ARCturus

The division of the universe into structural units according to size forms a chain from the largest unit to the smallest. The various units can be placed in order on a spread of a small notebook. Browsing the notebook is a way through the universe and this is how an impression of its structure is easily recalled. In the picture there are a few covers of the notebooks made by the students (picture IH, Finland).

 

Aim: Use parts of the chain to create a uniform imaginary model where each picture or drawing represents one structural unit and its location in the chain. The size of the structural unit is expressed as metres to the power of ten.

Explorations: Discuss at first with the students the structure of the universe on a general level. It is a way of creating an impression of their worldview. It is good to emphasize that the universe is not only visible and huge but can also contain very small parts invisible to the eye. Also the concept ‘structural unit’ needs to be defined. In the model presented here,  there is one basic choice made to indicate the number of structural units. Everyone may add units to the chain or take them away in whatever way that seems appropriate.

1)  The first job is to make a notebook. Take three A4-papers; they may have various colours if wanted. Cut the papers along the short edges in two. The result, six A5-papers are piled, folded in the middle and stapled along the folding to a notebook. On the left edge of every spread, draw or glue a small picture of a telescope and on the right edge of the spread accordingly a small picture of a microscope. These pictures remind the students of the direction to which the process is heading in the chain of the structural units.  These directions are of course only one choice. The places of the pictures on the spread can also be switched.

2)  The students plan the layout of the cover. The heading may be Micro-macro cosm or a similar expression in Finnish. All spreads can include pictures; it is even recommendable. In addition to them, it is useful to add small informative boxes or explanatory texts. The students are advised to write freely with their own words, even in a poetic form. Long text blocks on the pages are not a good idea.

3)  Start making the structural units in the middle spread. Using artist’s free hand, draw there the globe with its oceans and continents. There is no use copying the official map. Since the globe is our home and familiar to us, let us colour the oceans blue and continents green or brown. In the picture there is a spread of a notebook (picture IH, Finland).

 

 

 

On the top of the spread write the name of the structural unit. The students like to see the name written in many languages. The first name is Tellus in Latin. The following names accordingly in English, Swedish, French and German languages, and sometimes even in Russian or some other language rarely taught at school. On the top corner of the spread write the size of the unit as metres to the power of ten.

4)  When proceeding from the globe to the macro world (i.e. towards the telescope, the picture chosen to be on the left) the following spreads include the following topics in order: Solar System, Milky Way, local Galaxy Group, group of galaxies and giant group of galaxies.

The picture of the Solar System can be stretched over the whole spread without any scale. A diagram of the Solar System using a scale is built in another workshop (ARCII Solar System). The Sun is illustrated by drawing only a small piece of its edge. Then draw the planets in order and emphasize a little of the difference between the size of the terrestrial planets and the giant planets. Add into the picture an asteroid belt between Mars and Jupiter. The most remote ex-planet Pluto, nowadays classified to be a dwarf planet, and its moon Kharon are located in their positions on the opposite side of the Sun on the spread. Also comets may be added into the picture. Finally, discuss with the students the real motions and sizes of the parts of the Solar System.  

The Milky Way is illustrated both from above and sideways. Add into the picture the following information: diametre 100000 light years and the thickest part in the centre 10000 light years. Sketch the spirals around the centre. They are curved clockwise and become thinner away from the centre. Spherical clusters of stars may be added on both sides of the galaxy plane.

Local group of galaxies is illustrated as a group of galaxies like the Milky Way. The most famous galaxies can have their names in the picture, such as Milky Way, Andromeda and Virgo. Discuss with the students the various forms of galaxies or recall some familiar things about  them.

When drawing a group of galaxies emphasize how it is made of units like galaxy groups. This is when a single spiral galaxy is drawn so that its spiral can barely be seen. Leave some space between the groups. Mark the name clearly in the picture of the familiar member and local group of galaxies.   

Drawing a giant group in the classroom may sound like a rhythm of a silent drumming. The students find it funny to use their pencils stronger than necessary when drawing numerous clusters of dots. The giant group is formed of groups of galaxies. The distance to them is so huge that it is not possible to draw a single galaxy. The mark of a pencil is too massive for that and no lines can be drawn at all. Again, leave space between the groups of galaxies in order to make it easier to understand the structure.  

The macro world is now finished. Discuss with the students its structure, the chain of units as well as the question: How does a human being fit into this chain?

