Understanding the fundamental properties of the energetic particle population in the heliosphere is very important for two reasons:

1. These particles represent considerable hazard for both humans and radiation-sensitive systems in space, because they can penetrate through large amounts of shielding material.

2. They carry information about the large-scale properties of the heliosphere and the galaxy.

High-energy cosmic ray particles carry a large amount of kinetic energy. The deposition of this energy can cause permanent effects in the material through which the cosmic ray particle passes. In the case of biological materials or miniature electronic circuits, these effects can be very serious. In order to provide adequate shielding for radiation-sensitive systems, we need to know the basic properties of the high-energy particle radiation, including its elemental composition, energy spectrum, and temporal variations.

A significant portion of our present knowledge about the global structure of the heliosphere comes from energetic particle observations. These particles travel through space at velocities considerably higher than the characteristic velocities of the local plasma population. Because the propagation of the energetic particles is greatly affected by various physical properties of the medium, energetic particles sample regions of the heliosphere and the galaxy that are currently not accessible to spacecraft.

INTRODUCTION

Earth at the close of the Archean, 2.5 billion years ago, was a world in which life had arisen and plate tectonics dominated, the evolution of the crust and the recycling of volatiles. Yet oxygen (O2) still was not prevalent in the atmosphere, which was richer in CO2 than at present. In this last respect, Earth's atmosphere was somewhat like that of its neighbors, Mars and Venus, which today retain this more primitive kind of atmosphere.

Speculations on the nature of Mars and Venus were, prior to the space program, heavily influenced by Earthcentered biases and the poor quality of telescopic observations (figure 15.1). Thirty years of U.S. and Soviet robotic missions to these two bodies changed that thinking drastically. The overall evolutions of Mars and Venus have been quite different from that of Earth, and very different from each other. The ability of the environment of a planet to veer in a completely different direction from that of its neighbors was not readily appreciated until the eternally hot greenhouse of Venus' surface and the cold desolation of the Martian climate were revealed by spacecraft instruments.

However, robotic missions also revealed evidence that Mars once had liquid water flowing on its surface. It is tempting, then, to assume that the early Martian climate was much warmer than it is at present, warm enough perhaps to initiate life on the surface of Mars.

INTRODUCTION

We close the part of the book on techniques for discerning Earth's history with a conceptual tool. The concept of plate tectonics, whereby the outer layer of Earth is divided into a small number of distinct segments called plates which move relative to each other, represents a breakthrough in explaining a diverse range of geologic phenomena across our planet. Although the basic ideas are now 30 years old or more, this picture or concept of how Earth's geology works, in a unified way, continues to provide fresh insights into evolution of Earth, the stability of the gross climate of our planet, and the distinctions between Earth and the other planets. Because of its importance, we introduce the concept early to allow the reader to gain an understanding of the basic ideas. We come back to plate tectonics again and again as a fundamental process on Earth driving climate change, erosional processes, atmospheric chemistry, and even the nature of life.

EARLY EVIDENCE FOR AND HISTORICAL DEVELOPMENT OF PLATE TECTONICS

Revolutions in scientific thinking often take place when increasing numbers of observations challenge existing theories, which in many cases have become dogmatic over time in the face of conflicting data. Particularly satisfying is the synthesis of widely diverse data into a single framework that explains well all of the data.

As early as Sir Francis Bacon over 350 years ago, but mostly since the early nineteenth century when maps of the world became good enough to reveal the true shapes of the continents, the significance of the curious matching of the edges of distant continents has been pondered.

Nature produces many different kinds of waves and oscillations. In general, these periodic phenomena are very different from each other. However, certain physical and mathematical properties are common to small-amplitude waves almost irrespective of their nature. For instance, all small-amplitude waves can be characterized by dispersion relationhips and they transport physical quantities with the group velocity of the wave.

In this chapter we will examine some fundamental proprties of small-amplitude waves in neutral and conducting fluids. We will see that although neutral fluids exhibit a relatively small number of fundamental wave phenomena, conducting fluids (especially when they are magnetized) are a very fertile medium for the generation of a huge variety of plasma waves.

