Radio serial on astronomy
Episode1: Overview of the radio serial
[Note for script writer: This brief has been prepared keeping the average non-specialist viewer in
mind. The attempt has been to develop the subject in a logical sequence that could bring out the
excitement of the process of making new discoveries and relating them to the gradual understanding
of the nature of the Universe. It is not designed to be a popular account of the development of
astronomy as a scientific discipline and its impact on our understanding of the cosmos. Since the
treatment is not rigorous, many details are not included. The script has to be developed along the
outline suggested using simple colloquial language as far as possible. The dialogues and
conversations need to be lively without any suggestion of pedagogy.]
Points to be covered:
This episode provides a brief outline of the contents of the serial.
Outline of content:
If we stand on the ground the Earth appears flat and all the astronomical bodies – the Sun, Moon, stars
and planets – appear to go round the Earth at different speeds. It is no wonder that our distant
ancestors believed the Earth to be at the centre of the Universe. The ancient people did not know what
the stars and planets were made of, or how far they were from us. They were frightened by common
natural occurrences such solar eclipse and the appearance of comets. Yet, by meticulous observation
of the sky they were able to develop systems of calendar to keep track of time over the year.
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 Universe 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 puzzle 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
insignificant 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 celestial bodies like the Moon, the planets and the Milky Way – the
galaxy of which the Sun and planetary family is a part. As more powerful telescopes came, distant
galaxies were discovered which extended the limits of our Universe many fold. The vastness of the
Universe gradually started unfolding. Astronomers discovered that the stars that we see as tiny specs
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 ordinary and medium-sized star the like of which
there are billions and billions in the Universe, making up billions of galaxies like our Milky Way
galaxy.
As techniques of astronomical observation were further 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 then died. Even our Sun will die
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Radio serial on astronomy
eventually, but not in the near future. Astronomers say, it will continue to shine like it does now for
at least five billion years more.
Technological developments during the Second World War led to yet another breakthrough – the
discovery of radio waves coming from space – that opened up a new dimension in our understanding
of the Universe. Galaxies and stars, and even our Sun, which appeared serene and shining steadily,
turned out to be objects seething with extreme violence, spewing out highly energetic particles and
powerful radiation. The Universe as seen through the radio telescope appeared totally different from
the Universe we are familiar with.
Radio telescopes also brought forth new kinds of star-like objects such as pulsars and quasars the
existence of which were never known before. Pulsars turned out to be fast spinning dead stars that
behaved like extremely accurate celestial clocks, sending out precisely timed pulses of radio waves.
Quasars on the other hand are extremely distant objects, which emit extremely powerful radio waves.
The real nature of quasars and the source of its enormous energy still remain a mystery.
The study of radio waves from space also provided a proof of the way the Universe was born, some
14 billion years ago. It is now widely accepted that the Universe was created in a giant cosmic
explosion, which the British astronomer Fred Hoyle termed the ‘big bang’. Initially the Universe was
extremely hot, only in the form of energy, which later cooled and condensed into various subatomic
particles. These particles, in turn, came together to form atoms and molecules of hydrogen that filled
the Universe. Cosmologists had predicted that if indeed there were a big bang, remnants of that
gigantic explosion would be still present and could be detected as very short radio waves known as
microwaves, uniformly distributed in space. This all-pervading radiation was finally detected using
radio telescopes in 1965. Subsequently, radiation in other wavelengths, such as infrared, ultraviolet,
x-rays and gamma rays have also been detected from space, which have further changed our ideas
about the Universe.
Our knowledge about the nature of the Universe has undergone sea change over the millennia since
our early ancestors looked up at the sky. Ancient Greeks believed the Universe to be an orderly
system – a collection of a handful of celestial bodies – that worked with clockwork precision and
called it ‘cosmos’. Today we know that the cosmos is much vaster than the Greeks could ever have
imagined. As this serial will tell you, our present understanding of the cosmos has been made
possible only because of the dedicated effort of pioneers, and the scientific and technological
innovations that we have witnessed in the past few hundred years. Without these marvels of science
we may not have ever been able to fathom the almost limitless depths of our Universe.
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