Tuesday, March 7, 2017

"With Great Power Comes Great Responsibility"

Today is the birthday of Ernest Lindelöf born 1870 in Helsinki, Finland. He worked on topology and differential equations. He also wrote the history on Scandinavian mathematics.

Today's quote is "The best car safety device is the rear view mirror with a cop in it."
- Dudley Moore


I have a t-shirt that I wear on teacher workshop days. It reads, "I teach MATH, what's your superpower?" I find the shirt funny because many people believe I have a super power in regards to mathematical instruction. I don't. I just love what I do and work hard at it. There are many people who work hard every day and are passionate about their jobs. They should probably get their own super power t-shirt.


My super power is a gift that I have nurtured and practiced since I was a child. I like to daydream. When I daydream, I imagine. I focus. I remove all nonessentials. I can sit in a chair and enter my room. This room contains books, music, movies, and mathematics. This room provides for a solitary existence. To enter my room, I transport myself across the time-space continuum and reside in the lone outpost of my mind. I usually travel quicker when I am reading or doing mathematics.


As a child, I found out I was able to gain access to my room during church services, family reunions, and authoritarian lectures. Boredom was the equivalent of a "radioactive spider bite."

As I have progressed through the teaching vocation, I have been given ample opportunities to practice and hone my exceptional power. My most prolific and intense work in my room has happened at meetings where the discussion centers around the proper syntax in a strategic planning document, a curriculum document, a staff development document, a student handbook, a teacher handbook, a coaching handbook, and a manual on the proper grammatical structure for work related forms.

I have also known to be inattentive during faculty meetings. I have been able to sneak by with my lack of attention by "taking notes" during the meeting. Some of my best mathematics has happened during these meetings.
This bingo card, given to me by colleague, illustrates other opportunities for me to "do math." 

I now have ability to gain access to my sanctuary on demand. I am able to look someone in the eye, nod my head, even carry on a conversation, and not be there. Where am I? Usually, I am sitting in a corner of my burrow, knees folded under my chin, thinking of my beautiful mistress and her most recent gift.

As I have become older, I have noticed that at times my power has become unwieldy. I sometimes slide to my vestibule and not know that I am there. This lack of self-awareness can be troublesome and cause some tense moments with colleagues as I described at the end of "Point A Began in the Shop."

My most recent excursion was both embarrassing and expensive. I was on the way to work early one morning prior to the weekend of Super Bowl LI. I have only two stoplights that I encounter on my particular path to school and between the two of them I noticed a highway patrol car coming up on me fast with lights flashing and siren blaring. "Holy crap," I thought, "there must be a severe accident up ahead!" However, I soon realized the urgent highway patrol officer was indicating to me to "pull over." Confused, I found my driver's license and insurance card and waited for the officer. I rolled down my window and he surveyed the interior of my car. He seemed somewhat confused that there was no cell phone, no coffee container, no breakfast sandwich, or any other item that may have caused the error of my ways.

"Did you see me next to you at the stoplight?" he inquired.  By this time, I left my room and returned to a state of coherent conversion.

"No, I didn't," I replied, still bewildered why I was stopped.

"Did you see that the stoplight was red?" he probed.

"No officer, and I am extremely sorry," I responded, though I now know that I had been preoccupied with a difficult math problem concerning the requirements needed to determine the convergence of a particular infinite series. Her majesty had led me to the room to be charmed by this problem. Due to this distraction, I had tuned out the entire experience of driving to work.

"Well," he chuckled, "you were stopped, but when the left turn signal turned green, you drove straight ahead." He went to his car and returned after an agonizing few minutes and handed me a ticket for $138.

I tweeted this experience and many, including my wife, were concerned that I was texting while driving. No, worse, much worse, I was doing mathematics!


Sunday, February 26, 2017

C2 - The Point of No Return

Today is the birthday of Al-Amili born 1547 in Lebanon. He wrote influential works in mathematics, astronomy, and grammar.

Today's quote is by Andrew Lloyd Weber, "The Point of No Return," lyrics from the "Phantom of the Opera".





I recently visited my parents and became lost in the past, their's and mine. Stories swirled about and occasionally, their's bumped into mine. Most often the recollections lazily rotated towards "The Shop," the concrete building that encased my dad's business and was the sanctum that contained my dad's philosophy.

I commented that I had learned at an early age that welding was not to be my occupational choice. "No," my mother reflected, "You would rather read than be in the shop."

