By Addisalem Mulat 21-2-2017
Legesse Wetro is a doctor of astrophysics. He is the Founder of Ethiopian Space Science Society (ESSS) and founding member of the Ethiopian Academy of Sciences, African Astronomical Society, African and Ethiopian Physical Societies. He is a lead scientist in theoretical pulsar astrophysics. Dr. Legesse is as well member of the International Astronomical Union (IAU)-Commissions 40 A – B – C and Ethiopia’s Liaison at IAU. To everyone’s surprise, he solved the 460 years world problem of geomagnetic filed reversals. Following his outstanding research in pulsar astrophysics, he got “Man of the Year” award from the American Biographical Institute (ABI) in 2011.
Also, Dr. Legesse is editorial board member of AFRICAN SKIES, the only Astronomy Journal in AFRICA. He is the Leader of the Astronomy – Astrophysics Group at Addis Ababa University since 1998. Currently, he is seeking a patent for oil and gas exploration technique based on travel time data. The Ethiopian Herald had a short stay with Dr. Legesse with a view to familiarising his personal and professional life with our readers. Excerpts:
Would you please enlighten us about yourself .
With pleasure, my name is Legesse Wetro. I am a doctor of astrophysics. I was born in Arsi Negele province at a place called Arsi Sire. I am the only child of my mother. But on my father’s side, I have got three brothers and a sister. Unfortunately, my parents got separated earlier than I was born following the tradition of the time as it was believed the first born would die in the blink of an eye. In fact, I nearly escaped death as I was born when my mother was returning home attending a festival from a certain place. I just came to this world all of a sudden with no sign of labor. It was a miracle of God. From that moment on ward, I began living under the same roof with my mother. My dad was living with his second wife. My mom and my dad were a business woman and a farmer respectively.
Did you play a part in helping your dad in farming activities?
Not really! To be honest, I did not play a part in farming activities as I was a small kid. Afterward, I went to Asella to pursue high school education. In fact, I left my birthplace when I was nine and started school at the age of five. It was not allowed to enter school earlier than the age of seven at that point. I attended elementary school at Haile Aba Merssa. When I was nine years old, I sat for elementary school leaving exam and joined high school at the age of eleven. I did not finish at Ras Andarge School until grade twelve as there was a program called Bedemariam at Addis Ababa University. At that juncture, best students from grade eleven were chosen and brought to Sidist Kilo campus. This being the case, I ended up joining the university.
How do you describe your overall academic performance?
At the time when I was in elementary school, I had triple promotion. I am really a gifted mathematician. In fact, I was not studying day and night. When I grew up, I discovered that I had to study with the intention of achieving the intended target. My mother had a strong belief in me.She knew very well that I was an outstanding student.
When I was in the university, I joined the department of physics. My favorite subjects were mathematics and physics. I did not care about other courses. Mostly, I cut classes and stayed behind deliberately. When exams approached, I studied all subjects for one night and grew to be very successful. To be frank, I was taken up by Pentecost religion almost immediately. I turned out to be ardent believer in Jesus Christ and began producing spiritual songs. I possess more than 80 spiritual songs at this moment in time. As I was completely taken up by religious meetings, I did not often go to classes. Everybody was hunting for me everywhere. Eventually, I stayed in the department of physics for four years and earned my degree. My GPA was not good but fair.
Where was your first assignment?
As graduates who came out of Bedemariam School had to teach two years in government schools for a minimum of two years, I ended up teaching at Nifas Silk Secondary School. Following Mengistu Haile Mariam’s revolution, police were all around my working place. They considered me as one of the trouble makers. When I was at a loss what to do, I went to Addis Ababa Education Bureau and informed the situation I was in. I also told him that I would like to work as a lecturer at Addis Ababa University in view of the fact that I have a good GPA. After that, I brought a letter from Addis Ababa University confirming my success. Luckily, having passed through little steps, I began working at Addis Ababa University as a lecturer in the department of physics.
What was your next move?
