,,! ,,my/]i\s ,,box3 ,nucle> ,sci5ce & ,art by ,b]n>d ,keis* ,cont5ts ,! ,my/]i\s ,box #b ,h[ ,old ,is a ,pa9t+8 #aa ,:o ,0 ! ,arti/8 #bd ,o!r ,new ,tools = ,art ,au!ntication #cf ,"o ,my/]y ,solv$ #db ,read+ ,li/ #dd ,unit$ ,/ates ,atomic ,en]gy ,commission ,(fice ( ,in=mation ,s]vices ,libr>y ( ,congress ,catalog ,c>d ,numb]3 #gj-fjfjdj #aigj2 #aigd 7rev47 ,! ,au?or ,illu/ration3 ,b]n>d ,keis* ,dr4 ,b]n>d ,keis* receiv$ 8 ,b4,s4 degree f ,r5ssela] ,polyte*nic ,in/itute & 8 ,ph4,d4 f ,wa%+ton ,univ]sity4 ,he is a ,s5ior ,fell[ ) ! ,division ( ,sponsor$ ,rese>* ( ,c>negie-,mellon ,univ]sity 9 ,pittsburgh4 ,he is pres5tly engag$ 9 a project t deals ) ! applications ( nucle> te*nology to art id5tification4 ,?is is jo9tly sponsor$ by ! ,u4 ,s4 ,atomic ,en]gy ,commission & ! ,national ,gall]y ( ,art4 ,previ\sly he 0 a nucle> rese>* *emi/ ) ! ,phillips ,petroleum ,company & s5ior sci5ti/ at ! ,nucle> ,sci5ce & ,eng9e]+ ,corporation4 ,he has contribut$ articles on art au!ntication to a numb] ( j\rnals4 ,= ! ,,aec1 9 addition to ?is booklet1 he has writt5 ,! ,atomic ,f+]pr9t3 ,neutron ,activation ,analysis1 ,secrets ( ! ,pa/3 ,nucle> ,en]gy ,applications 9 ,art & ,ar*aeology1 & ,lo/ ,worlds3 ,nucle> ,sci5ce & ,ar*aeology4 ,nucle> en]gy is play+ a vital role 9 ! life ( e man1 woman1 & *ild 9 ! ,unit$ ,/ates today4 ,9 ! ye>s ahead x w affect increas+ly all ! peoples ( ! e>?4 ,x is ess5tial t all ,am]icans ga9 an und]/&+ ( ?is vital =ce if !y are to dis*>ge ?\ghtfully _! responsibilities z citiz5s & if !y are to realize fully ! myriad b5efits t nucle> en]gy (f]s !m4 ,! ,unit$ ,/ates ,atomic ,en]gy ,commission provides ?is booklet to help y a*ieve su* und]/&+4 ,! ,cov] ,?is pa9t+1 orig9ally believ$ to be ! "w ( ! ,dut* arti/ ,frans ,hals 7#aehj-afff71 is a fake4 ,measurem5ts ( ! naturally radioactive isotopes1 polonium-#baj & radium-#bbf1 9 lead :ite f ! pa9t prov$ t x 0 no m ?an #ej ye>s old4 ,illu/ration3 ,a ,van ,meeg]5 =g]y ( a ,v]me]4 ,! ,my/]i\s ,box ,! ,new ,j]sey sun 0 high ov]head & ! day 0 hot4 ,! ?ree boys walk+ along a des]t$ /ret* ( bea* didn't m9d because !y 7 b>efoot & 9 _! swimsuits4 ,occasionally !y w\ld da% 9 & out ( ! surf to cool (f4 ,sudd5ly ,m>t9 let out a yell z 8 toe hit some?+ h>d hidd5 9 ! s& at ! wat]'s edge4 ,a mom5t lat] ,bill & ,h>ley 7 help+ ,m>t9 dig out a l>ge wood5 case4 ,x 0 heavy1 well built1 tightly seal$1 & _h =eign words writt5 on x4 8,maybe x's a pirate treasure *e/10 said ,m>t91 :o 0 almo/ eight & _h j read ,treasure ,isl& = ! fir/ "t ! week be=e4 8,y're crazy10 said ,h>ley1 :o1 ne>ly t51 0 mu* old] & wis]4 ,bill1 go+ on twelve1 ?\ght al\d1 8,x mu/ be some?+ wor?:ile2 maybe we c sell x & buy ^? model rockets we want$40 ,! ?ree boys soon f\nd t !y c\ldn't op5 ! box & t x 0 too heavy to drag along ! s& easily4 8,m>t910 said ,bill1 8get ,dad :ile ,h>ley & ,i /& gu>d40 ,two h\rs lat] ! box 0 at _! h\se & ev]yone 9 ! family 0 try+ to read :at 0 writt5 on x4 ,ab\t all t 0 readable 0 a l>ge 8,u0 foll[$ by :at appe>$ to be two numb]s4 ,"s ( ! o!r m>ks look$ l old ,g]man script & !re 0 a date1 #aide4 8,y "k10 said ,bill1 8,i bet t came f a ,_w ,w> ,,ii ,g]man subm>9e t our ,coa/ ,gu>d or ,navy sank40 8,let's op5 x up60 said ,h>ley z ,m>t9 ran to get ! screwdriv]s4 ,inside !y f\nd a ?or\ghly wax$ c>ton t !y _h to cut op54 ,ev]yone held _! brea? z _! fa!r lift$ ! top4 8,no?+ b a bun* ( pictures10 said ,m>t9 :o 0 /ill hop+ = pirate treasure4 8,pa9t+s c be wor? a lot ( money10 said ,dad1 8?\s&s or ev5 millions ( doll>s40 8,well !n we're ri*60 yell$ ,h>ley & ,bill toge!r4 8,n s fa/10 said ,dad4 8,fir/ ( all1 we don't "k if ! pa9t+s are really valuable4 ,also1 x looks l ^! might be "p ( ! art treasures t ! ,nazis /ole f ! c\ntries !y conqu]$ 9 ,_w ,w> ,,ii4 ,maybe someone 0 try+ to get !m by subm>9e to a neutral c\ntry1 l ,arg5t9a1 j be=e ! end ( ! w>1 & ! sub 0 sunk4 ,if !y are real & /ol51 !y'll h to g back to _! rightful own]s4 ,b *e] up1 maybe !re's a rew>d40 8,h[ d we collect x80 ask$ ,bill4 8,if ! ,nazis grabb$ !m1 ar5't !y real = sure80 8,n necess>ily10 ,dad cont9u$4 8,! ,nazis 7 fool$ sometimes by p :o sold !m fakes4 ,!re 0 "o pa9t+ t ,hitl]'s sidekick1 ,gr+1 b\ght t 0 suppos$ to be a #ag? c5tury pa9t+ by ,v]me]1 a ,dut* pa9t]4 ,because ,v]me]'s "w is s valuable1 x's usually impossible to buy "o = any am\nt ( money4 8,v]me] is reg>d$ z a national h]o by ! ,dut*4 ,! matt] 0 inve/igat$ & ! pa9t+ trac$ to ,han ,van ,meeg]51 a mod]n ,dut* pa9t] :o _h only a fair tal5t4 ,:5 ,van ,meeg]5 realiz$ he might be *>g$ ) treason by ! ,dut* = sell+ a ,v]me] to ! ,nazis1 he confess$ t he _h pa9t$ x himself4 ,he also confess$ t he _h pa9t$ o!r =g]ies t fool$ "s ( ! exp]ts & 7 sold = a lot ( money4 8,_m p1 h[ev]1 ?\ght ,van ,meeg]5 0 only ly+ to save himself f ! *>ge ( treason1 & ! :ole ?