Until eighth grade, reading surpassed any activity I was involved in. However, I soon had two events that jolted my conscience in such a cataclysmic way that literature became discarded and I was allured to a mistress that Carl Gauss proclaimed was "the queen of all sciences." 
The Alluring Queen - Mathematics by Farwah Tariq
She was beautiful in structure and mysterious to behold. Her declarations would seem obvious and dismissive but those words could include mysterious riddles and ambiguous teasers such as Zenos' Paradoxes or Schroder's Cat . As my relationship with her became more serious, my perception of her generous nature was replaced with a miserly greed that would only be succumbed by a perseverance that bordered on obsessiveness.

My first experience was due to this obsessive nature. In eighth grade, we were given a mathematics problem. A real problem that extended beyond the arithmetic problems I had experienced in the past. I was introduced to algebra as an eighth grade and my teacher, Evan Schiller, was able to draw me in with its structure and language. Letters replaced numbers but those letters (variables) fell into generalities that included all the numbers I knew at the time.

I can't recall the problem that I was struggling with, only that I agonized over it. That particular problem has been erased by time but I do remember using every waking moment trying to solve the it. I wrote on notebook paper. I doodled on napkins. I found I had a place in my mind that I could go to and close out all intruders. I was not cognizant of delivering newspapers, supper time conversations, or sermons during church. I was able to leave my surroundings if I focussed. This experience was the same experience I encountered when I read a good book. The only difference, I couldn't turn the page. I was locked in the arms of mathematics and drawn to her body. I was held a prisoner of my own desire. The desire to solve the problem.

Eventually, I resigned to let it go, to acknowledge defeat or I thought I had consciously let it go. That night, in my sleep, I solved the problem. The solution was clear. I woke with a start, quickly wrote the solution down. I was elated. I was more than elated. I was addicted. My first thought, "How can I experience this feeling again?" I later found out that this experience of finding solutions during sleep is not unique. This process is called "lucid dreaming".

The thrill of solving a problem that I struggle with and finding its solution was the best high I have ever experienced. I was hooked. My next experience was in geometry. I was studying proofs. I was struggling, again. I had concluded that I had reached a maximum point in my intellectual growth. I was unable to solve a problem involving a proof. Previous experiences in school led me to acknowledge that as each year's topics in mathematics became more challenging I had grown intellectually and I was able to meet the challenge. This year was to be the exception. I was at an impasse. I had worked on this proof at home and at school for days. The solution was beyond my reach so I let it go.

At the moment of letting go, the queen extended her hand, grasped mine, and I entered my room of solitude. As I did, her eyes twinkled, and she laughed. The laugh, though constrained, conveyed the enjoyment of a joker whose solution was directly in front of me if I were to only open my eyes. I did. The rush was immense. The gratification was insurmountable. I was hooked. She then opened her clenched fist and gave me another.





Wednesday, June 15, 2016

0.9999999999999999....

Today is the birthday of Nikolai Chebotaryov born 1894 in Kamenets-Podolsk, Ukraine. Chebotaryov was a mathematician contributed to number theory. He created a density theorem which generalized Peter Gustav Lejeune Dirichlet's prime number theorem.

Today's quote is from Jack Nitzsche and Sony Bono.






My first love was books. I was at an early age, a library groupie. Our city librarian was Mrs. Herman and in today's vernacular, was a rock star. She was the wife of Vern Herman, a legendary educator, a coach of a multitude of sports, a physical education teacher, and a driver's education instructor during the twilight of his career. Mrs. Herman became my literacy advisor many years before Vern guided me through the travails of parallel parking. I visited the library at least twice a day during the summer months of my preteen years. Each time I was greeted with a warm smile and was shepherd through a list of intriguing possibilities. The back of each possible book was secured with a code.  That code was a dewey decimal which gave the appearance of the "Good Housekeeping Seal of Approval", assuring that this budding reader would be gratified.


Reading is one of my sanctuaries. When I read, I am transported to exotic locales, struggle with vile scoundrels, peek into the minds of historic figures, and am stunned by plot twists as in Gone Girl by Gillian Flynn, Fight Club by Chuck Palahniuk or The Red Wedding in A Game of Swords by George R. R. Martin. I cherish the unexpected. The surprise twist or ending in a book is like the shock that vibrates through your brain as an unsuspecting snowball strikes the side of your head as you turn the corner of garage and contains that shiver. The shiver that trickles down your spine like the slow melting snowball whose cold stream meanders the rise and fall of the quivering vertebra. This shiver, this prickly sensation, feels like needles and pins.

