The United Nations briefly considered the issue of extra-terrestrial intelligence at the 32nd session of the General Assembly in 1977. As a result, the Office of Outer Space Affairs was tasked to prepare a document on issues related to 'messages to extra-terrestrial civilizations', but this area has not been followed through in more recent times. This discussion paper describes the United Natio...

One of the main reason of earth-dam breaks is inner erosion which is caused by washing fine soil particles and finally lead to seepage inside the dam. Seepage will decrease effective tension in the earth-dam's core and arching phenomena is occurred. More settlement of core than to shell is the consequence of arching and occurrence of cracking. In this paper, GeoStudio software based on finite e...

, Jessica Suplie and Elsa Tsioumani . The Digital Editors are Andrei Henry and Nabiha Megateli . The Editor is Pamela S. Chasek, Ph.D. and the Managing Director is Langston James “Kimo” Goree VI . The Sustaining Donors of the Bulletin are The Netherlands Ministry of Foreign Aff...

Of the many fields of science in which increased numerical simulations and information technology have accelerated recent developments, perhaps none holds more promise than computational earth system science, a field of research within the new science of GeoComplexity. In the past, researchers observed physical and chemical processes to clarify the physics of such natural systems as earthquake ...

1-1 1-2 1-3 & 2-1 2-2 2-3 & 3-1 The Earth Simulator System By Shinichi HABATA,* Mitsuo YOKOKAWA† and Shigemune KITAWAKI‡ *Computers Division †National Institute of Advanced Industrial Science and Technology (AIST) ‡Earth Simulator Center, Japan Marine Science and Technology Center The Earth Simulator, developed by the Japanese government’s initiative “Earth Simulator Project,” is a highly paral...

Definitions and characteristics The rare earth elements (REE) (sometimes referred to as the rare earth metals) are a group of 17 chemically similar metallic elements, including the 15 lanthanides, scandium and yttrium. The lanthanides are elements spanning atomic numbers 57 (lanthanum, La) to 71 (lutetium, Lu) (Table 1). The lanthanides all occur in nature, although promethium, the rarest, only...

focus on conservation in this issue of Science appears on the eve of Earth Day, which is being celebrated by scientists in meetings and public events worldwide. Conservation professionals, who have long condemned attacks on the environment, will gather for Earth Optimism events to highlight conservation achievements. Separately, but simultaneously, marches for science will highlight science’s a...

About a decade ago, systems biology hit the life sciences with the promise that it would revolutionize biological research and create new products, drugs and therapies along the way. As with so many over-hyped ‘breakthroughs’, it inevitably failed to deliver, prompting criticism from a number of eminent biologists. Nobel Prize winner Sydney Brenner, for example, accused systems biologists of us...

No known rocks have survived from the first 500 m.y. of Earth history, but studies of single zircons suggest that some continental crust formed as early as 4.4 Ga, 160 m.y. after accretion of the Earth, and that surface temperatures were low enough for liquid water. Surface temperatures are inferred from high d18O values of zircons. The range of d18O values is constant throughout the Archean (4...