+ _h to be decid$ by a committee ( sci5tific art exp]ts appo9t$ by a c\rt ( law4 ,us+ ! me?ods t 7 !n available1 ! exp]ts %[$ t ,van ,meeg]5 _h done a rem>kable job ( =g]y & !y 7 conv9c$ t he _h be5 tell+ ! tru? ab\t pa9t+ ^? pictures4 8,at ! "t1 ! important ways ! exp]ts us$ to exam9e a pa9t+ includ$ /udy+ ! "w ) ,x rays1 :i* c\ld %[ ano!r pa9t+ und]nea?1 analyz+ ! pigm5ts 7or color+ mat]ials7 us$ 9 ! pa9t1 & exam9+ ! pa9t+ = c]ta9 signs ( old age4 ,illu/ration3 ,han ,van ,meeg]5 li/5s to ! evid5ce at 8 trial 9 ,am/]dam4 ,9 ! backgr\nd is 8,! ,bless+ ( ,jacob01 :i* 0 sold 9 #aidb z ! "w ( ,v]me]4 ,illu/ration3 ,an au!ntic ,piet] de ,hoo* "w1 8,! ,c>d ,play]s01 pa9t$ 9 ! #ag? c5tury4 ,illu/ration3 ,a =g]y ( a ,piet] de ,hoo* picture pa9t$ 9 ! #bj? c5tury by ,han ,van ,meeg]54 ,illu/ration3 8,head ( ,*ri/0 by ,van ,meeg]54 8,van ,meeg]5 0 well acqua9t$ ) ^! me?ods4 ,he scrap$ ! pa9t f old pa9t+s t w]5't wor? mu* j to get ! canvas & tri$ to use pigm5ts t ,v]me] w\ld h us$4 ,he knew t old pa9t 0 v1 v h>d & impossible to dissolve2 s he clev]ly mix$ a *emical 7ph5ol=maldehyde7 into 8 pa9t1 & ?is h>d5$ into ,bakelite :5 he heat$ ! f9i%$ pa9t+ 9 an ov54 8,= "s ( ! pa9t+s1 ,van ,meeg]5 became c>eless & ! exp]ts did f9d traces ( a mod]n pigm5t 7cobalt blue7 9 ! pa9t4 ,!y also f\nd ! ,bakelite4 ,= "o or m pa9t+s1 ,van ,meeg]5 did s well t1 9 spite ( all ?is evid5ce1 a few p /ill w]5't conv9c$ t ^! pa9t+s 7 pa9t$ by ,van ,meeg]5 & n by ,v]me]40 ,bill1 :o by ?is "t 0 bur/+ ) que/ions1 int]rupt$1 8,y mean !y /ill ar5't sure ab\t "s ( ^? pa9t+s aft] #be ye>s8 ,ar5't !re bett] ways ( tell+ :e!r a pa9t+ is g5u9e or n8 ,y're a sci5ti/4 ,c't sci5ti/s l y d some?+ ab\t x n[80 8,yes1 rec5tly a me?od 0 develop$ to settle j su* a "q4 ,x's bas$ on measurem5ts ( natural radioactivity 9 "o pigm5t t all arti/s us$ hundr$s ( ye>s ago4 ,& ! me?od 0 appli$ to "s ( ! ,van ,meeg]5 pa9t+s includ+ ! be/ "o ( !m all40 8,h[ did x come out80 ask$ ,m>t94 ,illu/ration3 ,an ,x ray ( "p ( ! ,van ,meeg]5 =g]y1 8,*ri/ & ,8 ,disciples at ,emmaus04 ,9 ! :ite circle are traces ( pa9t f ! orig9al pa9t+ t ,van ,meeg]5 scrap$ (f to obta9 ! old canvas4 ,:5 ! pa9t+ 0 believ$ to be a g5u9e ,v]me]1 x 0 sold = ab\t #cjj1jjj4 ,illu/ration3 ,! complete pa9t+4 ,illu/ration3 ,a ,van ,meeg]5 =g]y ( a ,v]me]4 8,h[ does x "w80 ask$ ,h>ley4 8,y mean pa9t+s are radioactive80 exclaim$ ,bill4 8,c we d x to ! pa9t+s we f\nd80 ask$ all ?ree toge!r4 ,h[ ,old ,is a ,pa9t+8 8,"o "q at a "t4 ,i'll tell y h[ ! me?od works & :at x does if y're really int]e/$40 8,we're int]e/$6 ,we're int]e/$60 *orus$ ! boys4 8,9 ! fir/ place1 ?is me?od works only 9 c]ta9 cases ( suspect$ =g]y4 ,ov] ! la/ #ej or #ajj ye>s1 a numb] ( pa9t+s h turn$ up t seem$1 ev5 to ! be/ art exp]ts1 to be sev]al hundr$ ye>s old4 ,"s ( ^! 7 g5u9e1 & "s 7 pa9t$ by =g]s :o c\ld n resi/ ! high prices paid = works ( art4 ,! ,national ,gall]y ( ,art1 9 ,wa%+ton1 ,d4 ,c41 ?9k+ t !re might be a way ( detect+ ^! =g]ies1 gave its support to a gr\p ( sci5ti/s :o develop$ a me?od = ?is purpose4 8,to und]/& h[ ! me?od works1 y ne$ to "k a little ab\t h[ radioactive atoms dis9tegrate to =m atoms ( o!r elem5ts4 ,9 ?is case we are int]e/$ 9 ! natural radioactivity t occurs 9 c]ta9 rocks4 ,z a matt] ( fact1 9 almo/ all rocks 9 ! e>?'s cru/ !re is a c]ta9 small quantity ( uranium40 8,i ?\ght uranium 0 r>e10 int]rupt$ ,bill4 8,x is1 b we're talk+ ab\t su* small quantities t its difficult = sci5ti/s us+ ! mo/ s5sitive equipm5t to detect x4 ,! uranium 9 ! rock decays to ano!r radioactive elem5t & t "o decays to ano!r1 & ano!r1 & ano!r1 & s =?1 9 a s]ies ( elem5ts t results 9 lead1 :i* is n radioactive4 ,9 ?is s]ies are two radioactive elem5ts1 radium & a radioactive isotope ( lead1 t help u to date pa9t+s4 ,to und]/& ?is1 we mu/ fir/ und]/& h[ radioactive elem5ts decay4 8,all radioactive elem5ts h :at is kn[n z a #8half-life'2 t is1 9 a c]ta9 p]iod ( "t1 half ( ! elem5t dis9tegrates to ano!r =m4 ,9 ano!r equal p]iod ( "t1 half ( :at is left dis9tegrates1 & !n half aga91 & s on4 ,9 ! case ( ! uranium1 :i* />ts ! s]ies ,i am describ+1 ! half-life is ov] #d1jjj1jjj1jjj ye>s4 ,because ( its long half-life !re is pl5ty ( uranium ar\nd & w be = a long1 long "t4 ,on ! o!r h&1 radium1 :i* ,i m5tion$ a mom5t ago1 has a half-life ( only #afjj ye>s4 ,9 #afjj ye>s1 half ( x w\ld be gone1 & 9 ano!r #afjj ye>s half ( t w\ld be gone1 & s on4 8,! radioactive lead t we're int]e/$ 9 has a half-life ( only #bb ye>s4 ,?is means t if y />t ) a small quantity ( ?is radioactive isotope ( lead1 :i* is call$ lead-#baj1a !n 9 only a few hundr$ ye>s x w\ld h disappe>$4 ,h[ev]1 9 rock1 :]e !re is uranium1 ! uranium keeps fe$+ ! elem5ts foll[+ x 9 ! s]ies1 s t z fa/ z !y decay !y are reproduc$ by ! elem5t be=e !m40 ,illu/ration3 ,! ,uranium ,s]ies4 ,9 ?is simplifi$ diagram1 ! d\ble v]tical arr[s repres5t alpha radioactivity & ! s+le slant$ arr[s repres5t beta radioactivity4 ,! times %[n on ! arr[s are ! half-lives = ea* /ep4 ,uranium-#bch #d billion ye>s ,?orium-#bcd #bd days ,protoactimum-#bcd #a m9utes ,uranium-#bcd million ye>s ,?orium-#bcj #hj ?\s& ye>s ,radium-#bbf #afjj ye>s ,radon-#bbb #c days ,polonium-#bah #c m9utes ,lead-#bad #bg m9utes ,bismu?-#bad #bj m9utes ,polonium-#bad less ?an "o second ,lead-#baj #bb ye>s ,bismu?-#baj #e days ,polonium-#baj #ach days ,lead-#bjf 7,n ,radioactive7 8,i don't q und]/& h[ t works10 said ,h>ley4 8,:at d y mean #8x keeps fe$+ x'80 8,well1 ?9k ( a s]ies ( lakes connect$ by wat]falls4 ,at ! top1 ! highe/ lake has an enorm\s supply ( wat]4 ,foll[+ ! wat]fall com+ out ( ! lake y f9d a small] lake & !n maybe a m$ium-siz$ lake1 & aft] ano!r wat]fall1 a small] lake1 !n a t9y lake1 & s on4 8,z long z t big lake on top is full or ne>ly full1 all ! o!r lakes1 :e!r !y are small or m$ium-siz$1 w /ill be gett+ wat] z fa/ z x p\rs out4 ,b if y cut (f ! supply ( wat] f ! upp] lake to ! next lake1 !n ! small] lakes w 9 "t run dry4 ,! same ?