gender equality in science

A Geophysicist From IIT Kharagpur Talks About the Tricks of Her Trade

Sudha’s area of concern is geophysics that directly impacts environmental issues such as groundwater contamination and aquifer detection.

Sudha Agrahari. Credit: Author provided

Kolkata was chillier than I expected in January and it took quite some effort to drag myself out of bed to catch an early morning train to Kharagpur. Kharagpur, where the first of the IITs was established in 1951, is just about two hours away from Kolkata. When I reached, it was still early hours. On my way to the Department of Geology and Geophysics, giant banners informed me that the annual Alumni Meet was underway. That explained the clusters of middle-aged men – looking casually spiffy and successful – wandering around reminiscing with cameras in hand and nostalgic smiles on their faces. I wasn’t too surprised to spot no women among them.

Kolkata. Credit: Author provided

The IITs are notorious for their poor gender ratios – currently standing at about 8% of female students, compared to > 40% in other engineering colleges in India. This disparity has been recognised and there now seems to be some intentions to rectify it, but in the meanwhile, women scientists among the faculty will no doubt serve as a reminder to the students that science can indeed be a space that women belong in. I was looking forward to chatting with one among this small community – Sudha Agrahari, who joined IIT Kharagpur in 2013.

Sudha is a geophysicist, but unlike IISc’s Kusala Rajendran who we interviewed last year, Sudha doesn’t investigate tectonic plate movement; she is more concerned about geophysics that directly impacts environmental issues such as groundwater contamination and aquifer detection.

Groundwater worries

‘Groundwater’ refers to the deposits of water that collects in pores of soil and rocks. The layers of rock where these water deposits are found underground are called aquifers. In order to use groundwater for our daily use and consumption, we dig borewells that connect aquifers to the surface. Sudha specialises in using principles of physics to predict and detect the precise location of aquifers. “Our earth works as a natural filter (that’s why groundwater is fit to drink). It is easier to dig only a few meters to collect water but we may have to go deeper if the shallow aquifers are contaminated,” she said. In coastal areas, this contamination is often by seawater.

Seawater. Credit: Author provided

It’s natural for salty seawater to ‘intrude’ through the sand into pure groundwater – making it unfit for consumption. Coastal areas have to be careful about not digging wells too close to the sea. This is another area where Sudha’s geophysics helps. “We do measurements to say for example: because of sea intrusion, the groundwater up to this point is contaminated. Beyond this, it is safe to use’,” she explained. With this information, inhabitants of the area can decide to stay safe and fulfill their groundwater requirement from deeper, uncontaminated aquifers, or if they have no choice but to use groundwater close to the contaminated area, they can purify the water.

Seawater intrusion is more hazardous if industrial waste is routinely disposed into the sea. According to Sudha, when such a disposal is done by the government, they ensure the wastes pass through a lining of cement so there is less seepage. In due course of time even this cement degrades. Geophysicists can provide advice in these situations too. And they can do this non-invasively, i.e. with no digging.

Sudha recounted her experience researching mountainous areas. “The problem here (in the mountains) is that if a borehole is made, they may get water today, but after a few months or a year, there is no more water. This happens when the water resides [only] in a small pocket.” Thankfully, physics can come to the rescue.

The Art of ERT

The electric and electromagnetic properties of materials allow scientists like Sudha to know what is underground without any digging. “I use a method called electrical resistivity tomography (ERT) to tell how big the aquifer at this location is, whether it is laterally extended, connected to any other aquifer, if there are nearby aquifers… and so on,” said Sudha. These kinds of studies are tremendously useful when borewells or handpumps are being set up in cities and villages.

So how exactly does ERT work? I asked Sudha to take me through the practical steps in setting up an experiment on site. She took a deep breath before launching into a vivid explanation (see circuit diagram). “It’s a huge setup – we use two electrode rods connected to a battery through a cable. We insert the rods into the ground so that it is stable and can stand up. Now we connect another two electrodes to the ground and measure the potential difference in between these two rods. When we start the power supply, current will start flowing in the earth’s subsurface. We also connect here an ammeter to see how much current is flowing.”

