,! ZEPTOV]SE IS ! "N PHYSICI/S H 2GUN US+ = ! SMALLE/ SLICE ( NATURE "E R1*$ BY AN EXP]I;T A R1LM NE> ! ZEPTOMETRE1 #AJ_< METRES1 AB A HUNDR$ BILLION "TS SMALL] ?AN AN ATOM4 ,ON #C ,NOVEMB] #BJBF1 A ,CAMBRIDGE-L$ T1M "W+ ON ! ,L,H,CB EXP]I;T AT ,,C]N ANN\NC$ !Y _H CAU* LA/+ M ?AN F\R DECADES1 HUMAN;Y _H KNOCK$ LIT]ALLY ON ! DOOR ( ! SMALLE/ PLACE 9 ! UNIV]SE4 ,! H1DL9E S.DS L SCI;E FIC;N1 & ! "N DOES TOO B :AT MAKES ! ZEPTOV]SE G5U9ELY /RANGE IS :AT LIVES "!1 & :AT X ALR DID TO Y4 ,! "PICLES T MAY LURK AT ^! SCALES >E ! L1D+ SUSPECTS = D>K MATT] & = ! R1SON MATT] EXI/S AT ALL4 ,& ! DEEPE/ FACT 9 COSMOLOGY IS T ! L>GE/ /RUCTURES 9 ! UNIV]SE E GALAXY1 E CLU/]1 E PLANET 7 SE$$ BY QUANTUM FLUCTUA;NS F> SMALL] ?AN ! ZEPTOV]SE1 9FLAT$ 9TO P]MAN;E 9 ! F/ 9/ANT AF ! ,BIG ,BANG4 ,! SMALLE/ SIGNALS 9 ! _W >E N A FOOTNOTE TO ! COSMOS4 ,9 A PRECISE PHYSICAL S5SE1 !Y >E ! COSMOS1 CAULY4 ,:AT J HAPP5$ AT ,,C]N ,! ANN\NCE;T1 MADE AT A SEM9> AT ,,C]N ON #C ,NOVEMB] #BJBF1 3C]NS A "PICLE CALL$ ! ,BP MESON A B.D PAIR ( A B1UTY QU>K & A D[N ANTIQU>K4 ,B1UTY "PICLES >E PRODUC$ COPI\SLY :5 ! ,,LHC SMA%ES PROTONS TGR1 B A ,BP LIVES = ONLY AB A TRILLION? & A HALF ( A SECOND 2F X 49TEGRATES4 ,ALM ALW X FALLS A"P 9TO ORD9>Y DEBRIS4 ,B ONCE 9 R\K & ! ANTIQU>K ANNIHILATE EA* O!R COMPLETELY1 & ! :OLE "PICLE VANI%ES 9TO A PAIR ( MUONS H1VI] C\S9S ( ! ELECTRON WRITT5 ,BP ;Z_<4 ,T VANI%+ ACT IS S IMPROBABLE T X TOOK =TY-TWO YE>S TO SEE4 ,! HUNT 2GAN 9 #AIHD AT ,CORNELL'S ,,CLEO EXP]I;T & HAS RUN "? E COLLID] G5]A;N S9CE4 ,9 #BJAE A JO9T ANALYSIS BY ,L,H,CB & ! ,,CMS EXP]I;T CLAIM$ F/ EVID;E = ! DECAY1 B FOLL[-UP DATA "? #BJAH FAIL$ TO 3FIRM X ! APP>5T SIGNAL FAD$ BACK 9TO NOISE4 ,! DI6];E ? "T IS ! REBUILT DETECTOR3 ,L,H,CB'S ,UPGRADE ,I1 COMPLET$ 9 ! E>LY #BJBJ;S1 LETS X RECORD COLLI.NS FIVE "TS FA/] ?AN 2F M ?AN A HUNDR$ MILLION PROTON COLLI.NS A SECOND1 A FIREHOSE ( AB F\R T]ABYTES ( DATA P] SECOND :ILE MA*9E-LE>N+ CLASSIFI]S /RIP AWAY ! VA/ BACKGR.D ( LOOK-ALIKE EV5TS4 ,COMB9+ ! NEW #BJBD#BJBE DATA ) "EY?