Whether it’s organising
a conference to discuss the future of particle physics, or serving on the
advisory committees in Europe, US, Japan, and China on building next-generation
particle accelerators, or fixing the gender imbalance in Indian science as an
elected fellow at the three Indian academies of science, Prof Rohini Godbole
has a lot on her plate.
This is all the more impressive, considering that she encountered the world of science as late as high school. Godbole had a vantage viewpoint on the most exciting field of physics of the last 40 years—the standard model of particle physics. The standard model is a theory describing three of the four fundamental forces, and all known elementary particles in the universe.
Her work on her PhD coincided with the “November revolution” that took place in 1974. She was also present at CERN on July 4, 2012, when the discovery of the Higgs boson was announced—the final puzzle in the standard model. Godbole has contributed significantly in designing a new class of experiments, and also in designs for next-generation particle colliders.
Godbole has also served several committees to improve the participation of women in science. She also co-edited Lilavati's Daughters, a highly acclaimed collection of biographical essays on women scientists of India, which was released in 2008. Currently, Godbole is a professor at the Centre for High Energy Physics at the Indian Institute of Science in Bangalore. Edited excerpts from an interview:
So how did you decide to become a scientist?
I went to an all-girls school in Pune, His Highness Chintamanrao Patwardhan (HSCP) High School, perhaps the first high school for girls ever started in India. As a result, we were taught Home Science, and not science till the seventh grade.
Those days there used to be a state scholarship examination. The scholarship would be one rupee less than the school fees. From my school nobody had got it. And the reason was very simple. There was one whole paper on general science.
When I was appearing for the exam I went to my teacher and I said I have to learn science. Her husband used to teach science in another school. She said why don't you come home and he will teach you. That was the beginning of science in my life. I became the first girl from my school to get the scholarship.
When I was passed my 11th standard, I was in the top ten in the state. And usually you are interviewed by the media. And they asked me what are you going to do. Others with me said they wanted to become doctors or engineers. I have no idea why I said this, but I said I'm going to be a scientist. Or I'm going to be a Sanskrit scholar.
I was not eligible for most scholarships because my father's income was above a certain limit. Not that we were very rich. But one day, my sister came over with the National Science Talent Examination scholarship, which had no income barriers. I applied for it, appeared and got it. And that was really the turning point.
I don’t think I really had a concept of what being a scientist means. The science talent programs gave young people a feeling for it, and through it, I attended three summer schools — Delhi, Bangalore, and Visakhapatnam.
By the third year of BSc, I was giving equal importance to mathematics and physics. And then I said “No, no, physics is better from a job perspective”. Which was completely stupid (laughs).
Can you describe the field of particle physics when you entered it in the early 70s?
I did my Masters at IIT Bombay, and had a teacher who inspired me to do theoretical physics. At that time, it meant either nuclear or particle physics for me.
In those days, I wanted to go and attack areas with the most pressing and interesting challenges. And particle physics was it. The 70s were, in my mind, the most exciting time to do particle physics.
Just to give you an idea, I started my graduate work at the state university of New York at Stony Brook in August 1974. In November 1974, there was this accidental discovery of a new particle, what is known as the bound state of charm and anticharm Quark. This was called the November revolution. So that just tells you that something stupendous happened at the time as far as particle physics was concerned.
I couldn't have started my life at a better point than that. This was from 1974. The world of particle physics had devoted its total energy in establishing the standard model, figuring out the tests that you can perform to see if there is any physics beyond standard model, and to find the Higgs boson. And luckily this is what I did all my life.
The stage was the beginning of establishing the so-called standard model of particle physics. I couldn't have started my life at a better point than that. This was from 1974. The world of particle physics had devoted its total energy in establishing the standard model, figuring out the tests that you can perform to see if there is any physics beyond standard model, and to find the Higgs boson. And luckily this is what I did all my life.
What were your initial years of research into the standard model like?
It was quite interesting. My first foray was into whether one can find the Higgs boson in neutrino reactions. Because nothing was known about the Higgs boson at that point, apart from its interactions. It's mass was a complete unknown. The world of particle physics was developing with experimentalists studying collisions of neutrino with matter. That is high energy neutrinos incident on targets or collisions of high energy protons with each other etc. And then you study what happens.
You did theoretical physics, yet you also did a lot of work in providing feedback to experiments. Can you explain how that works?
You can see that by and large my whole working life has been defined by testing the correctness of standard model, and looking for physics beyond it.
There is a very precise theoretical framework. And you need to work out the consequences of this theoretical framework in a particular experimental set up and tell the experimentalist what they should see if the theory is correct. And if they see something else come back and try to see what aspects of theheory need to be modified .
As a phenomenologist, I had to understand what the theory says very well and also to understand what their experiments are trying to tell you anyway. I have worked on all three different interaction theories—namely strong, electromagnetic and weak.