Sudha on site with an ERT setup, Credit: Author provided

This is where the fun starts. We know that current flows from the (+) electrode to the (-) electrode and that is what one would expect to see here as well. But it is not the case, Sudha pointed out. “Earth’s subsurface is not uniform. Resistivity changes everywhere…”

What is resistivity?

It is the property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current through it. A material with high resistivity opposes it more so the current has to put more effort to cross it and an electric potential drop is recorded.

According, to Sudha, most contamination is conductive in nature, meaning it has low resistivity. Some, like hydrocarbons or biological contaminations, are not – so they show high resistivity. The experiment can detect these irregularities (a potential drop indicates resistivity), which Sudha interprets to further characterise the nature of the contaminations.
The resistivity of any subsurface material on earth varies wildly – from 10^-8 to 10^8 ohmmeters. In coastal areas, groundwater can have a resistivity of 0.1 ohm-meter and in hard rocky areas, it can be around 90 ohm-meters. “But if the groundwater is contaminated with hydrocarbons, then it will show a resistivity of 200 ohm-meters. Canned water we buy has a resistivity of 50-70 ohmmeter. A lot depends on the geology of the subsurface and your expertise, but in crude language, we can say 50-90 ohmmeter groundwater is suitable for drinking.”

Credit: Author provided

Sudha’s PhD fieldwork took place around the Sivalik hills in the Himalayan region where a moody river troubled the locals. “In the rainy season, it filled up but at most other times it remained dry. There were people dependent on it for irrigation and on the groundwater for drinking water supply. We did several surveys to understand why groundwater is present for the whole year in some aquifers but not in others.” Using ERT, she created a map of the area that colour coded the resistivity of the subsurface and show the network of aquifers that lay underneath. This explained why some areas were better water-stocked than others.

Sudha added that the set-up she had described earlier is the simplest possible one; most of their experiments involve not four but up to 42 electrodes. Add to this the Himalayan terrain and Sudha had a bumpy task ahead of her. “The Himalayas are one of the toughest terrains to do fieldwork. You have to go everywhere by foot, carry huge equipment all the time. Several times we had to return because the land was not suitable.”

Transportation challenges. Credit: Author provided

This was when she realised it would be worthwhile to get expertise in airborne electromagnetic methods. In these methods, helicopters and drones are payloaded with equipment that uses electromagnetic and inductive properties which allow the analysis of the subsurface without any contact. The instrument may be hovering ninety metres above the land. Interest in this technology led Sudha to do her postdoctoral studies in airborne electromagnetic methods at the University of Cologne in Germany.

Choosing a science for humankind

As the daughter of a railway serviceman growing up in Gorakhpur, Uttar Pradesh, Sudha’s aptitude for academics was evident even in school. She recalled her crushing disappointment every time she ranked second in exams. “It felt as if I had failed, you know?” she smiled. “I didn’t study in big schools – but my teachers always forced me to go to better schools. And somehow I got scholarships and fellowships to support my studies. This much was very clear to me – that I will go for science.” And physics was her favourite. She did her BSc. from Gorakhpur University and MSc. at IIT Roorkee. She cleared the exams necessary for proceeding with a PhD and then it was finally time to decide what area of physics she would do research in.

Another picture of Sudha. Credit: Author provided

Her primary insistence was to pursue something not just experimental, but also something that is impact driven. “I wanted to do something directly related to mankind. I didn’t want to develop something that goes to some industry before it comes to people; I wanted to be in direct contact with people.”

She decided to accompany a geophysics professor to the field and was elated to find that this was where she was meant to be. “In the field, you talk to people, and you hear about the problems people are facing. And it’s very interesting to see that a farmer – who has had no education in his life – has made a groundwater recharge system, just out of his experience and his need. I get educated so much on the field. Here you are no longer in the science community, and you get to know what the real requirements of common people are.”