Here we shall concentrate on small-amplitude waves, when the wave equations can be linearized. This does not mean that nonlinear phenomena are unimportant — they are just too complicated for this introductory text. Also, we will limit our discussions to single species gases (or in the case of plasmas, to single ion plasmas). The results can be generalized to multispecies plasmas, when needed.

Linearized Fluid Equations

First of all, let us consider the linearized version of the ideal MHD equations. We choose to use the MHD equations, because mathematically the Euler equations represent a subset of these equations (one just has to set B to zero everywhere at all times). Let us assume that we have a solution of the full equation set, that is, ρm0, u0, p0, and B0 represent a steady-state solution of Eqs. (4.89).

INTRODUCTION

The period from the formation of Earth, some 4.56 billion years ago, to the time when the oldest rocks still in existence today were formed, roughly 3.8 billion to 4.0 billion years ago, is called both the Hadean era and Priscoan eon of Earth. The term Hadean, referring to the classical Greek version of hell, is well chosen, because all evidence that we have is that the Hadean Earth was very hot and extremely active, with widespread volcanism and frequent impacts of debris left over from planetary formation. This time encompasses the assemblage of Earth from the smaller planetesimals, dramatic internal rearrangements such as core formation, the creation of the ocean and earliest atmosphere, and the origin of Earth's Moon. Forces that acted on Earth were essentially the same as those acting on Mars and Venus, and a traveler visiting Earth would have seen little to distinguish it from the two neighboring terrestrial planets.

Each planet initially had a molten, or nearly molten, silicate surface, followed by cooling and establishment of a solid crust. Each had an atmosphere dominated by carbon dioxide (CO2), with little free molecular oxygen (O2). Evidence exists that each planet had liquid water on its surface during a portion of the Hadean era. Most important, no sign of life could be seen on any of these three planets – conditions were too severe and variable to allow life-forms to survive except near the end of the Hadean on Earth, and perhaps at about the same time on Mars.

In this chapter we will briefly consider some of the basic theoretical tools used in describing the transport of superthermal particles. By superthermal particles we mean a very small fraction of the total particle population with energies far exceeding the average thermal energy. These superthermal particles contribute negligibly to the particle density and bulk velocity (due to their very small number compared to the total number of particles), but in some cases they may represent a significant contribution to the pressure and heat flow.

We will consider the basic transport equations describing two kinds of superthermal particles: energetic solar particles and photoelectrons. Since our goal is to provide an introduction to the theoretical tools of space physics, we will constrain our derivations to the most fundamental processes. More sophisticated treatments can be found in the literature.

Transport of Energetic Particles

As in most cases, we start from the Boltzmann equation describing the evolution of the particle distribution function. The main difference this time is that because superthermal particles can be relativistic, we need to derive a transport equation that is valid for relativistic particles as well. To achieve this we use the form of the Boltzmann equation given by Eq. (2.36), where the variables of the distribution function are time, location, and full (inertial) velocity.

The beginnings of this second international colloquium on Astronomy Teaching, eight years after the famous one in Williamstown, came during a meeting of Commission 46 in August 1994, in the Hague. It was then submitted as an IAU Colloquium by the President of Commission 46, John Percy, with the support of the newly born European Association for Astronomy Education.

When I was asked to chair the Scientific Organising Committee, I considered this proposal to be a great honour, that I acknowledge, and also an exciting way to learn more about the new developments in astronomy education that you are performing, so many of you, all around the world.

Then came a hard work! Step by step the programme was built, thanks to the help and suggestions from the SOC members, and I would like to mention more particularly Julieta Fierro, Andy Fraknoi, Barrie Jones, Derek McNally, John Percy.

It was my great pleasure, each day, to read your mails on my computer, or on the fax machine a pleasure mixed with some increasing anxiety, when their number began to grow rapidly! The Internet gives this beautiful possibility to interact so easily with people spread out all over the world – you have just to take account of the time zones, which could be also considered as a good astronomical exercise.