Around 1984, how to look for the top quark was a very hot topic. This was also the first time at the [CERN] collider, a new particle was produced and that was the W boson and Z boson. It was a big thing. I was a postdoc at that time and we figured out how, what might be the best strategy to look for a top quark if it is heavy compared to let's say the bottom quark which had already been found at the time.
Because top quark, being heavy, was produced in a billion collisions very rarely.Maybe around ten times. So it's like saying that you have a big haystack and there is one needle. How can you find the needle? You need to figure out how to paint that needle some bright blue or bright red so that it can suddenly show itself up. So what we did is that we actually figured out the criterion by which you would be able to see the needle above the rest of the hay. So this is something as a theorist I point out and the experimentalist uses.
Can you explain the collaboration that
goes on between theorists and experimentalists before building a collider?
I grew up in a period
where this interaction between experimentalists and theorists really increased,
I would say exponentially.
Before the machine is actually built theorists and experimentalists get together and the theorists kind of work out things. What energies do you need to produce this particle so that you can study this property to a great accuracy. I was part of the bridge between pure theory and experiments.
What was your most exciting time working with these colliders?
Me and a young student, to our surprise, actually found that at these colliders, you could measure a completely new aspect of strong interactions which people had not thought about. That it could be measured at this ep (Electron-Proton) collider. And this actually became then one of the big areas of study at HERA, a particle accelerator in Hamburg. We pointed out that you could study aspects of the theory of strong interaction by making measurements of processes which were initiated by a cloud around the photon—a cloud comprising quarks, anti-quarks, and gluons.
And then we actually figured out that the same effect would be present in e+e- colliders collisions at the LEP collider in Geneva at CERN. These processes are actually very large in certain parts of the detector and then you can use them to learn about the theory of strong interactions. So that was something that I personally considered one of my best piece of work because we actually told the experimentalist about an entirely new type of experiment and measurements that they could make. This was 1990.
This is obviously something exciting. You tell them, please study these kinds of processes. They are going to give you very different information about the dynamics of strong interaction. It gives you one more laboratory to study strong interactions.
Since 1990 these were studied enthusiastically till 1998 or so. Then there was a lull. Now it has come almost come full circle at the Large Hadron Collider (LHC). I was asked last May to give a talk on this old work of mine because now LHC has become one more laboratory where you can study these processes. I'm only sharing something that is really at the top of my excitement curve. We found out then that with the increase of rates of these interactions of the colliding photons at high energies, they can produce all kinds of things which you didn't imagine earlier or you neglected before.
People were thinking of making linear colliders, because beyond a certain energy, electrons going in a circle emit radiation. In linear colliders, you need to make your bunches very thick, so that you will get enough collisions. But we found that beneath these collisions, there is a photon-photon collision. And what we found is that this photon-photon collision happening along with every collision will actually mess up the environment of the electron-positron collider.
So it became very important that when you build this linear collider, you make sure that these photons are not emitted. And luckily you can do that by some clever beam design.
Again I'm extremely proud of this because this is an example how research into something which is very basic such as interactions of high energy photons, find application in an entirely different area—design of high energy accelerators.
You were there when the Higgs discovery was announced at CERN. Can you describe that day for me.
It was an event that gives me goose bumps even today. I really thank my stars that I was at CERN that day. CERN conducts some summer schools and that year I was asked to give lectures on the standard model. And this course was to begin on that day. Of course, our lecture course was shifted to some other place because they announced the discovery of the Higgs.
The days leading to the announcement, it was clear to everybody that things are happening and any day the announcement is going to come. In fact I remember some experimentalist friends of ours invited me and my collaborator to dinner. They were trying to understand the features of the results to make sure that it is indeed right. We knew clearly that something is happening and they were not allowed to tell us. But then they would still ask the question—if this should happen what will be your conclusion. If that happens what will be your judgment.
On the day of the announcement, there was a lecture in the big hall and all the summer school student treated this like a concert. They slept outside the hall in the night and entered the hall. There was very little place left. Everybody was there and luckily I got into the lecture hall with a friend and Fernando Quevedo, director of the International Centre for Theoretical Physics (ICTP). It was a great feeling. I mean to me, along with a thousand other high energy physicists, it was the culmination of a 30-year-old quest.
I think that was the best day of my life.
So what after Higgs discovery? You have been working on some aspects of physics beyond the standard model?
By finding the Higgs where our theory predicted it, we particle theorists have proved the correctness of the standard model to an extremely high degree of accuracy. But now it also gives one a whole new way to probe for physics beyond standard model.
Some of us are trying to see how you can make precision measurement of the Higgs particle and the top particle, so that you can see the footprints of physics which is beyond standard model in deviations of these properties from the expectations in the standard model.
