25.3.2017:
Dr. S. Seetha: Program Director, Space Science Program Office ISRO. B.Sc Hons. from Hindu College, Delhi Univ., and M.Sc from IIT-Madras. PhD in Physics at IISc - research on white dwarf pulsations. Specialized in study of variable stars, x-ray and gamma ray experiments on Indian satellites. Key role in ISRO's Mars Orbiter Mission, India's 1st inter-planetary mission. Principal investigator of AstroSat. Best Indian women scientist award in 2012. Young scientist award earlier.Till 35 years ago, ISRO satellites were used only for remote sensing and communication, not on space observation. Initial years - worked on optical astronomy - ground-based observatories (Kavalur, Nainital, Mt. Abu). Later used piggy-back payloads in satellites for space research. Photometry - light intensity of stars and their variation with time. Developer 3-channel photometry technique. Light curve analysed per Fourier transform or power-density spectrum. These give hints about spin and orbital periods. Most of her research has been about variability of stars.
3-channel photometer contributed towards holar telescope. Helps overcome atmospheric effects. Led to area called astro-seismology. Also studied optical counterpart of x-ray binaries. Companion star is observed in optical and correlated with x-ray of neutron stars or black holes. This led to 2 space experiments - gamma-blast experiment. This led to discovery of around 50 gamma ray bursts. ASTROSAT itself was conceived following the success of those experiments. Simulation and calibration needed to check whether sensors are working correctly. Calibration often needs to be done both on ground and in space - are challenging. Mentions that to calibrate, Sahara desert was observed - the best "near"-uniform surface (not perfectly uniform, but the best that could be got on earth).
ASTROSAT - India's 1st dedicated space telescope satellite. Many indigenous technologies developed for ASTROSAT. Says many of these technologies have gone beyond similar prior satellites of other countries. Dr. TVV asks why ASTROSAT is termed telescope, not observatory, because observatory would mean catering to projects of different institutions/researchers - requires sequencing of tasks, close monitoring of those (Dr. TVV - like look at this place, then turn here, then turn back - very complex operations). ASTROSAT - multi-wavelength astronomy asset. X-rays are the richest source of information about compact objects like neutron stars. For companion stars, it is light or UV rays. Studying all 3 types of rays gives more information about the system.
3 major important discoveries of ASTROSAT. UV-imaging telescope - very well-resolved images of galaxies - has helped many previously unresolved components of some galaxies. Discovered a very unique pair of binary stars in an open cluster NGC188 - 1 proven to be a hot blue star one while the other a cool star. Discovered a high-energy object, micro-quasar that has evoked interest of many space researchers as target for observation. Polarization of X-rays from crab nebula studied. 4 payloads onf ATROSAT are co-aligned - observed the same target. 5th payload - scanning sky monitor.
Future - Chandrayaan2 - orbiter, lander, robot. Aditya L1 - mission to sun. Small satellite - xrosat to study polarization on of xray.
Interested in science from school. Father's profession - engineering, might have helped. Space science can be challenging for women around times of satellite launch. Difficult for women to be scientists without family support.
1.4.2017:
Dr. Shantanu Bhattacharya: Director, Indian Association for the Cultivation of Science (Kolkata). Works at the interface of chemistry, biology and material science. Prof. of organic chemistry at IISc, and Hon. prof. at JNCASR. PhD at Rutgers Univ and 3-year post doctoral study at under the guidance of Dr. Hargobind Khurana at MIT. Dr. TVV prefaces the program with mention of research on anti-aging drugs, pesticide-free agriculture etc.IACS is the oldest institution of its type in India, started in 1878. Founded by Dr. Mahendralal Sircar. Much of Dr. C.V.Raman's research work leading to his Nobel Prize too was done at IACS. 28.2.1928 - discovery of Raman Effect announced - day celebrated as "'National Science Day'". Dr. Meghnad Saha, considered in some sense the founder of astrophysics, associated with IACS. Also Dr. K.S.Krishnan, a PhD student under Dr.Raman and a key person in the development of National Physical Laboratory.