This blog is the second in my series of Point A to B. My calculus students would be remiss if I didn't identify this particular moment in my progression as C1, somewhere in the interval, [A, B], but closer to A than to B.

In 1972, I was in 8th grade and a student at Immanuel Lutheran School in Plainview, Minnesota. My teacher was Evan Schiller. His enthusiasm as he taught math captured my attention. I was an average mathematics student. My scores in previous grades in the subject oscillated between B's and C's. The concentration of my math experience to this point was with arithmetic and I had been applying those skills for 4 years in my dad's welding shop. My teacher was introducing algebra and generalizing arithmetic concepts with letters. He was moving numbers to a different and more abstract level.

The lesson of the day was fractions and decimals. All rational numbers (fractions) can be written as decimals and vice versa. 0.5 is an example of a terminating decimal because it ends with a repeating 0. All decimals that end this way are called terminating decimals. The fraction equivalent for 0.5 is 1/2. 0.666... is a repeating decimal because it ends with a repeating digit other that 0. Its fractional representation is 2/3. I knew that, but Schiller continued, "What about 0.999...?" He extended the algebra that he just taught us to demonstrate.

x = 0.999...
10x = 9.999...

10x = 9.999...
- x =  -.999...
9x = 9
x = 1
1 = 0.999...

I was flabbergasted. Really, how can this be true? 1 is the same as 0.999... I experienced for the first time the exact same feeling I treasured in reading, the staggering "needles and pins". This meant that 2.999... was equivalent to 3 but more importantly, mathematics contained a mystery, a twist and turn, and I could find the joy of surprise. I could feel "needles and pins".

In  1978, I found out that 89.999996 was not 89.999... and definitely not 90. I was in college and taking a computer programming class entitled FORTRAN. Prior to the final, my percentage was 91. 91% was important. To earn an A, I had to have a 90% or greater. 89% grade was the same as 80%, a B. I did not do well on the final and when I received my grade report, the course notated a grade of a B. I did a little arithmetic and determined that I had a percentage of 89.999996. I mustered some courage and approached my instructor, Dr. Jim. Dr. Jim was amenable when I nervously suggested that I would like to examine the computation of my grade. Dr. Jim pulled out his red grade book and his Hewlett Packard 35 pocket calculator. "Mmm," he pondered. His eyes squinted and an eye brow raised to form a question mark. "Mmm... 89.999996%," he summarized, "What is your question?" I looked into his clear, blue, stoic eyes. "Nothing," I murmured. I knew that 89.999996% is not 90%.

This nightmarish decimal would resurface again in college when a calculus discussion about divergent and convergent series emerged. The instructor was demonstrating how a repeating decimal could be written in its fractional form using a series and the example being used was 0.999....  He wrote it as a sum of a sequence of 9's, each multiplied by 0.1. 0.9 + 0.09 + 0.009 + 0.0009 + ... = 0.999... This series is called a geometric series and using limits its sum could be found by the following computation: 0.9/(1 - 0.1) and yes, that sum is 1!

Finally, in 1998, I was giving same lesson to my class of seventh graders as Schiller gave me 26 years prior when one of my students, Ben Stommes, raised his hand and offered his proof. "Mr. Kruger, it appears quite obvious," Ben confidently pointed out.
1/3 = 0.333...
+ 2/3 = 0.666...   
1  =  0.999...

There have been other mysteries that have opened their cocoon unsuspectedly. The derivative of e^x is e^x and e^(iĎ€) + 1 = 0. These moments I have cherished and have attempted to replicate in my teaching. This year in my BC Calculus class when I used Taylor Series to show e^(iĎ€) + 1 = 0, my students hushed and then in unison murmured "wow". This was my third greatest moment this year. I had two presentations for finals. My greatest were yet to come. One was entitled Calculus in Nature and the other, The Gaussian Integral. Both of these gave me "needles and pins". Nature connected for me Ecology and mathematics using the Lotka-Volterra Equations. These differential equations model prey versus predator. The Gaussian Integral bridged the assumed crevice that separated Calculus and Statistics. The ending of this presentation redirected my isolationist view of statistics.

The unsuspected realities that arise in literature and mathematics should not be confused with the "aha" moments that can also come to fruition in both subjects. Those epiphanies are topics to be examined at a later date. The mysteries that result in "needles and pins" abound in literature and mathematics. Those unexpected nuggets invite me to explore the continuous depth and complexities in those disciplines and have moved me along my path. The path that I have followed to this point in time.

