,,! ,,highe/ ,,aim ,,( ,,! ,,physici/#a ,,pr(essor ,,h5ry ,a4 ,,r[l& ,,sci5ce ,,editorial ,,committee3 ,s4 ,,newcomb1 ,ma!matics2 ,r4 ,s4 ,,woodw>d1 ,me*anics2 ,e4 ,c4 ,,pick]+1 ,a/ronomy2 ,t4 ,c4 ,,m5d5hall1 ,physics2 ,r4 ,h4 ,,?ur/on1 ,eng9e]+2 ,,ira ,,rems51 ,*emi/ry2 ,j4 ,,le ,,conte1 ,geology2 ,w4 ,m4 ,,davis1 ,physiography2 ,,h5ry ,f4 ,,osborn1 ,paleontology2 ,w4 ,k4 ,,brooks1 ,c4 ,,h>t ,,m]riam1 ,zoology2 ,s4 ,h4 ,,scudd]1 ,entomology2 ,c4 ,e4 ,,bessey1 ,n4 ,l4 ,,britton1 ,botany2 ,c4 ,s4 ,,m9ot1 ,embryology1 ,hi/ology2 ,h4 ,p4 ,,b[dit*1 ,physiology2 ,j4 ,s4 ,,bill+s1 ,hygi5e2 ,j4 ,,mcke5 ,,cattell1 ,psy*ology2 ,j4 ,w4 ,,p[ell1 ,an?ropology4 ,,am]ican ,,association ,,= ,,! ,,advancem5t ,,( ,,sci5ce ,,friday1 ,,decemb] #h1 #ahii ,,g5tlem5 ,,& ,,fell[ ,,physici/s ,,( ,,am]ica3 ,we meet to day on an occasion :i* m>ks an epo* 9 ! hi/ory ( physics 9 ,am]ica2 may ! future %[ t x also m>ks an epo* 9 ! hi/ory ( ! sci5ce :i* ?is ,society is organiz$ to cultivate6 ,= we meet "h 9 ! int]e/ ( a sci5ce :i* above all sci5ces deals ) ! f\ndation ( ! ,univ]se1 ) ! con/itution ( matt] f :i* ev]y?+ 9 ! ,univ]se is made & ) ! e!r ( space by :i* alone ! v>i\s portions ( matt] =m+ ! ,univ]se affect ea* o!r ev5 at su* di/ances z we may nev] expect to trav]se1 :atev] ! progress ( our sci5ce 9 ! future4 ,we1 :o h devot$ our lives to ! solution ( problems connect$ ) physics1 n[ meet toge!r to help ea* o!r & to =w>d ! int]e/s ( ! subject :i* we love4 ,a subject :i* appeals mo/ /rongly to ! bett] in/9cts ( our nature & ! problems ( :i* tax our m9ds to ! limit ( _! capacity & sugge/ ! gr&e/ & noble/ ideas ( :i* !y are capable4 ,9 a c\ntry :]e ! doctr9e ( ! equal rights ( man has be5 di/ort$ to mean ! equality ( man 9 o!r respects1 we =m a small & unique body ( m51 a new v>iety ( ! human race z "o ( our greate/ sci5ti/s calls x1 ^: views ( :at con/itutes ! greate/ a*ievem5t 9 life are v diff]5t f ^? ar\nd u4 ,9 ?is respect we =m an ari/ocracy1 n ( weal?1 n ( p$igree1 b ( intellect & ( ideals1 hold+ him 9 ! highe/ respect :o adds ! mo/ to our k or :o /rives aft] x z ! highe/ good4 ,?us we meet toge!r = mutual sympa?y & ! int]*ange ( k1 & may we d s ev] ) appreciation ( ! b5efits to ourselves & possibly to our sci5ce4 ,above all1 let u cultivate ! idea ( ! dignity ( our pursuit s t ?is feel+ may su/a9 u 9 ! mid/ ( a _w :i* gives its highe/ praise1 n to ! inve/igation 9 ! pure e!rial physics :i* our ,society is =m$ to cultivate1 b to "o :o uses x = satisfy+ ! physical r ?an ! intellectual ne$s ( mank9d4 ,he :o makes two blades ( grass gr[ :]e "o grew be=e is ! b5efactor ( mank9d2 b he :o obscurely work$ to f9d ! laws ( su* gr[? is ! intellectual sup]ior z well z ! great] b5efactor ( ! two4 ,h[ /&s our c\ntry1 !n1 9 ?is respect8 ,my answ] mu/ /ill be1 n[1 z x 0 fifte5 ye>s ago1 t mu* ( ! intellect ( ! c\ntry is /ill wa/$ 9 ! pursuit ( s-call$ practical sci5ce :i* m9i/]s to our physical ne$s & b little ?