5)   The micro world is built to the right from the centre fold towards the microscope. There may be many kinds of opinions on the structural units chosen into this part of the chain. For example, the question: Is man a sensible structural unit or not? As representatives of the living nature this model includes man and a cell as independent structural units. That is how it is easier to ponder the position of the humans as part of the structural chain in the universe. This choice was made also for the reason that this teaching could be integrated with other subjects at school. When proceeding from the globe to the micro world the following spreads include in order: human being, cell, molecule, atom and nucleus. As an advanced topic discuss quarks or introduce more elementary particles.

The spread introducing man is a sketch the students like to shape. It is fun to draw a male and a female human being, introduce their characteristics or even write a beautiful poem about them. The name of man in Latin, Homo sapiens, arouses both hilarity and a lot of discussion. It is worthwhile to explain to the students the difference between the Latin name and a connotation they think it refers to. The students are surely astonished when learning that the size of man is about ten to the power of zero metres.

Drawing cells requires knowledge of biology. This certainly is a matter of integration between the subjects. Nevertheless, it is no use to increase the accuracy of the drawings. Two or three pictures are enough. Several types of cells may be named.

Molecules may be introduced by drawing a few most common types. The water molecule is easily remembered and also may be familiar to the students. In addition to drawing simple gas molecules with two atoms, it is worthwhile to draw at least one molecule that is a little bit more complicated, e.g. acetic acid or ethanol. In the discussions it is good to point out that the dna-spiral is some kind of a giant molecule.

The atoms are usually introduced as balls in various sizes. That may be the beginning of understanding the difference between a light and a heavy atom. It is also an opportunity to tell about the presence of atoms in nature, their participation in a natural cycle as well as their possible disadvantages.

It is worthwhile to regard nucleus as an independent structural unit. Its size differs significantly from that of an atom. There have been many deeply touching events in the history of humankind and the universe that have to do with nuclear fusions and fissions. It is best to discuss these themes with the students peacefully and without unnecessary threats.

Diving even deeper into the micro world is possible if it can be done within the limits of time resources available and the students’ level of development. The world of elementary particles is a fascinating and varied selection of oddly behaving particles. They are a challenge to the exploration of modern physics.

6)  * The instructions for making a structural notebook, given above, favour especially younger students who need guidance from the teacher for producing the contents and proper order for the spreads. Advanced students can build the notebook more independently by using illustrative material from the chaos-pages. These three pages consist of all illustrative material needed in the notebook but it is in no order, i.e. it is a chaos. The same part may be on many pages except for the globe, the one and the only place with known life. Various parts of the same spread may be found on all pages. The size of the units may be found in a ready-made table in the form used in literature. The students have to convert it to metres using scientific notation.

The student’s task is to arrange the chaos on the pages of the notebook in correct order in a previously mentioned way. The order is made according to the structural units starting from the biggest to the smallest or vice versa. In this method the pictures of the units are ready-made but the students have to position the pictures independently to the right places in the chain of the worlds. The teacher chooses the method the students use in this exercise.

Methods: Construction guided by the teacher, the contents produced mainly by the students. Or an independent construction activities using ready-made materials. The teacher is a guide working on the background. Unit conversions.

Materials: Common craft materials, paper, colours, pencils, calculator.

Pondering: In what way and how much is it necessary to clarify the structural units of the chain to the students if the notebook is made by using chaos-pages? Globe in the middle pages, however, is an absolute starting point for both implementations. What kind of information is needed on the pages? Where is the limit for free contents of the pages? Art or science?

Evaluation of results: When all pages have been finished, the students will be given some time to put their final touches to the pages. Browse quickly through everyone’s notebook to make sure that the order of the chain is correct. Errors on the spreads must be corrected in order to avoid misunderstandings.

Hints: Using the drawing method causes more work for the teacher. On the other hand, it guarantees a proper and flawless proceeding in constructing the chain. It is easier to avoid errors not easy to correct. The chaos-pages and the sizes of the structural units in tables are in the Internet on the web pages of EAAE/Workshops/2005. In the following picture there is a giant cardboard macro-micro notebook made by students in an Italian school (picture IH, Finland). The imagination has no limits!

 

 

 

Keywords: Structural principle, galaxy system, nuclear physics, elementary particle.

 

 

---