Table Of ContentPOPULAR SCIENCE I
A Popular History of Astronomy
Biman Basu
Popular Science
COSMIC VISTAS
A Popular History of Astronomy
BIMAN BASU
NATIONAL BOOK TRUST, INDIA
ISBN 81-237-3942-7
First Edition 2002 (Saka 1924)
© Biman Basu, 2002
Rs 65.00
Published by the Director, National Book Trust, India
A-5 Green Park, New Delhi 110 016
Contents
Acknowledgemen ts vii
Preface ix
1. In the Beginning 1
2. Patterns in the Stars 7
3. Vedic Concepts 15
4. Earth at the Centre 21
5. Place of the Sun 28
6. Planetary Paths 36
7. Beyond the Eye 44
8. Newton's Genius 53
9. Einstein's Universe 63
10. Amazing Reflectors 71
11. The Radio Sky 80
12. View from Space 93
13. Planetary Worlds 105
14. Measuring the Cosmos 115
The Nakshatras 125
Recommended Reading 127
Index 129
Acknowledgements
My interest in astronomy was kindled in my childhood when
I watched with awe the star-filled night sky lying in a cot on
the lawns of our house during the summer months. In sub-
sequent years, I was inspired by the writings of eminent
writers like Patrick Moore and Isaac Asimov. Although I
never studied astronomy formally, my interest in the sub-
ject grew with age and I began enjoying sky watching more
and more. I still remember the thrill of watching the famous
Halley's comet in the early hours of a March day in 1986
and the glorious sight of the Hale-Bopp comet in 1997.
As I read more and more about the new developments
taking place in observational astronomy, I was impressed
by the enormous range of information available. But, sadly,
reports of most of the breathtaking developments in as-
tronomy remain hidden in research journals or in scattered
articles published in popular astronomy journals. I decided
to bring together all the exciting stories available on
astronomical techniques and the remarkable discoveries
made with the new techniques in a popular science
book. The National Book Trust, India, helped me by
agreeing to publish the book. I am grateful to them for the
gesture.
One person who has constantly encouraged me in my
astronomical forays including writing this book is the former
Director of Positional Astronomy Centre, Kolkata, Prof.
Amalendu Bandyopadhyay. I am deeply indebted to him
for going through the original manuscript and making
viii COSMIC VISTAS
valuable suggestions for improvement, which have helped
me in bringing the text into its final form.
I am also indebted to all the authors whose books and
writings have been of invaluable help in checking facts and
figures for the book.
New Delhi BIMAN BASU
Preface
We all become familiar with the sky above right from our
childhood days. We see the daily journey of the Sun across
the sky the waxing and waning of the Moon and the star-
filled night sky. But in my childhood days we hardly ever
gave a thought to what these celestial objects were or why
they behaved or moved the way we saw them in the sky
We gradually learnt about them as we grew up. Today, how-
ever, things have changed. Children know a lot about the
celestial objects thanks to the discoveries made by scientists
over several centuries. The story of their discoveries has all
the elements of a detective thriller. The exploration of space
during the past four decades has further changed the sce-
nario, revealing the solar system and the Earth's cosmic
neighbourhood like never before.
To our distant ancestors, the Sun, Earth, Moon, plan-
ets and the stars made up the entire universe, with our Earth
at the centre of it. Our ancestors believed that all the celes-
tial bodies visible to the unaided eye—the Sun, Moon, five
planets and the stars—move around the Earth in very com-
plex paths. The ancient people did not even know what the
stars and planets really were or how far they were from us.
There is, however, evidence that tells us that Vedic In-
dians, who probably lived more than 6,000 years ago, had
considerable knowledge of astronomy. We find evidence of
astronomical observations as early as 4,000 B.C. in the verses
of the Rig Veda. But the oldest astronomical text in India is
the Vedanga Ji/otisha, which is dated about 1,400 B.C.
viii COSMIC VISTAS
Gradually, with advances in science and technology,
as telescopes and other observation tools were invented to
study the universe, the real nature and shape of the uni-
verse gradually unfolded. With the help of astronomical
records of hundreds of years, the Polish astronomer Nicolaus
Copernicus in the 16th century established the Sun at the
centre of the planetary family we call the 'solar system'.
Later work by Johannes Kepler and Isaac Newton explained
the way the planets moved around the Sun, thus solving a
long-standing riddle of planetary motions. But more than
that, these developments shifted the position of the Earth
from being the hub of the universe to that of an insignifi-
cant member of the solar family.
The invention of the telescope in early 17th century
brought in a revolution of sorts. For the first time, a single
technological development radically changed all our ideas
about the universe. It revealed the real nature of the celes-
tial bodies like the Moon, the planets, and the Milky Way—
the galaxy of which the Sun and its planetary family is a
part. As more powerful telescopes came, distant galaxies
were discovered which extended the limits of our universe
manifold. The vastness of the universe gradually started
unfolding. Astronomers discovered that the stars that we
see as tiny specks of light in the night sky are actually suns,
many of them hundreds or thousands of times larger than
our Sun. In fact, it turned out that our Sun is a very ordi-
nary and medium-sized star the like of which there are bil-
lions and billions in the universe, making up billions of gal-
axies like our Milky Way galaxy.
As techniques of astronomical observation were fur-
ther refined and newer tools were put to use, giant clouds
of gas and dust were discovered in space where stars were
being born. Astronomers also recorded the dying moments
of giant stars that end up with flashes of brilliance so bright
that sometimes they can be seen in broad daylight. Stars
were found to be mortal, like us humans. They were born
from giant clouds of gas and dust, lived till old age and
