Why do I want to be a teacher?

"We don't act rightly because we have virtue or excellence, but we rather have those because we have acted rightly.  Excellence, then, is not an act but a habit"
Aristotle.

Teaching has been my occupation for more than twenty years. I want to keep doing this job as it satisfies me, and I find it very fulfilling. When I teach I feel that I play a crucial role in the life of my students. I am responsible for finding a way to help them understand, to gain knowledge, to become better. When I succeed in tuning into my students way of thinking and lead them to form the correct cognitive structures, I feel really great.

I want to keep teaching because I feel renewed when I am with young people who possess pure and plentiful enthusiasm, and who face knowledge as something to be explored. I must admit that their humor and spontaneity makes me forget my concerns which accompany me as an adult. I can remember several instances when I left home pensive, and in a melancholic mood, and then after 10 minutes of teaching I felt optimistic and full of life again.

I insist that in my teaching role I  love coaching my students with their career choices. I am so happy when I am informed about their achievements.  I concede my feeling of pride.

I want to keep teaching because I feel that I have much more to do and to learn. I want to be a part of a great team of teachers. As a private tutor I enjoy face to face interaction with my students, but teaching a class is challenging and rewarding too.

I want to keep teaching as I want to continue improving, as a teacher. I am used to working within strict time restrictions under continuing assessment of my methods and techniques. I have come to like it. However, I feel that there are a lot of steps which I haven’t taken. There exists enough creativity within me which hasn’t come out yet. Now I am mature enough for it to so  in a consistent, and prudent way.

I love mathematics and physics, and I constantly try to pass this love on to my students. This is one more reason for me to keep on teaching. These two sciences are considered difficult, almost inaccessible to many people. My aim is to dissolve this misconception. The most important part of one’s relation to these sciences is the very first experience. A lot of care should be taken during the early school years. Physics and mathematics have their own language, and their own way of being thought about, and acted on. This can be grasped if it is taught properly. We characterize a child as clever, when they understand maths. But clever is not what you are, is what you become. 

Teaching is more challenging now than ever. Students of the 21^st century try multitasking and face multiple stimuli. Their attention is easily distracted.  Today our students live and walk with a mobile phone in their hand. They are all immersed in the internet, and struggle to accommodate all this data in their brains. Our  teaching approach is challenged to accommodate the "gadgets" of our time to an effective learning plan.  

I want to keep teaching to build upon the excessive enthusiasm of the previous decade in new Instructional Computer Technology and participate in forming a better, more effective and up-to-date exploitation of it.

Considering myself as a teacher: I think there is a long path ahead which calls for being walked along. I really want to become a (better) teacher. 

OUR LIGHT MILL IN ACTION

DESCRIPTION

“The Crookes radiometer, also known as the light mill, consists of an airtight glass bulb, containing a partial vacuum. Inside, a set of vanes is mounted on a spindle. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity.”

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

EXPLANATION

The motion of the air molecules in the radiometer from the hotter (black) to the colder (silver) surfaces of the vanes contributes to the rotation of the vanes. Molecules hitting the black side get heated up slightly and bounce off with higher energy. Due to the momentum conservation, this causes the vanes to recoil in the opposite direction. 

 Certainly this is a simplistic way to explain how solar radiometer works. The full detailed explanation was given by Reynolds in 1879. He used the term “thermal transpiration”. Let's try to explain a little bit more.  When the solar radiometer is placed under the sunlight, heat is being introduced in the form of light. Each of the four vanes has a silver

reflective side and darker black side. That  darker black side tends to  absorb light and hence heat which means we  have one side of the vane  a bit hotter than  the other side. However,nature likes to even things out by sending colder air on the silvery side around to the darker side

cool it off and  when it does that the balance of the gases changes.Air pressure builds up on the darker side while decreasing on the silvery side . As the cool air moves air particles move around to the warmer side and sometimes they displace some the warmer molecules which go to the other site. Now by definition warmer air molecules have more energy and are more excited , so they strike the vane with more speed. They  actually strike the black side to the vane  while on the other side there is  very little resistance because of the lower air pressure there. So the vane spins  around with the dark side leading.

Note that the first explanation made by Crookes himself, was based on the air pressure fact.  However, while light does exert a pressure, it's too tiny to cause the effects seen in the radiometer. Moreover, if this was true, then the reflective side of each one vane

should have been pushed along and the vane would have spined

in the opposite than the observed direction.

Uphill rollers: some double cones and a pseudosphere.