It took some getting used to for Sudha, who at the time was used to the confines of a lab. For instance, she had to learn to yell out to her teammates. “You can’t communicate quietly up there in the field. I was not used to shouting, but there’s no choice – the setup itself is 700 metres long… I liked all of this, and decided to jump from physics to geophysics.”

A rock solid relationship

During her PhD, Sudha applied for and won a German Academic Exchange Service (DAAD) scholarship which enabled her to spend three years in Germany getting trained in electromagnetic and modelling techniques. In between, she returned to India to submit her PhD thesis. She got married around this time; her husband is a chemical engineer trained in IIT Kanpur and currently working in Rajiv Gandhi Institute of Petroleum Technology in Rae Bareli, nearly 900 kilometres away.

Sudha admits that when she got the offer from IIT Kharagpur, it was not an easy decision for her as her husband was in Belgium at the time. “He was the one who forced me to join – he reminded me that this is a big achievement. But it was very difficult for us – we met only once a year.” They have been married for five years but Sudha is grateful that her husband has never suggested that she leave her job to join him. “Sometimes I get weak, but he supports me.”

Though the couple does not have children yet, Sudha is clear that in any event, children or no children, her future in science is certain. She narrated an incident when a man on her DAAD interview panel questioned her motivations. “He asked me this: Let’s say we give you the fellowship. You will go abroad, do the work, then you will come back get married have children and leave science… I replied ‘yes, you are right. I will go abroad, come back, get married, have children. But I will not leave science.” From then on, Sudha always goes back to these words when faced with tough decisions. ‘‘It has always been very clear to me that I will remain in science whatever happens.

I replied ‘yes, you are right. I will go abroad, come back, get married, have children. But I will not leave science.”

Encountering Feminism on the Field

Sudha’s team on a field site. Credit: Author provided

“Geology has a lot of women these days. It’s not like the past. Now there is no reason at all for girls to be afraid. In fact, sometimes I benefit from being a woman! While working in a rural place Garhwal (in Uttarakhand), suddenly a group of women came holding sickles. You know how they normally say that the male is the earning member? But in those places we saw that it was the women did the the household stuff and the farming work also. These women told us we cannot do our experiments – they were scared we would disturb their land. Somehow, when I told one of the ladies that this was for my PhD work, they gave full permission. She was able to convince all the women – it was important to all of them that women should be educated. Once they got to know that this was for the academics of a girl, they supported us even without knowing us…”

This piece was originally published by The Life of Science. The Wire is happy to support this project by Aashima Dogra and Nandita Jayaraj, who are travelling across India to meet unsung women scientists.

A Planetary Scientist and Her Box of Pre-Solar Grains

Scientist Kuljeet Kaur is working on ‘experimental indirect astronomy’, which is one of the few ways to study the cosmos without telescopes.

Kuljeet Kaur. Credit: Author provided

A rickshaw dropped me just outside the PRL scientists’ quarters. I entered my details in the security register and began searching for Kuljeet’s flat. When I found it, I realised I was perhaps a bit early. Her living room lay happily scattered with her six-year-old daughter Esha’s toys and stickers. The fragrance of freshly-made parathas filled the room. Though she wasn’t prepared, Kuljeet welcomed me warmly into her home. I watched her very patiently negotiate a few hours of quiet with her young child in exchange for some tablet time so we could do the interview.

Credit: Author provided

“It hasn’t been easy for me since I’m alone,” she said strongly, looking at me straight in the eye. Kuljeet describes the early years of her job at PRL as a divorcee and single parent the toughest time in her life. Though she has since remarried, she is still awaiting the day the new family can start their life together.

Even scientifically, Kuljeet lacks peers in the country. She said she is the only person in the country working on ‘experimental indirect astronomy’ which is one of the few ways to study the cosmos without telescopes. For a long time, there was no permanent staff in her team while she operated a giant sophisticated instrument to answer big questions such as ‘where do elements come from?’ and ‘what happened before the birth of our solar system?’

