Part 1: ISSUES AND FOUNDATIONS
Chapter 1: The big questions
This Chapter introduces the major themes considered in this text: a broad
view of the nature of the physical Universe and the nature of life, explaining their physical foundations, but also looking at the nature of the scientific method and the
limits of what can be achieved by the scientific method.
Cosmology is the science that
studies the physical structure of the Universe. Building on the results of
other sciences (particularly physics and astrophysics), it has led to major new
understandings about the nature and evolution of the matter around us; and this
in turn has led to an understanding of the physical conditions that make life
possible on earth. In particular it has led us to understand:
* There was a hot early phase
to the universe when all that existed were particles and radiation
* The universe is presently
expanding, and indeed this expansion seems to be speeding up
* What we see is just a small
fraction of all there is: the universe is dominated by dark matter
* We can detect the black body
relic radiation of the hot big bang
* Huge structures like
clusters of galaxies grew our of small inhomogeneities in the early universe
* The part of the universe we
can see is limited because of the existence of visual horizons
However the aims of the present
science of cosmology are much narrower than implied in the anthropological use
of the term, where Cosmology refers to an overall world-view that throws light
not only on the structure and mechanisms of the Universe, but also on its
meaning. We can characterise some of the big questions that have concerned
humanity since the dawn of consciousness, as follows (cf. [1]):
* The nature of the physical
Universe: What is it made of and how does it work?
* The question of creation:
How do things originate?
* The issue of the final
state: What will happen in the end?
* The place of humanity in the
Universe: How does this all relate to us?
* The meaning of existence:
What is the purpose of it all?
They are all the concern of the
broader understanding of anthropological or philosophical views of Cosmology (`What is the universe about? How do I relate to it?'). The modern scientific theory has made great strides on the first issue, and presented many interesting theories concerning
the second and third. However it has - for perfectly good reasons - very little
to say on the last two. It is precisely by limiting its scope to the
experimentally verifiable that modern science has had such enormous success
within its domain. The downside is that it cannot therefore by itself provide a
satisfactory overall worldview, even though this is sometimes attempted. The
failure of such attempts, and the realisation that major areas of human concern
lie outside the scope of the modern scientific vision, underlie a present
widespread turning away from science towards various a-scientific or even
anti-scientific worldviews (see e.g. [2]). These do not take seriously the
major achievements of science and the understanding it has achieved.
This text looks at the way we attain
scientific understanding and then at the physical foundations of the structures
in the universe, including life. Then it discusses the nature, history, and
future of the expanding universe, emphasizing on the one hand what is
well-known and on the other what is not known, or may even be unknowable. Thus while it does not explicitly enter the domain of `Cosmology' in the anthropological or philosophical sense of discussing the relative merits of overall worldviews related to ethics, metaphysics, and meaning, its does take a broader view of cosmology than most texts on physical cosmology in that it looks seriously at the nature and functioning of complex structures, including life. It does so because of a conviction that in the end the origin of life must be one of the main concerns of scientific cosmology. If that is accepted, then the nature of life must be taken seriously (going way beyond what is usually included in discussions on the Anthropic Principle).
PART I (`Issues and Foundations')
defines (this Chapter) the major questions which are considered on this text - the scope of the discussion. It is concluded by Chapter 2, which outlines the approach that will be adopted in tackling them - a discussion of the scientific method and its relation to evidence. In particular it makes an important distinction between how science works in the case of the experimental sciences on the one hand, and the historical/geographical sciences on the other.
PART II (Chapters 3 to 6) presents
the present scientific understanding of the Universe. The scientific method has
led to a tremendous growth in knowledge of the way matter is organised and functions.
The chapters in this part give a brief outline of some of the most important of
these discoveries. Chapter 3 focuses on the underlying fundamental laws,
covering concepts from physics and chemistry. It then comments on how these laws underlie the nature of the physical world (minerals, rocks, mountains, the Earth). Chapter 4 focuses on the functioning of complex systems, covering the range of biological sciences, and proposing a set of basic principles that underlie the functioning of truly complex systems such as life. Chapter 5 focuses on the environment within which all this takes place (the Universe around us), covering astronomy and cosmology. However this cosmological understanding is uncertain in some aspects, and limited in others; Chapter 6 discusses some of these uncertainties and limitations, ultimately founded in the uniqueness of the universe .
PART III (Chapters 7 and 8) turns to the theme of humanity and the Universe. Chapter 7 introduces the Anthropic question, i.e. the puzzling fact that the physical Universe seems fine-tuned to permit the existence of complex physical organisms, including human life. A purely scientific approach to understanding this feature is found to be inconclusive. This discussion provides the scientific basis for whatever approach one chooses to take towards the `big questions' mentioned in Chapter 1. Finally the limits of science are discussed in Chapter 8. There are important aspects of human existence that will forever remain beyond its domain. That statement does not of course in any way undermine its magnificent achievements within its proper domain, which is presented in the rest of this text.
This is a non-technical text; it is aimed at use in the context of courses on the theme of `Science for Non-Scientists'. Because of its overall intention, it necessarily aims is to give a broad-brush overview of all the major `hard' sciences. Given this attempted scope, it obviously cannot achieve depth. Rather the aim is to explain the most important concepts and key understandings in each of these areas. This clearly cannot give depth of understanding in any of these areas. However I have included selected webpage references throughout the text, indicated by [webpage] (for example, the one below), that open the way to much deeper understanding. They should enable the interested reader to pursue any chosen topic in much greater depth, as well as considerably enhancing the learning experience.
I have had to decide whether to use
some technical words in this presentation, or to try to avoid them altogether.
I have chosen the first course, because while it is a nuisance to the reader
having to learn their meaning if it is unfamiliar, it is essential to have some
label for each important concept; one may as well use the usual one, for this
opens up access to the literature of the subject.
Overall, the text should help anyone
interested to become `scientifically literate' - something valuable to all
citizens. This does not answer any of `the big questions', but it does provide
an overview of a key part of our present understanding - required knowledge if
one is to adequately consider the deeper philosophical issues. Also this text does not attempt to cover (i) mathematics and logic, (ii) applied sciences,
engineering, and medicine, nor (iii) the human and social sciences; including
them here also would have been an impossible task. It would be useful if someone
were to provide similar broad overviews of each of these areas also - but that will be a very difficult task. In the meantime an
excellent email site covering useful developments of science in Africa is at [webpage].
References for Chapter 1
Major issues in Philosophy are
discussed in
[1] R C Solomon: The big
questions. A short introduction to philosophy. (Harcourt Brace Jovanovich,
1982).
The humanist reaction against the
pure scientific approach is presented in
[2] B Appleyard: Understanding
the present: science and the Soul of Modern Man (Picador, 1992).
Some great books on cosmology are
[3] J Silk: A Short History of
the Universe (Freeman, 1997),
[4] E R Harrison: Cosmology: The
Science of the Universe (Cambridge University Press, 2000).
A good book explaining the new
physics and its relation to cosmology is
[5] J Allday: Quarks, Leptons,
and the big Bang. (Institute of physics, 2002).
The closest I am aware of to the
present text in terms of scope and coverage is
[6] R M Hazen and J Trefil:
Science Matters. Achieving Scientific Literacy. (Anchor Books, 1990).
I will frequently refer to that book
in what follows. However it does not emphasize the limits of science as is done
here. A text that covers much of the same ground but looks more at mathematics
and applications is
[7] F J Rutherford and A Ahlgren: Science
for all Americans. (Oxford University Press, 1990).
Either of the last two would be a
good companion to what is presented here.
[Version 2002-07-20].
Chapter 1 of The Universe Around Us by George Ellis .