Monday, May 23, 2016

Point A Began In the Shop

Today is the birthday of Juan Caramuel, born 1606 in Madrid, Spain. Caramel was a mathematician and a member of the Cistercians religious order. He developed and explained the general principle of numbers to base n and the benefits of using bases other than 10.


Today's quote is a joke that I told my father while working with him in his welding shop. I was a 22 year old college graduate and believed that I knew the solutions to all the world's problems.

"The parts of the human body were having an argument about who should be the boss of the body. The legs proposed that they should be the boss because they carried the body from home to work each and every day. The hands retorted, 'We should be the boss because we build homes, hold children's hands, and feed the body.' The brain countered, 'I should be the boss because I coordinate the systems of the body and solve a variety of problems.' Finally, the rectum spoke up and stated, 'I should be the boss because of all the crap I have to deal with every day.' The other body parts just laughed so the rectum stopped working. After a few days, the body parts were in panic and relented and the rectum became the boss. The moral of the story, you don't have to be a genius to be a boss, just an asshole."

My dad chuckled and replied, "Yep, that's about right."


Recently my editor, Maria Burnham, suggested that I reflect about my journey in becoming a mathematics teacher. I was hesitant at first but I was then asked in class if I always wanted to be a math teacher. I teach juniors and seniors and many are exploring their occupational options. This question floated in my mind and I found the answer more complicated than I anticipated. It remained in my thoughts like a sliver working its way through my epidermis, constantly pestering me until I addressed it and removed it. This blog begins my series of reflections that I entitle from Points A to B. Between two points, there are an infinite number of points which form a smooth curve that is continuous and differentiable. Similarly, the teacher I am today is a result of many mathematical experiences, each forming a link to the beginning. That beginning, that point A, began in my dad's welding shop.


I started working in my dad's welding shop at the age of 9. I earned a quarter an hour and received a $10 bill at the end of each week. The shop was dirty. The walls and floor were covered with a dingy, grayish, brown film that was a mixture of oil, grease, and toxins created by a firework's display of acetylene torches and arc welding. One of my duties was to clean the inside of windows to provide additional light into the shop. However, the walls were never cleaned. These blacked walls reduced the chance of receiving flash burns. Amidst the cacophony of rings provided by a hammer striking an anvil, the sizzle of water cooling iron, and the pop liquid metal exploding on the cement floor, I was introduced to the power of mathematics.



Each day was a lesson in geometry. Terms like square, rectangle, area, volume, height, perpendicular, and plum were added to my vocabulary with an example of what each looked like and how they were to be applied in the task at hand. The 3, 4, 5 rule was introduced early and the properties of rectangles such as equal diagonals were considered truths long before I was to prove them in my 10th grade geometry class. I was introduce to orientation when I made fifty, 4 foot, cylindrical rods each with a 6 inch, right handed, course thread on one end. My jobs weren't complicated but rather repetitive. I was only told once and the repetition was helpful.



The tape measure was my first introduction into fractions. My dad told to halve any fraction, just double the denominator. From that nugget of advice, I was quick to realize that a progression occurs if I kept halving, 1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, ... This sequence, I would later determine was a geometric sequence and when written as a series, 1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + ... , ad infinitum, had a sum of 2.

I became quick with fractions because it was a job requirement. I remember I was to cut a 37-inch piece of 4-inch flat iron, center punch two holes (1/2 inch in diameter) 3 inches from each end, and a hole (3/4 in diameter) centered between the two end holes. I was doing my computation on a piece of paper and my dad asked what I was doing. After I responded, he gruffly remarked that he wasn't paying me to think and proceeded to explain to me how I was to do that in my head. He continued, "One center punch is at 3 inches and another at 34. Their difference is 31. Half of 31 is 15 1/2, added to 3 is 18 1/2. Done. Center punch your holes 3 inches, 18 1/2 inches, and 34 inches. Remember, I'm not paying you to think."

A few weeks later, I had completed a different job and my dad surveyed my work. He shook his head in dismay and asked, "What were you thinking?"

After I had gained some experience. My dad would leave the shop and travel to onsite jobs. The busywork of the shop was in my care, a curious, pre-teen boy. I recall two stories of when I was left unattended.

