scientific american special edition - 2002 vol 12 no2 - the once and future cosmos

... AMERICAN THE ONCE AND FUTURE COSMOS Cone Nebula, captured in April 2002 by the Hubble Space Telescope cosmos the once and futurethe once and future INTRODUCTION 2002 SCIENTIFIC AMERICAN Volume 12 Number ... Energy and Dark Matter the once and future the once and future WWW.SCIAM.COM Display until December 31, 2002 $5.95 U.S. $6.50 CAN...

Ngày tải lên: 12/05/2014, 16:26

... task uses certain brain re- sources; the harder the task, the more of these resources are needed and the more one half of the brain must call on the sub- cortex or the other hemisphere for help. ... the split-brain subject. The left and the right hemispheres easily picked the correct card. The left hand point- ed to the right hemisphere’s choice and the right...

Ngày tải lên: 12/05/2014, 16:26

... called the U.S. Bur- den of Disease and Injury, by the Harvard School of Pub- lic Health, found a staggering 40-year gap between the longest-lived Americans —Asian -American women and the shortest, ... future bene- fits once the huge baby-boomer genera- tion retires. The basic cause of the shortfall resides in the awesome, glacial pressures of demographics. The pay-as...

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... strategies. In the late 1980s the first National Survey of Adoles- cent Males provided some of the only in- formation on the attitudes and sexual be- havior of 1 5- to 19-year-olds. The survey The female ... finan- cially responsible for their proge- ny and the 1995 Clinton adminis- tration effort to design federal pro- grams that include and promote the involvement of...

Ngày tải lên: 12/05/2014, 16:23

... bias be the result of a slight imbal- ance in the war between the X and Y chromosomes? Although the theory is controversial and there is no solid evi- The Key to Masculinity24 SCIENTIFIC AMERICAN ... DIRECTOR 21 2-4 5 1-8 561 tpotratz@sciam.com Timothy W. Whiting SALES DEVELOPMENT MANAGER 21 2-4 5 1-8 228 twhiting@sciam.com Kevin Gentzel 21 2-4 5 1-8 820 kgentze...

Ngày tải lên: 12/05/2014, 16:24

... whether the Tanzanian and Ethiopian fossils were of the same spe- cies; and whether the fossils had been dated correctly. But the most divisive debate con- cerns the issue of how extensively the bipedal ... HUMAN The jawbones in anamensis and chimpanzees are U-shaped The human jaw widens at the back of the mouth In the tibias of anamensis and humans, the top o...

Ngày tải lên: 12/05/2014, 16:27

... I expe- rience severe nitrogen narcosis in the dark underneath the stern of the wreck of the fa- mous Japanese battleship Naga- to. The 216-meter-long flag- ship of the Imperial Navy dur- ing ... whom these bells tolled and why. In the middle of the night, a dead- ly combination of winds and tides had raised the level of the North Sea to the brim of the Netherlands’...

Ngày tải lên: 12/05/2014, 16:24

... DIRECTOR 21 2-4 5 1-8 561 tpotratz@sciam.com Timothy W. Whiting SALES DEVELOPMENT MANAGER 21 2-4 5 1-8 228 twhiting@sciam.com Kevin Gentzel 21 2-4 5 1-8 820 kgentzel@sciam.com Randy James 21 2-4 5 1-8 528 rjames@sciam.com Stuart ... MANAGER 41 5-4 0 3-9 030 fax 41 5-4 0 3-9 033 dsilver@sciam.com DALLAS THE GRIFFITH GROUP 97 2-9 3 1-9 001 fax 97 2-9 3 1-9 074...

Ngày tải lên: 12/05/2014, 16:24

... spacetime. www.sciam.com THE EDGE OF PHYSICS 15 COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. drew together all the work on T-duality, S-duality and string-string duality under the umbrella of M-theory in 11 dimen- sions. ... volts, so much ener- gy and therefore mass—becomes con- centrated in a tiny volume that gravitation- al forces outweigh all others. The result- ing collisions...

Ngày tải lên: 12/05/2014, 16:26

... including the pres- ence or absence of nearby radiation-emitting stars. On the other hand, astronomer David F. Gray of the Univer- sity of Western Ontario in Canada has challenged the existence of the ... Bracewell, Léger and his colleague Jean-Marie Mariotti of the Paris Ob- servatory, as well as some 20 other scientists and engineers. The two of us at the University of A...

Ngày tải lên: 12/05/2014, 16:23