At first sight, the following poem looks like a fairly
standard, slightly overly melodramatic, example of
Victorian verse. But there is more to it than meets the
eye:
I often wondered when I cursed,
Often feared where I would be—
Wondered where she’d yield her love
When I yield, so will she,
I would her will be pitied!
Cursed be love! She pitied me…
This poem has an unusually clever structure which enables it
to be read both horizontally and vertically. Although it has
been largely forgotten for many years, its author is still very
well known, for he was none other than Lewis Carroll, most
famous as the writer of Alice in Wonderland and Through the
Looking Glass.
As many people know, ‘Lewis Carroll’ was a pseudonym.
His real name was the Reverend Charles Lutwidge Dodgson
(1832-1898), a mathematics lecturer and Church of England
clergyman from Oxford. For Dodgson, writing children’s
books, puzzles, and verses was just a hobby. His day-job was
teaching mathematics at Christ Church, the largest of the 39
colleges in the University of Oxford.
In addition to this, he also wrote and published a
considerable number of books on mathematical subjects under
his real name, including A Syllabus of Plane Algebraical
Geometry (1860) and Euclid and his Modern Rivals (1879).
Although more of a recreational mathematician than a serious
researcher, Dodgson did make a number of small contributions
to the subject, most of which are largely unknown to today’s
mathematicians. One of these is of direct relevance to
undergraduates, dealing as it does with a concept fundamental
to linear algebra: the determinant.
Determinants emerged gradually during the 18th century
through the theory of equations in the work of Leibniz,
Maclaurin, Cramer, and Laplace. By the 19th century, the
subject had become a mathematical area of increasing
significance. Gauss (who invented the name ‘determinant’),
Cauchy, and Cayley all produced important results on the
subject, and in 1841, the German mathematician Carl Jacobi
published three major papers that finally brought the subject
into the mathematical mainstream. An illustration of this was
the publication, ten years later, of the very first textbook on the
subject, Elementary Theorems Relating to Determinants, by
Dodgson’s Oxford contemporary, the English mathematician
William Spottiswoode.
A Brief Introduction to Determinants
As every algebra student knows, given a 2 × 2 matrix
its determinant, det A or ⎜A ⎜, is equal to ad–bc. Given a matrix
A, its determinant provides useful geometric and algebraic
information about the matrix. Geometrically, the row entries of
an n × n matrix A define the edges of a parallelepiped in ndimensional
space, of which the volume is simply the absolute
value of det A. Algebraically, the same matrix represents the
coefficients of a system of n linear equations in n unknowns.
The determinant of A determines whether or not this system is
solvable. In particular, if det A is nonzero, we know that the
inverse matrix A–1 exists, and this in turn promises a unique
solution to the system of linear equations represented by
matrix A.
Although 2 × 2 determinants can be calculated very easily,
computing determinants is more time-consuming for larger
matrices. The standard way of computing a determinant (both
today and in Dodgson’s time) is to break it down into more
determinants of lower degree by taking the product of any row
or column entry and the determinant of its complementary
minor, then alternately adding and subtracting the results.
A
a
c
b
d
=
⎛
⎝ ⎜
⎞
⎠ ⎟
,
Lewis Carroll’s
Condensation Method for
Evaluating Determinants
“Although more of a recreational mathematician than a serious
researcher, Dodgson did make a number of small contributions to
the subject, most of which are largely unknown to today’s
mathematicians.”
Adrian Rice and Eve Torrence
Randolph-Macon College
At first sight, the following poem looks like a fairly
standard, slightly overly melodramatic, example of
Victorian verse. But there is more to it than meets the
eye:
I often wondered when I cursed,
Often feared where I would be—
Wondered where she’d yield her love
When I yield, so will she,
I would her will be pitied!
Cursed be love! She pitied me…
This poem has an unusually clever structure which enables it
to be read both horizontally and vertically. Although it has
been largely forgotten for many years, its author is still very
well known, for he was none other than Lewis Carroll, most
famous as the writer of Alice in Wonderland and Through the
Looking Glass.
As many people know, ‘Lewis Carroll’ was a pseudonym.
His real name was the Reverend Charles Lutwidge Dodgson
(1832-1898), a mathematics lecturer and Church of England
clergyman from Oxford. For Dodgson, writing children’s
books, puzzles, and verses was just a hobby. His day-job was
teaching mathematics at Christ Church, the largest of the 39
colleges in the University of Oxford.
In addition to this, he also wrote and published a
considerable number of books on mathematical subjects under
his real name, including A Syllabus of Plane Algebraical
Geometry (1860) and Euclid and his Modern Rivals (1879).
Although more of a recreational mathematician than a serious
researcher, Dodgson did make a number of small contributions
to the subject, most of which are largely unknown to today’s
mathematicians. One of these is of direct relevance to
undergraduates, dealing as it does with a concept fundamental
to linear algebra: the determinant.
Determinants emerged gradually during the 18th century
through the theory of equations in the work of Leibniz,
Maclaurin, Cramer, and Laplace. By the 19th century, the
subject had become a mathematical area of increasing
significance. Gauss (who invented the name ‘determinant’),
Cauchy, and Cayley all produced important results on the
subject, and in 1841, the German mathematician Carl Jacobi
published three major papers that finally brought the subject
into the mathematical mainstream. An illustration of this was
the publication, ten years later, of the very first textbook on the
subject, Elementary Theorems Relating to Determinants, by
Dodgson’s Oxford contemporary, the English mathematician
William Spottiswoode.
A Brief Introduction to Determinants
As every algebra student knows, given a 2 × 2 matrix
its determinant, det A or ⎜A ⎜, is equal to ad–bc. Given a matrix
A, its determinant provides useful geometric and algebraic
information about the matrix. Geometrically, the row entries of
an n × n matrix A define the edges of a parallelepiped in ndimensional
space, of which the volume is simply the absolute
value of det A. Algebraically, the same matrix represents the
coefficients of a system of n linear equations in n unknowns.
The determinant of A determines whether or not this system is
solvable. In particular, if det A is nonzero, we know that the
inverse matrix A–1 exists, and this in turn promises a unique
solution to the system of linear equations represented by
matrix A.
Although 2 × 2 determinants can be calculated very easily,
computing determinants is more time-consuming for larger
matrices. The standard way of computing a determinant (both
today and in Dodgson’s time) is to break it down into more
determinants of lower degree by taking the product of any row
or column entry and the determinant of its complementary
minor, then alternately adding and subtracting the results.
A
a
c
b
d
=
⎛
⎝ ⎜
⎞
⎠ ⎟
,
Lewis Carroll’s
Condensation Method for
Evaluating Determinants
“Although more of a recreational mathematician than a serious
researcher, Dodgson did make a number of small contributions to
the subject, most of which are largely unknown to today’s
mathematicians.”
Adrian Rice and Eve Torrence
Randolph-Macon College
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