Lot of current emphasis on IACS is on interdisciplinary science. Another strong area of IACS is material science. Integrated PhD offered in many branches of science. Scholarship offered is higher than in many other institutes. Expects the institute to become a degree-awarding univ in the future.
Current research work on certain polymers that are used to create gels that would be useful in medicines and pesticide-free agriculture. Gels used as pheromone trap - gels are more resistant to leaching, better withstanding heat and rain, whereas conventional pesticides would be leached.
Working on small molecular structures - related to telomere biology. Controlling the activity of telomerase helps control aging. Shorter telomore length also related to some age-associated, non-infectious diseases. 2/3 of world's population will be above 65 by 2050.
New generation of antibiotics an emerging area of research. All cancs caused by damaged genes, mutations. Gene therapy promising for curing diseases like this as well as other gene-damage-related diseases. But delivering the genes is a difficult task. Viruses were tried for delivering genes in 1980s, but severe allergic/anti-microbe reactions made it unsuccesful. Working on new methods to deliver corrective genes.
Worked on chemical biology. especially on rhodopsin, under the guidance of Dr. Hargobind Khurana.
Need dedicated teachers who can disseminate science to people in interior areas of the country. Need demonstration of science to reach out to more people.
Life mantra: Choose the job you like. If you like it, won't feel like a burdensome job.
8.4.2017:
Prof. Somak Raychaudhury: Director, IUCAA (Inter University Centre for Astronomy and Astrophysics), Pune. Was Prof and Head of Physics Department at Presidency Univ, Kolkata and Dean of Faculty of Natural and Mathematical Sciences. Completed B.Sc in Physics in 1983 from Presidency University, Kolkata. Pursued further studies from Trinity College, Oxford. Obtained, in 1990, Ph.D in astrophysics from University of Cambridge. Has made outstanding contribution in research areas related to supermassive black holes, gravitational lensing, cosmology, super clusters of galaxies (largest structures in universe).It is now known that our galaxy is just 1 of billions of galaxies, and sun is a very ordinary small star. Milky way is a part of Virgo super cluster. At least 10 billion galaxies, the number being just a lower limit. Around 75% of galaxies are flat like chappatis, with spiral structures; they are relatively young. Old galaxies are more round. Has studied interaction between galaxies - lot of action going on as galaxies smash into each other. Galaxies are not uniformly distributed in space. Rather, they are distributed like filaments of a spider web. Milky way will smash into neighbouring galaxy in another 4 billion years. Galaxies move along these filaments and fall into galactic clusters. Studying how Milky way is moving and its interactions with other galaxies; these weren't studied earlier due to lack of powerful telescopes.
Galaxies moving through dark matter which is not visible, like trucks moving through highways with highways not being visible but trucks and dhaabaas (stars, gas, dust) being visible.
All big galaxies, including ours, have a super massive black hole in their centre. These black holes have mass ranging from a million to a billion times the mass of the sun, but their size is just about the size of solar system or smaller. Says till a few years ago, Stephen Hawking had a bet with astronomers that existence of black holes cannot be proved. But now astronomers not only know the existence of black hole in Milky way but also know its mass very precisely - about 40 lakh times the solar mass. With powerful telescopes available now, it has become possible to study precisely the movement of stars around black holes - by definition, black holes themselves cannot be seen. Impressive videos of orbiting of stars around this unseen black hole available on the internet. By combining data on speed of these stars and knowing that they haven't collided with the black hole yet, the size of the black hole is inferred. Most of the matter we know of, consisting of protons and neutrons, a.k.a. baryons, form only a small fraction of all matter, and are only few 100 to thousand degrees. But large amount of matter is 10 lakh degrees hot. Black holes cause gas and stars around them to move extremely fast and heat up to such high temperatures. This is studied through radio and x-ray observations. This study was not possible till around 15 years ago. GMRT (Giant Meterwave Radio Telescope) is world's largest radio telescope and gives very detailed, precise information - not possible to obtain through other telescopes. NCRA-TIFR developed GMRT.