I realised over the course of our conversation that if anyone was strong enough to pull this off, it had to be Kuljeet.

Sweat, blood and a broken NanoSIMS

In 2007 Kuljeet returned to PRL, Ahmedabad (where she did her PhD) after spending three years doing postdoctoral research at Max Planck Institute in Germany and a brief stint at Washington University. She got right to the task of setting up a pioneering planetary science laboratory. The centrepiece of her lab would be the NanoSIMS – a highly sophisticated mass spectrometer, costing Rs 14 crores; a true national treasure considering there are only 22 of these in the world.

“When it reached India, the instrument fell down and broke,” Kuljeet began the story of her initial ordeal. The broken NanoSIMS was shipped back to France, where the manufacturers are located. It took around a year to return to PRL and to her dismay, Kuljeet found it still wasn’t completely fixed. ‘’No company will replace all the parts, so it started breaking again one by one. On one day the pump would stop working, the next day it would be the controller, and another day the regulator would break down.” With no permanent staff or technical/lab assistants at hand, Kuljeet repaired the NanoSIMS. “I was all alone. I was pregnant. I took no leave, no break…”

‘‘You should have seen me,” she chuckled good-naturedly. “With a big pregnant stomach – I was a divorcee at that time – I was fixing a broken instrument with screwdrivers and spanner, ultimate down (bad) time. I fixed the instrument with a lot of difficulties.”

Kuljeet did not take any kind of break during her pregnancy. She merely decided on the date she would have a C-section birth and then rested briefly before returning to work. “I made a PRL ID-card for Esha and from then on, my 40-day-old daughter was with me in the lab, sleeping there in the temperature of 19 degrees, night and day.”

“I have given my sweat, my blood and my daughter’s precious time to this instrument,” she confessed.

After this rough start, the situation slowly normalised and things began to look up for Kuljeet. The ordeal with the broken instrument had delayed her experiments to 2011 but she has caught up. Temporarily, she could get one permanent research staff thanks to funds from the Women’s Excellence Award she has received for her promising research. She updated me last week via email with the good news: “I have permanent staff with me now – so I am not alone in the laboratory – after 7-8 years!’’ Today, Kuljeet is proud of her studies published in “high impact journals – five in Science’’ including one on the activity of the young sun.

What does the NanoSIMS do?

The NanoSIMS. Credit: CAMECA

“So this is the NanoSIMS,” she showed me a picture on her laptop. “This is my machine. It’s a beautiful instrument with 250 parameters – that’s a lot of tuning.”

The samples Kuljeet takes into her instrument are sometimes older than the Sun. The NanoSIMS can precisely separate different isotopes present in them based on their atomic mass. “I work with pre-solar grains. I analyse them in the NanoSIMS to look for isotopic ratios (heavy to light) which are signatures of events taking place when our sun was forming and the time before that,” she said.

Before delving into the complex stuff, Kuljeet introduced to isotopes. “In your blood there is iron, in your teeth there is phosphate, in bones there’s calcium. If I want to separate these elements I could do some chemistry – it is not a big deal. But isotopes are different. A single element can have versions with different number of neutrons, hence different isotopes. For example, oxygen can come in 3 mass numbers – 16, 17 and 18. These are oxygen’s isotopes. If I want to separate 16, 17 and 18, I need a mass spectrometer.”

A piece of the Itokawa asteroid that Kuljheet is studying. Credit: Kuljeet Kaur

A mass spectrometer like the NanoSIMS has a large magnetic field with which it can spread out the sample into isotopes. This is possible as each of the isotopes has a different mass to charge ratio. What Kuljeet has in her hands is really a mass separator in the nano level. Once she has a ratio of heavy to light isotopes in the sample, she can tell where and when it might be coming from – is it from the baby sun or from another kind of star – and from which point in the stellar-solar evolution.