\ght & money is giv5 to ! gr&] portion ( ! subject :i* appeals to our intellect alone4 ,b y\r pres5ce "h gives evid5ce t su* a condition is n to la/ =ev]4 ,ev5 9 ! pa/ we h a few names :om sci5ti/s ?r\gh\t ! _w delight to honor4 ,frankl91 :o almo/ revolutioniz$ ! sci5ce ( electricity by a few simple b pr(\nd exp]im5ts4 ,c\nt ,rum=d1 ^: exp]im5ts almo/ demon/rat$ ! nature ( heat4 ,h5ry1 :o might h done mu* = ! progress ( physics _h he publi%$ m fully ! results ( 8 inve/igations4 ,may]1 ^: simple & +5i\s exp]im5ts h be5 a s\rce ( pleasure & pr(it to _m4 ,?is is ! meag] li/ ( ^? :om dea? all[s me to speak ( & :o h e>n$ m5tion "h by do+ some?+ = ! progress ( our sci5ce4 ,& yet ! record has be5 se>*$ = m ?an a hundr$ ye>s4 ,h[ diff]5t _h ,i />t$ to record ^? :o h made useful & b5eficial inv5tions6 ,b ,i "k1 :5 ,i look 9 ! faces ( ^? be=e me1 :]e ! eag] intellect & high purpose sit en?ron$ on bodies possess+ ! vigor & /r5g? ( y\?1 t ! writ] ( a hundr$ ye>s h5ce c no long] ?r[ su* a reproa* ^u our c\ntry4 ,nor c we blame ^? :o h gone be=e u4 ,! progress ( e sci5ce %[s u ! condition ( its gr[?4 ,v few p]sons1 if isolat$ 9 a semi-civiliz$ l&1 h ei!r ! desire or ! opportunity ( pursu+ ! high] bran*es ( sci5ce4 ,ev5 if !y %\ld be able to d s1 _! influ5ce on _! sci5ce dep5ds ^u :at !y publi% & make kn[n to ! _w4 ,a h]mit philosoph] we c imag9e might make _m useful discov]ies4 ,yet1 if he keeps !m to himself1 he c nev] claim to h b5efit$ ! _w 9 any degree4 ,8 unpubli%$ results are 8 private ga91 b ! _w is no bett] (f until he has made !m kn[n 9 language /rong en\gh to call att5tion to !m & to conv9ce ! _w ( _! tru?4 ,?us1 to enc\rage ! gr[? ( any sci5ce1 ! be/ ?+ we c d is to meet toge!r 9 its int]e/1 to discuss its problems1 to criticize ea* o!r's "w &1 be/ ( all1 to provide means by :i* ! bett] portion ( x may be made kn[n to ! _w4 ,fur!rmore1 let u enc\rage discrim9ation 9 our ?\ghts & "w4 ,let u recognize ! eras :5 great ?\ghts h be5 introduc$ into our subject & let u honor ! great m5 :o introduc$ & prov$ !m correct4 ,let u =ev] reject su* fooli% ideas z ! equality ( mank9d & c>efully give ! great] cr$it to ! great] man4 ,s1 9 *oos+ ! subjects = our inve/igation1 let u1 if possible1 "w ^u ^? subjects :i* w f9ally give u an advanc$ k ( "s great subject4 ,i am aw>e t we _c always d ?is2 our ideas w (t5 fl[ 9 side *annels2 b1 ) ! great problems ( ! ,univ]se be=e u1 we may sometime be able to d our %>e t[>d ! great] end4 ,:at is matt]2 :at is gravitation2 :at is e!r & ! radiation ?r\gh x2 :at is electricity & magnetism2 h[ are ^! connect$ toge!r & :at is _! relation to heat8 ,^! are ! great] problems ( ! univ]se4 ,b _m inf9itely small] problems we mu/ attack & solve be=e we c ev5 guess at ! solution ( ! great] ones4 ,9 our attitude t[>d ^! great] problems h[ d we /& & :at is ! f\ndation ( our k8 ,newton & ! great array ( a/ronom]s :o h succe$$ him h prov$ t1 )9 planet>y di/ances1 matt] attracts all o!rs ) a =ce v>y+ inv]sely z ! squ>e ( ! di/ance4 ,b :at sort ( pro( h we ( ?is law8 ,x is d]iv$ f a/ronomical obs]vations on ! planet>y orbits4 ,x agrees v well )9 ^! imm5se spaces2 b :]e is ! evid5ce t ! law holds = small] di/ances8 ,we measure ! lun> di/ance & ! size ( ! e>? & comp>e ! =ce at t di/ance ) ! =ce ( gravitation on ! e>?'s surface4 ,b to d ?is we mu/ comp>e ! matt] 9 ! e>? ) t 9 ! sun4 ,?is we c only d by assum+ ! law to be prov$4 ,aga91 9 desc5d+ f ! e>?'s gravitation to t ( two small bodies1 z 9 ! ,cav5di% exp]im5t1 we assume ! law to hold & d$uce ! mass ( ! e>? 