemingly sci-fi questions that can now be experimentally tackled in the lab.'

It is clear that this line of research opens up a whole new area of brain and memory research, and also has implications for legal and ethical issues. Here comes the brave new world! Let's see how it all turns out.

This blog post is by Neelima Gupte and Sumathi Rao.

Sao Paulo Summer

The Sao Paulo summer was winter, really. The city is in the southern hemisphere after all. After the first half of May in Chennai, the cold was bracing and refreshing (the rain wasn't!).

Paulistinos tell you there is nothing special about their city, it is just another big city. However, there is no doubt that it is a metro city which is a metro city, with big, beautiful buildings, ranging from
old fashioned, graceful buildings to glass clad skyscrapers, parks, theaters, wide avenues and boulevards, modern and efficient transport systems, and well known universities and schools. The city resembles the major cities of western Europe, but contributes its own South American charm in the form of its unique vegetation, cozy neighbourhoods and vibrant street paintings.

Weekends  in Sao Paulo have a relaxed flavour. Neighbourhood markets, street singers (the one on Avenue Paulista dresses often as Elvis) and people dressed as statues, who bow and scrape in exchange for a few coins. The Avenue Paulista is the main avenue in Sao Paulo, which witnesses everything from the Gay parade in May, to the current street protests. The beginnings of both were interesting to see, even for nervous spectators from half a world away. The gay parade kicked off with Elvis clones (maybe inspired by the Sunday singer), and drag queens in ostrich feathers, a positive army of policemen and women and a hovering helicopter.

The protests were more frightening, one dark rainy evening we saw a long procession with huge banners followed by an even longer ghostly procession of policemen (wearing fluoroscent paint and glowing in the dark!). This was topped by the evening when the metro staff went on strike in some lines, and commuters emerging from Paulista metro station after a convoluted and crowded commute saw a posse of riot police mounted on magnificent horses. This was highly appropriate, as the protests were triggered off by an increase in transport tickets by 20 cents! Of course, the protests aren't about 20 cents, any more than Taksim square is about the location of a mall. However, it is hard to say what they are about, and they haven't died out after two weeks (the fare hike has been reversed). The Brazilian economy is booming, as is the most of South America (Yes,  Brazil, Peru and Colombia are on the up and up. Sceptics say this boom is excessively based on commodities, such as oil and minerals, but optimists believe there is a genuine upswing based on manufacturing and services). The annoyance is about the  inequalities, and the general perception that the voice of the people is nowhere heard. President Dilma Roussef today has proposed wide reaching changes including the formation of a constituent assembly, and the spending of oil royalties on the expansion of education and health care. This is a far more conciliatory response than that seen in, for example, Turkey. It is hoped that this translates into a lasting change that addresses the root causes of the simmering anger that lies under the surface of a happy go lucky nation. `Brazil should not just be about football and models', said a friend. If the current unrest sets its path towards less evanescent forms of achievement, it will have succeeded in its purpose.

This blog post is by Neelima Gupte and Sumathi Rao.

Cusco Saturday

Here was  a cold blustery Saturday in the historic city of Cusco in Peru.
At 11,000 feet, the air is spare and bracing, but not for everyone. They
keep oxygen at the airport and in every hotel,for those who need it
(people do).The city is in the middle of a valley surrounded by
mountains. As the plane comes down, the feeling of familiarity
intensifies. The city looks and feels exactly like Bhutan, despite being
on the other side of the world.

The streets are narrow and steep, and lined by cobblestones. You need to 

skip out to the high footpath each time an Alto goes by (Suzuki seems to 

have good sales here). If two cross each other, one has to squeeze itself 

flat against the kerb (yes, the streets are two way, but one Alto and one 

llama facing each other is what the two way can handle).The cathedral in 

the main square was rain drenched, but was still thronged with 

worshippers. The clouds and sunshine chased each other, around the little 

park in the middle, and the shops round the square (Inca silver, Inca 

pottery, Inca shawls, alpaca and llama woolens). The school children were

going home, the little girl had a big smile.

The hotel was old and full of antiques and atmosphere. There was a steep 

staircase and a courtyard full of plants, and a terrific view from the 

terrace. The drawing room had a fire-place, the internet and coca leaf tea. 

The staff was truly sweet.  What more could one ask for? It was too short a

trip, one could ask to go again, if Pacha Mama so wills! 

This blog post is by Neelima Gupte and Sumathi Rao. 

Dark Matter

This topic is a bit late, but is too important to be left out altogether.The  Alpha Magnetic Spectrometer experiment in the International  space station has seen the excess of positrons at high energies that is supposed to be one of the characteristic signatures of dark matter. Dark matter is supposed to neither emit nor absorb light. Its presence is inferred from its gravitational effects on normal matter. Dark matter is supposed to account for about  85 percent of the total matter in  the universe. The current experiments carried out by the AMS experiment measured the excess of high energy positrons in earth bound cosmic rays, as predicted due to the presence of dark matter.

