# My mathematical trajectory

Stories and lessons on diversity in mathematics from a globe-trotting number theorist.

Image: Flickr user Kevan Emmott, CC BY-NC-SA 2.0

This post was part of Black Mathematician Month 2017.

My name is Lassina Dembélé, and I am a mathematician who specialises in number theory. This piece is somewhat related to mathematics. I grew up in the north of Côte d’Ivoire, near the border with Mali. We spoke both Malinke and Senoufo at home, the most common languages in the region. So, for curiosity, if you want to know how Malinke sounds like, I recommend that you rent the movieAmistad by Steven Spielberg. At some point in the movie, Roger Sherman Baldwin, the lawyer played by Matthew McConaughey, can be seen beating the ground up and down while saying the words “keley, filah, sabah, nani”, etc. He is simply counting in Malinke, the language spoken by the Mande people who were on board the hijacked ship.

Several years ago, I came across the story of William Kamkwamba, “The boy who harnessed the wind”. I thought I was reading about a younger self. I was one of the few survivors of a polio epidemic which swept through my village. My twin sister was fortunately spared by the disease. I was left paralysed in both legs as a result of this, which meant that I couldn’t do any of the traditional manual labours. So for a period of time, my parents struggled to decide on my future. A family friend, named Mr Koné, was a teacher in the school of my village and, under his relentless insistence, my family sent me to school.

In high school, I became very passionate about the sciences. But I was always left in a great deal of frustration given the limited resources. Indeed, very often, when there was a physics or chemistry experiment at school, only the teacher would have access to the equipment. On a few occasions, when the experiments did not require that much equipment, I always tried to replicate them at home.

Newton’s experiment on splitting light using a prism. Image: Flickr user Alfredo Louro, CC BY-NC-SA 2.0.

I remember one Sunday afternoon, when I busy working on Newton’s experiment on the dispersion of light. I had just emptied an expired light bulb, which I was going to fill with water, and I was busy cutting a cardboard box to make a screen when my mom interrupted. “Sina!,” that’s how she calls me, “what are you doing?” As a twelve-year-old, I certainly did not have the vocabulary in Malinke or Senoufo to describe the experiment to her. On the other hand, I knew that my mom was not a big fan of my experiments. So, in anticipation of what her reaction would be, I simply told her that I was about to create a “God sabre”, which is the word for “rainbow” in Senoufo. With a bit of anxiety in her voice she replied, stretching each word to make sure she heard me correctly, “A God sabre…!” Before she could finish, I interrupted: “Then, whatever you find, please keep it to yourself!”. Over time, I had learned to turn her favourite catchphrase against her to let her know that she was being silly. So, we both burst into a giggle.

I guess for my mom, my experiment on the dispersion of light was the equivalent of the big bang experiment many people feared a decade ago—her whole life, she had always been told that a rainbow was more than what it really is.

Like William Kamkwamba, I remember how some of my cousins and other kids, who were less inclined towards science, would ridicule or laugh at me every time they saw me doing one of those experiments or working on one of my DIY projects. But, my passion for the sciences only grew stronger when I went to the lycée, which is roughly the equivalent of sixth form in the English system. I was especially interested in electronics. During my spare time, I would wander around garbage dumps to collect old radios. I would then painstakingly remove all the components (resistors, transistors, capacitors, etc) which were still working. I used those components to build my own stuff.

During my first year at the lycée, my physics teacher was called Jacques Resch. He is probably one of the most influential teachers in my whole life. Professor Jacques Resch, as we used to call him, is better known as a surrealist painter, and many of his paintings are scattered around the internet. To set himself apart from the other teachers, he often said of himself “I am a physicist, not a physics teacher”. For the summer holidays of that first year, I got a present from Professor Resch. It was a full electronic kit, which he received from one of his expat friends who was returning to France for good. This was probably one of the most memorable summers I’ve ever had. Finally, I could take my passion for electronics to the next level. I remember the first time I built my own transmitter using some of those recycled electronic components. I was very proud of myself given that I had limited access to books or magazines on the subject, and that the transmitter could cover between 1000 and 1500 metres. Occasionally, I would use it to improvise my own radio station, and broadcast music around the neighbourhood.

After lycée, I wanted to become an engineer. I took the entrance exam to the best engineering school in Côte d’Ivoire, École Normale Supérieure d’Ingénierie d’Abidjan (ENSIA). I did very well on the written part of the exam. But when I went for the oral part, they told me that I could not join the school because of my disability. I was told that the engineers who graduated from that school must have certain physical abilities, which according to them I did not have. In hindsight, I guess this was the first time I was discriminated against. After this setback, I decided to go to university and study sciences and mathematics.

Laval University, Quebec. Image: Wikimedia commons user Colin Rose, CC BY-SA 2.0.

Despite all of the obstacles, I believe that I have managed to have a reasonably successful career in number theory, although sometimes I do feel that I am still fighting for my own acceptance. Through my work and my research, I know that I have gained the respect of lots of my colleagues in the number theory community, especially those working in the area of modular forms and automorphic representations, and the so-called Langlands Program.

## …And what it taught me about diversity

As a black mathematician who was born in Africa and spent the second half of his life living in Canada and Europe, I have thought a great deal about the issue of underrepresentation of black people in sciences, and particularly in mathematics. This lack of diversity can be attributed to different factors.

