Download Scientific american (November 2004) by Scientific American PDF

By Scientific American

Show description

Read or Download Scientific american (November 2004) PDF

Best nonfiction_1 books

Geographic Information Science: Mastering the Legal Issues (2005)(2nd ed.)(en)(474s)

Cho (University of Canberra) explores either how the legislation impacts using geographic info and the way geographic info has formed the legislations and coverage in numerous nations. He identifies the standards influencing public use and pricing rules, describes using alternate criteria to percentage and commercialize geographic info, and descriptions a global framework for the advance of entry guidelines.

Additional info for Scientific american (November 2004)

Sample text

If you give the satellites too much energy or pack them too closely together, they will form a black hole and will no longer be able to participate in mapping. ) The maximum total energy of the constellation of satellites is proportional to the radius of the region being mapped. Thus, the energy increases more slowly than the volume of the region does. As the region gets bigger, the cartographer faces an unavoidable tradeoff: reduce the density of satellites (so they are spaced farther apart) or reduce SETH LLOYD and Y.

Bender; Scientific American, February 1998]. Intense, abrupt warming episodes appeared more than 20 times in the Greenland ice records. Within several hundreds or thousands of years after the start of a typical warm period, the climate reverted to slow cooling followed by quick cooling over as short a Global warming should be more of a worry than ever: it could be pushing the earth’s climate faster toward sudden shifts. massive ice sheet in the early 1990s. These colossal rods of ice — some three kilometers long— entomb a remarkably clear set of climate records spanning the past 110,000 years.

S c ia m . c o m COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. the energy available to each satellite (so that their clocks tick more slowly). Either way, the measurement becomes less precise. Mathematically, in the time it takes to map a region of radius R, the total number of ticks by all the satellites is R 2 /l P2. If each satellite ticks precisely once during the mapping process, the satellites are spaced out by an average distance of R1/3l P2/3. Shorter distances can be measured in one subregion but only at the expense of reduced precision in some other subregion.

Download PDF sample

Rated 4.14 of 5 – based on 28 votes