+ works ) ! radioactivity4 ,9 ?is s]ies head$ by uranium1 z long z uranium is pres5t all ! o!r elem5ts bel[ x are kept suppli$ s t !y don't run out40 8,i und]/& t10 said ,bill1 8b h[ d we use t to date a pa9t+80 8,"o ( ! pigm5ts us$ by arti/s = ov] #bjjj ye>s is kn[n z lead :ite & x is made f lead metal4 ,! lead metal 9 turn is extract$ f a rock call$ lead ore1 9 a process call$ smelt+4 ,! radioactive lead1 ?is lead-#baj t ,i m5tion$1 behaves l ord9>y lead metal & goes along ) x4 8,! radium1 :i* has a fairly long half-life1 doesn't foll[ ! lead metal1 b is remov$ ) o!r wa/e products 9 a mat]ial call$ slag4 ,s9ce ! long]-liv$ ance/or ( ! lead-#baj is remov$1 ! supply ( lead-#baj is cut (f4 7,or we c say t "o ( ! wat]falls is %ut (f47 ,! lead-#baj w !n decay ) its #bb-ye> half-life40 ,illu/ration3 ,! radioactive s]ies t />ts ) uranium is l a s]ies ( lakes connect$ by wat]falls4 ,z long z uranium1 ! big "o on top1 has wat] 9 x1 ! o!rs w be full & ! falls w keep fl[+4 ,b :5 ! fir/ wat]fall is %ut (f1 ! small lakes bel[ x w run dry4 8,i get x10 said ,bill4 8,t means t :5 y take a sample ( old lead :ite pa9t1 !re %\ldn't be any radioactive lead-#baj left40 8,t's "r4 ,b t w\ld only be true if y remov$ all ! radium4 ,actually1 9 ! smelt+ process x's m usual to remove only #ij or #ie ( ! radium4 ,9 t case1 ! lead-#baj w\ld decay only until ! am\nt left w\ld be equal to ! small am\nt ( radium t wasn't remov$4 ,9 effect1 ?is w\ld be l %utt+ (f only "p ( ! wat]fall40 8,s :at d y f9d10 ask$ ,h>ley1 8if y measure ! radioactivity 9 a sample ( lead :ite pa9t80 8,we f9d t if ! pa9t is old1 comp>$ to ! #bb-ye> half-life ( ! lead1 let's say #ajj ye>s old or m1 !n ! am\nt ( radioactivity f ! lead-#baj 9 ! sample ( pa9t w be equal to ! am\nt ( radioactivity f ! radium 9 ! sample4 ,b if ! pa9t is mod]n1 let's say only #bj ye>s old or s1 !n ! am\nt ( radioactivity f ! lead-#baj w be great] ?an ! am\nt ( radioactivity f ! radium40 ,m>t91 :o _h be5 quiet ?r\gh all ?is explanation1 f9ally spoke up4 8,well1 0 x f9ally tri$ out8 ,h[ did x "w80 8,hundr$s ( samples 7 analyz$4 ,^! samples 7 tak5 f pa9t+s ( all ages1 f "s ov] #cjj ye>s old "r up to o!rs only a c\ple ( ye>s old4 ,! old samples always %[$ equal am\nts ( radioactivity f lead-#baj & radium :ile ! mod]n ones always %[$ l>g] am\nts ( radioactivity f lead-#baj ?an f radium4 ,t meant t sci5ti/s _h a way ( def9itely tell+ if a lead :ite pa9t 0 mod]n or n4 8,ev5tually1 ! me?od 0 tri$ on a numb] ( pa9t+s believ$ to be by ,van ,meeg]54 ,sure en\gh1 e "o ( !m %[$ t ! pa9t c\ldn't possibly h be5 m ?an #cj or #dj ye>s old & t ,van ,meeg]5 probably 0 tell+ ! tru? :5 he said t he _h pa9t$ !m4 ,! pa9t+s c]ta9ly 7 n g5u9e ,v]me]s f ! #ag? c5tury40 8,okay1 ,dad10 said ,m>t91 8c we use ! me?od on any ( ! pa9t+s we f\nd8 ,are any ( ^! pa9t+s suppos$ to be old en\gh s t we c use ?is te/80 8,n s fa/4 ,to f9d t out we h to d a lot ( *eck+ fir/40 8,h[ d we g ab\t x80 ask$ ,bill4 8,let's see n[4 ,!re are n9e pa9t+s 9 ! box y f\nd4 ,! fir/ ?+ we %\ld d is take !m d[n to a museum or gall]y & let ! art exp]ts look at !m4 ,s9ce we h a few weeks ( vacation "t left1 :at d y say we take a trip d[n to ,wa%+ton1 ,d4 ,c41 & %[ !m to "s exp]ts at ! ,national ,gall]y ( ,art80 ,ov] ! next few weeks q a few ?+s happ5$ to ! boys & _! pa9t+s4 ,?ree ( !m 7 disc>d$ "r away because !y 7 imm$iately recogniz$ z be+ copies ( no value4 ,two 7 relatively mod]n pa9t+s ) ! signature ,alfr$ ,sisley2 if g5u9e1 !y 7 less ?an #ajj ye>s old4 ,! rema9+ f\r appe>$ to be v old pa9t+s4 ,two ( !m seem$ to correspond to pa9t+s t disappe>$ dur+ ! ,second ,_w ,w>4 ,photographs & ,x rays 7 tak5 & s5t to ! museum 9 ,holl&1 :i* _h own$ ! miss+ pictures1 s t !y c\ld make a prelim9>y exam9ation4 ,illu/ration3 uncaption$ ,radioactivity ( ,lead-#baj ,lead-#baj decay+ ) a half-life ( #bb ye>s4 ,:5 no radium is pres5t !re is almo/ none left aft] #f half-lives or #acb ye>s4 ,radioactivity ( ,radium-#bbf ,ov] ! same p]iod ( "t1 a small am\nt ( radium decays v little because its half-life is ab\t #afjj ye>s4 ,radioactivity ( ,radium #bbf ,radioactivity ( ,lead-#baj ,b :5 lead-#baj decays 9 ! pres5ce ( radium-#bbf1 ! radioactivity ( ! lead-#baj only decreases until x is equal to ! radioactivity ( ! radium4 ,t left two t c\ld h be5 old b ^: orig9s 7 unkn[n4 ,a s]ies ( simple *emical te/s 7 begun on ^! & ! boys wat*$ exp]ts take v small samples ( pa9t = exam9ation "u ! microscope4 ,aft] sev]al mon?s a li/ ( ! pigm5ts pres5t 9 ! pa9t+s 0 prep>$4 ,all ! pigm5ts f\nd 7 typical ( old pa9t+s & ! ord9>y exam9ations & te/s c\ldn't prove :e!r ! works 7 old or n4 ,f9ally1 x 0 decid$ t ! only way to tell if ^! pa9t+s 7 truly old 0 to apply ! te/ t ,dad _h describ$ to ! boys4 ,! boys wat*$ a pa9t+ re/or] remove samples ( ne>ly :ite pa9t "r at ! edge ( ! pa9t+s4 ,he work$ c>efully1 us+ a v %>p scalpel & a /]eo-b9ocul> microscope1 ?r\gh :i* objects appe>$ to be sixty times l>g] ?an !y really 74 ,! sample ( pa9t weigh$ approximately tw5ty-?