9 t]ms ( our unit ( mass4 ,h5ce1 :5 we say t ! mass ( ! e>? is #e times t ( an equal volume ( wat] we assume ! law ( gravitation to be t ( ,newton4 ,?us a pro( ( ! law f planet>y d[n to t]re/rial di/ances is physically impossible4 ,aga91 t portion ( ! law :i* says t gravitational attraction is proportional to ! quantity ( matt]1 :i* is ! same z say+ t ! attraction ( "o body by ano!r is n affect$ by ! pres5ce ( a ?ird1 ! feeble pro( t we give by weigh+ bodies 9 a balance 9 diff]5t positions ) respect to ea* o!r _c be accept$ on a l>g] scale4 ,:5 we c te> ! sun into two portions & prove t ei!r ( ! two halves attracts half z mu* z ! :ole1 !n we %all h a pro( wor? m5tion+4 ,!n z to ! relation ( gravitation & "t :at c we say8 ,c we = a mom5t suppose t two bodies mov+ ?r\gh space ) great velocities h _! gravitation unalt]$8 ,i ?9k n4 ,nei!r c we accept ,laplace's pro( t ! =ce ( gravitation acts in/antane\sly ?r\gh space1 = we c readily imag9e "s comp5sat+ features un?\ght ( by ,laplace4 ,h[ little we "k !n ( ?is law :i* has be5 "u obs]vation = two hundr$ ye>s6 ,!n z to matt] itself h[ h our views *ang$ & h[ are !y con/antly *ang+4 ,! r\nd h>d atom ( ,newton :i* ,god alone c\ld break into pieces has become a molecule compos$ ( _m atoms1 & ea* ( ^! small] atoms has become s ela/ic t aft] vibrat+ #ajj1jjj times its amplitude ( vibration is sc>cely dim9i%$4 ,x has become s complicat$ t x c vibrate ) z _m ?\s& notes4 ,we cov] ! atom ) pat*es ( electricity "h & !re & make ( x a sy/em comp>$ ) :i* ! planet>y sy/em1 nay ! univ]se itself1 is simplicity4 ,nay m3 "s ( u ev5 claim ! p[]1 :i* ,newton attribut$ to ,god alone1 ( break+ ! atom into small] pieces ^: size is left to ! imag9ation4 ,:]e1 !n1 is t p]son :o ignorantly sne]s at ! /udy ( matt] z a mat]ial & gross /udy8 ,:]e1 aga91 is t man ) gifts s ,god-l & m9d s elevat$ t he c attack & solve its problem8 ,to all matt] we attribute two prop]ties1 gravitation & in]tia4 ,)\t ^! two matt] _c exi/4 ,! greate/ ( ! natural laws /ates t ! p[] ( gravitational attraction is proportional to ! mass ( ! body4 ,?is law ( ,newton1 almo/ neglect$ 9 ! ?\ghts ( physici/s1 und\bt$ly has va/ import ( ! v deepe/ mean+4 ,%all x mean t all matt] is f9ally con/ruct$ ( uni=m & simil> primordial atoms or c we f9d "s o!r explanation8 ,t ! molecules ( matt] are n r\nd1 we "k f ! facts ( cry/allography & ! action ( matt] 9 rotat+ ! plane ( pol>ization ( light4 ,t portions ( ! molecules & ev5 ( ! atoms are electrically *>g$1 we "k f electrolysis1 ! action ( gases 9 a vacuum tube & f ! ,zeeman effect4 ,t "s ( !m act l little magnets1 we "k f ! magnetic action ( iron1 nickel & cobalt4 ,t !y are ela/ic1 ! spectrum %[s1 & t ! vibrat+ portion c>ries ! electrifi$ *>ge ) x is %[n by ! ,zeeman effect4 ,"h1 !n1 we h made q a />t 9 our problem3 b h[ f> are we f ! complete solution8 ,h[ c we imag9e ! mat]ial ( :i* ord9>y or primordial atoms are made1 deal+ z we d only ) aggregation ( atoms alone8 ,=ev] beyond our sight1 vibrat+ an almo/ inf9ite numb] ( times 9 a second1 mov+ hi!r & yon ) re/less en]gy at all temp]atures beyond ! absolute z]o ( temp]ature1 x is c]ta9ly a wond]ful feat ( human reason & imag9ation t we "k z mu* z we d at pres5t4 ,enc\rag$ by ^! results1 let u n l+] too long 9 _! contemplation b press =w>d to ! new discov]ies :i* await u 9 ! future4 ,!n z to electricity1 ! subtile _s ( ! amb]1 ! demon :o rea*$ out 8 glutton\s arms to draw 9 ! light bodies )9 8 rea*1 ! fluid :i* c\ld run ?r\gh metals ) ! greate/ ease b c\ld be /opp$ by a frail piece ( glass6 ,:]e is x n[8 ,vani%$1 ?r[n on ! wa/e heap ( our disc>d$ !ories to be replac$ by a f> nobl] & exalt$ "o ( action 9 ! e!r ( space4 ,& s we are br\ght to consid] t o!r great entity--! e!r3 fill+ all space )\t limit1 we imag9e ! e!r to be ! only means by :i* two portions ( matt] di/ant f ea* o!r c h any mutual action4 ,by its means we imag9e e atom 9 ! univ]se to be b\nd to e o!r atom by ! =ce ( gravitation & (t5 by ! =ce ( magnetic & electric action1 & we conceive t x alone conveys ! vibratory motion ( ea* atom or molecule out into space to be ev] lo/ 9 endless radiation1 pass+ out into inf9ite space or absorb$ by "s o!r atoms :i* happ5 to be 9 its pa?4 ,by x all electromagnetic en]gy is convey$ f ! feeble attraction ( ! rubb$ amb] ?r\gh ! _m ?\s& horse-p[] convey$ by ! electric wires f ,niag>a to ! mighty ru% ( en]gy always fl[+ f ! ,sun 9 a flood ( radiation4 ,actions feeble & actions mighty f int]molecul> di/ances ?r\gh int]planet>y & int]/ell> di/ances until we rea* ! mighty di/ances :i* b\nd ! ,univ]se--all h _! be+ 9 ?is wondr\s e!r4 ,& yet1 h[ev] wond]ful x may be1 its laws are f> m simple ?an ^? ( matt]4 ,e wave 9 x1 :atev] its l5g? or int5sity1 proce$s onw>ds 9 x accord+ to well kn[n laws1 all ) ! same spe$1 unalt]$ 9 direction f its s\rce 9 electrifi$ matt]1 to ! conf9es ( ! ,univ]se unimpair$ 9 en]gy unless x is di/urb$ by ! pres5ce ( matt]4 ,h[ev] ! waves may cross ea* o!r1 ea* proce$s by itself )\t int]f]5ce ) ! o!rs4 ,s ) reg>d to gravitation1 we h no evid5ce t ! pres5ce ( a ?ird body affects ! mutual attraction ( two o!r bodies1 or t ! pres5ce ( a ?ird quantity ( electricity affects ! mutual attraction ( two o!r quantities4 ,! same = magnetism4 ,= ?is reason ! laws ( gravitation & ( electric & magnetic action includ+ radiation are ! simple/ ( all laws :5 we conf9e !m to a s-call$ vacuum1 b become m & m complicat$ :5 we treat ( !m 9 space conta9+ matt]4 ,subject ! e!r to imm5se electro/atic1 magnetic or gravitational =ces & we f9d absolutely no signs ( its break+ d[n or ev5 ( *ange ( prop]ties4 ,set x into vibration by means ( an int5sely hot body l ! sun & x conveys _m ?\s& horse-p[] = ea* squ>e foot ( surface z quietly & ) app>5tly un*ang$ laws z if x 7 convey+ ! en]gy ( a tall[ dip4 ,aga91 subject a millimet] ( e!r to ! /ress ( _m ?