Maybe the Large Hadron Collider will not find a new particle, but you can look at it through indirect measurements. That's what I'm working on in a big way. How can you study properties of the Higgs boson and top quark, more and more accurately and hence look for physics beyond the standard model through this window?
We have now come to a stage where we don't know clearly what the experimentalists will find for the first time in 40 years.
Theorists have to take a back stage and the experimentalists have to find something..Then we can go figure out what those experimental results mean.
Is this an exciting time?
It’s exciting but it’s worrisome. The LHC still has 20 years to run. It has not found the obvious things beyond the standard model, such as evidence for new particles that we thought it would find. But that just means that perhaps our theoretical ideas are not correct or the energy scale is too high because there are no clear indications at these low energies about what the Large Hadron Collider achieves.
Because we have this wonderful theory (standard model). The theory is working beautifully and we don't know which way really to go ahead.
But there are issues which we don’t understand. For example we don’t understand what is dark matter. We don’t understand why neutrinos have non-zero mass. While standard model has all the ingredients to explain why the universe contains only matter and no antimatter—the so called matter-antimatter asymmetry—it cannot quantitatively reproduce the observed value. Even more than that. If I wanted to be very fancy, I would say we don’t understand why electrons have the mass they have, and quarks have the mass they have. What is the principle that separates these masses? We don’t have an understanding why the electron charge has the value that it has. Most importantly, we do not understand why the Higgs boson has a small mass, i.e., a mass comparable to that of the W and Z. We think that someday maybe a theory ought to explain that.
But there are issues which we don’t understand. For example we don’t understand what is dark matter. We don’t understand why neutrinos have non-zero mass. While standard model has all the ingredients to explain why the universe contains only matter and no antimatter—the so called matter-antimatter asymmetry—it cannot quantitatively reproduce the observed value.
One of the leading contenders, which addresses many of them and is sort of highly popular, is called supersymmetry. I worked on supersymmetry from 1992 onwards. It could give a very nice explanation for many of the issues mentioned above. I worked really quite a lot on supersymmetry. In fact I wrote a textbook.
Unfortunately, we haven’t so far found evidence for supersymmetry at the Large Hadron Collider. In May, we held a workshop here and asked where is SUSY (supersymmetry) hiding? And if it is not there, are there any other good candidates theoretically which would solve these problems that the standard model has.
You co-edited Lilavati’s Daughters: The Women Scientists of India in 2008. How did that come about?
There is a small history behind the book. In 1979, I came back to India and was working in theoretical physics. I knew of just one woman doing theoretical physics in India at that time. But I didn’t think much of it. In 2002, the International Union of Pure and Applied Physics (IUPAP) decided to have its first international conference of women in physics and they called me to talk about my experience as a physicist in India. At that time, I was one of the two women fellows in physics of the Indian National Science Academy (INSA) and the only woman fellow in physics of the Indian Academy of Sciences, Bangalore.
I looked at things that had happened in my journey as a physicist, then probably for the first time I started asking this question: “Would it have happened if I were a man?” And I don’t think I could always come up with “Yes” as an answer. In certain cases, I cannot say it happened because of my gender but I cannot rule it out.
One of the recommendations that came out of the IUPAP conference was for academies to form committees to look into the issue of participation of women in science. In 2004, with INSA, we brought out a report on science career for women in India and the Indian Academy of Sciences formed a panel for women in science to encourage young women to continue on the path of science. Six or seven high profile women scientists from different areas would would go to colleges and talk about the science they do.
Another thing we did was to make a database of women in science. Then, we conducted a survey of women who had left science. The INSA report and another survey established that the real fall in numbers comes when women finish their PhD. So, we decided to find those women who did PhD in science but are not pursuing science.
The third idea was to let women tell their stories through a book about what brought them into science, what helped them stay, or what hindered them in continuing with science. This was the idea behind the book.
What did the survey with women who dropped out of science reveal?
This topic is very close to my heart. Many answers bore out the usual reasons we think why women are not as well represented in science. But, there was this question of the big and sudden fall after PhD. The most common statement was: Women choose to leave. But, when we asked this particular question to the women who have left, the answers were revealing. They didn’t choose to leave; they didn’t want to leave. They were not able to get a job which matched their abilities and sometimes, in an institute where their husbands were working. Also, there was no real effort from the institutions or the scientific community to help them get such jobs.
And, this is not a question of giving chance to a woman. It’s simply the fact that by training a person in science, institutions have invested in her and they are not getting any returns on that investment. This is wastage of resources.So, this small survey tells you that you need to change society. And the institutions, frankly, need to change their approach.
What was your biggest takeaway from stories from Lilavati’s Daughters?
