Steven Weinberg $ l' `/ Q1 o7 w' ~+ S; z& z! M' A: ]4 Z; w
Steven Weinberg is in the Department of Physics,0 j1 P2 E; Z9 L3 P+ l+ v1 U$ P
the University of Texas at Austin, Texas 78712, 9 _0 A8 K7 i% vUSA. This essay is based on a commencement talk$ ]$ J: o$ I2 y; e+ A2 N
given by the author at the Science Convocation at7 X/ o7 q5 O0 F- R% Z1 A
McGill University in June 2003.2 r! O' D& [2 [9 V& _8 X* T0 F j
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When I received my undergraduate degree — about a hundred years4 V! K- D7 z7 K9 B k4 m
ago — the physics literature seemed to me a vast, unexplored ocean, " x8 W$ W) J" Oevery part of which I had to chart before beginning any research of my own. How" b# c3 b8 F/ r% r" s& A
could I do anything without knowing everything that had already been done? 2 }: Z' d. |; f8 ~' f) zFortunately, in my first year of graduate school, I had the good luck to fall into the; {$ ] u3 p; G: U6 m8 a; p7 Q$ j
hands of senior physicists who insisted, over my anxious objections, that I must start 2 P/ U8 E% K, p9 Q* I7 [doing research, and pick up what I needed to know as I went along. It was sink or6 u! P/ ~ V% A0 B5 ~7 j
swim. To my surprise, I found that thisworks. I managed to get a quick PhD —4 m3 y; N- y* i
though when I got it I knew almost nothing about physics. But I did learn one big 6 ]( X* g F7 M* Ithing: that no one knows everything, and you don’t have to ., w' ~, y& d0 h+ @2 R k) A% b
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Another lesson to be learned, to continue* H5 x+ _- v+ F/ Z( H
using my oceanographic metaphor, is that " b( z" E6 G p6 K6 Z" Jwhile you are swimming and not sinking you - p! N9 R2 t6 d% Y* E1 L( ]should aim for rough water. When I was 5 f8 M) i) u) W# R' k! u/ vteaching at the Massachusetts Institute of 2 @. [. Q, @( L9 UTechnology in the late 1960s, a student told6 u0 U1 M( e z q. n X4 r5 Z w
me that he wanted to go into general # o2 M3 q# `' J' a3 ^' k# jrelativity rather than the area I was working 6 D3 s4 e. M. ~on, elementary particle physics, because- z- c- L! _9 B& b# }$ ?
the principles of the former were well! Y2 ?, {" y. e0 k, I' ~1 f S
known, while the latter seemed like a mess ! J/ C& D0 t1 E! fto him. It struck me that he had just given % K/ U4 e2 a7 y0 ?1 R: Ya perfectly good reason for doing the opposite.; r0 J6 D7 Q) V
Particle physics was an area where ; V# s* j! H0 _% f/ H$ q( Lcreative work could still be done. It really was: ]8 i4 q, Q; r0 E
a mess in the 1960s, but since that time the & p9 [4 r, ?& Iwork of many theoretical and experimental. r! ?, X8 ^1 o% g& ?6 [
physicists has been able to sort it out, and: b+ _. B$ O; B0 P7 k1 q8 `+ k
put everything (well, almost everything) 6 l; _' \: w; j6 K* X }6 J4 J8 q# ztogether in a beautiful theory known as' l0 `' l5 p# f2 c& \8 }
the standard model.My advice is to go for the % E4 I5 }, X+ Kmesses — that’s where the action is./ a' F( H d/ s Y) Y7 p
9 m' o- O0 {5 kMy third piece of advice is probably the4 j, l8 }. v+ n% r) k/ k% `/ B
hardest to take. It is to forgive yourself for8 ]. g7 @* }4 L5 P# h0 N0 i8 Y
wasting time. Students are only asked to, [$ z9 w: u+ ?: I+ F
solve problems that their professors (unless# c' o, w* [6 T9 J+ K- t
unusually cruel) know to be solvable. In b% V6 P! @5 G+ d6 t. L
addition,it doesn’t matter if the problems are 4 j- x% D2 K3 f* c% I; i0 y# xscientifically important — they have to be . y( x# r F, s) Vsolved to pass the course. But in the real 9 w0 o$ M L! }+ \, f& W0 I9 Qworld, it’s very hard to know which problems ) B8 p( J" _6 Uare important, and you never know whether) L0 V( L8 V% j* L! i7 s
at a given moment in history a problem is 5 ]6 c: u. y: w7 i: Ksolvable. At the beginning of the twentieth$ I! h. f: b r& r* b
century, several leading physicists, including 6 h& W! `0 n. U: ELorentz and Abraham, were trying to work / g% U& j" o/ x! L- }* d) D+ H2 Uout a theory of the electron. This was partly / r* _) y/ ~+ w( F T* q. Y; Iin order to understand why all attempts to }6 f4 h1 G; kdetect effects of Earth’s motion through the 7 v8 u1 x5 k9 G* uether had failed. We now know that * }/ K4 x4 u! K# v8 `) {5 qthey were working on the wrong problem. 1 |0 g: Z3 K) g) }, {& d6 Q' ~6 \At that time, no one could have developed a: E0 x1 ]. j+ [