\s&1 nay ev5 a million1 volts & yet we see no signs ( break+ d[n4 ,h5ce ! prop]ties ( ! e!r are ( ideal simplicity & lead to ! simple/ ( natural laws4 ,all =ces :i* act at a di/ance1 always obey ! law ( ! inv]se squ>e ( ! di/ance1 & we h also ! attraction ( any numb] ( p>ts plac$ ne> ea* o!r equal to ! ari?metical sum ( ! attractions :5 ^? p>ts are sep>at$4 ,s also ! simpl] law ( e!rial waves :i* has be5 m5tion$ above4 ,at ! pres5t "t1 ?r\gh ! labors ( ,maxwell supplem5t$ by ^? ( ,h]tz & o!rs1 we h arriv$ at ! great g5]alization t all wave di/urbances 9 ! e!r are electromagnetic 9 _! nature4 ,we "k ( little or no e!rial di/urbance :i* c be set up by ! motion ( matt] alone3 ! matt] mu/ be electrifi$ 9 ord] to h suffici5t hold on ! e!r to communicate its motion to ! e!r4 ,! ,zeeman effect ev5 %[s ?is to be ! case :]e molecules are conc]n$ & :5 ! p]iod ( vibration is imm5sely great4 ,inde$ ! exp]im5t on ! magnetic action ( electric convection %[s ! same ?+4 ,by electrify+ a disc 9 motion x appe>s z if ! disc holds fa/ to ! e!r & drags x ) x1 ?us sett+ up ! peculi> e!rial motion kn[n z magnetism4 ,h we n ano!r case ( a simil> nature :5 a huge gravitational mass l t ( ! e>? revolves on its axis8 ,has n matt] a feeble hold on ! e!r suffici5t to produce ! e>?'s magnetism8 ,b ! exp]im5t ( ,lodge to detect su* an action app>5tly %[$ t x mu/ be v feeble4 ,might n 8 exp]im5t h succe$$ _h he us$ an electrical revolv+ disc8 ,to detect some?+ dep5d5t on ! relative motion ( ! e!r & matt] has be5 & is ! great desire ( physici/s4 ,b we always f9d t1 ) "o possible exception1 !re is always "s comp5sat+ feature :i* r5d]s our ef=ts useless4 ,?is "o exp]im5t is ! ab]ration ( light1 b ev5 "h ,/okes has %[n t x may be expla9$ 9 ei!r ( two ways3 fir/1 t ! e>? moves ?r\gh ! e!r ( space )\t di/urb+ x1 & second1 if x c>ries ! e!r ) x by a k9d ( motion call$ irrotational4 ,ev5 "h1 h[ev]1 ! am\nt ( action probably dep5ds ^u relative motion ( ! lum9\s s\rce to ! recipi5t telescope4 ,s ! pr9ciple ( ,dppl] dep5ds also on ?is relative motion & is indep5d5t ( ! e!r4 ,! result ( ! exp]im5ts ( ,f\cault on ! passage ( light ?r\gh mov+ wat] c no long] be int]pret$ z due to ! p>tial movem5t ( ! e!r ) ! mov+ wat]1 an inf]5ce due to imp]fect !ory alone4 ,! exp]im5t ( ,lodge1 :o attempt$ to set ! e!r 9 motion by a rapidly rotat+ disc1 %[$ no su* result4 ,! exp]im5t ( ,mi*elson to detect ! e!rial w9d1 al?\gh c>ri$ to ! extreme ( accuracy1 also fail$ to detect any relative motion ( ! matt] & ! e!r4 ,b matt] ) an electrical *>ge holds fa/ to ! e!r & moves x 9 ! mann] requir$ = magnetic action4 ,:5 electrifi$ bodies move toge!r ?r\gh space or ) ref]5ce to ea* o!r we c only foll[ _! mutual actions ?r\gh v sl[ & uni=m velocities4 ,:5 !y move ) velocities comp>able ) t ( light1 equal to x or ev5 beyond x1 we calculate _! mutual actions or action on ! e!r only by ! light ( our imag9ation unguid$ by exp]im5t4 ,! conclusions ( ,j4 ,j4 ,?omson1 ,heaviside & ,h]tz are all results ( ! imag9ation & !y all re/ ^u assumptions m or less reasonable b always assumptions4 ,a ma!matical inve/igation always obeys ! law ( ! cons]vation ( k3 we nev] get out m f x ?an we put 94 ,! k may be *ang$ 9 =m1 x may be cle>] & m exactly /at$1 b ! total am\nt ( ! k ( nature giv5 out by ! inve/igation is ! same z we />t$ )4 ,h5ce we c nev] pr$ict ! result 9 ! case ( velocities beyond our rea*1 & su* calculations z ! velocity ( ! ca?ode rays f _! electromagnetic action has a great elem5t ( unc]ta9ty :i* we %\ld d well to rememb]4 ,inde$1 :5 x comes to exact k1 ! limits are f> m circumscrib$4 ,h[ is x1 !n1 t we he> physici/s & o!rs con/antly /at+ :at w happ5 beyond ^! limits8 ,take velocities1 = in/ance1 su* z t ( a mat]ial body mov+ ) ! velocity ( light4 ,!re is no kn[n process by :i* su* a velocity c be obta9$ ev5 ?\gh ! body fell f an inf9ite di/ance ^u ! l>ge/ aggregation ( matt] 9 ! ,univ]se4 ,if we electrify x1 z 9 ! ca?ode rays1 its prop]ties are s *ang$ t ! matt] prop]ties are completely mask$ by ! electromagnetic4 ,x is a common error :i* "y physici/s are apt to fall into to obta9 a law1 a curve or a ma!matical expression = giv5 exp]im5tal limits & !n to apply x to po9ts outside ^? limits4 ,?is is sometimes call$ extrapolation4 ,su* a process1 unless c>efully gu>d$1 ceases to be a reason+ process & becomes "o ( pure imag9ation specially liable to error :5 ! di/ance is too great4 ,b x is n my purpose to ent] into detail4 ,:at ,i h giv5 suffices to %[ h[ little we "k ( ! pr(\nd] que/ions involv$ 9 our subject4 ,x is a curi\s fact t1 hav+ m9ds t5d+ to ! inf9ite1 ) imag9ations unlimit$ by "t & space1 ! limits ( our exact k are v small inde$4 ,9 "t we are limit$ by a few hundr$ or possibly ?\s& ye>s3 inde$ ! limit 9 our sci5ce is f> less ?an ! small] ( ^! p]iods4 ,9 space we h exact k limit$ to portions ( our e>?'s surface & a mile or s bel[ ! surface1 toge!r ) :at little we c le>n f look+ ?r\gh p[]ful telescopes into ! space beyond4 ,9 temp]ature our k ext5ds f ne> ! absolute z]o to t ( ! sun b exact k is f> m limit$4 ,9 pressures we g f ! ,crookes vacuum /ill conta9+ myriads ( fly+ atoms to pressures limit$ by ! /r5g? ( /eel b /ill v m9ute comp>$ ) ! pressures at ! c5t] ( ! e>? & sun1 :]e ! h>de/ /eel w\ld fl[ l ! mo/ limpid wat]4 ,9 velocities we are limit$ to a few miles p] second4 ,9 =ces to possibly #ajj tons to ! squ>e in*4 ,9 me*anical rotations to a few hundr$ times p] second4 ,all ! facts :i* we h consid]$1 ! liability to error 9 :atev] direction we g1 ! infirmity ( our m9ds 9 _! reason+ p[]1 ! fallibility ( witnesses & exp]im5t]s1 lead ! sci5ti/ to be specially sceptical ) ref]5ce to any /atem5t made to him or any s-call$ k :i* may be br\ght to 8 att5tion4 ,! facts & !ories ( our sci5ce are s mu* m c]ta9 ?an ^? ( hi/ory1 ( ! te/imony ( ord9>y p on :i* ! facts ( ord9>y hi/ory or ( legal evid5ce re/1 or ( ! value ( m$ic9es to :i* we tru/ :5 we are ill1 inde$ to ! :ole fabric ( suppos$ tru? by :i* an ord9>y p]son guides 8 belief & ! actions ( 8 life1 t x may seem om9\s & /range if :at ,i h said ( ! imp]fections ( ! k ( physics is correct4 ,h[ %all we regulate our m9ds ) respect to x3 !re is only "o way t ,i "k ( & t is to avoid ! discont9uity ( ! ord9>y1 inde$ ! s-call$ cultivat$ legal m9d4 ,!re is no su* ?