\s&?s ( a gram4 ,! boys & _! fa!r took ! samples to a radio*emical laboratory :]e !y wat*$ a radio*emi/ d ! requir$ analysis = lead-#baj & radium 9 ! samples4 ,fir/ ! *emi/ dissolv$ ! pa9t 9 acetic acid4 ,?is remov$ ! lead :ite f ! oil & f ! small am\nts ( o!r pigm5ts 9 ! pa9t4 ,! solutions 7 !n heat$ & /irr$ ) a silv] disc hang+ 9 ! liquid4 ,aft] sev]al h\rs ! disc /ill look$ clean1 b ! *emi/ said t a radioactive elem5t1 polonium-#baj1 0 n[ plat$ onto ! silv]4 ,polonium-#baj is a memb] ( ! uranium s]ies foll[+ ! lead-#baj1 & a measurem5t ( its radioactivity w\ld be an accurate measurem5t ( ! radioactivity ( lead-#baj4 ,! silv] discs prep>$ f ! two samples 7 ea* plac$ 9 an in/rum5t call$ an alpha-p>ticle spectromet]4 ,?is in/rum5t is extremely s5sitive & c measure ! v small am\nts ( polonium-#baj prep>$ f ! t9y sample ( pa9t t !y />t$ )4 ,:ile ! in/rum5ts 7 mak+ ! measurem5ts1 :i* took a c\ple ( days1 ! *emi/ turn$ to ! rema9+ solutions & began ! analyses = radium4 ,illu/ration3 ,a pa9t+ be+ sampl$ "u a /]eo-b9ocul> microscope4 ,illu/ration3 ,lead :ite weigh+ tw5ty-?\s&?s ( a gram 7#bj milligrams74 ,?is is ! am\nt ne$$ to measure lead-#baj & radium-#bbf to det]m9e if ! lead :ite is old4 ,9 a s]ies ( *emical /eps1 he purifi$ ! solutions1 remov+ ! lead & o!r mat]ials s t f9ally he _h a small am\nt ( solution t conta9$ little else b ! orig9al radium & a v small am\nt ( b>ium 7an elem5t t he delib]ately add$ & "o :i* is v simil> to radium 9 its *emical prop]ties74 ,by add+ dilute sulfuric acid1 he prep>$ an insoluble mat]ial1 b>ium sulfate1 :i* 0 b>ely visible susp5d$ 9 ! solution4 ,illu/ration3 ,polonium plat+ app>atus4 ,a heat$ solution ( lead :ite 9 acetic acid is /irr$ ) silv] discs = #d to #h h\rs4 ,illu/ration3 ,! disc above appe>s clean aft] removal1 b on its surface x reta9s a m9ute am\nt ( polonium :i* c be measur$4 ,by =c+ ! solution ?r\gh a special ?9 pla/ic filt] hav+ t9y holes1 ! p>ticles ( b>ium sulfate toge!r ) ! radium t _h be5 9 ! solution 7 caught on ! surface ( ! filt]4 ,?is 0 m\nt$ on a solid disc s t x too c\ld be plac$ 9 ! alpha-p>ticle spectromet] = ! measurem5t ( radioactivity f ! radium4 ,two weeks lat] ! results 7 ready4 ,dad1 ! boys1 & "o ( ! exp]ts f ! museum met ) ! *emi/ to discuss !m4 ,= "o ( ! two pa9t+s1 ! polonium-#baj radioactivity 0 ab\t t5 times t ( ! radium activity4 ,! boys 7 disappo9t$ because ?is meant t ! pa9t+ c\ld n h be5 #cjj or #djj ye>s old z x fir/ appe>$ to be4 ,illu/ration3 ,an alpha-p>ticle spectromet] is us$ to measure ! radioactivity ( ! radium & polonium prep>$ f ! lead :ite4 ,illu/ration3 ,a pla/ic disc on :i* is cem5t$ a filt] conta9+ a ne>ly invisible deposit ( b>ium sulfate 7,ba,s,o7 t 8c>ri$0 ! radium4 ,b 9 ! second pa9t+ ! radioactivity f ! polonium-#baj & f ! radium-#bbf 7 j ab\t equal4 ,t meant t ?is pa9t+ 0 at lea/ #ajj ye>s old &1 f its appe>ance1 probably m4 ,! boys 7 excit$4 8,we h a really valuable pa9t+60 said ,m>t94 8,n s fa/1 boys10 caution$ ,dad4 8,we don't "k :o pa9t$ x & we don't "k exactly h[ old x is40 ,! ,gall]y's exp]t 0 happy too4 ,he believ$ t ! second picture 0 a g5u9e ,dut* pa9t+ f ! #ag? c5tury4 ,x 0 a l&scape & ! arti/ might h be5 ,aelb]t ,cuyp4 ,illu/ration3 8,! ,maas at ,dordre*t01 a g5u9e pa9t+ by ,aelb]t ,cuyp4 8,:at d we d n[80 ask$ ,h>ley4 8,h[ c we prove t ! pa9t+ 0 pa9t$ 9 ,holl& 9 ! #ag? c5tury by ,cuyp80 8,!re is a me?od n[ be+ develop$10 said ,dad1 8t c\ld give u t k9d ( in=mation40 8,h[ does x "w80 ,m>t9 ask$4 ,:o ,0 ! ,arti/8 8,d y "k h[ crim9als are caught by us+ f+]pr9ts80 ask$ ,dad4 8,sure we d10 said ,m>t94 8,ea* p]son has a set ( f+]pr9ts t is diff]5t f anyone else's40 ,h>ley spoke up4 8,did ! arti/ leave 8 f+]pr9ts on ! pa9t+s80 8,probably n10 said ,dad4 8,besides1 !y w\ld h be5 wip$ (f long ago4 ,also1 :o kn[s :at ea* arti/'s f+]pr9ts 7 l80 8,!n :at d y mean80 ask$ ,bill4 8,:at ,i mean is1 !re is ano!r k9d ( #8f+]pr9t' t sci5ti/s are j n[ le>n+ to use 9 all k9ds ( id5tification problems4 ,x's n really a f+]pr9t1 b x's j z di/9ctive z a real f+]pr9t4 8,y see1 9 e mat]ial1 no matt] h[ pure y try to make x1 !re are always o!r sub/ances conta9$ 9 x 9 v1 v small quantities1 :i* are !re only by *ance4 ,usually ! p]son mak+ or us+ t mat]ial doesn't ev5 "k !y are !re1 & ! quantities are s small !y don't d any h>m4 ,dur+ ! la/ sev]al ye>s1 sci5ti/s h develop$ extremely s5sitive me?ods ( analysis1 :i* h be5 appli$ to all k9ds ( problems4 8,"o su* me?od is call$ neutron activation analysis4 ,9 ?is me?od ^! small am\nts ( impurities c be detect$ 9 t9y samples ( mat]ial4 ,?is is q important because only v small samples c be tak5 f a preci\s pa9t+ )\t damag+ x4 ,normally1 a sci5ti/ or an art re/or] takes samples t are no bigg] ?an ! head ( a p940 8,h[ c y d any?+ ) a sample t small80 ask$ ,bill4 ,illu/ration3 uncaption$ 8,) neutron activation analysis y c d a great deal4 ,to give y an example ( h[ s5sitive ?is me?od is1 ?9k ( a ba?tub conta9+ #ejj qu>ts ( milk4 ,add #a drop ( an acid conta9+ a speck ( gold dissolv$ 9 x4 ,aft] y mix ! acid & milk ?or\ghly1 y won't be able to tell by look+ at x t any?+ 0 add$4 ,b if y take a ?imble full ( liquid out ( ! ba?tub1 y c easily tell ) neutron activation analysis t gold 0 add$ to ! milk4 8,sci5ti/s call l[ conc5trations ( accid5tal impurities #8trace elem5ts'1 & ! am\nts t are pres5t are measur$ 9 p>ts p] million r ?an p]c5t4 ,"o "p p] million is "o t5-?