Tuesday, July 14, 2015

New Horizons

Nasa's spacecraft, New horizons is flying by Pluto today, its point of closest approach scheduled for this morning EST (late afternoon for us). The mission is expected to yield new insights into the last known world, the icy dwarf planet, which had its status demoted from a planet a few  years ago, much to the chagrin of those who always thought it was a planet (viz. us!). Since this is the first fly by Pluto, the planetary scientists are licking their lips, waiting for data of kinds never seen before. Every first fly by other planets like Mars, Saturn and Jupiter has revealed unexpected features. Pluto is about to reveal its secrets. New horizons are about to be seen in planetary astronomy. Do stand by.

Photo: NASA, Pluto and Charon, July 12, 2015. Picture taken by the New Horizon spacecraft.


New horizons emerged safely from the fly by and communications blackout, and is beaming stunning pictures from the fly by. Here is an icy mountain.

 This mountain is as high as the Rockies, and is fairly young, as seen by the lack of craters. This evidence of recent geological activity in the icy planet will provoke much speculation, and new geological theories. Meanwhile CERN found the pentaquark yesterday, so quantum mechanical scales are competing with astronomical scales in new discoveries. This is truly an exciting time to be a physicist. Let's see what both scales throw up next.


More goodies from the New Horizons bag. A mountain in a moat on Charon. Here is the picture.

The heart shaped feature seen in the most popular Pluto picture are really icy plains which look like this:

By the way, the processor on New Horizons is a reprogrammed PlayStation chip. It shows anything that can play video games, can fly across the Solar System and and send back the most amazing data and pictures. Was it worthwhile having a nine year mission for a three minute flyby? You bet it was!
Just look above.

This blog post is by Neelima Gupte and Sumathi Rao.

Tuesday, June 30, 2015

The Chennai Metro

This is a highly local post, but why must we always be global?  The Chennai Metro was inaugurated yesterday, with minimal fanfare via video-conferencing,  by Tamil Nadu CM Jayalalitha, and with great enthusiasm by Tamil Nadu's (or more accurately) Chennai's general public. The first line from Alanthur to Koyambedu was crammed with everyone from children to housewives to office-goers to policemen, all in great spirits and busy clicking selfies, to mark the occasion. The first metro was driven by a young lady,  A. Preethi, who changed jobs to fulfil her dream of becoming a loco driver, and whose mother burst into tears at the happiness of the occasion.
Here you see the train, festooned with jasmine, as befits a smartly dressed lady from our city, and here you see where she is dressed up to go.  Alas, it's nowhere near us as yet. We will have to make do with the MRTS (that is the mustard line in the map), which was equally thrilling when it came, and still causes squeals of excitement when it whizzes past our balcony, albeit in the distance.  Finally,  fast cars, aeroplanes, rockets and the Mangalyaan not withstanding, there is nothing like a train!

This blog post by Neelima Gupte and Sumathi Rao.

Tuesday, May 12, 2015

Land of kings 3

Here is instalment three of the Land of Kings series. This time its Udaipur, Kumbhalgarh, Ranakpur and Mount Abu. Of these Udaipur needs no introduction. It's the most scenic location in Rajasthan, and as such, has featured in everything from movies to TV. Its most iconic son, Rana Pratap, is honoured in legend and song. The city palace at Udaipur has everything a palace should ever have, from the Sun symbol of the Sisodias, to grand rooms, beautiful murals, shady courtyards, and of course a sheesh mahal, apart from some of the

the most beautiful paintings that can be seen in Rajasthan. The lake palace, is a distant mirage in the lake, alas; only accessible to the well-heeled.  Haldi ghati, with its famous battle, and tales of valour, loyalty and betrayal, is also far from the city, but Rana Pratap and his loyal horse Chetak stand guardian over the city.

On next to Kumbhalgarh, made by Rana  Kumbha and used by Udai Singh and Rana Pratap during their long drawn battles with the Mughals. The fort  wall is second only to the great wall of China in length. The history of the fort consists  of happy occasions, such as the birth of Rana Pratap in 1540 as well as unhappy ones such as the murder of Rana Kumbha by his own traitorous son Ude in 1468.  The fort owes its existence to the sacrifice of a sage who offered himself as sacrifice so that the fort could be built. The gate of the fort was made where his head fell, and the walls where his body did.  A temple to him was made inside the fort walls. The fort is almost impregnable, and only fell in battle once. A spectacular view of the Aravallis can be seen from the topmost ramparts. The sound and light show at night is full of these wonderful stories, far better than the show at Amer, those who fought the Mughals make for the good stories, not the ones who fought for them! We had the good fortune of seeing it on a full moon night, when the air is full of the whisperings of those who lived here before.