After four or so years service, I left for England for my PhD training for I did my MSc training in Addis Ababa University. Our instructors were foreigners as the staff wanted a graduate program in physics. They were brilliant. They had Landau theory. They considered Landau as a Russian Albert Einstein. Davido was my advisor. He was a student of Landau. He came to Ethiopia as a chief of the Russian staff. Last but not least, he forced the embassy to allow him to teach physics.
When I left for England to pursue my PhD studies, they ordered me to do another MSc. The thing that I did with Davido was published in journal of physics. They had Giant Quantum oscillation theory. I even made some correction concerning David’s theory. I showed them everything I did but they refused. There was no other way out. They assigned an advisor whose paper was published recently. He explained everything about the paper and ordered me to do it on my own apart from giving me warning not to come to his office for any help. Lastly, I produced the inevitable paper on my own. It was an amazing paper. Eventually, I defended my thesis and got the best grade.
Following my success, my advisor wanted me to be his advisee. When I realized their plan, I strongly refused the department not to assign him. I have the courage to say, he did not have the quality at all. He was incapable. His advisor was an amazing Professor. When I was at a loss what to do, I went to the department and said, “This guy is a reader. He does not have the capacity to train me for my PhD. Please assign a qualified Professor. I do not accept anyone less than the rank of a full professor.” Lastly, they assigned my advisor’s advisor. He was a well-known Professor. When I went to my advisor, he welcomed me warmly and gave me an identification card within the shortest time possible. Sorrowfully, something unexpected happened.
What it that?
Would you please tell me about the success story of your publications?The scholarship money was administered by the British Council. It was UNDP scholarship money. At that point in time, I had to move from Sheffield to East England. Moreover, I had to inform the transfer to Addis Ababa University. This time, the university official became furious and said, “You are arrogant.” The thing was, at the time when I was doing my master’s study at Addis Ababa University, there was something I did. When the dean arranged some doctors to train us, I started a move saying that they were incapable. Against this back drop, when the dean heard the news of my shift from Sheffield to East London, he was not able to control his feelings. This gave him a chance to say that I was a trouble maker. This time, he said, “I do not allow you to go from Sheffield to East London. If you refuse, I will send you a return ticket. That was what he exactly did. I did not return to Sheffield. When he discovered the truth, he sent a return ticket to Ethiopia.
Did you return home?
No, I did not. Unfortunately, I had a friend living in Los Angeles. We grew up together. When I told him the problem I was in, he arranged some people to help me out with a visiting visa. In this way, I headed to Los Angeles. The dean’s effort went for nothing. My friend was with me until I sat for Graduate Record Examination (GRE). Then, I went to the University of California to join the department. My interest was condensed matter physics. After that, they gave me a piece of advice to go and ask the department of condensed matter physics and see if they had money to help me. Their response was discouraging.
But, when I requested students which of these groups had a lot of money, they told me to join the department of astrophysics. This time, I went to the head of the department, Professor White and told him that I sought after to study astrophysics. When I talked to him, he promised that he would give me money. Of course, we made different agreements. They were constantly helping me. Eventually, I sat for qualifying exam and got promoted to start PhD training with Professor White. The fund was from the National Aeronautics and Space Administration (NASA).
What was your PhD dissertation all about?
I worked with one of the programs that built balloon flight. You put your small telescope inside a balloon and then sent it above the earth atmosphere, long distance. That particular instrument collects data and they told me to record that particular balloon to come back and so it came back. So my first thesis problem was calibrating that instrument collected by the balloon. I calibrated the data to almost theoretical value and they loved it very much. My work was posted all over the campus. After that, they came up with another question.
Where did the question come from?
The question came from the California Institute of Technology (Caltech) . It is part of NASA positioned close to our campus. They said, “We always see so many objects which are very close to each other. We do want data inversion technique about the data we collected which can isolate the individual source. I thought Caltech would give me a job after I graduated. I told them that I would do using inversion techniques. I told them that I would give them image construction technique no matter how close they are. After two months I found everything which can isolate individual objects. When they discovered what I did, they forwarded their appreciation. When I told them that I was going to use that particular paper for a job with Caltech, they got disappointed.