\s&? ( a p]c5t40 ,bill spoke up aga94 8,s h[ does t make a f+]pr9t1 ,dad80 8,x works ?is way4 ,suppose an arti/ us$ lead :ite 9 sev]al pa9t+s4 ,n[ if ! lead :ite 7 absolutely pure x w\ld conta9 only lead1 c>bon1 oxyg51 & hydrog54 ,b ! lead :ite ! arti/ us$ w\ld also conta9 v small quantities ( o!r elem5ts1 ^! trace elem5ts t ,i spoke (4 ,9 t p>ticul> bat* ( lead :ite1 c]ta9 trace elem5ts w be pres5t 9 a c]ta9 quantity4 ,! k9d & am\nt ( ! trace elem5ts w be pres5t 9 t exact patt]n only 9 t bat* ( lead :ite4 8,n[ suppose y analyze ! lead :ite f sev]al pa9t+s t y "k 7 pa9t$ by t p>ticul> arti/1 & y f9d t !re is silv]1 m]cury1 antimony1 t91 & b>ium 9 e "o ( ! samples4 ,also1 ea* ( ^! elem5ts is always pres5t 9 a c]ta9 conc5tration4 ,suppose also1 t y h a pa9t+ :i* looks l x 0 pa9t$ by t p>ticul> arti/ b y're n q sure4 8,well1 if y take a sample ( lead :ite f t unkn[n pa9t+ & y f9d t ! patt]n ( impurities is ! same z 9 ! pa9t+s y knew 7 g5u9e1 !n ! #8f+]pr9ts' mat*4 ,! *ances ( duplicat+ impurities ( ?is k9d by pure accid5t are extremely small1 j ab\t z small z ! *ances ( f9d+ two p ) ! same f+]pr9ts4 ,t's :y we call ?is a #8f+]pr9t me?od'40 8,t s\nds l a good idea10 said ,h>ley4 8,:o ?\ght x up80 x "o "p p] million 7ppm7 ,a kn[n ,rembr&t4 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x silv] *romium z9c manganese iron cobalt ,unkn[n pa9t+ ,a x x x x x x x x x x x x x x x x x x x x x x x x x x x x silv] *romium z9c manganese iron cobalt ,unkn[n pa9t+ ,b x x x x x x x x x x x x x x x x x x x x x x x x x x x x x silv] *romium z9c manganese iron cobalt ,kn[n =g]y x x x x x x x x x x x x x x x x x x x x x x x x x x x x silv] *romium z9c manganese iron cobalt ,mat* ! patt]ns ( ^! lead :ite 8f+]pr9ts04 ,unkn[n pa9t+ ,a is n a ,rembr&t2 x is by ! same =g] :o pa9t$ ! kn[n =g]y at ! bottom4 ,unkn[n pa9t+ ,b is ei!r by ,rembr&t1 "o ( 8 fell[ citiz5s1 or "o ( 8 /ud5ts us+ ! same pa9t4 8,x 0 ?\ght ( _m times by _m p4 ,b1 x's nev] be5 us$ = id5tify+ pa9t+s4 ,9 #aifd 9 ! ,ne!rl&s1 two sci5ti/s1 nam$ ,h\tman & ,turk/ra1 analyz$ ab\t #dj diff]5t samples ( lead :ite1 #bj ( :i* came f ,dut* & ,flemi% pa9t+s4 ,! re/ 7 samples ( lead :ite n tak5 f pa9t+s b obta9$ directly f ! manufactur]s4 ,!y analyz$ ^! samples = diff]5t elem5ts4 ,^! includ$ silv]1 m]cury1 *romium1 manganese1 t91 antimony1 & a c\ple ( o!rs4 8,!y f\nd t ! conc5trations ( ^! elem5ts 9 ! lead :ite f all ! old ,dut* & ,flemi% pa9t+s 7 v simil>4 ,& ! trace elem5t conc5trations 7 q diff]5t 9 ! mod]n lead :ite samples analyz$ 9 ! same way4 ,at ! "t1 !y presum$ t x 0 because ! lead :ite 9 ! pa9t+s 0 manufactur$ s long ago4 ,!y may h be5 "r to a c]ta9 ext5t4 8,= example1 !y f\nd t 9 all ! old pa9t+s !re 7 f #aj to #cj p>ts p] million ( silv] 9 ! lead :ite1 :ile 9 ! mod]n samples ( ?is pigm5t !re 7 g5]ally less ?an #aj p>ts p] million ( silv]4 ,all ( !m _h be5 pa9t$ be=e ! #ai? c5tury1 & all ! samples ( pure lead :ite 7 manufactur$ dur+ ! latt] "p ( ! #ai? c5tury or dur+ ! #bj? c5tury4 ,!y believ$ t ! reason ! silv] conc5tration 0 l[] 9 ! m mod]n mat]ial 0 because dur+ ! #ai? c5tury1 lead ref9]s 7 do+ a bett] job ( remov+ all ! valuable silv] f lead4 ,illu/ration3 ,silv] conc5trations 9 lead :ite4 ,! conc5trations g5]ally decreas$ aft] ! middle #ahjjs4 ,notice also h[ ! conc5trations 7 v simil> = all ! old] pa9t+s 7be=e #agjj7 :i* 7 ,dut* or ,flemi%4 8,h[ev]1 9 #aifg 9 ,g]many1 two m51 nam$ ,lux & ,braun/e91 discov]$ t 9 "s old pa9t+s produc$ 9 ,italy1 lead :ite also conta9$ l[ quantities ( silv] j l mod]n mat]ial4 ,!y believ$ t ! high] conc5trations ( silv] 9 lead :ite 7 typical ( ,dut* & ,flemi% pa9t]s :ile ! l[] conc5trations 7 typical ( ,italian pa9t+s ( ab\t ! same age4 8,! :ole case is /ill unsettl$ because n en\gh measurem5ts h be5 made to %[ h[ reliable ?is me?od c be4 ,t is1 no "o kn[s if samples ( pa9t f sev]al pa9t+s by "o arti/ w\ld all h ! same patt]n ( impurities 9 ! same pigm5t4 ,x may be t ( ! _m pigm5ts pres5t 9 an arti/'s pa9t+s only a few w be suitable = use 9 ?is #8f+]pr9t+' me?od40 ,illu/ration3 ,qu>tz vials 7"r7 conta9+ samples are seal$ 9 ! alum9um c on ! left4 ,!y are !n bomb>d$ ) neutrons 9 a reactor l ! "o 9 ! picture bel[4 8,x s\nds complicat$10 said ,bill4 8,x is1 & x's go+ to take ye>s ( "w be=e ! me?od is prov51 if x is at all4 ,x may turn out t y c't tell "o arti/ f ano!r1 b only gr\ps ( arti/s l #ag? c5tury ,dut* pa9t]s or #ai? c5tury ,engli% pa9t]s40 8,tell u some?+ ab\t neutron activation analysis10 said ,m>t94 8,h[ d y measure su* small am\nts ( impurities80 8,! be/ way to tell y h[ ?is works is to %[ y4 ,h[ w\ld y boys l to visit a laboratory :]e neutron activation analysis is be+ done80 8,d y h to ask80 said ,h>ley4 8,( c\rse we w\ld60 ,a few weeks lat] x 0 all arrang$4 ,at a laboratory close by a nucle> reactor1 ! boys wat*$ a radio*emi/ place a few specks ( mat]ial inside small qu>tz tubes t 7 !n seal$4 ,! tubes 7 put 9 an alum9um c & plac$ 9 ! nucle> reactor4 ,! c 0 fa/5$ on ! end ( a long pole t 0 !n subm]g$ 9 a deep pool ( wat]4 ,at ! bottom ( ! pool ! boys c\ld see a bright blue gl[4 ,illu/ration3 ,?is type ( nucle> reactor is us$ = neutron activation analysis4 8,s t's :at a nucle> reactor looks l60 said ,bill4 8,yes10 said ,dad4 8,:]e y see ! blue gl[ y c also see r[s ( fuel elem5ts4 ,ea* "o conta9s slugs ( uranium encas$ 9 alum9um4 ,?is is "o ( a numb] ( diff]5t types ( reactors4 ,b e nucle> reactor is arrang$ s t ! uranium atoms divide 7or fission7 _m1 _m times ea* second4 8,:5 ?is happ5s1 heat is produc$ t is c>ri$ away by ! wat]1 & also _m1 _m free neutrons are produc$4 ,^? samples1 plac$ d[n next to ! reactor 9 ! bottom ( ! pool are be+ bomb>d$ by ! neutrons1 & "s ( ! elem5ts 9 ! samples absorb ! neutrons & become radioactive40 ,aft] a :ile ! samples 7 remov$ & c>ri$ back to ! laboratory 9 a lead box4 ,a %ort :ile lat]1 ! radio*emi/ op5$ ! alum9um c1 broke op5 ! qu>tz capsules1 & remov$ ! samples = analysis4 ,! boys wat*$ ! *emi/ m\nt ea* sample on a c>d & take x to a room :]e !re 0 equipm5t = measur+ radioactivity4 ,illu/ration3 ,gamma-ray spectromet]4 ,! sample to be measur$ is plac$ on a /& ov] a gamma-ray detector4 ,! pulse-height analyz] is a device t sorts electrical impulses f ! detector accord+ to ! en]gy ( ! gamma rays caus+ ! impulses4 ,! scre5 displays ! gamma-ray spectrum & ! electric typewrit] automatically types out ! data collect$ :5 ! measurem5t is complete4 ,"o by "o ! samples 7 plac$ inside a %ield consi/+ ( a big pile ( lead bricks4 ,:5 ! heavy door 0 op5$1 ! boys c\ld see a metal c inside ! %ield1 :i* h\s$ a detector 7call$ a li?ium-drift$ g]manium detector7 t measur$ ! gamma rays emitt$ by ! sample4 ,z ea* sample 0 plac$ ne> ! detector ! *emi/ turn$ on a gamma-ray spectromet] to :i* ! detector 0 connect$4 ,a t9y sample ( lead :ite sample is seal$ 9 a qu>tz vial vial :i* is bomb>d$ ) neutrons 9 a reactor4 ,illu/ration3 uncaption$ ,_m ( ! atoms become radioactive1 emitt+ gamma rays4 ,illu/ration3 uncaption$ ,! sample is plac$ 9 a gamma-ray spectromet] & ! gamma rays are sep>at$ accord+ to _! en]gy4 ,illu/ration3 uncaption$ ,gamma-ray spectrum ,copp] ,z9c ,antimony ,lead ,silv] ,height ,antimony ,! location 7en]gy7 ( ea* peak indicates :at is pres5t & ! height indicates h[ mu*6 ,illu/ration3 ,a gamma-ray spectrum z x appe>s on ! scre5 ( a pulse-height analyz]4 ,! gamma-ray peaks are m>k$ ) ! "n ( ! elem5t ^: radioactive isotope emits ! gamma ray2 two = cobalt & z9c & "o = cesium4 ,!re1 on :at look$ l a small television scre51 fla%es ( light appe>$ t gradually =m$ a curve ) _m peaks & valleys4 ,aft] a few m9utes ! spectromet] 0 /opp$ & an electric typewrit] automatically typ$ out r[s & columns ( numb]s4 ,! *emi/ expla9$1 8,?is curve1 :i* y see on ! scre51 is a gamma-ray spectrum & tells u :at elem5ts are 9 ! sample4 ,! typ$-out data give u an accurate measure ( ! %ape ( ! curve on ! scre54 ,by measur+ ! gamma-rays' en]gies we "k :at elem5ts 9 ! sample 7 made radioactive4 ,! height ( ea* gamma-ray peak tells u h[ mu* ( t elem5t is pres5t 9 ! sample4 8,t gives u ! in=mation we ne$ to calculate ! conc5trations ( ! small quantities ( mat]ials 9 our samples4 ,we c d ?is because at ! same "t ,i irradiat$ a set ( /&>ds4 ,/&>ds are mat]ials t are j l ! samples except t !y conta9 kn[n am\nts ( ! impurities ,i am try+ to measure40 ,z ! boys 7 leav+ ! laboratory1 ! *emi/ apologiz$ = n hav+ en\gh "t to expla9 ! activation analysis proc$ure m ?or\ghly1 b he did give ! boys a li/ ( books to read on ! subject ( radioactivity & radioisotopes4#b ,!y ?ank$ him = 8 help4 ,dur+ ! ride home1 !y discuss$ ! pa9t+s t 7 /ill unprov54 8,x's too bad t ! me?od ( activation analysis f+]pr9t+ hasn't be5 fully develop$ yet10 said ,dad4 8,yes10 said ,bill4 8,!n we c\ld prove :e!r or n t la/ old pa9t+ 0 really by ,aelb]t ,cuyp z ! exp]t f ! gall]y believ$4 ,b :at ab\t ^? pa9t+s t we f\nd 9 ! box t 7 n s old80 8,well10 said ,dad1 8if ! activation analysis me?od 7 workable1 we might be able to prove if !y 7 pa9t$ by ,alfr$ ,sisley4 ,mean:ile1 until ! me?od is really develop$ we don't "k if we c d x t way or n40 8,s :at d we d n[80 ask$ ,m>t94 8,we'll h to wait until sci5ti/s c ?or\ghly inve/igate ?is me?od & sev]al o!rs t !y're work+ on40 8,o!r me?ods60 exclaim$ ,bill4 8,:at o!r me?ods80 ,illu/ration3 8,! ,banks ( ! ,oise01 a g5u9e pa9t+ by ,alfr$ ,sisley4 ,o!r ,new ,tools = ,art ,au!ntication 8,!re are sev]al new tools t sci5ti/s are work+ on n[10 said ,dad4 8,^! involve me?ods t h be5 develop$ by sci5ti/s = o!r purposes1 b are n[ be+ explor$ = use 9 au!nticat+ works ( art4 8,= example1 9 ,los ,angeles1 ! c\nty museum pur*as$ an in/rum5t kn[n z a ,sp>k ,s\rce ,mass ,spectromet]4 ,l activation analysis1 ?is in/rum5t w also measure small traces ( impurities1 b !y h j set t up & x w take !m ye>s to explore ! use ( x = ! type ( problem we h be5 discuss+4 8,x-ray diffraction is ano!r me?od t has be5 ar\nd = q a:ile b hasn't be5 us$ mu* = art id5tification until rec5tly4 ,) ,x-ray diffraction1 samples ( pigm5ts c be id5tifi$ by ! patt]n =m$ :5 ,x rays are b5t by pass+ ?r\gh ! sample ( pigm5t40 8,h['s t80 ask$ ,h>ley4 8,!re are #c or #d diff]5t comp\nds ) ab\t ! same *emical composition z lead :ite4 ,*emically1 !y are almo/ impossible to di/+ui%4 ,b ) ,x-ray diffraction1 a *emi/ c easily tell !m ap>t4 ,! hope is t ! type ( lead :ite w indicate h[ x 0 manufactur$4 ,until ! middle ( ! #ai? c5tury1 lead :ite 0 produc$ ma9ly by pack+ /rips ( lead 9 clay pots ) a little v9eg> 9 ! bottom4 ,! clay pots 7 /ack$ 9 a l>ge build+ ) lay]s ( decay+ organic matt] on ! floor4 ,! build+ 0 seal$ = sev]al weeks dur+ :i* "t ! lead corrod$ 9 ! fumes & became cov]$ ) a :ite sub/ance4 ,! :ite sub/ance1 