Eight years have elapsed since the first IAU Colloquium (No. 105) on astronomical education “The Teaching of Astronomy”. In that time there have been substantial changes in the world of education – not just astronomical education. On the one hand, there has been erosion of funding, while on the other there has been an unprecedented opening up of access to information: there has been a change from educational experiment towards more regulation of curricula and determination of standards. But, as a reading of this volume will clearly show, there is still a healthy creativity in astronomy education. There is much important new work being done – there are adventurous schemes in public education, there is new detailed research on how our students and pupils may learn and on the portfolio of misconceptions under which they may be labouring when first confronted with astronomical teaching. One of the new features since 1988 is access to the Internet. An overwhelming variety of information is now readily available from the latest Hubble Space Telescope picture to the Web Page of the local astronomy society. But it is also clear that the sheer richness and variety of the Internet offering creates yet another problem – how to organise that information to maximum teaching and learning benefit. The North American continent is once again in a period of curriculum renewal and it is of great interest to see the interaction between that renewal, electronic media and the Internet. Such enterprises are receiving support in particular from the National Science Foundation in the USA. It is encouraging to see that the Internet is being used to support undergraduate projects.

Primary school

School education in Latvia, as in many other countries, is divided into two stages: primary and secondary education. Primary education is compulsory. Every year 30 000 new school children start attending primary school. This is a potential audience that can study astronomy fundamentals. During first grade studies school children learn the basics of natural science which include some elements of astronomy. These lessons are given once a week. At this stage children's interest in the Universe is great; therefore the most active teachers use some out of curriculum activities to give the schoolchildren an idea about the stars, planets and other celestial bodies. The science curriculum itself contains very few elements of astronomy (Karule, 1995). Even more many teachers have problems teaching science at the elementary school, because they are afraid that it is too sophisticated. This situation should be corrected, but at the moment no teacher training in science is planned.

In higher grades of primary school some astronomy elements are taught in different disciplines. In geography there are some topics about the Earth, Seasons and Tides (Klavins, 1992). In physics there are some topics about Eclipses of the Sun and the Moon (Kokare, 1992). And that is all. It leads to the situation that a young person, graduated from primary school, has heard nothing about constellations, Moon phases, comets and many other astronomy questions.

The expected positive changes are the following: new textbooks of the basics of natural science, where more attention is paid to astronomy, are being developed. The textbook for 1st grade has already been published (Vaivode et al., 1995), the others will follow.

Introduction

In recent years much research into conceptual understanding of science has been carried out. Oddly, Astronomy (one of the smallest sciences in terms of pupil numbers) is possibly one of the most widely studied subjects, with numerous papers being produced revealing the intuitive ideas of (usually) young school children. Within these papers it is generally recognised that if students cannot assimilate the fundamental concepts of a subject, then their own initial frameworks are altered accordingly, producing mis-conceptions.

Much of this research into pre/mis-conceptions, alternative frameworks etc, has been concerned with the knowledge of gravity or the shape of the Earth, the Sun and other such bodies. Another area heavily researched is that of phases/eclipses, and how the young children of today perceive these phenomena.

The research presented here takes the findings from earlier papers and extends it by assessing astronomy students at the University of Plymouth. The experiment probed two areas, the phases and eclipses of the moon and Sun and the ability of students to de-centre.

Previous Studies

It has been known for many years now that children usually start to think of the Earth as flat (Vosniadou et al (1989)), with age usually removing or adjusting initial frameworks. This may be demonstrated by assuming we have two children, A and B, which both hold the notion of a flat Earth. From the flat Earth model, child A may ‘leap’ to the concept of a spherical Earth straight away; the child's flat Earth conceptions have been removed and replaced with a model which the child is able to associate with ‘space’ and thus a spherical Earth.

Origins of Misconceptions

Students come into our classrooms with many misconceptions about science in general and astronomy in particular (see numerous papers and references in Novak, 1993 and Pfundt & Duit 1993). These beliefs evolve from a variety of sources throughout childhood and adolescence (Comins, 1993a, 1993b, 1995). I have found that directly addressing these incorrect beliefs in the context of their origins helps my students replace them with correct knowledge. By understanding the origins of their misconceptions students can screen information more effectively, i.e., they learn to think more critically. My purpose in this paper is to briefly identify origins of misconceptions and classroom techniques for replacing them.