One of the instructors wanted to give my work to his student. I refused over and over again. He kept on arguing with me. They told me that I could not work with Caltech as I am not a citizen. I told them that I could work with Caltech for I knew people working without having citizenship. We started arguing. In due course, I sent the paper for publication. The editor appreciated my work and returned the paper in three days time. After a long fight with their thoughts, they requested me to show the method. I refused once again. There was no stone they left unturned to convince me. After many failed attempt, I began to teach them for two weeks despite they failed to understand. Finally, they sent a letter to the Immigration Office saying, “He is taking scientific information to the place where we do not know. I think he is a KGB,”
When I went to the immigration office to renew my visa, they caught me there. The officer was a black person. He said. “The university wrote something terrible about you. They want you to get out of America. According to our calculation, September 12 is the day you are supposed to go back to Ethiopia. It is a well-known fact that Ethiopia does not have an astronomer. You are the only astronomer in your country. As a black person, I love your return home. In this country, there are so many astronomers. You are just a drop in an ocean. Please, do not stay in America after September 12. The police will pick you up. Then, we put you in jail for two years. After that, we take you back to Ethiopia.” Later, I earned my PhD and returned home. With the best paper. I informed the university that I would come back. By the way, my research interests revolve around high energy pulsar astrophysics and the development of a pulsar theory; applied geophysics: oil and underground water prospecting; geomagnetic field reversal.
What is Standard pulsar theory all about?
Standard pulsar theory is based on fields that are conserved from progenitor stars. This has limited the scope of pulsar astronomy to a kind of study very much confined to a limited type of pulsars, so called field pulsars. The large majority of pulsars are technically eliminated from statistical studies because they are either too massive, or are of very high magnetic field with no mechanism yet known which forces them to decay to very low frequency rotators in a matter of a few thousands of years. This is one distinct property of these highly magnetized pulsars.
The current presentation focuses on a new source for the generation of pulsar fields namely spinning separated surface charges and it shows that pulsar fields are strictly mass dependent. Massive neutron stars are strongly magnetized ( ≥ 1018 G) and less massive ones are weakly magnetized (1011 – 1013 G). This work therefore dismisses the current belief that there have to be two classes of pulsars (field pulsars and anomalous pulsars). It leads to a decay law that provides results that are consistent with observations from these two so called distinct classes of pulsars. This work also suggests that pulsar fields should be infinitely multi-polar which helps to successfully address the longtime issues of pulse shape and promises that the current problem of pulsar radiation could be solvable.
Would you please tell me about the success story of your publications?
Well, one of my papers broke the long-time feud between Experiment and Theory. It led to the decision that there are not two classes of pulsars as NASA scientists tried to portray. Instead this work led world scientists into accepting the fact that there is only a single family of pulsars driven by their own magnetic fields. Besides, the other publication highlights that at the early stages of pulsar studies, experimentalists were wondering why in the early years of pulsar studies a large fractions of pulsars were getting reported as missing and some are known to have reappeared after long delays. This was hard to address for the old pulsar theory. In my PhD work I included the idea of plasma diffusion that leads to charge separation inside the NS structure. This in return was then shown to be a source of magnetic – moment that has dynamics the feature of which is able to address two scenarios mentioned earlier.
Likewise, the other paper carries the dynamical features. Now the world understands why we have several phases of pulsar dynamics chaotic phase – pulsar phase – and the dead phase in which the dynamics will lead the magnetic moment stay aligned with the spin axis of the neutron star during which the pulsar will cease emitting pulses. This was impossible for the old theory to address by any means.
What is your take on the current status of Ethiopia’s Space Science?
Well, in the Eastern part, Ethiopia is found in a strong position for the reason that Teffera Waliwa, the patron of the society, is struggling day in and day out to take our country’s space science to a new level of success. At this point in time, a number of African countries possess telescopes. If truth be told, most countries take space data from places. It is almost akin to copying. As far as I am concerned, achieving the intended target in the aforesaid way would be very difficult. In spite of the fact that we are making an effort to be effective in the field, much attention is not paid. They collect data but do not use the instruments. Much attention has not been given. To the best of my knowledge, Students should be able to use the instrument found in Entoto instead of simply collecting data.
Currently, I am engaged in producing competent professionals in the area through advising PhD and MA students in the Addis Ababa University in addition to conducting high level researches.