+ RECORD$ 9 #BJAA#BJAH1 ! COLLABORA;N REPORTS EVID;E AT #C4B SIGMA AB A "O-9-#A1EJJ *.E ( 2+ A /ATI/ICAL FLUKE4 ,TWO H"O/ CAV1TS 2L;G 9 ! L1D1 & ? >TICLE W KEEP FLA7+ !M3 "PICLE PHYSICS RES]VES ! ^W 84COV]Y0 = #E SIGMA A "O-9-#C4E-MILLION *.E ( A FLUKE S ? IS =MALLY EVID;E1 N 4COV]Y1 & X HAS N YET BE5 PE]-REVIEW$4 ,& ! M1SUR$ RATE IS 3SI/5T ) ! ,/&>D ,MODEL'S [N PR$IC;N4 ,T S.DS ANTICLIMACTIC1 B X IS ! 9T]E/+ "P EXPLA9$ 2L4 ,H[ SMALL IS ! ZEPTOV]SE1 EXACTLY8 ,! PREFIX ZEPTO- M1NS A FACTOR ( #AJ_< A "O FOLL[$ BY TW5TY-"O Z]OS1 A SEXTILLION? 9 SCI5TIFIC NOTA;N4 ,! ZEPTOV]SE IS ! _W ( ?+S T HAPP5 AT 4T.ES APPROA*+ A ZEPTOMETRE4 ,TO FEEL ": T SITS ON ! LADD] ( SCALES3 HUMAN HAIR @9 #AJ_<;T ;M :AT Y C SEE UNAID$ ATOM @9 #AJ_<;P ;M #AJJ1JJJ SMALL] ?AN A HAIR ATOMIC NUCLEUS @9 #AJ_<;T ;M #AJ1JJJ SMALL] ?AN AN ATOM PROTON @9 #H#AJ_<;V ;M ! NUCLEUS ( HYDROG5 ,,LHC QU>K PROBES @9 #AJ_<;Y ;M NO QU>K SUB/RUCTURE SE5 YET ,,! ,,ZEPTOV]SE ZEPTOMETRE @9 #AJ_< ;M R>E-DECAY PHYSICS FRONTI] @&& F> 2L@& ,PLANCK L5G? @9 #AJ_<;U ;M ": SPACE XF MAY /OP 2+ SPACE ,*RIS ,P>KES1 A ,UNIV]S;Y ( ,MAN*E/] PHYSICI/ ON ! PROJECT1 PUT X Z WELL Z ANY"O3 Z A P]SON IS TO AN ATOM1 AN ATOM IS TO ! ZEPTOV]SE4 ,NOBODY SMA%ES _! WAY D[N TO A ZEPTOMETRE DIRECTLY NO MICROSCOPE RESOLVES X4 ,! TRICK IS SUBTL]4 ,QUANTUM ME*ANICS SAYS E DECAY C PROCE$ "? VIRTUAL "PICLES IES T FLICK] 9 & \ ( EXI/;E = ! DURA;N ( ! REAC;N4 ,! M MASSIVE A VIRTUAL "PICLE1 ! M FLEET+ & %ORT-RANG$ XS 9FLU;E4 ,A DECAY T HAPP5S ONLY ONCE 9 T5 BILLION TRIES IS EXQUISITELY S5SITIVE TO ^? E DECAY IS A MAGNIFY+ GLASS = ! SMALLE/ _W & T IS ! 5TIRE /RATEGY ( ! ZEPTOV]SE PROGRAM4 .DW>E ( ! ,L,H,CB EXP]I;T ! UPGRAD$ EXP]I;T RECORDS OV] A HUNDR$ MILLION COLLI.NS P] SECOND & USES MA*9E LE>N+ TO F9D ! "O-9-T5-BILLION NE$LE "<,,C]N1 ,,CC ,,BY-,,SA #C4J">.> ,! SMALLE/ SIGNALS "E CAUKABLE FAMILY ( M1SURE;TS SIGNALS S FA9T !Y ONCE SEEM$ IMPOSSIBLE TO REGI/] AT ALL4 ,! ZEPTOV]SE N[ HOLDS ! 