scientific american - 2001 02 - are we almost tapped out safeguarding every drop of clean water

... infrared, at the 1.3 1- and 1.55-micron wavelengths need- ed for medium- and long-range telecom- munications. The big technical glitch re- lates to the spacing of atoms in the crys- tal lattice of ... YEARS OF QUANTUM MYSTERIES Are We Almost Copyright 2001 Scientific American, Inc. Profile32 Scientific American February 2001 has a sibling around which it do-si-dos every...

Ngày tải lên: 12/05/2014, 16:07

... about: Washington Redskins. ■ Favorite escape: Relaxing on his boat. ■ Core belief: American competitive policy says we don’t care about companies we care about consumer welfare.” MICHAEL POWELL: ... des- tination. (Western Europe as a whole, how- ever, took in 21 percent.) One fourth of all migrants to the U.S. went to California; fa- vorite cities, in order of the number of for-...

Ngày tải lên: 12/05/2014, 16:11

... the ma- jor cause of death of black males be- tween the ages of 15 and 24. Blacks are also six times more likely to be arrest- ed for a violent crime than are whites. The Þve-year, $400-million ... Calif. Copyright 1993 Scientific American, Inc. ber of wells Arabs can drill in the terri- tory, the amount of water Arabs are al- lowed to pump and the times at which they can...

Ngày tải lên: 12/05/2014, 14:48

... acknowledges that not everyone is cut out for teach- ing partnerships. ÒThere are some sci- entists who alienate me,Ó he concedes. And Alberts says he is aware of the dangers of letting well-meaning re- searchers ... guide to appro- priate American tank strength. Ger- many deploys almost 4,000 top -of- the- line tanks, which are as good or better than the Þnest American tanks....

Ngày tải lên: 12/05/2014, 14:50

... oÝspring if the parentsÕ share of the beneÞts from having chil- dren exceeds their share of the costs. In addition, where conjugal bonds are weak, as they are in sub-Saharan Africa, fathers often do ... eastern Austra- lia is increasingly be- ing sought by real-es- tate developers. Koalas have come to live cheek-by-snout with people moving into coastal areas pop- ulated with the ani-...

Ngày tải lên: 12/05/2014, 15:00

... his visions of the future with a dose of skepticism. In his instant best-seller The Road Ahead, the mega-entrepre- neur ruminates (along with two co-au- thors) about where the computer revo- lution ... properties of brains similar to software in a computer. In everyday life, we assume unthink- ingly the intentional stance when deal- ing with people. The behaviorist move- ment in psych...

Ngày tải lên: 12/05/2014, 15:04

... already been sketched for 1 9-, 3 1-, 3 9- and 75-pas- senger craft) and new federal regula- tions governing the certification and op- eration of tilt-rotors in heavily populat- ed areas. Such regulations, ... Boeing 609 will actu- ally be an updated version of the exper- imental, 1970s-era XV-15, which was a test-bed for a military tilt-rotor known as the V-22 Osprey. The V-22’s de...

Ngày tải lên: 12/05/2014, 15:20

... a “competi- tor” to Microsoft in one arena. Instead of continuing to innovate and beating Microsoft to the punch, howev- er, Netscape has fallen back on indus- trial-age techniques of litigation ... general approba- tion, Collins is not entirely with- out critics. John C. Fletcher, for- mer director of the Center for Biomedical Ethics of the Univer- sity of Virginia and an Episco-...

Ngày tải lên: 12/05/2014, 15:33

... a piece of one of the deadliest murder weapons ever: the 10-kilometer-wide (six- mile-wide) asteroid that wiped out the di- nosaurs 65 million years ago. Kyte found the tiny fossil, about as big ... nuclear burning of inflowing matter would account for the paradoxical brightness of the supersoft sources. But is it really possible? Here we were lucky. Just when we were dis- Supers...

Ngày tải lên: 12/05/2014, 15:53

... sepa- rated thousands of salt-grain-size for- ams from their muddy mass grave us- ing a tiny paintbrush. Her search re- vealed that 55 percent of the species of deep-sea forams had disappeared ... photo of a rela- tive of a Nobel laureate in chemistry ap- parently piloting some kind of flying vehicle. True, sort of. Captain Jean-Luc Picard of the Federation Starship Enterprise...

Ngày tải lên: 12/05/2014, 16:01