Kirjahaku

Fallait-il ?crire ces textes ? Apr's le drame apocalyptique de la Shoah, ? seul le silence est grand, tout le reste est faiblesse ?. Je me suis tu. Pendant cinquante ans? Mais je suis faible, tr's faible? Au moment de ce cinquanti?me anniversaire, en 1994, je n?ai pu continuer ? garder le silence. J?ai ?crit les premi?res pi?ces de ce petit livre, puis, au cours des ans, quelques autres. Fallait-il publier tout cela ? Lorsque viendra le centi?me anniversaire de leur d?part, que resterait-il d?autre de Victor et de Nelly Mes enfants, et les enfants de mes enfants, et leurs enfants, doivent comprendre, et savoir ce qui fut? Je voudrais? J-C. P.

Astronomy is the oldest and most fundamental of the natural sciences. From the early beginnings of civilization astronomers have attempted to explain not only what the Universe is and how it works, but also how it started, how it evolved to the present day, and how it will develop in the future. The author, a well-known astronomer himself, describes the evolution of astronomical ideas, briefly discussing most of the instrumental developments. Using numerous figures to elucidate the mechanisms involved, the book starts with the astronomical ideas of the Egyptian and Mesopotamian philosophers, moves on to the Greek period, and then to the golden age of astronomy, i.e. to Copernicus, Galileo, Kepler, and Newton, and ends with modern theories of cosmology. Written with undergraduate students in mind, this book gives a fascinating survey of astronomical thinking.

Astronomy is the oldest and most fundamental of the natural sciences. From the early beginnings of civilization astronomers have attempted to explain not only what the Universe is and how it works, but also how it started, how it evolved to the present day, and how it will develop in the future. The author, a well-known astronomer himself, describes the evolution of astronomical ideas, briefly discussing most of the instrumental developments. Using numerous figures to elucidate the mechanisms involved, the book starts with the astronomical ideas of the Egyptian and Mesopotamian philosophers, moves on to the Greek period, and then to the golden age of astronomy, i.e. to Copernicus, Galileo, Kepler, and Newton, and ends with modern theories of cosmology. Written with undergraduate students in mind, this book gives a fascinating survey of astronomical thinking.

Socrates knew all that was known by his contemporaries. But already in the Middle Ages it was becoming difficult for a single man to have a truly encyclopedic view of all human knowledge. It is true that Pico della Mirandola, Pius II, Leonardo da Vinci, and several other great minds were thoroughly in possession of considerable know­ ledge, and knew all that one could know, except no doubt for some techniques. The encyclopedists of the 18th century had to be content with an admirable survey: they could not go into details, and their work is a collective one, the specialized science of each collaborator compensating for the insufficiencies of the others. We know very well that our science of today is a science of specialists. Not only is it impossible for anyone person to assimilate the totality of human knowledge, it is impossible even to know ones own discipline perfectly thoroughly. Each year the presses of science pro­ duce a frightening quantity of printed paper. Even in very limited fields, new journals are created every day, devoted to extremely specialized, often very narrowly defined subjects. It is indeed evident that in a field whose scope extends well beyond astronomical or astrophysical research, it is materially impossible to be informed of everything, even with the richest of libraries at hand.

Le ciel est, par-dessus le toit, The sky is, up above the roof, Si bleu, si calme! So blue, so calm! Un arbre, par-dessus Je toit, A tree there, up above the roof, Berce sa palme. Waves leaves of palm. La cloche, dans le ciel qu'on voit, A church bell, in the sky I see, Doucement tinte. Softly tolls. Un oiseau, sur l'arbre qu'on voit, A bird, upon the tree I see, Chante sa plainte. Sadly calls. PAUL VERLAINE Like Verlaine, we are in prison. The prison is our Earth, "which is so pretty"; our atmosphere and its clouds, its "marvellous clouds". (You would think that Verlaine, Prevert and Baudelaire had been comparing notes!) The sky is up above the roof...A tree there, up above the roof...Stars in the sky, like birds ...their rays, like bells (and here we are with Apollinaire!) What we see opens the way to what we guess at; what we observe Ieads us towards the unobservable. A poem releases images, and the invisible grows big with reality. Astronomcrs are a little like poets (indirectly from the Greek 7tostco, make): they make the universe by interpreting messages, extrapolating spectra, and inventing 'models' of the cosmos or of stars - fictional constructions whose observable part constitutes only a small fraction of the whole, and which only the inductive logic of the theoretician allows us to consider as representing unique physical reality.