One thing in the majority of the stories is that women would not have been where they are but for chance. In the earlier generation, I think, chance played a very big role. So, I realised that we should try to create an environment so that chance can be taken out of this equation.
Today, I have two dreams. One, we should be known as scientists who happen to be women rather than women scientists. Second, a woman does not need chance, or a superlative ability or desire to be a successful scientist.
Of course, it is true that most of the women who you would see doing science successfully are very driven. A man need not be as driven to make it to the same level with the same abilities.
Which were your favourite stories from Lilavati’s Daughters?
The most impressive story is about Anandibai Joshi who got married at the age of 9 to a man who was 20 years her senior. She lost a child at the age of 14. And this girl didn’t know how to read or write, not even Marathi.
Her husband taught her. He took a transfer and took her to Kolkata. There, he sent her to a missionary school. At the age of 18-19, she went to the US on a grant from the mission. She became a doctor and her thesis was a study on pregnancy related problems of Hindu women because she had lost her child.
Meanwhile, her husband started writing letters, out of suspicion or jealousy. In reaction to this, she started wearing her nine yard saree there. She caught tuberculosis. She came back to India, where people refused to treat her because she had crossed the seas. Within two years she was dead.
But her correspondence is amazing. How strong this young woman was! The thoughts of clear feminist nature in these letters is simply amazing. And, she died at 23. I wonder how many women who are capable are lost to humanity forever because society says that they should not be doing X or Y. Every Maharashtrian girl grows up knowing about her. Her story is something truly inspiring for all ages.
Another story that I liked very much was that of the mathematician Mangala Narlikar. She came from a distinguished mathematical family. Since her husband Jayant Narlikar had an exciting career as an astrophysicist in the UK, she stepped away from mathematics for a really long time. The story is about how she made her way back to mathematics and how she still enjoys going to the library and reading mathematics and keeping her interest alive. This touched me deeply. Many of us do science because we love it, because of the kick it gives you, because of the feeling of “Ah! I know how this works!”.
One of the most interesting stories was R.J. Hans Gill, a professor of mathematics in Chandigarh. When she was young, she used to dress as a boy to go to a class to study mathematics because girls’ schools in Punjab didn’t teach mathematics. For her, it was it was forbidden to study mathematics. That story struck me. Each story did this in its own way. I’m especially amazed at the stories of women who are older than me, for example, Rajeshwari Chatterjee, who was the first woman professor in engineering in IISc. I am simply amazed by GV Satyavati, the first woman Director General of the Indian Council of Medical Research. Her story impressed me very much.
How did people, especially women, react to these stories?
There are girls who write to them; I’m telling you this because they forward the emails to me. These girls said things like “I read your story and I got inspiration” and “Now I know that I will have troubles but I will try to sort them out”. This was the purpose of this book, to tell girls that you are not alone and that it’s possible to succeed in science. Another purpose was to let the other scientists realise what they have to change in order to make things easier for women. Following this reaction, we brought out The Girl’s Guide to a Life in Science. We have tried to explain the science to a much younger crowd, girls of 10-12 years of age.
Has the number of women in science improved now?
It has improved. We have understood where the problems are. The measures we have are not bad. For example, there are schemes of DST (Department of Science and Technology) for women to get back to science. They’re good, but why should you have to provide ways to come back if you can stop them going out?
The first director of the Indian Botanical Survey was a woman—Janaki Ammal. The early ICMR director was a woman—Dr G.V. Satyavati. The first director of the Meteorological Survey of India (IMD) was Anna Mani. I don’t know when this trend vanished.
How are women represented at higher levels, like HODs or institute directors?
It’s quite interesting actually. The first director of the Indian Botanical Survey was a woman—Janaki Ammal. The early ICMR director was a woman—Dr G.V. Satyavati. The first director of the Meteorological Survey of India (IMD) was Anna Mani. I don’t know when this trend vanished. What happened after this? ISI has its first woman director in 85 years of its history only now. IISc still hasn’t a deputy director or even a divisional chair who is a woman. Frankly, the need of the hour is actually to have an academic audit where each institute takes a good look at what the gender representation in the faculty is and what we need to improve and what tools to use for it.
Nobody is saying 50-50 is a good aim. Then, what are the targets? The targets will depend on the discipline. Next, the funding agencies should ask the institutions what they are doing to reach these goals. This is not happening.
What is the next big discussion relating
to women in science?
A very important issue about women in science which is coming to the fore is gender-based harassment. Sexual misconduct, clearly, is as unethical as plagiarism. But, I’m talking about not just sexual harassment but gender-based harassment. There is a big difference between the two. Sometimes, it doesn’t even have to be harassment, it can be just bias. I think that is something we need to tackle. A lot of bad things happen to women because of this invisible bias. We have to think how to correct for this invisible gender bias.