The last leg of the journey were the Jain temples of Ranakpur and Mount Abu. The marble carving of the temples is literally lace in stone. No pictures, alas, photography being firmly prohibited. The Jain temples all over, over 300 in Kumbhalgarh, a huge number in Chittorgarh, reminds one that the history of Jainism in  the region predates both Rajputs and Mughals, and goes back to the 11th century. 
So we returned from the land of kings once again. No, no, this is not the last edition of the LOK. The golden fortress beckons still.

This blog post is by Neelima Gupte and Sumathi Rao.

Saturday, March 28, 2015

North by Northeast!

Last week was on the peripatetic side, involving both North and Northeast (with a brief stop at home base in the south!).  North was Delhi and Chandigarh. No long digressions on this one, having already appeared on this blog before. This is, however, the first appearance of the North east on this blog, except for peripheral references.

The Northeast excursion was to Manipur's capital Imphal, and its outskirts. While the journey is tedious, it can be surprisingly short, if you get the right connections (and incur the risk of missing one).
Coming out at Imphal blinking in the bright sunlight of the early afternoon into a small city in the middle of a flat valley, gives a sense of a culture which is very different from the plains with the influence of Myanmar, which lies barely 70 kilometres away, providing a strong flavour.

The first stop in the expedition was Kangla castle. Here the local museum firmly swept us out, literally with a broom, closing time being four p.m, and us having arrived at ten minutes to four. However, the rest of the castle made up for the loss(if it was one, we will never know!) . The castle contains many monuments, new and old, places of worship, and is the location of many legends. The entrance is guarded by horned animals, whose bodies resemble the lions seen all over southeast asia, but the horns provide a new touch. There are two temples in the complex. One is the ancient temple of Govindaji which is more than a hundred years old. The deities of Radha and Krishna are no longer here, and are to be found in the Govindajee temple of the new palace. The other important temple is the temple of Pakhangba, an important deity of the  indigenous religion of the Meitei, who is represented by the sacred snake sign. The palace also contains the sacred grounds of the Sani Mahi, another important deity of the region, to say nothing of a rock under which the devil has been trapped!  Sani Mahism, the indigenous religion of Manipur, co-exists in Manipur with Hinduism, which was later adopted by the Hindu rulers.  Every home contains a room dedicated to the Sani Mahi, who is worshipped with offerings of food, and vegetables, especially on the Manipuri new year day, which occurred during our visit.  Sani Mahism can be found in Manipur, Bangla Desh, and Myanmar, and is staging a comeback to the region, with the Manipur Times recently reporting the `ghar wapasi' of a fairly large contingent.

The next day was more recent history. The India peace memorial at Red Hills, the scene of the last battle between the Indian Army and the Japanese Army, with Indian troops on both sides. The memorial, built by the Indian and Japanese governments, commemorates those who died in this battle.
Even more historic is the Indian National Army memorial in Moirang, where the INA flag was first flown, with Netaji Subhash Chandra Bose's statue, and a museum which contains the proclamation of
the INA Government, and other historic photos and documents.

Finally some natural beauty, Loktak lake, the largest freshwater lake in India, with floating islands which are large enough to support settlements. Altogether a lovely trip, with new and old friends, and much yet left to explore, and hopes of another visit. BTW, we did some essential work too!

This blog post by Neelima Gupte and Sumathi Rao.

Thursday, March 5, 2015

Rahul Basu 04/03/1956-05/03/2011

Time is the root of all this earth;
These creatures, who from Time had birth,
Within his bosom at the end
Shall sleep; Time hath nor enemy nor friend.

All we in one long caravan
Are journeying since the world began;
We know not whither, but we know
Time guideth at the front, and all must go.

Like as the wind upon the field
Bows every herb, and all must yield,
So we beneath Time’s passing breath
Bow each in turn, – why tears for birth or death?

Bhartrihari, ‘Time’, tr. Paul Elmer More

This blog post by Neelima Gupte and Sumathi Rao.

Monday, February 2, 2015

Dust in our eyes?

