## Week 3: An Interview with Dr. Gilbert Strang

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Professor Gilbert Strang is the Mathworks professor of mathematics at MIT and an Honorary Fellow of Balliol College, Oxford University. He is widely known not only at these institutions for his superb mastery of applied mathematics but all over the world through his many textbooks and most of all his Open Course Ware lectures. He served as President of the Society of Applied Mathematics and has won too many medals and international prizes to list or even easily count.

It is a great honor to interview him today.

He is best known for his classic text on finite elements. After writing this book, he decided to focus more on linear algebra. He describes writing his linear algebra text as a" wonderful adventure" and says his motivation for writing the text was that, at the time, most math courses were missing the importance and beauty of the subject and had to change. At the time, Strang recalls that most courses emphasized proofs above all else, with no emphasis on applications. He believed that for math majors, even for theoretical mathematicians, this was not the correct approach. He states quite emphatically that there is a whole world of students that need and use linear algebra, and he is there for them.

**Amy Beth Prager**Professor Gilbert Strang is the Mathworks professor of mathematics at MIT and an Honorary Fellow of Balliol College, Oxford University. He is widely known not only at these institutions for his superb mastery of applied mathematics but all over the world through his many textbooks and most of all his Open Course Ware lectures. He served as President of the Society of Applied Mathematics and has won too many medals and international prizes to list or even easily count.

It is a great honor to interview him today.

He is best known for his classic text on finite elements. After writing this book, he decided to focus more on linear algebra. He describes writing his linear algebra text as a" wonderful adventure" and says his motivation for writing the text was that, at the time, most math courses were missing the importance and beauty of the subject and had to change. At the time, Strang recalls that most courses emphasized proofs above all else, with no emphasis on applications. He believed that for math majors, even for theoretical mathematicians, this was not the correct approach. He states quite emphatically that there is a whole world of students that need and use linear algebra, and he is there for them.

When asked if all the more theoretical ideas of linear algebra from the course he teaches and book he wrote for an intended audience of engineers, he replies not at all. As an example, he gives the case of the "Four Fundamental Subspaces", i.e. the column spaces and the null spaces of a matrix, which are all possible combinations of the columns and of vectors perpendicular to the columns. These ideas are central to the great and classic equations of continuity and conservation, and in addition, the key to least squares is a projection onto the column space.

Prof. Strang is particularly proud of his work on the SVD (Singular Value Decomposition) method. As we discuss this, he is writing on the board proving that the key to the whole method is that the eigenvectors are orthogonal, and he says, "Damn! I can’t stop teaching this stuff, even for an interview!" He observes that his class is mostly engineers, not mathematicians, and he feels determined to show them that math is useful.

He is particularly excited about the potential for web based learning, such as MITx and Edx here at MIT. His lectures on OCW, and more recently other platforms, have broadcast his message of the importance of mathematics to people throughout the world, even to engineers. He admits that doing all this is very hard work.

However, he joyously adds that when a job is worth doing, it is a pleasure to work hard.

More info about Dr. Strang:

http://www-math.mit.edu/~gs/

http://www-math.mit.edu/~gs/books/books.html

http://en.wikipedia.org/wiki/Gilbert_Strang

http://ocw.mit.edu/resources/res-18-001-calculus-online-textbook-spring-2005/textbook/

Prof. Strang is particularly proud of his work on the SVD (Singular Value Decomposition) method. As we discuss this, he is writing on the board proving that the key to the whole method is that the eigenvectors are orthogonal, and he says, "Damn! I can’t stop teaching this stuff, even for an interview!" He observes that his class is mostly engineers, not mathematicians, and he feels determined to show them that math is useful.

He is particularly excited about the potential for web based learning, such as MITx and Edx here at MIT. His lectures on OCW, and more recently other platforms, have broadcast his message of the importance of mathematics to people throughout the world, even to engineers. He admits that doing all this is very hard work.

However, he joyously adds that when a job is worth doing, it is a pleasure to work hard.

More info about Dr. Strang:

http://www-math.mit.edu/~gs/

http://www-math.mit.edu/~gs/books/books.html

http://en.wikipedia.org/wiki/Gilbert_Strang

http://ocw.mit.edu/resources/res-18-001-calculus-online-textbook-spring-2005/textbook/

## About the Blogger

Amy Beth Prager is a mathematics educator interested in outreach efforts. She is currently expanding her knowledge of mathematics, computer science and engineering.She is spending the summer in the mathematics department of MIT pursuing coursework in applied numerical methods; taking a class known as 18.085, Computational Science and Engineering. The course teaches methods of applied mathematics useful in engineering and science. |