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By Samuel Gugliotta
For Variety
LIVING in a world
that seems so our of whack with our ideals of hope, justice, love and
peace, it might be a helpful counterpoint to our trials and tribulations
to glance, if only for a moment, at some aspect of our universe in which
beauty and balance still hold sway over our lives. The aspect I have chosen
to look at is the notion of symmetry.
Symmetry is a big idea. Ideas, of course, do not have physical
characteristics. They are not, strictly speaking, big, small, heavy, light,
blue, yellow, or furious. Ideas are not in the world like tables, chairs,
houses, cars, and bill collectors. Still, symmetry is a big
idea because its instances or exemplifications
are so pervasive and various. It applies to almost every area of human
endeavor. For example, in one of its senses, as applied to art, it is
defined as beauty of form arising from balanced proportions.
Living on the beautiful island of Saipan, you need only to look at a flower
or a leaf to see many aspects of symmetry. In fact, when teaching the
subject, letting students explore the environment for examples of symmetry
is an excellent way to show the connection between mathematical pattern
and the physical world.
Forms of symmetry are exemplified in the evolution of the universe, sub-atomic
physics, the construction of our bodies, the senses of beauty, reason,
justice, and the unity of opposites, like good and evil, sadness and joy,
yin and yang. It is precisely because symmetry is so common, and always
present, that we take it for granted and it is so difficult to notice.
As Whitehead remarked, We habitually observe by the method of difference.
Sometimes we see an elephant and sometimes we do not.
In mathematics, a geometrical figure is said to be symmetrical when certain
operations, such as rotations and reflections, are performed on them and
they remain unchanged. These form the congruence motions of the figure,
and are associated with algebraic structures known as groups.
For example, a square has rotational symmetry every time it is rotated
by 90 degrees. In every such rigid motion the square will
appear to be exactly the same. It also has line symmetry with respect
to its diagonals and lines drawn to the centers of its sides. A cube,
believe it or not, has 48 such symmetries, remaining unchanged after 48
different turnings, reflections and flippings.
The letters of the English alphabet exhibit various types of symmetry.
The letters A H I M O T U V W X Y (as well as the human body) all have
bilateral symmetry. They remain unchanged when the vertical line drawn
through the center of the shapes is considered as the line of reflection.
When such shapes are reflected in a mirror, they remain unchanged. Another
way to see this is that if you place a mirror vertically down the center
of the letters, you will still see the same letter.
The letters H I O X B C D E K all have reflective symmetry around the
horizontal line drawn through the center of the shapes. Of these, H I
O X have both vertical and horizontal reflective symmetry.
The letters H I O X also have a third type of symmetry known as rotational
symmetry. Rotating these letters by 180 degrees (or looking at them upside
down) gives the same letter. This property is also shared by N S and Z.
The letter richest in symmetry is O, the ancient shape of perfection.
It has reflective symmetry around an infinity of diameters, and rotational
symmetry through an infinity of rotations. Thus O is infinitely symmetrical,
and thus an apt symbol for the immense secrets lurking behind zero, as
well as the mandala (magic circle) of self, consciousness, and world.
The symmetry, and near symmetry of letters and numbers are involved in
palindromic recreations and designs. A palindrome is a word or number
which reads the same way backwards or forwards.
The Zoological Society of San Diego publishes a magazine called ZOONOOZ.
This word reads the same backwards, forwards, and also upside down.
The phrase NOW NO SWIMS ON MON does not read the same backwards but it
does upside down.
The phrase YOU CAN CAGE A SWALLOW, CANT YOU, BUT YOU CANT
SWALLOW A CAGE, CAN YOU? has reversibility with respect to words, and
not letters. If you turn the word CHOICE upside down and view it in a
mirror you will see the same word.
Words like WOW LEVEL REDDER DEIFIED read the same backwards or forwards
and so are palindromes, properly speaking. So are whole sentences such
as A MAN, A PLAN, A CANAL PANAMA! or WAS IT A BAT I SAW? or RISE
TO VOTE, SIR or NAME NOW ONE MAN or LIVE NOT ON EVIL.
Numerals have many symmetry and broken symmetry properties that allow
for quaint and entertaining puzzles. Rotating digits by 180 degrees (that
is, turning them upside down) often result in shapes which may be interpreted
as letters. These are good games to play on calculators Consider, for
example, the number 7734. If you think of the 4 in the old
fashioned way, that is, as the lines open on top, and not the closed
lines of the typewritten 4, you will see that inverted it becomes an h,
while 3 becomes and E, and the two sevens inverted
are two Ls. Thus turning 7734 upside down gives you
that sinister location directly opposite to heaven.
Another old puzzle is to write the number 11030 down and ask someone to
add two lines to transform the number into a person. The answer is HOBO.
Another old favorite, to be done with a calculator, is to tell the story
of the 337 Arabs and 337 Israelis who battled over a square property 8424
meters on a side. If you sum the squares of 337 and 8424, you find out
who won by turning the result, 71077345, upside down. (Did you try it?
Shall I spoil your fun and tell you the inverted numerals spell SHELLOIL?)
Lastly, here is a mirror puzzle. Consider the apparently outlandish addition
statement:
3414 + 340 + 74813 = 43374813
In order to show that this sum is correct hold up the statement
to a mirror and you will be enlightened. Now this time I wont spoil
your fun. Its good to look in the mirror now and then, not for your
vanity, but to notice many properties of that big idea, symmetry, in the
reflection of your mind. And last of all, when symmetry is thought of
in the artistic sense of the balance and unity of opposites, know that
you sadness is balanced with joy, hidden perhaps in a subconscious which
compensates distortions of conscious perception.
Puzzles
1. Suppose there are 500 voters in San Vicente. All of them voted on the
two issues of allowing casinos on Saipan, and funding a new gym for the
high school. Three hundred seventy-five were in favor of casinos and 275
in favor of the new gym. If there were 40 votes cast against both issues,
how many votes were cast in favor of both issues?
2. Can you find two numbers such that their product, quotient, and difference
are the same?
3. What is the smallest odd integer which has the property that if its
cube is added to twice its square, the result is a perfect square?
Answers To Last
Weeks Puzzles
7203^2 + 343^3 = 98^4
2000 meters long
20, 15, 12, is one solution, the least.
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