Very few astronomers of the present have actually looked through a telescope! Not like old days (as still imagined by school children) where scientists (astronomers) had to look through telescope. Even with optical telescopes, astronomers now look on a computer the visuals captured by telescopes. Sitting in a small air-conditioned room in Bangalore, observes data captured by a telescope in Ladakh. Even optical astronomy produces terabytes of data. Radio telescopy, in a few hours, gives 15 GB of data. Data explosion in astronomy - so no longer possible to compute and find things manually. Automation needed. Machine learning needed to classify things and help look for interesting things. Big data techniques used like in many other fields now. Has collaborated with computer scientists and biologists on papers on how the same big data techniques can be used in various domains - astronomy, study of brain and its disorders etc.
India now involved in global projects related to astronomy. These projects are of such a large scale that a single country cannot fund it - hence international collaboration. Astrosat launched recently by India - now in a conference in Jaipur (where the interview was recorded), scientists are studying the 1st set of data collected by ASTROSAT. Data currently for use only by India. Will be made available to global research community after a year. India building some of the components for what will become the largest telescope in the world. India also playing an important role in SKA project, which is building a multi radio telescope in South Africa and Australia, which will be world's most sensitive radio telescope.
IUCAA is a part of a consortium related to the world's largest telescope in South Africa. Data from this telescope is made available by IUCAA to scientists and research labs from other countries.
UGC realized in the 1980s that nuclear physics, particle physics and astrophysics need resources that cannot be handled by a single university. Hence 3 inter university centres established by UGC and IUCAA is one of those. A new telescope in Nainital was unveiled last year - researchers early in their research career can start observing data from this telescope before they start working on data from larger telescopes. Astronomy has become a multi-disciplinary field - mathematicians, chemists, physicists, engineers and even biologists who are interested in the implications of techniques and findings from astronomy.
Dr.TVV: Astronomy and cosmology serve mankind's quest to understand its who are we, where are we questions, but is there a practical use to astronomy and astrophysics beyond this serving quest?
Reply: Astronomy has pushed the frontiers of technology. Most of the technologies in mobile phone borrow from radar technologies used in astronomy. Phones in camera use technology that was developed to send digital images from Hubble telescope. Infrared technology used in nigh-vision cameras for defence use technology originally developed for infrared telescopes. Gravitational wave observation technology used to detect tiny displacements under the earth that are used predict/detect earthquakes, find minerals under the soil etc. Lot of new industries have been spun off from such technologies for precise measurements in astronomy. Dr. TVV summarizes: research in basic sciences is the foundation on which technological research can build up.
15.4.2017:
Prof. Ashok Sen:22.4.2017:
Dr. Phanikanta Mishra: (b. 1956??) Eminent archaeologist. Retired. regional director, ASI, Kolkata. Doctorate from School of Archeaology, Delhi. Well known for his discovery of a Buddhist stupa in Madhya Pradesh that was declared as a heritage site and protected site in 1996 (or 1999?).Dr. TVV: How are archaeological artifacts like terracotta dated? Reply: Beads, pottry etc. follow a style reflecting their period. Mauryan period - northern black polished ware. Gupta period - pottery changed - pottery was of red or ochre colours. Both carbon-dating and thermoluminescence used to date archaeological specimens. Archeaology is pure science in that sense. (and combined art and science).
On development of stone age tools and stone age culture. Prehistoric man cranial capacity - 2000 cc; current human's cranial capacity is 1500. Sudden increase in IQ capacity before stone age, yet hunting techniques evolved gradually. Early stone age humans tried to use boulders to hunt animals coming to drink water; artifacts from this period are larger and don't have much human work done on them (almost no chiselling?). In middle stone age, they used smaller, chiselled stones to hunt animals more effectively and to get tastier part of animal meat. Late stone age saw development of microliths - small chips, tools to remove animal skin.
Oldest animal or human artifact available to archaeologists? 130000 B.C. - skull of boscomolatica elephus (??, some extinct type of elephant?) - same type of skull dating to the same period found in Narmada basin, India as well as South Africa.
Evidence of earliest human habitation in India are megaliths - stone monuments from stone age, found in several places in south India as well as north India.