One day a man entered the shop and wanted a 6-ft. piece of 4-inch flat iron. I retrieved the piece of metal, measured it, and cut it on our band saw. This piece was to have two holes at each end, so I again measured, and centered punch the location for the holes. The piece was heavy for me, and I lugged it to the standing drill press. The bit was large, perhaps, a 3/4-inch bit. I knew that I was to oil the bit, but I was unaware that I also needed to change the ratio of the pulleys that rotated the bit, slowing its rotation. This knowledge would not have been of any use because I was too short. I barely could reach the handles used to lower the spinning bit on to the piece of metal. As I applied pressure, the bit bound, wrenching the 6 ft piece of metal from my hands, and almost decapitating the customer. I dropped to the ground and pushed the foot pedal to off. I stood up, stepped away shaking with tears welling in my eyes. The kind and patient man offered to finish the job and did. My dad anticipated that I might need to assistance in completing a job because I was told to give any customer a 10% discount for helping finish the job.
The other story involves my curiosity. I wondered how everything worked and I investigated everything; the torch, the welder, the grinder, and the forge. Now that I look back, the explosion that never occurred on the north end of Plainview, Minnesota, is in itself, quite remarkable. Leaning in the corner of the shop, my father had an old 22-caliber rifle. I admired it from afar for a few weeks and then had an opportunity to examine it when my dad was again asked to make a "house call". I found a screw driver and took the rifle apart. After scrutinizing each piece, I started to put the gun back together. I was 99% successful. The trigger had fallen to the floor and easily assimilated with the various shards that surrounded me. I scoured the floor, relentlessly looking at each piece of shining metal, praying for a miracle, but none intervened. I shrugged my shoulders and put the gun in the corner. I reassured myself that a missing trigger on an old gold would avoid detection. That evening, a man came to our house and my dad greeted him eagerly and quickly walked to the shop. They were back just as quick and my dad asked if I had "played" with the gun. My face became grim and I nodded. He inquired, "Did the trigger fall to the floor?" I again nodded. "Where did it fall?" he gravely countered. "Among the chains by the door," I whispered, again praying for this last chance of redemption. They never found the trigger and my dad never discussed the topic further.

My dad would always tell me he wasn't a teacher but he held the position in high regard. He was a man of few words. His directions were only given once. I can recall four gems of wisdom. 1) Be smarter than the tool you're using. He told me this right after I hit my finger with a hammer. I have used the quip many times as students try to negotiate the result on their calculator with the mathematics they are trying to learn. Unfortunately, the digital estimator usually wins. 2) The boss may not always be right but he is something you're not, the boss. He told me this when I was disagreeing with some procedure done at the shop. I have carried this into my career. The school district can sometimes create a policy that I disagree with, such as a no-hat policy. My obligation as an employee is to enforce that policy. If all teachers adhere to the policies given by their "bosses" the school system runs much more smoothly. 3) Keep your pecker in your pants. My brothers and I were working together the summer after I graduated from college. A farmer strolled into the shop and announced to dad that he had seen his El Camino parked in the long drive way leading to the farm house. Dad chuckled and told the farmer it must have been one of his boys. After the farmer left, Dad raised his eyebrows and asked which of us were on a date last night. After an awkward amount of silence, he chuckled again, and gave his only sex education talk with that one line. 4) Find a job you love to do and it for the rest of your life. I heard this bit of advise the most often. My dad loved what he did. When I asked him why, he stated that every day there was a new problem to solve and he loved solving problems. I love what I do. Every day is different and every day I have a new problem to solve.

A few days ago, I was interrupted by a colleague as I was tutoring a student. The concept I was reteaching was complex and required a great deal of effort on my part to make the idea attainable. I snapped at the intruder like an old dog focused on a bone and then followed with a confused response to his question. He was taken aback. I have reacted like this before. He accepted my apology but I was left upset with my behavior. At lunch, my confessor (a member of my department) approached me. He had heard the reverberations of the incident. "Your passion," he explained,"is teaching mathematics. You're oblivious to your environment when you enter your passion and you don't transition well. Those people that know you, understand. You are really asking us to enter your passion." My dad had the same reputation. When he was working on a project, you could wait for what seemed like hours before he would acknowledge your presence. He would growl, bark, and snapped as he transitioned from his problem solving to interpersonal communication. The growl, bark, and snap were really invitations to his passion. My final lesson of the shop was a lesson of passion.


Thursday, January 21, 2016

Happy Birthday Numero Unus

Today is the birthday of Theodore Olivier born 1793 in France. Olivier was a mathematician who specialized in geometry. He is known for his string models of ruled surfaces.




Today's quote is by Al Jolson, Billy Rose, and Dave Dreyer.