I define misconceptions as deep seated beliefs that are inconsistent with accepted scientific information. Unless we directly address these incorrect ideas at their roots, most students cannot replace them with correct knowledge. Most students retain correct material only long enough to pass tests, and then lapse into believing their prior misconceptions.

In previous works (Comins, 1993a & 1995) I identified a heuristic set of origins that account for all the misconceptions I have identified. It is well worth noting that such a list is by no means unique and, given that I have since added another category, nor is it complete. Nevertheless, this set of origins is an extremely practical one, providing a significant set of tools for understanding and dissecting misconceptions and how these beliefs are used by different people. In an effort to make this set more tractable, I have now revised it to an even dozen (see Sections 1.1–1.12).

Introduction

The Star Centre is a national astronomy and space science base which

• facilitates public access to news and information

• promotes public awareness, interest, enjoyment and understanding.

The Star Centre meets these twin aims by providing an information service which can be accessed in a variety of ways and by offering a menu of public observing events.

The concept of a national astronomy base developed as part of the Centre for Science Educations growing portfolio of initiatives in both the formal education sector and the wider umbrella of the Public Understanding of Science. In December 1996 the Star Centre was launched with the aid of a Royal Society COPUS development grant and matching funding from Sheffield Hallam University.

This paper summarises the main activities of the Star Centre, gives some impression of the public response and outlines plans for future development.

The Star Centre in Context

The Star Centre reaches out directly to schools and the general public and is part of the growing network of long-term projects at the Centre for Science Education (CSE) within the School of Science and Mathematics as shown in Figure 1. The largest of these projects is the UK Research Council funded Pupil Researcher Initiative (PRI) in which school pupils in the 14–16 age range explore science topics through research briefs. The PRI provides resources, activities, strategies and support for science teachers and their pupils so that pupils will experience the excitement and relevance of science and engineering research and so develop a lasting interest and enthusiasm. All aspects of the research process are involved and there are opportunities for Science Fairs, Pupil Researcher Conferences and Roadshows.

The reader of this proceedings volume might ask why was it thought interesting to publish a few pages about the posters presented at IAU Colloquium 162? It had been decided that indeed the history of the meeting would not have been complete without some words about the poster presentations. The final success of the entire Colloquium depended on all presentations, either oral or poster.

The posters themselves have been different but it has been interesting to note that sometimes similar projects and ideas have been elaborated at very distant places in the world.

The basis of our teaching should be related to our roots; we ought to mention old traditions in our own country, such as the cosmological ideas of old Guarani Indians or the story of the first South American 18th century. Observatory of F. Buenaventura Suarez which have been shown by A. E. Troche Boggino of the University of Asuncion, Paraguay. However, I found most interesting the history of evolution of the human mind as depicted by the diagram of A. E. Troche Boggino showing chronological sequences of contemporary scientists, philosophers, writers, painters, sculptors and composers, from the times of Copernicus to the present day. It is easy to make a perpendicular cut or cross-section of the diagram at a given epoch, for instance that of Copernicus, and get to know what other famous persons have been living during his life-time.

In another part of the world, at the University of Glamorgan, UK, Mark Brake had been also in favour of a historical/cultural approach when telling his audience scientific facts, both when dealing with university students and with the general public.

Introduction

Comets and quasars, black holes and the big bang, pulsars and planets all feature in the media and excite people to find out more – astronomy might be described as the popular face of modern science. In the UK, recent changes in Advanced Level (A-level) physics courses mean that many students have the option of studying astrophysics to a depth beyond the merely descriptive. This option is proving popular with teachers and students, but presents particular challenges shared by few other areas of A-level physics courses.

Astrophysics within A-level physics

A-level courses are taken by students who choose to stay in education beyond the age of sixteen. Students typically study three subjects at A-level over the course of two years. A-level is approximately equivalent to 12th grade and the first year of a bachelors degree in the USA. Students are awarded grades for their A-level work which depend on their performance in external examinations and on evidence of experimental skills collected by their teachers. The examinations are set, and the grades awarded, by independent examination boards which specify the content on which students are to be examined and the skills for which teachers are required to provide evidence. For many students, A-levels are a preparation for more advanced study at university.