Dr. TVV: How do archaeologist differentiate between a status of Buddha from that of Mahavira, given that both are portrayed as having very similar facial features, very calm composure? Says this quesytion arose when he visited Chennai museum recently. Reply: Ideally, any educated person, not just archeologists should know about this. This knowledge should be marketed in a way which is lacking at present. Buddha often portrayed as having curly hair, signs on head, peepal tree nearby, and in various mudras, dhyaan mudra, bhoomi sparsh mudra, abhaya mudra etc. Mahavira not portrayed as displaying mudras, very plain and simple - sometime accompanied by chauri-bearers.
Similarly, portrayals, figurines of sacred rivers differentiable based on associated symbols/signs. Yamuna on crocodile, Ganga on tortoise. Dr. TVV says this indicates that Yamuna once had many crocodiles and Ganga abounded with tortoises, but due to human intervention and pollution, these have almost disappeared from these rivers. Dr. Mishra agrees and says children must be made to understand the historical significance of these ancient statues and this will lead to ecological awareness too.
Mentions Khajuraho's importance in depictions of scenes from Ramayana and Mahabharata. Is happy that he discovered and excavated the 35th temple in Khajuraho in 1999. It was in a dilapidated condition. Went for horizontal excavation. Had to expand by 30 feet horizontally and needed to acquire land. Local residents protested and man-handled workers engaged in excavation. He explained to people the importance of excavation work and how people will benefit from tourism, after which residents supported the excavation work.
Dr. Mishra's father too was an internationally renowned eminent archeologist known for major discoveries in places like Vaishali and Pataliputra. Started career in ASI in 1981. Initially had to work at a northern district (Rewa) in Madhya Pradesh. In those days, exploration was very difficult - small team of 2-3 people working in scorching heat with paper maps. Could not find anything for long and decided to move to a different place for exploration. When he mentioned this casually to a village head, the mukhya said he could take Dr. Mishra to an "Ita kaa bhatta", in a densely forested area, from where villagers were collecting bricks. They started in a tractor at 7 PM and reached the place at 9 PM - the `ita ka bhatta1` turned out to be a Buddhist stupa from Mauryan period, over 2300 years old. Found a huge monastery and several artifacts. Went to library next day to verify that the place was in fact undiscovered. A very exciting moment for Dr. Mishra. Felt that God had left this site undiscovered by others only for Dr. Mishra to find!
Buddha bowl carried by Kanishka to Peshawar during 3rd Buddhist council. Deputed to work in Kabul. Found the bowl in Kabul museum, but some addition inscriptions in Persian and Brahmi script were added later - presence of swastik symbol, lotus symbol, and the material being the same as one known to be used . Excited to discover the bowl!
Dr. TVV: List 3 major unresolved mysteries in archaeology. Answer: Lots of unsolved problem; ongoing work and in many, final answer not arrived at yet! Deciphering Harappan script. Dating the period of Ramayana and Mahabharata based on archeological findings. Finding the source and course of mythological lost Saraswati river. Dr. TVV's summary - interesting field with lots of opportunity to discover.
29.4.2017:
Dr. P. Sreekumar: Director, Indian Institute of Astrophysics (Bengaluru). Interview at Pune. Played a key role in Project Chandrayaan. Ph.D from Univ. of New Hampshire after M.Sc in physics from IIT Bombay. Worked for 10 years as research scientist at NASA's Goddard space research laboratory. Has 120+ publications. NASA's achievement award in 1991. 40 years of research experience.Dr. TVV: Top 3 research areas that you worked on?
Worked on high energy gamma ray astronomy. It was rarely explored till 1990s. Was a part of the science team associated with Compton Gamma-ray Observatory (CGRO). Aim of CGRO (launched in 1991) was to map the sky and identify active galaxies, quasars etc. CGRO was the 2nd of NASA's "great observatories" (1st being the Hubble space telescope?). Microwave background has been studied from 1950. There was a prediction that a similar phenomenon would exist with gamma rays too. Worked on characterizing gamma ray glows and finding whether a glow was a real emission; produced one of the first spectrum that showed what the glow was all about. 'CMB' among the major findings of the observatory; it's a faint glow that fills the entire universe.
