Introduction and survey. 2: Concepts from astrophysics and cosmology

Boerner, G.

doi:10.1007/978-3-642-74391-7_2

Introduction and survey. 2: Concepts from astrophysics and cosmology

G. Boerner
(
- Garching, Max Planck Inst.
)

1988

58 pages

Part of Particle physics and astrophysics: Current viewpoints. Proceedings, 27. Internationale Universitätswochen für Kernphysik : Schladming, Austria, February 22 - March 3, 1988, 23-78

Contribution to:

27th Internationale Universitatswochen fur Kernphysik (International School of Particle Physics: Particle Physics), 23-78

Published: 1989

DOI:

10.1007/978-3-642-74391-7_2

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Abstract:

Astrophysics and astronomy try to understand the objects found in the sky: the stars, their assembly into large systems, the galaxies and their clustering, the various radiation fields, the cosmic ray particles, and the global underlying structure of the universe. Information about these objects is collected through patient observation of the stream of radiation and particles that reaches telescopes and detectors on or near earth. This soft way of looking at things which does not influence or change their nature has quite a different quality from the hard way in which nature is forced by lab experiments to reveal her secrets. An obvious drawback is the unique nature of events, such as e.g. the supernova explosion in the Large Magellanic Cloud in 1987 — this was an experiment that cannot be repeated. Astronomers, and neutrino astronomers as well, will have to wait for a long time before they’ll have another neutrino burst to analyse. Another interesting aspect is the way in which new instruments have changed our view of the world. The picture of an eternally unchanging universe filled uniformly with stars prevailed until the early 1920’s (even Einstein had this view originally, as is testified by his attempts to find a static solution of his field equations of general relativity through the introduction of a cosmological constant), when Hubble made use of the new large telescopes at Mt. Palomar and discovered the existence of other galaxies and the general expansion of galaxies. Radio observations by Penzias and Wilson in 1964 established the existence of a 3K background radiation field which is interpreted as a relic of a hot and dense early phase of the universe. The concept of an unchanging sky broke down completely, when the first x-ray satellites went to work in the early 1970’s, and demonstrated that rapid changes, flare activity, explosions were the common way of life in this spectral range. Since then with each new instrument new and sometimes seemingly exotic phenomena have been found.

lectures
cosmic radiation: particle source
n: matter
cosmic background radiation
thermodynamics
light nucleus: production
production: light nucleus
baryon: production
production: baryon
inflation