In Africa, access to basic education is a more fundamental and pressing issue. I experienced this first hand in my family. Not only was there a lot of resistance from my family to sending my other brothers and sisters to school, but also many of my relatives never made it to school because their parents could not afford the cost. Fortunately, in the last two decades, there have been tremendous efforts by NGOs to promote basic education in Africa. I know, for a fact, that there are other initiatives by many UK universities which specifically target sciences and mathematics education in high school. However, although all those efforts must be encouraged, they are so focused on providing basic necessities that they tend to fail other kids that are more gifted. Indeed, I have never been able to recognise my younger self in the kids that are targeted by these programmes.

In other words, there are lots of ambitious and curious African kids who would not simply be content with a sheet of paper and a pencil. But most of them get discouraged by the countless setbacks they encounter. One such kid was my closest friend, Ladji Silué, whom I considered to be more talented than myself. He was equally passionate about sciences and electronics. Despite his talent he never made it to university or any engineering school. So, while we strive to reach a goal of education for all in Africa, there is also a need for programmes which target kids like Ladji Silué and William Kamkwamba.

In the UK, and more generally in Western countries, the near absence of black kids wanting to go into science and mathematics is due to a different dynamic. Indeed, a black kid living in London is surrounded by science in all its glory. He is only a short trip away from the Science Museum, where he can immerse himself in the history of science. But most of them never make that trip. Many black parents would rather encourage their children to go into sports and art rather than science or mathematics. More often, they don’t know better. So, unwillingly, they contribute to perpetuating the stereotype that black people are not capable of doing science. We need to make those kids understand that not every black girl can become a Serena or Venus Williams, nor every black boy a LeBron James. We must show them that there are other areas of life where they can excel, and have a real impact on society.

I believe that those are goals that we can achieve through outreach programmes, which target elementary and high school students. Elite universities need to be more actively engaged with disadvantaged students. It is not enough to simply organise traditional open days, and hope that they will just wander in. There needs to be people in those ivory towers who are willing to leave their daily comfort, and go into community schools and tell those kids about the beauty of science and mathematics.

Labour MP David Lammy’s recent report showed major access issues for black students at top universities. Image: Wikimedia commons user Policy Exchange, CC BY-2.0.

It is also important to note that the issue of underrepresentation of black British people in science and mathematics is tied to the lack of social mobility, which equally affects the white working class. Like with black British kids, many kids in those communities are often the first generation of students to attend university. Elite universities in the UK are routinely accused of not doing enough to encourage social mobility and diversity. The most recent report was made public on 20 October 2017. In an article which appeared in the Guardian, Labour MP David Lammy accuses Oxford University of social apartheid. Having observed this discussion over the years, I do somewhat agree that there is some kind of ‘Downton Abbey syndrome’ among the British elite whereby people tend to think that their social status is solely a result of the fact that they are the hardest working and most deserving people in the society. They cannot seem to think that they might have benefited from favourable circumstances. I strongly believe that elite UK universities, those that form the ‘Russell Group’, need to do more on this given that they are the institutions that have the most resources — in the past, they have objected that only the government can act on the matter.

## Redefining the notion of a role model

The fight to achieve a better representation of black people in science and mathematics must be led primarily by black communities. But I also believe that there is some collective responsibility.

LeBron James is a role model for aspiring basketball players, both white and black. Image: Flickr user Keith Allison, CC BY 2.0

It is very common to hear a white girl tell you that their role model is Serena Williams, or a white boy that he admires LeBron James. Similarly, we need to encourage black kids to look for role models beyond their own race. Although I grew up in a remote corner of Côte d’Ivoire, my role models were Franklin Delano Roosevelt and Albert Einstein. I admired the former for the fact that he transcended his polio to become one the most influential American presidents, and the latter for his theory of relativity which revolutionised modern physics. So, we need to tell black boys that it is okay for them to aspire to becoming the next Albert Einstein, and black girls the next Marie Curie. We must tell them to listen more to Neil deGrasse Tyson than rapper B.o.B, who still believes that earth is flat.

We need more leading white figures in science and mathematics that are willing to engage with kids from disadvantaged communities. The same is also true for visible minorities that are more successful than others. We must try to break the stereotype of the studious Asian versus lazy black kid. The only way this can happen is to have more Asian scientists and mathematicians being actively involved in black communities.

There are precedents of leading scientists being involved in this kind of activism. A few years ago, I discovered that in 1946 Einstein visited Lincoln University, then a predominantly black college, where he received an honorary degree. He spoke about the plight of racism, and later taught the students about his theory of relativity. He also played with some young children in the courtyard. One of those children, who eventually became president of the NAACP (1998–2010), was the now deceased Julian Bond.

Since receiving his Fields medal, Cédric Villani has travelled to Africa countless times. Recently, he gave a very passionate interview about his involvement in the continent. We need more scientists and mathematicians to follow their lead. They don’t have to travel as far as Africa, just to be a little bit more involved in communities that surround them.

Lassina Dembélé is a number theorist who has worked in Ivory Coast, Canada, the UK and Germany. He is currently based at King’s College London.
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