4T.E RECORD1 B ! CLUB X JO9$ IS WOR? T\R+1 2C E MEMB] R$EF9$ :AT 8UNDETECTABLE0 M1NS4 ,! :ISP] T B5T SPACE"T4 ,9 ,SEPTEMB] #BJAE1 ! TWO ,,LIGO DETECTORS CAUS AWAY4 ,! WAVE /RET*$ & SQUEEZ$ EA* #D-KILOMETRE >M BY AB #AJ_<;X METRES R\ 9 ! OBS]VABLE UNIV]SE 9 GRAVITA;NAL P[] & 7 HE>D Z A RIS+ BLIP LA/+ A FIF? ( A SECOND4 .S AWAY "<,,LIGO_/,CALTE*_/,,MIT1 ,,CC ,,BY-,,SA #D4J">.> .MS ^: MIRRORS MOV$ BY LESS ?AN A ?\S&? ( A PROTON'S WID? "<,CALTE*_/,,MIT_/,,LIGO ,LABORATORY1 PUBLIC DOMA9">.> ,! %ORTE/ "T "E M1SUR$4 ,9 #BJBJ1 PHYSICI/S 9 ,FRANKFURT "TD H[ L;G A PHOTON TAKES TO CROSS A HYDROG5 MOLECULE #BDG ZEPTOSECONDS1 OR #BDG #AJ_< SECONDS4 ,T IS ! %ORTE/ "T 9T]VAL "E RECORD$4 ,TO GIVE X SCALE3 LIY #AIHG1 ?REE "UGR.D DETECTORS ,KAMIOK&E-,,II 9 ,JAPAN1 ,,IMB 9 ,OHIO1 & ! ,BAKSAN OBS]VATORY CAUS TO GET "H1 REL1S$ 9 ! F/ 9/ANTS ( ! SUP]NOVA ,,SN #AIHG;,A1 & !Y >RIV$ H\RS 2F ! EXPLO.N'S LI4 ,TWO DOZ5 "PICLES1 F "O EXPLO.N1 & !Y 3FIRM$ ! CORE-COLLAPSE ME*ANISM & LAUN*$ NEUTR9O A/RONOMY4 ,! DETEC;NS E>N$ A %>E ( ! #BJJB ,NOBEL ,PRIZE4 . ^: COLLAPS+ CORE ANN\NC$ XF TO ,E>? 9 @9#BD NEUTR9OS1 H\RS 2F XS LIRIV$ "<,,NASA_/,,ESA1 PUBLIC DOMA9">.> ,! S WEI<+ ! NEUTR9O BY WAT*+ ! FA9TE/ TAIL ( TRITIUM 2TA DECAY & 3CLUD$ ! "PICLE WEI-NO?+ T TURN$ \ TO MATT] 5ORM\SLY1 Z ! NEXT SEC;N %[S4 ,EA* ( ^! M1SURE;TS WAS1 9 XS ]A1 4MISS$ Z IMPOSSIBLE SPACE"T RIPPLES TOO SMALL1 "TS TOO %ORT1 NEUTR9OS TOO Y ADDRESS4 ,:Y ! SMALLE/ PLACE IS ! BE/ PLACE TO LOOK = NEW PHYSICS ,! ,/&>D ,MODEL ( "PICLE PHYSICS IS >GUABLY ! MO/ SU3ESS;L !ORY "E BUILT & X IS "KN TO 2 9COMPLETE4 ,X _C EXPLA9 :Y "! IS M MATT] ?AN ANTIMATT] "1 X 3TA9S NO "PICLE T CD 2 D>K MATT]1 & X SAYS NO?+ AB GRAV;Y4 ,! MISS+ PIECES M/ EXI/ "S":1 & A C5TURY ( EXP]I;E SAYS NEW PHYSICS %[S UP F/ ": ! OLD PHYSICS IS W1KE/ OR QUIETE/4 ,R>E DECAYS >E ! QUIETE/ PROCESSES 9 ! SUBATOMIC _W1 : IS :Y ,BP ;Z_< IS A 8GOLD5 *ANNEL40 ,9 ! ,/&>D ,MODEL1 ! DECAY C ONLY HAPP5 "? A CLUMSY *A9 ( QUANTUM LOOPS : IS :Y X IS "O-9-T5-BILLION R>E4 ,B T CLUMSI;S IS A F1TURE3 IF ANY UNDISCOV]$ "PICLE EXI/S T C JO9 ! LOOP A H1VI] C\S9 ( ! ,HI7S1 A D>K-MATT] PORTAL "PICLE1 ANY?