Scientific American - September 2018

(singke) #1

2 Scientific American, September 2018


3Z”r§Ü”Z ¡r͔ZD§·33%ððÞדsÖÞÞ ̧d<«›æ¡rÞ® ̈d%æ¡OrÍÞd3rμÜ r¡OrÍäð®sdμæO›”Ґrf¡«§Ü›ëOë3Z”r§Ü”Z ¡r͔ZD§dDf”è”Ò”«§ «{3μ͔§†rÍ%DÜæÍr ¡r͔ZDd§Z»d®%ré?«Íš0›DîDd3æ”Ürƒ€ððd%ré?«Íšd%»?»®ðððƒ“®€×ä»0r͔«f”ZD›Ò
μ«ÒÜD†rμD”fDÜ%ré?«Íšd%»?»dD§fDÜDff”Ü”«§D›¡D”›”§†«}ZrÒ» D§DfD0«ÒܧÜrͧDܔ«§D›0æO›”ZDܔ«§Ò$D”›· D§Df”D§”ÒÜ͔Oæܔ«§ ̧3D›rÒ †Írr¡r§Ü%«»ƒðð®ä€ðƒ» D§Df”D§
%%«»®äÖÞsÖ׀ä25Õ5<1®ä®sð€ ̈äր51ððð®»
0æO›”ZDܔ«§$D”› †Írr¡r§Üªƒðð®ä€ðƒ»2rÜæͧæ§fr›”èrÍDO›r¡D”›Ü«3Z”r§Ü”Z ¡r͔ZD§d0»'»
«ês® ̈d3ܧ$D”§d$D͚D¡d'%"Þ0s ä»Individual Subscription rates: ®ërDÍnƒ ̈» ̈ ̈·73 ̧d D§DfDn€ ̈» ̈ ̈·73 ̧d§ÜrͧDܔ«§D›
n× ̈» ̈ ̈·73 ̧»Institutional Subscription rates: 3Z««›ÒD§f0æO›”Z"”OÍD͔rÒc®ërDÍnsƒ·73 ̧d D§DfDns ̈·73 ̧d§ÜrͧDܔ«§D›n ̈×·73 ̧»
æҔ§rÒÒrÒD§f «››r†rÒØ7§”èrÍҔܔrÒc®ërDÍnÞ ̈ ̈·73 ̧d D§DfDnƒð€·73 ̧d
§ÜrͧDܔ«§D›nƒ®®·73 ̧»0«ÒÜ¡DÒÜrÍc3r§fDffÍrÒÒZD§†rÒÜ«3 Z”r§Ü”Z ¡r͔ZD§d
«êÞ®sÖdD͛D§d«éD€®€ÞÖ»Reprints available: é͔Ür2rμ͔§ÜrμDÍÜ¡r§Üd3Z”r§Ü”Z ¡r͔ZD§d®%ré?«Íš0›DîDd3æ”Ürƒ€ððd
%ré?«Íšd%»?»®ðððƒ“®€×äÕ{Dêc׃ד€×ޓ֮ÞsÕÍrμ͔§ÜÒN3Z” ¡»Z« ¡»3ùUåàŸÈ ́ Ÿ ́ÕùŸàŸyåi 7Î3Î D ́m D ́DmD Ê~ĈĈË ñññžÀÀμμè¹ï›yà ʋÀ‹Ë ÷Ž~žéê~ŽÎ 3y ́m yž®DŸ ̈ ï¹ åDùåïåyàÿSmå†ù ̈Š ̈ ̈®y ́ïÎ`¹®Î
0͔§Ürf”§7»3» » «μë͔†Üeäð®sOë3Z”r§Ü”Z ¡r͔ZD§dDf”è ”Ò”«§«{3μ͔§†rÍ%DÜæÍr ¡r͔ZDd§Z» ››͔†ÜÒÍrÒrÍèrf»


3Z”r§Ü”Z ¡r͔ZD§”ÒμDÍÜ«{3μ͔§†rÍ%DÜæÍrd鐔Z«é§Ò«ÍDÒZ«¡¡rÍZ”D›Ír›Dܔ«§Òé”ܐܐ«æÒD§fÒ«{ÒZ”r§Ü”ZμæO›”ZDܔ«§Ò·¡D§ë«{ܐr¡ZD§Or{«æ§fDÜééé»Òμ͔§†rͧDÜæÍr»Z«¡ØæÒ ̧»3Z”r§Ü”Z ¡r͔ZD§¡D”§ÜD”§ÒDÒÜ͔ZÜ
μ«›”Zë«{rf”Ü«Í”D›”§frμr§fr§Zr”§Írμ«Íܔ§†frèr›«μ¡r§ÜÒ”§Ò Z”r§ZrÜ««æÍÍrDfrÍÒ»3μ͔§†rÍ%DÜæÍrÍr¡D”§Ò§ræÜÍD›é”ܐÍr†DÍfÜ«™æ͔Òf”Zܔ«§D›Z›D”¡Ò”§μæO›”Ґrf¡DμÒD§f”§ÒܔÜæܔ«§D›D}›”Dܔ«§Ò»


00


00


00


Microplastics Threat
Scientific American examines researchers’ efforts to
locate microplastics pollution and to stem the tide of
these particles entering the environment.
Go to http://www.ScientificAmerican.com/sep2018/microplastics

ON THE WEB

4 From the Editor
6 Letters
10 Science Agenda
We ignore racial and ethnic minorities in clinical trials
at our own peril. By  the  Editors
11 Forum
The sex-specific risks of Alzheimer’s point to targeted
interventions for men and women. By  Rebecca  Nebel
12 Advances
Extinct dogs were bone crushers. Fending off art-
eating fungi. A little oil could keep wine yeasts alive.
Toward personalized colon cancer screenings.
24 The Science of Health
The “Right to Try” law raises false hope for the very sick.
By  Claudia  Wallis
27 TechnoFiles
Think you know hearing aids? By  David  Pogue
100 Recommended
Seaweed as a resource. Racing to build an artificial heart.
Astrophysics powers military might. Driverless cars
make good. By  Andrea  Gawrylewski
101 Skeptic
Education and birth control are slowly making the
politics of abortion less relevant. By  Michael  Shermer
102 Anti Gravity
Examining the outsized influence of beavers on America.
By  Steve  Mirsky
103 50, 100 & 150 Years Ago
104 Graphic Science
Even with social media, we have only 150 real friends.
By  Mark  Fischetti and Jen  Christiansen

27

12

10
Free download pdf