It appears that the latest Planck satellite data is conducive to the conclusion that the discovery of gravitational waves claimed by the BICEP2 collaboration last year, is not yet one to get starry eyed about. The latest data which measures the concentration of dust in the region where the BICEP2 measurements are carried out indicates that the quantum of dust is sufficiently large that it could be responsible for about half the B-wave polarisation observed in the BICEP2 signal. This has led to wide-spread disavowal of the BICEP2 results, and caused some dismay in circles that have been heartened by their support for inflationary scenarios. Those that went overboard in the opposite direction even said `Big Bang theory disproved' ! (The Times of India should really get some proper science reporters).

However, these reports of the demise of the theory are also highly premature (as in the case of Mark Twain!). The European Space Agency, which manages the Planck satellite,  puts it more soberly, “Despite earlier reports of a possible detection, a joint analysis of data from ESA’s Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial gravitational waves”.

 This null result does not disprove the existence of gravitational waves, nor does it rule out inflation. It merely indicates that BICEP2 has not detected gravitational waves yet, with a high degree of certainty. The gravitational wave signal may still exist in the observed BICEP2 data, but may be obscured by the noise, so this new result can place an upper limit on the possible strength of the B-mode polarisation caused by gravitational waves. The search for gravitational waves still continues, and we look forward to more conclusively established results in the near future.

This blog post is by Neelima Gupte and Sumathi Rao.

BTW: Speaking of science reporting, this is a good place to draw attention to the  IIT Madras science magazine brought out completely by IITM students on some of the research done at IIT Madras, including research on inflationary scenarios carried out at the Physics Department. Do have a look.

Friday, December 26, 2014

The IPA Rahul Basu Memorial Award

The IPA Rahul Basu Memorial Award  (2014) for the best thesis in High Energy Physics was presented on 12th December, 2014, at the DAE Symposium held at IIT Guwahati. As mentioned in one of the earlier posts, the two awardees for the 2012-2014 period were Dr. Pratishruti Saha (Univ. of Delhi) for her thesis entitled `Addressing some issues beyond the standard model at Hadron Colliders', and Dr.  Nikhil Karthik (TIFR, Mumbai) for his thesis entitled `Studies on gauge link smearing and their applications to lattice QCD at finite temperature', and two  honourable mentions, Dr.  Ritu Aggarwal (Panjab University) for her thesis entitled `Measurement of High x neutral current ep cross sections and extraction of xF3 structure function using Zeus detector at Hera', and Dr.  Amaresh Jaiswal (TIFR, Mumbai) for his thesis entitled `Formulation of relativistic dissipative fluid dynamics and its applications in heavy-ion collisions'.  The two awardees gave talks on their work during the award ceremony, Dr. Saha, in person, and Dr. Karthik via a Skype connection.

Dr. Saha explained how her work on  direct and indirect searches at various accelerators could be used to identify new physics.  A very well cited paper of her's identifies  how measurements at the Tevatron and the LHC could be used to distinguish between various scenarios which go beyond the Standard Model. Dr. Saha and co-workers had  considered how top polarisation could be used to distinguish between various scenarios, which had been used to explain asymmetries in the top quark production process. The work also had relevance to observations at the Large Hadron Collider.  Her thesis focused on the fact that the top quark occupies a special place in the standard model, and hence, the analysis of its behaviour can have important implications in scenarios which attempt to go beyond the Standard model, in various sectors like the Higgs sector.  She had also analysed the behaviour of the bottom quark and its contribution to resonances.

Dr. Nikhil Karthik spoke about the work in his thesis, which contributes to important technical advances in  lattice QCD, and also studies its deconfined phase. Although the coupling constant in this  phase is not too large, perturbative estimates of quantities like the viscosity and the screening mass do not agree with expectations due to discretization effects. Specifically, existing lattice studies based on the staggered discretization of quarks, found a screening mass which, contrary to expectations is smaller than that of the free field theory. Smoothed gauge configurations are the prescription to ameliorate such unwanted discretization effects. Dr. Karthik's thesis investigated the effects of different types of smoothing, and devised an optimum smoothing strategy which succeeded in   identifying the reasons why the screening mass shows the observed behaviour.  Dr. Karthik's talk was also notable due to the clarity with which technical issues were conveyed to the audience.

The award ceremony was well attended, with many students and many well known physicists in the audience. It was heartwarming that three of these were  Rahul's friends in graduate school,  Prof. Rohini Godbole, Prof. Ashoke Sen, and Prof. Sunil Mukhi, distinguished physicists, and in the case of Profs. Mukhi and Godbole, members of the award committee. We congratulate the winners, and wish them all success in their future endeavours.

This blog post is by Neelima  Gupte and Sumathi Rao.