+ ) A FOO?OLD AT ZEPTOMETRE SCALES X WD OP5 A SIDE ROAD = ! DECAY & %IFT ! RATE4 ,2C ! ,/&>D ,MODEL RATE IS S T9Y & S PRECISELY PR$ICT$1 EV5 A SMALL NEW 3TRIBU;N /&S \ L A C\< 9 A SIL5T ROOM4 ,? IS AL :Y ! ,NOVEMB] RESULT 2+ 3SI/5T ) ! ,/&>D ,MODEL IS N A LETD[N4 ,E M1SURE;T ( ! ZEPTOV]SE IS A F;E L9E3 :AT"E UNDISCOV]$ "PICLES LIVE "! N[ H A TIE KAON DECAYS 9 EXACTLY ? WAY TO 9F] ! *>M QU>K 2F X 0 4COV]$ 9 #AIGD4 ,H[ ! SMALLE/ SIGNALS BUILT ! GALAXIES ,"H IS ! "P T MAKES ! ZEPTOV]SE M ?AN A "PICLE-PHYSICS /ORY1 & X IS N SPECULA;N X IS ! /&>D A3.T ( H[ ! UNIV]SE GOT XS /RUCTURE4 ,QUANTUM ME*ANICS GU>ANTEES T EMPTY SPACE IS N"E TRULY /3 FIELDS FLUCTUATE1 UNAVOIDABLY1 AT E SCALE4 ,9 ! F/ SLIV] ( A SECOND AF ! ,BIG ,BANG1 ! !ORY ( COSMIC 9FLA;N HOLDS T ! UNIV]SE "UW5T A RUNAWAY EXPON5TIAL EXPAN.N & ^? MICROSCOPIC VACUUM FLUCTUA;NS1 EA* F> SMALL] ?AN ANY?+ ! ZEPTOV]SE W "E RESOLVE1 7 /RET*$ TO A/RONOMICAL SIZE & FROZ5 9 Z SLIE EXACTLY :AT WE SEE #CHJ1JJJ YE>S LAT] Z ! COSMIC MICR[AVE BACKGR.D TEMP]ATURE RIPPLES PAT*ES "O "P 9 A HUNDR$ ?\S& W>M] OR COOL] & !Y >E EXACTLY :AT GRAV;Y !N SP5T #AC4H BILLION YE>S AMPLIFY+ 9TO /RUCTURE4 ,! OV]D5SE SPECKS 2CAME ! SE$S T PULL$ 9 GAS1 IGNIT$ ! F/ />S1 & ASSEMBL$ ! GALAXIES4 . LEFT1 9FLAT$ & FROZ5 9TO ! ,,CMB RIPPLES T SE$$ E GALAXY "<,,NASA_/,,WMAP ,SCI;E ,T1M1 PUBLIC DOMA9">.> ,R1D T AG1 2C X IS "O ( ! /RANGE/ E/ABLI%$ FACTS 9 SCI;E3 E GALAXY IS A QUANTUM FLUCTUA;N T GOT BIG4 ,! ,MILKY ,WAY1 ,&ROM$A1 ! HUNDR$ BILLION GALAXIES 2Y ALL ( !M1 & E /> & PLANET 9SIDE !M1 >E FOSSILIZ$ NOISE F ! SMALLE/ 3CEIVABLE SIGNALS1 WRITT5 9TO SPACE"T 2F "! 0 ANY?+ TO WRITE )4 ,:5 A/RONOM]S MAP ! COSMIC WEB1 !Y >E R1D+ A FOSSIL RECORD ( QUANTUM EV5TS4 ,! SMALLE/ SIGNALS 9 ! _W DID N M]ELY 9FLU;E ! GALAXIES "U 9FLA;N1 !Y 2CAME !M4 ,NOR >E ! SMALLE/ PLAY]S D"O SCULPT+ ! L>GE/ /RUCTURES4 ,NEUTR9OS ! LY UNIV]SE S FREELY T !Y SMOO? \ /RUCTURE ON SMALL SCALES3 H[ M* GALAXY-CLU/]+ GETS SUPPRESS$ DEP5DS DIRECTLY ON H[ M* NEUTR9OS WEI<4 ,T NE>LY-Z]O MASS ,,KATR9 IS *AS+ TURNS \ TO 2 A DIAL ON ! %APE ( ! L>GE/ ?