+ z absolute tru? & absolute falsehood4 ,! sci5tific m9d %\ld nev] recognize ! p]fect tru? or ! p]fect falsehood ( any suppos$ !ory or obs]vation4 ,x %\ld c>efully weigh ! *ances ( tru? & error & grade ea* 9 its prop] position along ! l9e jo9+ absolute tru? & absolute error4 ,! ord9>y crude m9d has only two comp>tm5ts1 "o = tru? & "o = error2 inde$ ! cont5ts ( ! two comp>tm5ts are sadly mix$ 9 mo/ cases3 ! ideal sci5tific m9d1 h[ev]1 has an inf9ite numb]4 ,ea* !ory or law is 9 its prop] comp>tm5t indicat+ ! probability ( its tru?4 ,z a new fact arrives ! sci5ti/ *anges x f "o comp>tm5t to ano!r s z1 if possible1 to always keep x 9 its prop] relation to tru? & error4 ,?us ! fluid nature ( electricity 0 once 9 a comp>tm5t ne> ! tru?4 ,f>aday's & ,maxwell's rese>*es h n[ caus$ u to move x to a comp>tm5t ne>ly up to t ( absolute error4 ,s ! law ( gravitation )9 planet>y di/ances is f> t[>d absolute tru?1 b may /ill ne$ am5d+ be=e x is advanc$ f>!r 9 t direction4 ,! ideal sci5tific m9d1 !re=e1 mu/ always be held 9 a /ate ( balance :i* ! slighte/ new evid5ce may *ange 9 "o direction or ano!r4 ,x is 9 a con/ant /ate ( skepticism1 kn[+ full well t no?+ is c]ta94 ,x is above all an agno/ic ) respect to all facts & !ories ( sci5ce z well z to all o!r s-call$ beliefs & !ories4 ,yet x w\ld be folly to reason f ?is t we ne$ n guide our life accord+ to ! approa* to k t we possess4 ,nature is inexorable2 x puni%es ! *ild :o unkn[+ly /eps (f a precipice q z sev]ely z ! gr[n sci5ti/ :o /eps ov]1 ) full k ( all ! laws ( fall+ bodies & ! *ances ( _! be+ correct4 ,bo? fall to ! bottom & 9 _! fall obey ! gravitational laws ( inorganic matt]1 slightly modifi$ by ! muscul> contortions ( ! fall+ object b n 9 any degree *ang$ by ! previ\s belief ( ! p]son4 ,natural laws !re probably are1 rigid & un*ang+ ones at t4 ,und]/& !m & !y are b5efic5t3 we c use !m = our purposes & make !m ! slaves ( our desires4 ,misund]/& !m & !y are mon/]s :o may gr9d u to p[d] or cru% u 9 ! du/4 ,no?+ is ask$ ( u z to our belief3 !y act unsw]v+ly & we mu/ und]/& !m or suff] ! consequ5ces4 ,our only c\rse1 !n1 is to act accord+ to ! *ances ( our kn[+ ! "r laws4 ,if we act correctly1 "r2 if we act incorrectly1 we suff]4 ,if we are ignorant we die4 ,:at great] fool1 !n1 ?an he :o /ates t belief is ( no consequ5ce provid$ x is s9c]e4 ,an only *ild1 a belov$ wife1 lies on a b$ ( illness4 ,! physician says t ! disease is mortal2 a m9ute plant call$ a microbe has obta9$ entrance into ! body & is gr[+ at ! exp5se ( its tissues1 =m+ deadly poisons 9 ! blood or de/roy+ "s vital organ4 ,! physician looks on )\t be+ able to d any?