lead :ite1 0 scrap$ (f1 gr\nd1 & wa%$ to make ! pigm5t4 8,b1 9 ! #ai? c5tury1 :5 p began to le>n m ab\t *emi/ry1 !y look$ = fa/] ways ( mak+ lead :ite & "s ( ^! me?ods produc$ a lead :ite ( some:at diff]5t composition4 ,by us+ ,x-ray diffraction1 *emi/s n[ hope t !y c tell h[ ! lead :ite 0 manufactur$4 ,?is may provide ano!r means ( dat+ ! lead :ite 9 a pa9t+40 8,are !re any o!r me?ods80 ask$ ,h>ley4 ,illu/ration3 ,! /ack process = mak+ lead :ite4 ,r[s ( clay pots conta9+ lead & v9eg> are pack$ to ! ceil+ ( ! build+1 & f]m5t+ tanb>k on ! floor produces c>bon dioxide & heat4 ,! fumes ( v9eg> & ! c>bon dioxide corrode ! lead 9 #b to #d mon?s1 & ! corrosion is lead :ite4 8,yes1 isotope mass spectrometry is "o4 ,all lead consi/s ( #d diff]5t isotopes or atoms ( diff]5t weights4 ,?ree ( ^! #d are ! end products ( a radioactive decay *a94 ,dep5d+ ^u ! hi/ory ( ! rock =mation 9 :i* ! lead ore occurr$1 ! relative am\nts ( ! lead isotopes v>y 9 a special way4 ,9 o!r words1 if we "k ! diff]5t am\nts ( lead isotopes 9 ! _w's lead ore deposits1 & we h a sample ( lead :ite f a pa9t+1 we c tell f :i* deposit ! lead1 :i* =m$ ! lead :ite1 came4 ,if1 = example1 we f9d t ! isotope patt]n 9 a sample f a pa9t+ is ! same z 9 lead ore f ,au/ralia1 !n ! pa9t+ c't be v old because lead :ite wasn't produc$ f lead m9$ 9 ,au/ralia until ab\t #ajj ye>s ago40 ,illu/ration3 ,x-ray diffraction patt]ns f ?ree diff]5t lead comp\nds t might occur 9 lead :ite4 ,! middle "o is ! ideal lead :ite produc$ = ov] #bjjj ye>s4 ,:ile "s ( ! bottom comp\nd may be f\nd mix$ ) x1 ! comp\nd %[n at ! top is only a #bj?-c5tury inv5tion4 #d,pb,c,o #b,,pb7,,oh7 ,pb,o #b,pb,c,o ,,pb7,,oh7 ,pb,c,o 8,h[ d y measure lead isotopes80 ask$ ,h>ley4 8,) an in/rum5t call$ a mass spectromet]4 ,?is in/rum5t is capable ( sep>at+ ! lead isotopes4 ,fir/1 ! atoms ( lead 9 ! sample are electrically *>g$ & #8fir$' 9 a beam d[n ! l5g? ( a tube betwe5 ! poles ( a /rong magnet4 ,!re1 ! *>g$ atoms 7or ions7 9 ! beam are deflect$ by diff]5t am\nts accord+ to h[ heavy !y are4 ,?us ! diff]5t isotopes are sep>at$4 ,?is me?od is also /ill be+ /udi$ &1 al?\gh x %[s great promise1 x w be "s "t be=e x c solve problems ( art id5tification4 ,also ! /udy ( ! natural v>iation 9 isotopes ( o!r elem5ts1 su* z sulfur1 is useful = id5tification ( o!r pigm5ts z well4 ,illu/ration3 ,diagram ( a simple mass spectromet]4 ,! ioniz$ atoms ( lead travel 9 a beam at ! same spe$4 ,! heavi] atoms b5d less ?an ! light] ones :5 ! beam passes ! magnet4 ,?us two beams em]ge in/ead ( "o4 ,actually !re are f\r isotopes ( lead s !re w be f\r beams4 ,illu/ration3 8,ago/9a01 a g5u9e pa9t+ by ,jean ,bapti/e ,camille ,corot4 8,ano!r new me?od t %[s great promise has be5 develop$1 b ?is "o is n applicable to ! pa9t+s t y boys f\nd 9 ! box40 8,:y n80 ask$ ,bill4 8,s9ce ! ,second ,_w ,w>1 ! art =g]y bus9ess has be5 gr[+ rapidly4 ,= example1 x has be5 said t ( ! #bjjj pictures t ,corot1 a #ai? c5tury ,fr5*man1 is kn[n to h pa9t$1 m ?an #ejjj ( !m are 9 ! ,unit$ ,/ates4 ,?is may be only a humor\s exagg]ation1 b a l>ge numb] ( =g]ies h be5 produc$ 9 ! la/ sev]al ye>s4 ,^! are usually suppos$ to be pa9t+s t are less ?an #ajj ye>s old4 ,pres5t-day =g]s l to =ge pa9t+s t ar5't v old because x's easi] to get away )4 ,n[ ?is new me?od1 :i* w detect su* rec5t =g]ies1 is bas$ ^u ! pres5ce ( c>bon-#ad1 a radioactive isotope ( c>bon1 9 our atmosph]e & 9 all ?+s t gr[ on our planet4 8,ord9>ily1 c>bon-#ad is produc$ only by cosmic rays1 & its conc5trations 9 ! atmosph]e & 9 gr[+ ?+s w\ld rema9 at a con/ant level4 ,b s9ce ! middle ( ! #aiejs ! te/+ ( nucle> weapons has increas$ ! am\nt ( radioactive c>bon 9 our atmosph]e by q a bit4 ,_m arti/'s mat]ials1 su* z l9se$ oil1 canvas1 pap]1 & s on1 come f plants or animals1 & s w conta9 ! same conc5trations ( c>bon-#ad z ! atmosph]e up to ! "t t ! plant or animal dies4 8,!re=e1 l9se$ oil 7f ! flax plant71 = example1 produc$ dur+ ! la/ few ye>s w h a mu* great] conc5tration ( c>bon-#ad 9 x ?an l9se$ oil produc$ m ?an #bj ye>s ago4 ,sci5ti/s at ,c>negie-,mellon ,univ]sity h %[n t ?is me?od w "w4 ,x is only a matt] ( mak+ ! measurem5ts on ! small samples available f presumably valuable pa9t+s40 ,illu/ration3 ,! *ang+ conc5trations ( c>bon-#ad 9 our atmosph]e4 ,high levels ( c>bon-#ad 9 l9se$ oil & o!r pa9t+ mat]ials w indicate t a "w ( art is only a few ye>s old4 ,c>bon-#ad radioactivity ,old] mat]ials conta9 less z ! c>bon-#ad decays away4 ,9 ?is p]iod1 decrease is due to ! burn+ ( l>ge quantities ( coal & oil z indu/ry grew4 ,?is dilut$ ! newly =m$ c>bon-#ad4 ,increases due to te/+ ( atomic weapons 9 ! atmosph]e4 ,c>bon-#ad produc$ by cosmic rays only ,neutron ,nitrog5 ,c>bon-#ad proton ,c>ri$ d[n by ra9 9 c>bon dioxide 8,!re are also a numb] ( o!r me?ods be+ /udi$ includ+ ! use ( ,messbau] ,effect ,spectroscopy to /udy pigm5ts t conta9 iron1 !rmolum9esc5t dat+ ( pott]y & t]ra-cotta /atu>y1 ,x-ray fluoresc5ce analysis z a g5]al tool1 & neutron autoradiography z a means ( /udy+ ! te*nique ( arti/s4 ,y c read all ab\t !m if y wi%40#c 8,x s\nds l =g]s are go+ to h a t\gh "t 9 ! future10 said ,h>ley4 8,t's "r4 ,x may ev5 turn out t produc+ =g]ies to pass all ^! new te/s w be s difficult & exp5sive t =g]s w /op try+40 ,"o ,my/]y ,solv$ ,a ye> lat] an important lett] arriv$ at ! boys' h\se4 ,dad op5$ x1 read x quickly1 & said1 8,good news1 boys6 ,?is lett] is f ! ,dut* gov]nm5t4 ,rememb] ^? two pa9t+s t we ?