 The "uphill roller" is a physics demonstration first reported by the English Mathematician William Leybourn in 1964. In the original version, a double cone placed on two divergent inclined ramps appears to roll uphill, apparently violating the laws of physics.
The uphill roller is an example of the center of mass of an object descending under the influence of gravity.




Nikos Kassastogiannis, an inspired woodworker and an invaluable friend of mine made a nice wooden demonstration of the uphill roller on my request. You can watch the demonstration in the following video. Nikos  didn't only make the double cones I asked him to, but he also made a brilliant pseudosphere which you can watch in the video to oscillate before it reaches its equilibrium.

A pseudosphere is a surface with a constant negative Gaussian curvature. Revolving a tractrix of radius r about its asymptote generates this surface. Although the resulting surface has an infinite extension along its central axis, it has finite area ,exactly the same  as a sphere of radius r, and half its volume. The pseudosphere played an important mathematical role in the acceptance of non-euclidean geometry.

If this video whetted your appetite for more information, here they are some links to explore.
1.  A mechanical paradox or, a new and diverting experiment by William Leybourn

2.  "Pleasure with profit:: consisting of recreations of divers kinds, viz. numerical, geometrical, mechanical, statical, astronomical, horometrical, cryptographical, magnetical, automatical, chymical, and historical. Published to recreate ingenious spirits; and to induce them to make farther scrutiny intor these (and the like) sublime sciences. And to divert them from following such vices, to which (in this age) are so much inclin'd" by William Leybourn"

3. Defying gravity: the uphill roller.
4. Nikos Kassastogiannis, handmade wood

Common mistakes that keep you from succeeding.

The following mistakes lead to low achievements. Take care to avoid them.

A) While doing homework

1) You do not study but you read instead.

Studying means to write down a lot of stuff, as many times as it is required to write it faultessly.
What is to be written down?
>>Symbols and their interpretation (according to their standard units when physics is concerned)
>>Definition formulas and their verbal explanation
>>Verbal definitions that are not given by formulas (for example :what is resonance, which numbers are called rational ànumbers e.t.c.)

2) Flat studying.

You give the same attention to all, despite their rank in the  scale of importance .
There are definitions, formulas, axioms, theorems which are fundamental in the mathematics/physics lessons you study. All the rest are less significant in the sense  that you can prove them using reasoning or mathematical operations. What I mean is that not any formula you come across is to be memorized. You have to know how you came to it using more your procedural than your declarative memory.

3) You do not exercise comparative studying.

Whenever you come across  something new (term, theorem, phenomenon) it is better to try integrating it within what you  have already learnt. Make a draft diagram of the relations between the new term and the other known ones. Make tables of similarities and differences between concepts. Try to compare to find out what is special in what you are to study.

4) You skip warming up.
You cannot start your problem solving effort at once. Undergo a procedure that prepares  you  to face the exercises you have to do. Repeat basic theory, examples and exercises which have been worked during the last lesson.  During this  warming up procedure you should  act as if you  have to make a presentation of what you have learnt in front of one who cares to understand what you say.  You have not understood something if you cannot articulate it.  If you are unable to follow this procedure you have to bring your questions back to the class. Remember: you had better ask everything on time, not afterwards. So keep  being concentrated during the lesson.

5) Do not give up easily.
The more you try, the more you gain. Do not give up.

6) Sloppy homework

Don’t excuse yourself. You will not do better during exams. Normally one performs in exams  in a manner equal or worse than she/he is used to perform, not better.

B) Common incorrect practices during exams.

1) You try to recall like recalling eidetic memories. You ask yourself: Which solved exercise is quite similar to the current one? But you judge similarity in a superficial way.  There is also the case of you thinking in what I cal “formula centric way”. This means that you seek a magic formula containing  everything: the given and the asked. It  is possible that such formula does not exist. You may, however,need to construct it yourself by using others.
The correct practice is to recall concept relations and methodology.

2) You do not make any draft preplan. You rush to the solution without selecting the proper strategy to approach it.

3) You give up easily, you get lost sooner than is expected.
You should make serious efforts  to solve a problem or to answer a tough question.

4) You do not re-examine your answers to check the validity of your statements or to correct probable mistakes. Sometimes you have to reflect upon your findings, don’t miss that.

5) You forget to consider time economy.
Each question must be given the right portion of the whole exam time duration.

6) You do not care for the “appearance” of your writings. You had better care more . There is no need to be meticulous but you must make sure  that your answers are written neatly enough.

Don’t forget.

"Excellence, then, is not an act, but a habit”, according to Aristotle.

Despoina Makri  
Physics/Mathematics teacher