Fifty percent of the content of all A-level physics syllabuses is now defined nationally (School Curriculum and Assessment Authority, 1994), whereas previously the examinations boards had a greater degree of autonomy. Current syllabuses have been discussed and summarized by Avison, 1994; most consist of a compulsory element, with a menu of optional topics of which students must study (and be examined on) a specified number.

Introduction

The total solar eclipse of October 24, 1995, whose central line cut across the subcontinent of India, was only the second total solar eclipse visible from India in this century. The previous total eclipse visible from India occurred on February 16, 1980. At that time the print media filed widely varying reports on what the effect of seeing the eclipse would be, without much coordinated input from astronomers. With the new confused advice reinforcing old fears, almost the entire population literally hid indoors, fearing the worst. Many Indian astronomers silently resolved to themselves then, that public education must be taken up with the same level of seriousness as research programmes during the next eclipse.

The Background

The total solar eclipse of October 24,1995 was visible along some of the most populated parts of India and took place during a season of generally clear skies. Elsewhere in the country the eclipse would be partial. So nation-wide, our class was a mere 900 million strong!

Even in the last decade of this century, astronomy education in India is very sparsely serviced below the post graduate level. Several new planetaria have been built around the country since 1980. Clearly they would play a role in public education. So our 900 million strong class could be apportioned between them as far as public education was concerned. But the school, undergraduate and amateur sectors continue to suffer from lack of focussed attention. Here, however, the numbers involved would be much smaller. The Nehru Planetarium decided to use this opportunity to design activities not only for the general public, but also for specific groups of school students, undergraduates and amateurs.

What is the EADN?

In 1986, a group of university astrophysics institutes in eleven Western European countries established a federation known as the European Astrophysics Doctoral Network (EADN). The aims of the EADN, then and now, are to stimulate the mobility of postgraduate students in astrophysics within Europe, and to organize pre-doctoral astrophysics schools for graduate students at the beginning of their PhD research. The network has by now expanded to include about 30 institutes in 17 Western European countries, and ways are being actively sought for expanding the EADN even further to include Eastern and Central Europe. The coordinators have been Prof. Jean Heyvaerts (France) until 1992, Prof. Loukas Vlahos (Greece) 1992-1993 and myself since 1993. The network is financially supported by the European Union “ERASMUS” and the “Human Capital & Mobility” programmes as well as by national funds.

The Student Mobility Scheme

The Student Mobility Scheme has been designed to encourage postgraduate, or in some cases senior graduate, students to undertake part of their doctoral or diploma thesis research at an institute which is part of the network. It offers ERASMUS funded grants intended to cover student travel expenses and extra expenses encountered by the student caused by living away from their home institute. The grants are not full grants since it is expected that the student can retain the home grant while at the partner institute. The duration of the visit is usually anywhere between 3 and 12 months and must be preceded by contacts between the student's regular thesis advisor and the network partner advisor.

Introduction

Informal and formal astronomy education is present through many channels: newspapers and TV; amateur associations; clubs and science associations; at school at any level. The teachers are not only the main agents of the educational process at school, but they are also very active in extra-curricular activities: they run clubs, educational projects etc.

These activities are present everywhere in the world, as can be seen from the reading of the National Reports published every 3 years by Commission 46 “Astronomy Teaching” of the International Astronomical Union and published in its Newsletter.

A quick look at these reports shows that there is a huge variety of educational systems from one country to another: some countries have a specific curriculum in astronomy, others are just beginning to develop it; in other places, astronomy has been considerably reduced in the newly created curricula. One more difference: in some countries, education has a national curriculum; in others the responsibility for teaching is left entirely to each Province, a term used here to refer to the local situation. Such a situation and its consequences was were depicted by Wentzel (Williamstown IAU Colloquium 105, 1986).

Why Astronomy in the curricula?

In spite of these differences, a general trend can be drawn: it is very rare that astronomy is considered as a separate subject; it is nearly everywhere part of the programme either of Mathematics, Physics and Chemistry or Natural Sciences.