One of Kuljeet’s graphs showing heavy to light ratio of Carbon and Nitrogen in different types of stars. Credit: Kuljeet Kaur

One of Kuljeet’s graphs showing heavy to light ratio of Carbon and Nitrogen in different types of stars. Credit: Author provided

Supernovae are massive stars that end their life cycle with a dramatic explosion ejecting newly formed elements and other star stuff like gas and dust with a shockwave, commonly triggering the formation of new stars. The stars commonly observed to ‘go supernova’ are around 90 times heavier than the Sun.‘‘I have worked on titanium isotopes, barium isotopes, silicon, nitrogen, carbon, oxygen, nickel, iron and most recently on chromium isotopes. These (chromium isotopes) are very special because supernovae are the only source of chromium – there is no other kind of stars that produce them. And they are made in the interior core of the supernova, like other transition metals like iron, not in outer layers where hydrogen, helium and oxygen can be found.”

Getting her hands on pre-solar grains

“When a supernova explodes, the inner core has to come out. Nobody can tell us what the inner core is composed of, how fast the inner core is reacting, what is the mixing taking place between the different shells of a star. But presolar grains can.”

Most of the pre-solar grains Kuljeet has worked were picked up from meteorites, often dubbed the poor man’s space programme. “It comes to your house. It falls down right in front of you and you are lucky if it is a primitive one.” There are also micro-meteorites that you can get from the depths of the ocean. Or if you fly a probe into the stratospheric region of the planet, there could be some dust that fell from comets passing close to Earth’s orbit.

Solar Grains. Credit: Kuljeet Kaur

Besides relying on primitive meteorites that fall on Earth, Kuljeet has been constantly writing proposals to obtain grains collected in sample return missions on space voyages by the likes of NASA and the Japanese Space Agency JAXA. “I recently got samples from an asteroid named Itokawa which was brought to Earth by a JAXA sample return mission called Hayabusa. In India, I am the only one to touch an asteroid sample! Isn’t that exciting?,’’ she exclaimed.

During her time at Washington University, Kuljeet was part of the international team tasked with analysing samples retrieved from a sample return voyage to a comet called the Stardust mission. “You see these tracks?” she pointed at an image on her laptop. “These are the comet grains on it. I worked on one of these pieces. I removed the grain, put it on a thin film, got it into my NanoSIMS and analysed it. I touched the grain – not really, but with forceps.’’

Where do elements come from?

In essence, Kuljeet’s work tries to point at something we have all wondered. We see elements everywhere, but where do they come from? Below Kuljeet explains the nucleosynthesis of elements, with which scientists like her are putting together the pieces of our galactic evolution.

Composite image of Kepler’s supernova. Credit:NASA/ESA/JHU/R.Sankrit & W.Blair

“The reaction that goes on in any star is hydrogen + hydrogen = helium. Then, three heliums connect to form carbon if the star is a little bit more massive. Then it will rotate around in the core and there will be carbon, nitrogen, oxygen plus helium and hydrogen. This is all normal stars can do.”

“But a supernova has a more intense structure because it is heavier. If the stars have more mass, there is material to burn. After lots of carbon is formed and we still have more helium, there will be more carbon to burn. If it has a good enough carbon core then it will get denser and go beyond (on the periodic table).”

“All heavy elements that exist should have come from supernovae. And then there are the hundreds of normal stars that add on to the chemical evolution.”

Schema. Credit: Wikimedia commons

“For explanation sake, let’s consider a time period of 1 billion years after the Big Bang with only two supernovae. Let’s assume these produce a certain amount of iron isotopes that enter the cosmos where more and more stars are being born. These new stars will process pre-existing iron isotopes to take the chemical evolution further. After 10 billion years there will be more supernovae, more elements being formed, but the early ones are also being processed in other stars. As they go into other stars, they are processed, meaning a neutron is being fitted into atoms. You feed a neutron to 54 isotope iron, it goes to 55, then it goes to 56. In this way, 56 iron is being enriched (‘enrichment’ signifies more than what you started with).”

