منابع مشابه
Spam Zombies from Outer Space
How can better email worms be created? How can spyware claim more victims? How can better spam be sent? It turns out that these three questions are all related. We look at the future threat posed by email worms, spyware, and spammers that use zombie machines in a new way: sophisticated data mining of their victims' saved email. The end result skirts many defenses, and could trick even experienc...
متن کاملMeasuring Economic Growth from Outer Space.
GDP growth is often measured poorly for countries and rarely measured at all for cities or subnational regions. We propose a readily available proxy: satellite data on lights at night. We develop a statistical framework that uses lights growth to augment existing income growth measures, under the assumption that measurement error in using observed light as an indicator of income is uncorrelated...
متن کاملMeteorites: Messengers from the Outer Space
Milhares de meteoróides, corpos sólidos do espaço extra-terrestre, entram na atmosfera da Terra a cada ano. São pedaços de rocha, metal ou aglomerados de rocha e metal, variando em massa de frações de grama a centenas de quilogramas. Aqueles que sobrevivem à passagem através da atmosfera e caem na Terra, são chamados meteoritos. Os meteoritos são as rochas primitivas, tão antigas quanto o Siste...
متن کاملFrom Inner Earth to Outer Space
On a cold day in February 2001, a spacecraft landed on 433 Eros, an asteroid between the orbits of Mars and Jupiter. The spacecraft had completed its five-year journey to investigate fundamental questions about the nature and origin of near-Earth objects for the first time. The technical demands of the Near Earth Asteroid Rendezvous NEAR-Shoemaker (NEAR) mission were immense. A multidisciplinar...
متن کاملJoining inner space to outer space
The purpose of this paper is to demonstrate that it is possible, in principle, to obtain knowledge of the entire universe at the present time, even if the radius of the universe is much larger than the radius of the observable universe.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1998
ISSN: 0028-0836,1476-4687
DOI: 10.1038/26858