Extragalactic cosmic ray Extragalactic cosmic ray Extragalactic cosmic rays are very-high-energy particles that flow into the Solar System from beyond the Milky Way galaxy. The energies these particles possess are in excess of 10 eV. Unlike solar or galactic cosmic rays, little is known about the origins of extragalactic cosmic rays. This is largely due to a lack of statistics: only about 1 extragalactic cosmic ray particle per square meter per year reaches the Earth's surface (see figure). There are many ideas about which processes may be responsible for cosmic rays with such high energies. In the 'bottom-up' approach, cosmic rays gain more
Beyond the Limits Beyond the Limits Beyond the Limits is a 1992 book continuing the modeling of the consequences of a rapidly growing global population that was started in "Limits to Growth". Donella Meadows, Dennis Meadows, and Jørgen Randers are the authors and all were involved in the original Club of Rome study as well. "Beyond the Limits" (Chelsea Green Publishing Company) and Earthscan addressed many of the criticisms of the "Limits to Growth" book, but still has caused controversy and mixed reactions. Billionaire investor Richard Rainwater indicates having been influenced by reading "Beyond the Limits"'. His niece Kelley Rainwater reports she gave