There are many problems that deal with shadows. Usually these problems use the relationships found in trigonometry or similar triangles. I have listed below three of my favorite shadow problems,

1) If I am 6 feet tall (in my dreams) and I cast a 5 foot shadow, how tall is a flagpole that casts a 10 foot shadow? Answer: 12 feet

2) A street light is mounted at the top of a 15 foot pole. I am walking away from the pole at a rate of 5 ft/second. How fast is the tip of my shadow moving when I am 40 feet from the pole? Remember: I am 6 feet tall. :-) Answer: 25/3 ft/second

3) My favorite problem that applies the use of shadows is the calculation of the Earth's circumference by Eratosthenes over 2000 years ago. Eratosthenes estimate was 25,000 miles. The actual circumference is 24,902 miles.



Today, I complete my Sibling Bond series. My previous blogs were tributes to my sister and younger brothers. The day to day conflicts and agreements with these three siblings acted as a rock tumbler, shaping and polishing me in my progression to adulthood.

Today is my brother, Russ' birthday. Today, he is a decade older than I am. Unlike my other siblings, Russ was a comet, following an unpredictable, elliptical path that when his intersected mine, his effect on my growth was more transitory but not any less impactful.

Russ was sixteen when I was six. The memories of my family became more distinct for me at that age. My younger brothers were energetic, four year old playmates and my sister was the ever present baby sitter. My brother, however, had his driver license, was involved in sports in high school, and was working with my father in his shop. He flew in my view like a bird at my window feeder, who departs to locations unknown as soon as I am aware of its presence.

I treasured any time I had with him. I adored this mysterious, independent, good natured brother. He occasionally included me in his excursions. I was oblivious to the task at hand and eagerly followed behind at a pace that could quite never keep up to his confident gate. I recall many times that I was introduced to his friends, as "his little shadow", a description that caused me to grin and swell with pride.

When I was nine, Russ was a senior in high school and his orbit grew. I saw him less often but desired his attention even more. During this time, I was watching shows such as Dennis The Menace and the Little Rascals. Each of these shows had booby traps involved in their plots. I was captured with the idea of setting traps and Russ became my victim. For a period of three months, a series of pranks greeted him when he came home from his late night excursions. As he entered his room, a barrage of novelties fell from a precarious bucket perched at the top of the door. Books, shredded paper, and water were all items that landed on my brother's unsuspecting head. Throughout this period of time, Russ never raised his voice. He took it in stride. He was patient with his annoying brother.

I became a teenager in the early 1970's and Russ was in his early 20's. He invited me to stay with him in Minneapolis for a weekend. I recall walking through Dinky Town, encountering the sights, sounds, and smells that defined the 70's. Those sensory inputs opened the eyes of this naive, small town kid. That evening, we decided to go to a movie. Our choices were: Magnum Force, Paper Moon, The Paper Chase, and Papillon. We chose Papillon. The night ended, falling asleep while watching Rat Patrol, and I, dreaming of my urban life.

As I have grown older, Russ is no longer the super hero that I thought he was when I was younger. He, like us all, is flawed and complex, but he is wise. He is patient and calm. He has the gift of diminishing my failings and applauding my achievements. He is someone I aspire to be.

As I write this blog about my brother, I am surprised about the details I can recall about our times together. I feel his interactions with me were intentional. I believe he wanted to impact me differently than what I experiencing at home.

I have learned from him that family allows its members to find their own way and encourages them to stitch their own block on the family quilt. He has taught me that family welcomes all its members, and, if necessary, rejoices on the return of its members to the fold, and that as members of the family, we should refrain from casting judgement.

Happy Birthday Numero Unus!




Thursday, December 17, 2015

O Tannebaum

Today is the birthday of mathematician, Mary Cartwright, born 1900 in Aynho, Northamptonshire, England. Cartwright was the first woman mathematician to be elected to the British Royal Society.

Today's quote is from The Littlest Christmas Tree: A Tale of Growing and Becoming by Janie Jasin. "Thank you, Dear Creator, for Life. Thank you for Dreams. Thank you for Ideas and Thoughts and Feelings. Most of all, thank you for choosing me to grow - just for today - and to know the wonder of Your World and its many Possibilities."

A tradition that has been established in our family is the assembly and decorating of our artificial Christmas tree on the day after Thanksgiving. Early in our marriage when my wife and I were hanging the lights on the tree, I noticed I struggled with the project. My placement of the lights as we circumnavigated the string about the tree just wasn't quite right. I had too many lights in the back of the tree or the plugin wasn't situated in accordance to our electrical outlet. As my children grew older, I happily abdicated my role of string assistant to more capable and eager hands.