“Galaxies are evolving in metallicity with time. It’s a time process that we can date back.”

For Kuljeet the fun of it all is in the fact that she can really go far back in time by working in her lab with isotopes found in pre-solar grains. “Just looking into data from my NanoSIMS I can see how the galaxy was evolving,” she said.

Facing the“two-body problem”

During the course of her work, she has collaborated with several scientists around the world. With one of her collaborators, she is also married. Kuljeet married a fellow planetary scientist Ritesh Kumar Mishra three years ago. The two of them have coauthored at least four research papers but the young family lives apart.

“Esha is a bright kid but misses her father time to time and has a repetitive question: Why dad doesn’t stay with us?”

This unofficial rule of not allowing spouses to secure jobs at the same institute seems to run historically through academic institutions of our country. During this project itself, we have come face to face with this so-called ‘two-body problem’ too many times. Given that a large number of married women scientists we have interviewed are married to other scientists (15 out of 39), we identify this unofficial rule as one of the institutionally sexist policies that keep women from science.The answer to Esha’s question depends on the fate of a job application file that remains to be dealt with at PRL. According to Kuljeet, her husband, an applicant and alumni of the institute has all the right qualifications. “He is a Humboldt fellow at Heidelberg University in Germany. He was at Johnson Space Center, NASA for two years. We are looking forward (to having him in Ahmedabad) provided they feel that spouses can be accepted.”

Kuljeet and her daughter Esha. Credit: Author provided

You always crib about brain drain, here there is a person who has the merit and he’s trying to come back but he is not being taken just because he is my spouse.

Some institutes like IISER and IIT Kanpur have taken steps towards disregarding this rule by promoting the hiring of couples. But at PRL, as evidenced by Kuljeet’s case, something has got to give.

Kuljeet wonders: ‘‘He has several prestigious fellowships and if his application is not being considered — is it the spouse factor or a planetary scientist is not needed in India?’’

‘‘You always crib about brain drain, here there is a person who has the merit and he’s trying to come back but he is not being taken just because he is my spouse,’’ she said, obviously disgruntled at the double standards.

Srubabati, another scientist at PRL we have interviewed, faced a similar situation but in her case, the rule was lifted. “Sruba got lucky in the end. They also lived separately for many years,” Kuljeet said.

“I think we should be given an opportunity to have a better life for our children.’’

I am a feminist, thanks to my father

Kuljeet’s family, she is on the bottom left. Credit: Kuljeet Kaur

Something she heard one woman say at a women’s forum rings in Kuljeet’s ears. “She said ‘I cannot do everything because I don’t have a wife back at home.’” This statement attests that in most Indian families, wives are still expected to manage all of the household chores so that the husbands are free to fulfill their dreams. “Science is something you have to devote your life to. If you do all the work at home, you cannot go and do science too.”

To close the gender gap, Kuljeet recommends more fellowships for early career women in science are needed, as well as an increase in stipend so they can be financially independent and extension of PhD time for married women.

Most important, she said, is support from parents. “Not every woman has the support like I did. My parents and my sisters were with me during my divorce and my second marriage. Even now, when I have to go to conferences, my parents come to take care of Esha – but if I say I want to go away for a sports meeting, they tend to refuse. As long as it’s for science, they will be there but for anything else, it’s hard to get them here.” she said jokingly. “When your family supports you, you can be very strong.”

Kuljeet is grateful to her father for her interest and progress. “His name is Sardar Singh Marhas. He had three daughters who stood against his conservative family brooding over ruined marriage prospects to make way for higher education of his daughters. He started as an assistant in Bhabha Atomic Research Centre, Mumbai in the glass blowing section and then worked very hard to retire as Scientist E, the same scale on which I joined PRL.”

Kuljeet said her father is famous among her family for his progressive values, particularly for having said, “My daughters are not made for the kitchen”.

This piece was originally published by The Life of Science. The Wire is happy to support this project by Aashima Dogra who is travelling across India to meet some unsung women scientists.