Living With Our Sun S Ultraviolet Rays

Sunlight is part of everyday life and we accept it as good-and good it is in a number of ways. The sun is our source of warmth, and of the light by which we see. It is, in fact, the source of the energy with which life continues on earth. It furnishes energy for photosynthesis, and the pro ducts of photosynthesis constitute our food, building materials, and fuel. A steady state of balance and fine interrelationships exists between life on earth and all the forces and stresses in nature. This book will pin point the balance and relationships we share with sunlight. Our primary focus will be on the ultraviolet radiation of the sun, and on the ultraviolet photobiology of life on earth. This is the story of the effects of the sun's ultraviolet radiation, both good and bad, on all of us and all of life. We will explore the nature of the sun's ultraviolet radiation as it reaches the earth's surface today, and as it probably affected the earth in the distant past; and examine the effect of such radiation on all life, unicellular organisms as well as multicellular plants and animals. The effects of the sun's ultraviolet rays are primarily a result of their action upon cells, and secondarily, a result of their interactions between cells. The cell of a multicellular organism-man included-is also part of the tissue of an organ, and the organ is part of the whole organism.

In the history of science the opening up of a new observational or experimental window is always followed by an increase in knowledge of the subject concerned. This is also the case with the subject of this book, ultraviolet radiation (hereafter UV). In principle, the ultraviolet range might be just one more of these windows, of no particular importance. However, the energy per UV photon provides the main peculiarity, its magnitude being great enough to produce important ch- ical reactions in the atmospheres of planets and satellites, thereby a?ecting the transmission of this radiation to the ground. The Sun is the main natural source of UV radiation in the Solar System and our planet is the body where its in?uences can be best tested and the only one where its relation with life can be studied. However, the terrestrial atmosphere blocksmostofthephotonsinthiselectromagneticrangeandastronomershavehad to develop various techniques (balloons, planes and rockets) to cross this barrier and access the information. These tools have been used in parallel to investigate the physical properties of the terrestrial atmosphere and the interaction of its constituents with light. This book will addresses most of these topics.

In the history of science the opening up of a new observational or experimental window is always followed by an increase in knowledge of the subject concerned. This is also the case with the subject of this book, ultraviolet radiation (hereafter UV). In principle, the ultraviolet range might be just one more of these windows, of no particular importance. However, the energy per UV photon provides the main peculiarity, its magnitude being great enough to produce important ch- ical reactions in the atmospheres of planets and satellites, thereby a?ecting the transmission of this radiation to the ground. The Sun is the main natural source of UV radiation in the Solar System and our planet is the body where its in?uences can be best tested and the only one where its relation with life can be studied. However, the terrestrial atmosphere blocksmostofthephotonsinthiselectromagneticrangeandastronomershavehad to develop various techniques (balloons, planes and rockets) to cross this barrier and access the information. These tools have been used in parallel to investigate the physical properties of the terrestrial atmosphere and the interaction of its constituents with light. This book will addresses most of these topics.

Ultraviolet Astronomy and the Quest for the Origin of Life addresses the use of astronomical observations in the ultraviolet range to better understand the generation of complex, life-precursor molecules. The origin of RNA is still under debate but seems to be related to the generation of pools of complex organic molecules submitted to heavy cycles of solution in water and drying. This book investigates whether these cycles require a planetary surface or may occur in space by examining both the theoretical and observational aspects of the role of UV radiation in the origin of life. This book offers the latest advances in these studies for astronomers, astrobiologists and planetary scientists. Addresses both the theoretical and observational aspects of the role of Ultraviolet (UV) radiation in the origin of life Builds on the requirements to produce prebiotic molecules in space and the implications for the origin of RNA Investigates the use of ultraviolet observations related to planetary system formation, the evolution of young planetary disks, and the interaction of stars with planetary atmospheres

" ... Concise explanations and descriptions - easily read and readily understood - of what we know of the chain of events and processes that connect the Sun to the Earth, with special emphasis on space weather and Sun-Climate."--Dear Reader.

Every second of every day, the sun emits wave after wave of radiation hurling toward our planet. Even though we can't see most of this radiation with the naked eye, scientists have learned how to use these invisible waves to our advantage. From infrared systems to guide missiles to ultraviolet-sterilized laboratory work areas, visible light's closest neighbors on the electromagnetic spectrum have a lot to offer us. This book explores the science and discovery of infrared and ultraviolet radiation, as well as the ingenious ways scientists and engineers have used them, including in common household devices such as remote controls for our televisions and in cutting-edge medical treatments.