+4 ,daily he comes & notes ! fail+ /r5g? ( 8 pati5t & daily ! pati5t goes d[nw>d until he re/s 9 8 grave4 ,b :y has ! physician all[$ ?is8 ,c we d\bt t !re is a rem$y :i* %all kill ! microbe or neutralize its poison8 ,:y1 !n1 has he n us$ x8 ,he is employ$ to cure b has fail$4 ,8 bill we *e]fully pay because he has done 8 be/ & giv5 a *ance ( cure4 ,! answ] is ignorance4 ,! rem$y is yet unkn[n4 ,! physician is wait+ = o!rs to discov] x or p]haps is exp]im5t+ 9 a crude & unsci5tific mann] to f9d x4 ,is n ! inf]5ce correct1 !n1 t ! _w has be5 pay+ ! wrong class ( m58 ,w\ld n ?is ignorance h be5 dispell$ _h ! prop] money be5 us$ 9 ! pa/ to dispel x8 ,su* dea?s "s p consid] an act ( ,god4 ,:at blasphemy to attribute to ,god t :i* is due to our own & our ance/ors' selfi%ness 9 n f\nd+ in/itutions = m$ical rese>* 9 suffici5t numb] & ) suffici5t means to discov] ! tru?4 ,su* dea?s are murd]4 ,?us ! pres5t g5]ation suff]s = ! s9s ( ! pa/ & we die because our ance/ors dissipat$ _! weal? 9 armies & navies1 9 ! fooli% pomp & circum/ance ( society1 & neglect$ to provide u ) a k ( natural laws4 ,9 ?is s5se !y 7 ! murd]]s & robb]s ( future g5]ations ( unborn millions & h made ! _w a *>nel h\se & place ( m\rn+ :]e peace & happ9ess might h be54 ,only _! ignorance ( :at !y 7 do+ c be _! excuse1 b ?is excuse puts !m 9 ! class ( boors & savages :o act accord+ to selfi% desire & n to reason & to ! calls ( duty4 ,let ! pres5t g5]ation take w>n+ t ?is reproa* be n ca/ on x1 = x _c plead ignorance 9 ?is respect4 ,?is illu/ration f ! dep>tm5t ( m$ic9e ,i h giv5 because x appeals to all4 ,b all ! sci5ces are l9k$ toge!r & mu/ advance 9 conc]t4 ,! human body is a *emical & physical problem1 & ^! sci5ces mu/ advance be=e we c conqu] disease4 ,b ! true lov] ( physics ne$s no su* spur to 8 actions4 ,! cure ( disease is a v important object & no?+ c be nobl] ?an a life devot$ to its cure4 ,! aims ( ! physici/1 h[ev]1 are 9 "p purely intellectual2 he /rives to und]/& ! ,univ]se on acc\nt ( ! intellectual pleasure d]iv$ f ! pursuit1 b he is upheld 9 x by ! k t ! /udy ( nature's secrets is ! orda9$ me?od by :i* ! greate/ good & happ9ess %all f9ally come to ! human race4 ,:]e1 !n1 are ! greate/ laboratories ( rese>* 9 ?is city1 9 ?is c\ntry1 nay1 9 ! _w8 ,we see a few mis]able /ructures "h & !re occupi$ by a few />v+ pr(essors :o are nobly /riv+ to d ! be/ ) ! feeble means at _! disposal4 ,b :]e 9 ! _w is ! in/itute ( pure rese>* 9 any dep>tm5t ( sci5ce ) an income ( #ajj1jjj1jjj p> ye>4 ,:]e c ! discov]] 9 pure sci5ce e>n m ?an ! wages ( a day labor] or cook8 ,b #ajj1jjj1jjj p] ye> is b ! price ( an army or a navy design$ to kill o!r p4 ,j ?9k ( x1 t "o p] c5t1 ( ?is sum seems to mo/ p too great to save our *ildr5 & desc5dants f mis]y & ev5 dea?6 ,b ! tw5tie? c5tury is ne>--may we n hope = bett] ?+s be=e its end8 ,may we n hope to influ5ce ! public 9 ?is direction8 ,let u g =w>d1 !n1 ) confid5ce 9 ! dignity ( our pursuit4 ,let u hold our heads high ) a pure consci5ce :ile we seek ! tru?1 & may ! ,am]ican ,physical ,society d its %>e n[ & 9 g5]ations yet to come 9 try+ to unravel ! great problem ( ! con/itution & laws ( ! ,univ]se4 ,,h5ry ,a4 ,,r[l&4 ,footnote #a3 ,address deliv]$ to ! ,physical ,society ( ,am]ica by ! ,presid5t1 at its meet+ 9 ,new ,york1 ,octob] #bh1 #ahii4