Well, dark matter is supposed to be made up of some hitherto undetected types of elementary particles, e.g. weakly-interacting massive particles, or WIMP-s, as well as many others. Particles of this type would be produced thermally in the early universe and are predicted by many theoretical extensions to the Standard Model of particle physics. If dark matter is made from such particles, and they encounter their own antiparticle, they may annihilate each other and produce some of the particles we are familiar with, e.g. protons and electrons. Some possible dark matter particles, are expected to be their own antiparticles, (e.g. photons, Z particles and Higgs bosons are examples of particles which are their own antiparticles), they are also expected to be rather heavy. If such dark matter particles encounter each other and annihilate to give lighter weight familiar particles, then these light particles would have high energy. This is a consequence of energy momentum conservation, by which pairs of heavy, slow moving dark matter particles would convert their energy into pairs of light, fast moving, familiar particles, as seen in cosmic rays, which the AMS measures. What the AMS does, is to count the number of electrons and positrons at a certain energy, and measure the fraction of positrons. At high energies, in the absence of dark matter annihilation, the number of electrons is expected to be much larger than the number of positrons. This is because, electrons are common in the universe, and can be easily accelerated to high energies, whereas positrons are produced out of collision processes of electrons, and consequently come out with lower energies than those of the electrons that produced them. However, if the electrons and positrons came out of dark matter particle annihilations, they would be equally energetic. In this case, the fraction of positrons would increase at large energies. The  typical energy of such electron positron pairs would be a little less than  the mass energy of the annihilating dark matter particles, and hence there would be a bump in the energy distribution of the positrons at this energy.

Experts say that the AMS result only confirms what other experiments, like, the measurements made by the Pamela and Fermi satellites, as well as terrestrial experiments. However, it is all to the good that all the experiments are pointing in the same direction. The AMS also has far more accurate measurements, and has narrowed the error bars. The AMS also finds that the distribution of positrons is isotropic, which was not quite expected from astronomical sources. All said and done, there are exciting days ahead in this direction. As for dark energy, may be some other day.

This blog post is by Neelima Gupte and Sumathi Rao.

For a more technical description of dark matter, and all the other experiments, see  this blog.


Tailpiece:

Two positrons walked into a bar.  `I'm much higher than you on the GeV scale' , bragged the high energy positron.  `And how did you do it' said the low energy positron, wistfully.  `By dark and annihilatory deeds', said the  high energy positron.

Land of Kings 2

Last month saw another excursion to Rajasthan, this time to Jaipur. Jaipur, of course, is a big city, the capital of Rajasthan, but it still manages to retain some of the appeal that small towns have, especially in the outskirts. The skyline is lowlying, the roads are wide, and there is a sense of space on the edge of the desert.

This was a work visit, to the LNMIIT (now headed by an old colleague from IIT Madras), which is blessed with a very well developed campus, and impressive architecture, especially that of the main building, which is inspired by the Jantar Mantar, and picks up the local flavour in the local sandstone. However, we managed to squeeze in a visit to the old fort at Amer, as well as to see the Sisodia Rani Bagh, missed on earlier visits.

Amer fort was earlier a small settlement of the tribe of Meenas, dedicated to the goddess Amba. This was taken over by the Raja Man Singh, who camped there one night, and on being told (if the sound and light show is to be believed) that the place belonged to the Meena tribe, laughed and said, `it used to belong to them', and promptly took it over. A prominent feature of the fort is the temple of Sila Devi, who it is said, appeared to Raja Man Singh in a dream, and agreed to take up residence at his fort. The Devi instructed the king to lead the way to the place where he wanted to install her, and that she would follow, but he should not look behind. The king did lead the way, but at some point turned round to look at the goddess, who froze on the spot. Thus, the temple to the Devi got constructed at the entrance of the fort, and the image of the Devi (Mahishasur Mardini) turns around.(Less fanciful versions of the story can be found in Wikipaedia).

The fort boasts of the most beautiful marble inlays and jaalis, as does the temple, second to none in India, including the Taj Mahal. The fort overlooks the Maota lake, and a beautiful garden, with beds of

crocuses whose stamens yield the precious saffron. 

The structure follows the traditional pattern, being built around courtyards, with halls of audience, halls of recreation, pleasure garden, the zenana, and a sheesh mahal.

 The sound and light in the evening, lights up the huge fort in a very impressive fashion. The stories that it tells, however, are not as impressive. The Kachhvahas of Amer, Raja Man Singh and his descendants, were always courtiers of the Mughals, and the stories of those who fought with the Mughals, like Rana Pratap, and Shivaji are more interesting! Still, the spectacle is not one to be missed.

A  highlight of the visit  was a quick, unexpected  glimpse of the one of the current owners of Amer, Princess Diya, the step-granddaughter of Maharani Gayatri Devi of Jaipur,  a chip of the old block, chiffon, dark glasses and all. Here's  hoping for another visit, maybe to another place in Rajasthan, so that there can be a Land of Kings 3 post.

This blog post by Neelima Gupte and Sumathi Rao.