相关论文: The Imperatives of Cosmic Biology
Planetary systems such as our own are formed after a long process where matter condenses from diffuse clouds to stars, planets, asteroids, comets and residual dust, undergoing dramatic changes in physical and chemical state in less than a…
Is life most likely to emerge at the present cosmic time near a star like the Sun? We address this question by calculating the relative formation probability per unit time of habitable Earth-like planets within a fixed comoving volume of…
The multiverse is a hierarchy in the number of universes, increasing stepwise towards infinity. It is an evolutionary system, in which universes survive only near critical mass. That mass is actually a factor of 1.94 less than the critical…
The evolution of our Universe is strongly influenced by the attractive force of gravity. A key aspect of this evolution, therefore, is the merging of galaxies. Here, we explore the role of mergers in shaping the properties of massive…
The large-scale structure of the Universe, as traced by the distribution of galaxies, is now being revealed by large-volume cosmological surveys. The structure is characterized by galaxies distributed along filaments, the filaments…
Young, massive star clusters are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions, mergers, and close encounters. Their contribution to the total luminosity induced by such…
We review observational evidence bearing on the formation of a prototypical large spiral galaxy, the Milky Way. New ground- and space-based studies of globular star clusters and dwarf spheroidal galaxies provide a wealth of information to…
The great advances in the network of cosmological tests show that the relativistic Big Bang theory is a good description of our expanding universe. But the properties of nearby galaxies that can be observed in greatest detail suggest a…
We describe observations in the nearby universe (<100 Mpc) with a 10-m or larger space-based telescope having imaging and spectral capabilities in the range 912-9000 \AA that would enable advances in the fields of massive stars, young…
Chemical evolution is essential in understanding the origins of life. We present a theory for the evolution of molecule masses and show that small molecules grow by random diffusion and large molecules by a preferential attachment process…
The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate. In the upper atmosphere of…
The improbability of a spontaneously generated self-assembling molecule has suggested that life began with a set of simpler, collectively replicating elements, such as an enclosed autocatalytic set of polymers (or protocell). Since…
Present-day elliptical, spiral and irregular galaxies are large systems made of stars, gas and dark matter. Their properties result from a variety of physical processes that have occurred during the nearly fourteen billion years since the…
Most stars, perhaps even all stars, form in crowded stellar environments. Such star forming regions typically dissolve within ten million years, while others remain bound as stellar groupings for hundreds of millions to billions of years,…
Terrestrial and extraterrestrial theories of the origin of life are discussed in the light of latest observations. The available data suggest a dual mode of origin, some of the ingredients, including possibly sugars, were brought to earth…
Cosmology is undergoing an explosive period of activity, fueled both by new, accurate astrophysical data and by innovative theoretical developments. Cosmological parameters such as the total density of the Universe and the rate of…
The breadth of topics that encompass the search for life has expanded and evolved significantly since the emergence of the field of astrobiology. Initial astrobiology centered investigations focused on detecting biosignatures in the Martian…
The oft-repeated claim that life is written into the laws of nature are examined and criticized. Arguments are given in favour of life spreading between near-neighbour planets in rocky impact ejecta (transpermia), but against panspermia,…
A simple stochastic model for evolution, based upon the need to pass a sequence of n critical steps (Carter 1983, Watson 2008) is applied to both terrestrial and extraterrestrial origins of life. In the former case, the time at which humans…
Life occurs in concentrated `Ringer Solutions' derived from seawater that Lesser Blum studied for most of his life. As we worked together, Lesser and I realized that the questions asked of those solutions were quite different in biology…