\ght might h be5 /ol5 f a ,dut* museum80 8,yes10 said ,bill4 8,well1 x seems t aft] a ye> ( /udy+ !m1 ! ,dut* h decid$ t !y really are ! pa9t+s t 7 /ol540 8,t is good news10 said ,h>ley4 8,at lea/ we "k t two ( ! pa9t+s we f\nd are g5u9e40 8,:at are !y go+ to d ) !m80 ask$ ,m>t94 8,( c\rse1 !y h to g back to _! orig9al own]s4 ,b ?is lett] says t ! ,dut* gov]nm5t wants u to come to ,holl& z _! gue/s z a rew>d = f9d+ ^? pa9t+s40 ,illu/ration3 ,^! two pa9t+s 8,! ,lacemak]0 & 8,! ,smil+ ,girl0 7 ?\ght to h be5 by ,v]me]4 ,a s]ies ( te/s1 includ+ "s ( ^? describ$ 9 ?is booklet1 %[$ t ! pa9t+s are fairly old4 ,h[ev]1 "s ( ! mat]ials us$ are n typical ( ,v]me]1 & ! pictures are n[ ?\ght to h be5 pa9t$ by a foll[] ( ! arti/4 8,t's great60 said ,bill4 8,looks l we're gett+ some?+ out ( f9d+ t box aft] all40 8,yes10 said ,dad4 8,& don't =get ! o!r unid5tifi$ pa9t+s may also be g5u9e4 ,we've prov$ t "o is a fake1 ! exp]ts believe t ?ree ( ! o!rs are copies1 & !n !re are ! two t might be ,sisleys & are only wait+ = a me?od to prove x4 ,& we h "o m t sci5ce manag$ to prove 0 really old4 ,i'm sure t 9 a few ye>s me?ods w be develop$ to tell u exactly :o pa9t$ x4 8,& n[ let's make arrangem5ts = our trip to ,holl&40 ,read+ ,li/ ,ab\t ,atomic ,p[] = ,p1 ,edw>d & ,ru? ,s4 ,radlau]1 ,*ildr5s ,press1 ,*icago1 ,ill9ois #fjfjg1 #aifj1 #dg pp41 #b4ej4 ,grades #e-i4 ,all ,ab\t ! ,atom1 ,ira ,m4 ,freeman1 ,r&om ,h\se1 ,inc41 ,new ,york #ajjbb1 #aiee1 #adf pp41 #b4ej4 ,grades #d-f4 ,atoms at ,y\r ,s]vice1 ,h5ry ,a4 ,dunlap & ,hans ,n4 ,tu*1 ,h>p] & ,r[1 ,publi%]s1 ,new ,york #ajjaf1 #aieg1 #afg pp41 #d4jj4 ,grades #g-i4 ,c>bon-#ad & ,o!r ,sci5ce ,me?ods t ,date ! ,pa/1 ,lynn & ,gray ,poole1 ,mc,graw-,hill ,book ,company1 ,new ,york #ajjcf1 #aifa1 #afj pp41 #c4ie4 ,grades #i-ab4 ,exp]im5ts ) ,atomics 7revis$ edition71 ,nelson ,f4 ,beel] & ,franklyn ,m4 ,branley1 ,cr[ell ,colli] & ,macmillan1 ,inc41 ,new ,york #ajjbb1 #aife1 #afj pp41 #c4ej4 ,grades #e-h4 ,! ,fabul\s ,isotopes3 ,:at ,!y ,are & ,:at ,!y ,d1 ,rob9 ,mc,kown1 ,holiday ,h\se1 ,inc41 ,new ,york #ajjbb1 #aifb1 #ahi pp41 #d4ej4 ,grades #g-aj4 ,inside ! ,atom 7revis$ edition71 ,isaac ,asimov1 ,abel>d-,s*uman1 ,ltd41 ,new ,york #ajjai1 #aiff1 #aig pp41 #d4jj4 ,grades #g-aj4 ,introduc+ ! ,atom1 ,roslyn ,le$s1 ,h>p] & ,r[1 ,publi%]s1 ,new ,york #ajjaf1 #aifg1 #bbd pp41 #c4ie4 ,grades #g-i4 ,our ,fri5d ! ,atom1 ,he9z ,hab]1 ,gold5 ,press1 ,inc41 ,new ,york #ajjbb1 #aieg1 #afe pp41 #d4ie 7out ( pr9t b available ?r\gh libr>ies72 #j4ce 7pap]back7 f ,dell ,publi%+ ,company1 ,inc41 ,new ,york #ajjag4 ,grades #g-i4 ,radioisotopes1 ,john ,h4 ,woodburn1 ,j4 ,b4 ,lipp9cott ,company1 ,philadelphia1 ,p5nsylvania #aiaje1 #aifb1 #abh pp41 #c4ej4 ,grades #g-aj4 ,! ,/ory ( ,atomic ,en]gy1 ,laura ,f]mi1 ,r&om ,h\se1 ,inc41 ,new ,york #ajjbb1 #aifa1 #ahd pp41 #a4ie4 ,grades #g-aa4 ,! ,useful ,atom1 ,william ,r4 ,&]son & ,v]non ,piz]1 ,! ,_w ,publi%+ ,company1 ,new ,york #ajjbb1 #aiff1 #ahe pp41 #e4ge4 ,grades #g-ab4 ,work+ ) ,atoms1 ,otto ,r4 ,fris*1 ,basic ,books1 ,inc41 ,publi%]s1 ,new ,york #ajjaf1 #aife1 #if pp41 #c4ej4 ,grades #i-ab4 ,footnotes #a;,x is call$ ?is because #baj is ! total numb] ( protons & neutrons 9 its nucleus4 #b,see ! read+ li/ on page #dd4 #c,see ,secrets ( ! ,pa/3 ,nucle> ,sci5ce & ,ar*aeology1 :i* is li/$ on ! inside back cov] ( ?is booklet4 ,,photo ,,cr$its ,cov] c\rtesy ,gron+] ,museum voor /ad en ,l&e ,page #e ,yale ,joel1 ,life magaz9e1 copyright ,"t1 ,inc4 #f ,h] ,maje/y ! ,que51 copyright res]v$ #g #h ,ull/e9 ,bild]di5/ #aj ,rijksmuseum1 ,am/]dam #bc ,national ,gall]y ( ,art1 ,wa%+ton1 ,d4 ,c41 ,&rew ,mellon ,collection #ce #dj ,national ,gall]y ( ,art1 ,wa%+ton1 ,d4 ,c41 ,*e/] ,dale ,collection #dc ,national ,gall]y ( ,art1 ,wa%+ton1 ,d4 ,c41 ,&rew ,mellon ,collection ,u4,s4 ,,gov]nm5t ,,pr9t+ ,,(fice3 #aigd--gdg-eef_/ae ,! ,u4 ,s4 ,atomic ,en]gy ,commission publi%es ?is s]ies ( in=mation booklets = ! g5]al public4 ,! booklets are li/$ bel[ by subject category4 ,if y w\ld l to h copies ( ^! booklets1 please write to ! foll[+ address = a booklet price li/3 ,,usaec--,te*nical ,in=mation ,c5t] ,p4 ,o4 ,box #fb ,oak ,ridge1 ,t5nessee #cghcj ,s*ool & public libr>ies may obta9 a complete set ( ! booklets )\t *>ge4 ,^! reque/s mu/ be made on s*ool or libr>y /ation]y4 ,*emi/ry ,,ib-#cjc ,! ,atomic ,f+]pr9t3 ,neutron ,activation ,analysis ,,ib-#cja ,! ,*emi/ry ( ! ,noble ,gases ,,ib-#cjb ,cryog5ics3 ,! ,uncommon ,cold ,,ib-#cjd ,nucle> ,clocks ,,ib-#cjf ,radioisotopes 9 ,indu/ry ,,ib-#cjg ,r>e ,e>?s3 ,! ,frat]nal ,fifte5 ,,ib-#cjh ,syn!tic ,transuranium ,elem5ts ,biology ,,ib-#aja ,animals 9 ,atomic ,rese>* ,,ib-#ajb ,atoms 9 ,agriculture ,,ib-#aje ,! ,g5etic ,effects ( ,radiation ,,ib-#aaj ,pres]v+ ,food ) ,atomic ,en]gy ,,ib-#ajf ,radioisotopes & ,life ,processes ,,ib-#ajg ,radioisotopes 9 ,m$ic9e ,,ib-#aji ,y\r ,body & ,radiation ,! ,environm5t ,,ib-#bja ,! ,atom & ! ,ocean ,,ib-#bjb ,atoms1 ,nature1 & ,man ,,ib-#dad ,nature's ,invisible ,rays ,g5]al ,int]e/ ,,ib-#jji ,atomic ,en]gy & ,y\r ,_w ,,ib-#jaj ,atomic ,pione]s--,book #a3 ,f ,anci5t ,greece to ! #ai? 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