+ HUMANS C OBS]VE4 ,! SMALLE/ SIGNAL SETS ! PATT]N ( ! L>GE/ MAP4 ,:AT ZEPTO-SCALE PHYSICS SAYS AB ! FUTURE ( PLANETS & GALAXIES ,! >TICLE'S CLICKBAIT PROMISE ! FATE ( FUTURE PLANETS & GALAXIES HAS AN H"O/ ANSW]1 & X LIVES AT ! SMALLE/ SCALES4 ,?REE ME*ANISMS1 9 9CR1S+ ORD] ( SPECULA;N1 3NECT ZEPTOSCOPIC PHYSICS TO ! DEEP FUTURE3 ,:Y "! >E PLANETS AT ALL4 ,! UNIV]SE 3TA9S MATT] PLANETS1 />S1 U 2C AT "S E>LY 9/ANT "S PROCESS TIPP$ ! MATT]ANTIMATT] BAL.E BY AB "O "P 9 A BILLION4 ,PHYSICS HAS PROV5 ME*ANISMS T C D S* TIPP+ "<,SAKH>OV'S 3DI;NS >E TEXTBOOK">1 B ! ,/&>D ,MODEL'S BUILT-9 IMBAL.E IS F> TOO W1K4 ,:AT"E DID ! JOB M/ 2 A R>E1 SUBTLE1 SYMMETRY-VIOLAT+ PROCESS PRECISELY ! CATEGORY ( PH5OM5ON ! ZEPTOV]SE PROGRAM HUNTS4 ,:5 ,L,H,CB WAT*ES B1UTY "PICLES DECAY "O-9-T5-BILLION "TS1 X IS 9T]ROGAT+ ! CLASS ( PHYSICS T EXPLA9S :Y "! IS A SKY4 ,H[ ! MAP 5DS4 ,TWO M1SUR$ QUANTITIES ( SMALL-SCALE PHYSICS ALR %APE ! 5D /ATE ( ! COSMOS4 ,D>K 5]GY ! PRESSURE A3EL]AT+ ! EXPAN.N 5SURES T GALAXIES 2Y ! ,LOCAL ,GR\P W KEEP REC$+ FA/] UNTIL !Y SLIP P]MAN5TLY 2Y ! R1*ABLE HORIZON2 A/RONOM]S H COMPUT$ T F>-FUTURE OBS]V]S 9 \R M]G$ GALAXY WD SEE AN ESS5TIALLY EMPTY SKY1 UNABLE EV5 9 PR9CIPLE TO M1SURE ! EXPAN.N WE C SEE TD4 ,& PROTONS3 _M EXT5.NS ( ! ,/&>D ,MODEL PR$ICT ! PROTON IS N ET]NAL EXP]I;TS H RUL$ XS LIFE"T ABV @9#AJ;T YE>S = ! FAVOR$ DECAY MODES1 : S.DS P]MAN5T UNTIL Y R1LIZE ! "Q IS DECID$ AT SCALES ( #AJ_< METRES & 2L4 ,IF PROTONS DECAY1 E ATOM 9 E FUTURE PLANET & GALAXY IS P]I%ABLE ON COSMOLOGICAL "TSCALES4 ,IF !Y DON'T1 MATT] IS E6ECTIVELY IMMORTAL4 ,ZEPTO-SCALE PHYSICS IS ! >BIT]4 ,! GR.D 2N "EY?+ LABEL$ SPECULA;N4 ,PRECI.N M1SURE;T ( ! ,HI7S BOSON & TOP QU>K MASSES PUTS ! ELECTR[1K VACUUM NE> ! B.D>Y 2T /ABLE & META/ABLE3 "! IS A R1L " POSSIBIL;Y T ! VACUUM T P]MITS ATOMS IS N ! L[E/-5]GY /ATE1 & CD "S"D TUNNEL TO A DEEP] "O1 REWRIT+ *EMI/RY ACR A LI.D ! 