After joining ISRO, moved from study of gamma rays to something closer, the study of solar system. Being associated with Chandrayaan 1, carried out study of moon's surface, especially its chemistry. Chemical mapping of moon's surface. The mapping was carried out by the orbiter itself, didn't have to depend on the sole lander. Sun emits flares and Xrays, and studying how these are absorbed by re-emitted by the surface helped identify the elements present in the surface. 1-to-1 mapping exists between energy of source emission and that of re-emission. This technique is used by gold merchants to assess presence of copper in gold. Challenges with studying moon's surface: cannot carry Xray source to moon, instead rely on solar emission. But solar emissions are unstable (time variant), unpredictable. Meaning energy of solar emission had to be measured in addition to re-emission/reflection from lunar surface. Theoretical models were developed to correlate the 2 and identify the elemental composition.
Currently involved with ASTROSAT. X-ray optics and focusing very different from focusing techniques for light. Refractive index of most materials is almost 1 for Xrays, meaning Xrays pass through with almost no bending. Only way to reflect Xrays is by using grating (grating index??) - make Xray hit at a very shallow angle (less than 1 or 0.5 degree) on a lattice structure, leverage "external" reflection. Dr. TVV's analogy - children throwing a stone on a pond's surface at a certain angle such that the stone bounces over the surface for quite a distance instead of sinking.
Thus scattering is used to achieve focussing of rays. Team has now embarked on improving this technique, so that mirror can become smaller - leads to next generation of Xray telescopes. Leverage multi-layered mirrors for this (100, 200 or 300). Working with ISRO satellite centre and Raja Rammana centre for advanced technology. Extra-polarimetry is an emerging field in astronomy.
Dr. TVV: What is the need for a new solar telescope in Ladakh, when one of the earliest solar telescopes, the Kodaikanal observatory's telescope, is under your institute? Reply: Science and technology improving and there is a thirst to get higher resolution images and more data. Kodaikanal telescope's data continues to be useful, provides daily observations that are now publicly available. India's biggest multi-application solar telescope is in Udaipur. Newer telescopes aimed at studying specific regions of sun, sunspots etc. Space-based telescopes have become prominent in the past 15 years, but putting 2 metre telescopes is an expensive proposition. Land-based telescopes like Ladakh's complement space-based telescopes.
On ISRO's Aditya mission. Is being designed specifically to study sun's corona as close as possible to sun's disk and unravel the mystery behind enormous difference in temperature between solar surface and corona, i.e. identify the source of the extreme heat of corona. Due to extreme contrast between corona and solar disk, the mission will have to produce artificial eclipse to observe the corona. The coronagraph will create artificial eclipse by reflecting sun light using a mirror through a hole that is about the size of sun disk's image, thus leaving out the light from corona to observe. The mission is extremely challenging as studying the corona from vicinity is very difficult.
We are in a golden age of astronomy. India involved in building the 30-metre telescope which will be world's largest; TMT project started in 2004. TMT consists of 492 1.4m diameter mirrors, hexagonal segments that act together as a single large mirror. India building 100 of these component mirrors. India has developed the technology to create these mirrors and the same technology and facilities can be used in future for indigenous projects, like India's own TMT. India has also developed control systems to align these mirrors to correct small misalignments that will occur when these mirrors are used for observation. Another work is building the mounting system for these mirrors. Thus, India is contributing not just money but also hardware and software.
What are the human resource challenges that India faces in such large projects? More academics, industry and students needed to boost the study. Another concern is the need to enhance student participation in astrophysics - need more students interested in experimental physics to enter the field. The institute has been running a program for the past 5 to 6 years to bring engineering students into experimental physics - a (dual??) degree course that will help engineering students work in astronomy projects. But the need for more students entering pure science research remains.
Astronomy facing challenges in terms of number of new students entering the field. Teaching community may have been lax in .
Institute conducts a lecture series on Sundays for public interested in astronomy - catering to general curiosity about astronomy. Offers a 20 session crash course for students (esp. engineering students), at the end of which students will be in a good position to decide whether they would like to pursue astrophysics. 3rd initiative is aimed as colleges - student groups can use institute's facilities to carry out small-scale experiments.