This year my eldest son, Jacob, asserted his birthright, erected the tree, and hung the lights. I assisted. I had been on administrative leave for about 25 years and I thought now is the time for redemption. I thought, "I can do this!" I also searched for another moment to atone for those instances that I was less than the parent I should have been. Jake is my practice child. What I mean is that I practiced being a parent on him.  There are several classes of students that graduated from Lake City Lincoln High School that I was allowed to practice on prior to my first teaching job. I did not have that convenience with Jake. I made mistakes. Mistakes that I still regret to this day. Our relationship has become more than father and son. We have become friends. He has become my confidant. I value his opinion. I look forward to our time together. I look forward to moments of redemption.

He had progressed to the finality of the tree construction when I began this annual event. Quickly a philosophical discussion emerged between my wife and son as to where to start the string of lights. 

"At the bottom," my wife insisted, "closer to the power source. The plug should be on the bottom right."

"At the top," countered my son, "next to the star. It can guide me to that source."

 My wife relented. Sometimes perseverance can appear as stubbornness.  Jacob and I weaved the lights counterclockwise about the tree. This weave appeared as a dance - a dance of a couple in which one is trying to lead and the other, not confidant in the placement the of step or the rhythm, is trying to follow. After a few rotations, a pirouette, and a few string entanglements, Jacob stopped me. "Dad, you're hanging them too low and you need to wind them around the tree so the strings rise and fall. They should make a wave", he instructed. I grew silent. "Dad, are you ok? Are you upset?", he inquired.

"No, I'm ok", I responded. He paused and placed the bubbler in the center of the tree. He regrouped, "Are you thinking about math?"

I smiled slyly. He sighed.

When we were done, he began hanging his ornaments. The ornaments that he was carefully placing on the tree marked his life. My wife and I choose ornaments for each member of the family that signify an event that we view as significant for that year. These ornaments have accumulated for the past 29 years.They can represent moments as exhilarating as birth and marriage or as humbling as rowing a boat across a lake after the motor stopped running.  Each member has their spot on the tree where their bauble is placed. These assortment of symbols, delicately removed from their containers and carefully hung above and below the periodic function of string of lights that winds itself, top to bottom or bottom to top, (depending on your view) around the tree.

His phrase "rise and fall of the strings" resonated in my mind. I have never thought about the mathematics in a Christmas tree. Years ago, I taught seventh graders. During this time of year, I taught prime factorization I would croak the tune "O Tannebaum" and insert the words "O Factor tree, O Factor tree, How beautiful are your factors!". The tree is obviously conical in shape and and the Greeks had described parabola, circle, ellipse, and hyperbola as planes intersecting a cone, but those words, "rise and fall" kept haunting me.

I searched for mathematics in the seemingly infinite Google search engine and found Treegonometry, a series of mathematical formulas that would compute the "perfect" amount of trimmings for ideal Christmas tree. These formulas were derived by students at the University of Sheffield in the United Kingdom. The formulas are as follows:
1) Number of ornaments = Square Root of (37) ÷ 20 x (height of tree in cm)
2) Length of tinsel (cm) = 13 x pi ÷ 8 x (height of tree in cm)
3) Length of lights (cm) = pi x (height of tree in cm)
4) Height of star/angel (cm) = (height of tree in cm) ÷ 10
A six foot tree would 37 ornaments, 919 cm of tinsel, 565 cm of lights, and a star that is 18 cm tall.

I realized in my blog, The Circle of GeometryI had described the helix as my best symbol of life and there was helix of lights that wound about the tree but this helix, as life, is more complex.



Above, I have provided a top view of the lights and a three dimensional view of the lights traversing the tree. The top view is a spiral. The second view is a conical compression spring often referred to as a tapered spring. I have seen these springs in faucets, holding in the gaskets. The advantage of these types of springs, is the stability they provide when placed on structures such as battery contacts or push buttons. Does the spring start at the bottom or the top?

In my son's description of "rise and fall" and "make a wave", he was expressing the sinusoidal curve which can be shown by stretching a spring.


Unlike the helix, I described in a previous blog, this tapered spring is a better symbol of life, with one addition. I would include "the rise and fall" of the spring as it rotates about its axis. The "ups and downs" that we encounter each day add to the overall wisdom we gain as each year passes.

The tapering of the spring represents the acceleration of time. When my children were born, my wife and I were excited about the brief celebrations of solid food, walking, no diapers, and eventually, no daycare. The time before each of those events were anticipated and calculated.

As a child, the days before the holiday break and ultimately, Christmas, could be excruciating long. I marked the days on my calendar and again, those days were anticipated and calculated.