5D ( ? DECADE1 W MULTIPLY ,L,H,CB'S DATASET S"EAL-FOLD 5 TO PU% A #C4B-SIGMA H9T PA/ ! #E-SIGMA 4COV]Y L9E IF ! SIGNAL IS R1L1 & TO %>P5 ! RATE UNTIL ANY DEVIA;N F ! ,/&>D ,MODEL %[S XS TEE?4 ,HYP]-,KAMIOK&E "<,JAPAN1 2G9N+ ? DECADE"> TAKES ! NEUTR9O-SIGNAL BATON F ,SUP]-;,K1 9CLUD+ A F> DEEP] SE>* = PROTON DECAY ! EXPIRY-DATE EXP]I;T = MATT] XF4 ,,LISA1 ! SPACE-BAS$ GRAVITA;NAL-WAVE >RAY PLANN$ = ! #BJCJ;S1 EXT5DS ,,LIGO'S ZEPTO-/RA9 TE*NIQUE TO ! L[-FREQU5CY RUMBLE ( SUP]MASSIVE BLACK HOLES4 ,& ,,CMB-,S#D W R1D ! FOSSIL-FLUCTUA;N RECORD ! SMALLE/ SIGNALS T 2CAME ! L>GE/ /RUCTURES AT NEW PRECI.N4 ,A NEC ^W ( CAU;N ,"EY?+ ABV ! 8CAV1TS0 L9E IS ": 5CYCLOP$IAS E>N _! KEEP4 ,! ,BP ;Z_< RESULT IS EVID;E AT #C4B SIGMA1 ANN\NC$ AT A SEM9>1 N YET "? PE] REVIEW ! #BJAE V].N ( ? CLAIM FAD$ ON LAT] DATA1 & ? "O CD TOO1 ?\< ! 5L>G$ DATASET & UPGRAD$ DETECTOR MAKE T LESS LIKELY4 ,! ^W 8ZEPTOV]SE0 XF IS WEEKS OLD A PHYSICI/S' NICK"N = A FRONTI]1 N AN E/ABLI%$ SCI5TIFIC T]M2 X MAY /ICK OR EVAPORATE4 ,& ! M1SUR$ DECAY RATE S F> AGREES ) ! ,/&>D ,MODEL M1N+ NO NEW "PICLES H BE5 CAURY ! MO/ 9=MA;N ,REF];ES - ,,C]N 8,L,H,CB F9DS EVID;E ( "O-9-T5-BILLION "PICLE DECAY0 "<#C ,NOVEMB] #BJBF"> - ,UNIV]S;Y ( ,CAMBRIDGE 8,PHYSICI/S KNOCK AT ! DOOR ( ! ZEPTOV]SE0 "<#C ,NOVEMB] #BJBF"> - ,,BBC ,NEWS 8,! ZEPTOV]SE3 :AT IS X & H[ W X TRANS=M PHYSICS80 "<,PALLAB , - ,NEW ,SCI5TI/ 8,PHYSICI/S GET F/ GLIMPSE ( ! ZEPTOV]SE F ,,LHC EXP]I;T0 "<,NOV #BJBF"> - ,,9FN ,FRASCATI 8,L,H,CB ID5TIFIES A DECAY T O3URS ONCE 9 T5 BILLION0 "<,NOV #BJBF"> - ,A2OTT ET ;AL4 "<,,LIGO_/,VIRGO"> 8,OBS]VA;N ( ,GRAVITA;NAL ,WAVES F A ,B9>Y ,BLACK ,HOLE ,M]G]10 ,PHYS4 ,REV4 ,LETT4 #AAF1 #JFAAJB "<#BJAF"> - ,GRUNDMANN ET ;AL4 8,ZEPTOSECOND BIR? "T DELAY 9 MOLECUL> PHOTOIONIZA;N10 ,SCI;E "<#BJBJ"> - ,HIRATA ET ;AL4 ,KAMIOK&E-,,II DETEC;N ( ,,SN #AIHG;,A NEUTR9OS1 ,PHYS4 ,REV4 ,LETT4 "<#AIHG"> - ,,KATR9 COLLABORA;N NEUTR9O-MASS B.D1 ,NATURE ,PHYSICS "<#BJBB"> & UPDATES - ,P]LMUTT]1 ,RIESS1 ,S*MIDT 4COV]Y ( A3EL]AT+ EXPAN.N1 ,NOBEL ,PRIZE #BJAA - ,SAKH>OV 8,VIOLA;N ( ,,CP 9V>I.E4440 "<#AIFG">1 B>YOG5ESIS 3DI;NS - ,SUP]-,KAMIOK&E COLLABORA;N PROTON-DECAY LIFE"T LIMITS