My first year of teaching was, in my mind, the longest of my career. I made the mistake of marking each day of school and highlighted my last day of the year. Calculated? Yes. Anticipated? Very much so.

Now, I don't measure the day. I do not look forward to the last day of school. I don't calculate and I avoid anticipation.

My parents are in the twilight of their lives. They have often remarked about how time has quickly passed. As the tapered spring reaches the apex, time is rapidly revolving.

I believe the wavy tapered spring is life. As each year turns, and each experience raises the rotation, the circumference of the circle becomes smaller. Time shortens. Opportunities to mend torn moments pass by. Children become adults. The time spent with them becomes rarer and more treasured.



Friday, November 13, 2015

The Dark Side of Math: A PHS Gopher Tale

Today is the birthday of Lene Hau born 1959 in Vejle, Denmark. Hau is famous for her experiments to slow down light. Her team was able initially slow light to 17 meters/second and, in 2001, were able to stop light to one-thousandth of a second.

The first quote of the day is from Steven Wright. He quipped, "It doesn't matter what the temperature of the room is, it's always room temperature."

The second quote is from Brian Holland, Lamont Dozier, and Eddie Holland.



When I was in high school, I was a self absorbed student that waffled between nonconformity and the compliance of peer expectation. I liked mathematics and was a motivated student in that subject, but I was rather fickle in other subject areas--my motivation was dependent on the connection I formed with my teachers.  I made strong connections with my Language Arts teachers but not so much with my science teachers.

I also had a fear that I was underprepared for the rigors of college and that fear drove me to take an array of academic classes. One of those classes, German, I studied my junior year. I was really not aware of what I was getting my self into and very quickly, I was in a conundrum. Learning a foreign language was, well, foreign to me. I was already struggling with the verbal portion of the English language. Why did I think that speaking German would be any different? In addition, I had to memorize. I don't learn by rote. I develop connections that lead from one point to another. Some people believe these connections are linear, but I view them as a web. When I encounter a new idea it vibrates a single string and the entire web pulsates. That pulsation allows me to find the connections to other concepts. This process wasn't working for me in German. I struggled with Der, Die, and Das. I was briefly gratified to find out that these articles are assigned to the gender or neutrality of the subject but was as quickly mortified to realize there are a seemingly endless assortment of exceptions to the rule.

In addition, I was required to join German Club.  German Club was more than a social club for the students. The underlying purpose of the club was to market world language and a student exchange program, AFS. I am not typically a joiner and I was a reluctant participant. This reluctance was transformed to paralyzing dread when I found out I was a founding member of the Schottische Dancers. Our first public performance was surprisingly witnessed by a large audience that included my younger brothers and girlfriend.

This combination of attitude, self prophesying  experiences, and personal characteristics that included cantankerousness and defiance contributed to a student that simply did the minimum requirements. I was complacent but had an underlying frustration that was waiting for its moment to surface. That moment came when the class discussion moved to the measure of temperature.

 Temperature was not new to me. In my mathematics classes, students were already taught how to convert Celsius to Fahrenheit and vice versa. My mathematical education also include that each resulting formula was an inverse of each other, a reflection over the line y = x, and an intersection at -40°. I ask you to examine the table of temperatures.


My German teacher was demonstrating how to convert Celsius to Fahrenheit using the formula, F = 9/5C + 32. She was selecting nice, positive values that were divisible by 5, 15°C = 59°F, 10°C = 50°F, and 35°C = 98°F (body temperature). She was on a roll but then a mistake. "As you notice students", the youthful teacher quipped in a confident, almost "cocky" air, "the Celsius temperature is always a lower number than Fahrenheit." My head perked up. I raised my hand. She smiled in the achievement of drawing me in, yet another mistake. "Could you convert -40°C for me", I inquired. "Negative numbers?", she murmured, somewhat shaken. "I can do this", she responded energetically. "Uh, the answer is ... -40°F that's not possible, I must of made mistake. Give me another one." Eagerly, I made my play in the game. "Oh, how about -50°?" I inquired, again. "-50°C is ... oh, my, a -58°F, how can that be?" she responded with sweat on her brow and a quivering lip. The blinds rattled  ominously above the closed windows. I leaned back, closed my eyes, and let the piranha feast.

Our German teacher wasn't in class until the following Monday. I don't know if her absence was the result of the failed lesson plan on temperature, the loss of credibility with our class, or a preplanned absence. On Monday, she retaught the lesson and explained how negative numbers had impacted her calculations. She did admit she needed a brief lesson from a resident math teacher. I am sure that with each preceding year, she used this experience as a building block to advance her teaching skill.