successful theory of the electron, because 5 c+ m+ L W8 g Qquantum mechanics had not yet been0 M1 j j G" o" Z
discovered. It took the genius of Albert % Y3 r% w! F% ?Einstein in 1905 to realize that the right+ S2 T3 `* g! q' {, i
problem on which to work was the effect 0 D2 M" Y3 x$ k3 `7 \of motion on measurements of space and' Z' B/ o- A: v( P. f7 L* E; e" G
time. This led him to the special theory of* @7 w3 g8 ^( V
relativity. As you will never be sure which ' ]* p2 u4 B: ]. f, Sare the right problems to work on, most7 r' }- u/ a J* J; j% U( }
of the time that you spend in the laboratory) X6 _! R3 c$ y: d0 |
or at your desk will be wasted. If you want ) {; X6 d R3 Ito be creative, then you will have to get used; D3 e# \. Q- N F
to spending most of your time not being+ t- K+ j8 G$ U; _4 J$ [$ j3 m
creative, to being becalmed on the ocean of1 ~; R* v9 H$ a: q
scientific knowledge., o1 p5 T: T) F* G& i6 h
- i# ~, _. V0 \Finally, learn something about the history' h i& ^. ]$ h
of science,or at a minimum the history of your ; a0 F4 c9 L0 z8 F+ Iown branch of science. The least important4 ~7 b" e+ h3 b- j
reason for this is that the history may actually 7 m; k* C' @# Jbe of some use to you in your own scientific3 e( T6 d, g( H
work. For instance, now and then scientists ( j- ^* j& E5 |3 u5 Care hampered by believing one of the oversimplified) o2 {; {! j) d/ G
models of science that have4 T6 o' j+ ?; n- R1 j- J q
been proposed by philosophers from Francis 0 Z) w+ b ?% j- Q0 l: w1 pBacon to Thomas Kuhn and Karl Popper.% O8 W. I5 g5 B$ R4 U3 L
The best antidote to the philosophy of science/ H9 d g2 v( {; ]! W. A* d, T
is a knowledge of the history of science. # S# d' L& h7 Y: o7 t, B8 KMore importantly, the history of science / Y9 V2 v$ @: Z" Z2 y9 q1 n9 Ucan make your work seem more worthwhile 4 f& ]1 C1 N3 I$ oto you. As a scientist, you’re probably not 1 ~1 U8 e- k1 q" }3 D4 k* C# Egoing to get rich. Your friends and relatives + i+ E5 W' H" X5 \probably won’t understand what you’re f% w4 |" \/ ~1 t9 c
doing.And if you work in a field like elementary' U+ m- X1 M1 X! x+ M- Q
particle physics, you won’t even have the # U% R6 A5 [+ U6 ~satisfaction of doing something that is 6 N0 {; {: R6 u w- Z5 M0 Uimmediately useful. But you can get great. ~& y F+ S$ @" G+ ]; ]
satisfaction by recognizing that your work in+ u7 w/ Y* y) x7 A
science is a part of history. # L/ u! ?8 z6 x. S5 D1 X" r. ~! e2 _0 M+ q# X. [
Look back 100 years, to 1903. How . x' s. ] z0 y' y8 a# K- Eimportant is it now who was Prime Minister- r% C( F+ A& s
of Great Britain in 1903, or President of the ( {9 f3 {& g) W, YUnited States? What stands out as really 9 i1 Y% O C' A) Iimportant is that at McGill University,' x* i& G2 C' S- p9 R& C
Ernest Rutherford and Frederick Soddy were$ Q: E. z! y- s2 G2 D
working out the nature of radioactivity. ( ]+ X' u& e! `This work (of course!) had practical applications, ; m) S0 ]& d5 v/ ybut much more important were its7 C% T( h- H( \7 v! k" {
cultural implications. The understanding of * m* N( h9 O$ n" g" \radioactivity allowed physicists to explain6 t; _7 B. b( v3 {+ a, k+ C
how the Sun and Earth’s cores could still be ; H$ l7 V, ]4 G% w6 q8 ?( Ahot after millions of years. In this way, it; t) `7 \* n1 F+ Q
removed the last scientific objection to what 5 U% Z# R3 v% r& r. F7 xmany geologists and paleontologists % V# Z# k/ W, R+ F/ O+ z' sthought was the great age of the Earth and # d! s7 ~7 W& Y( h: o- Z. E5 bthe Sun.After this,Christians and Jews either 8 c2 W6 Y8 W3 K# F' N- H& I7 V- Dhad to give up belief in the literal truth of) m* L- Q) u( t" B" i% s! s3 M" X
the Bible or resign themselves to intellectual8 N1 N: {& L3 ?5 x
irrelevance. This was just one step in a, b4 I2 O# M6 t5 w! S: K
sequence of steps from Galileo through0 e" U% p, Q$ z" _& g9 I- g
Newton and Darwin to the present that,time: m/ P( d! u' v
after time,has weakened the hold of religious 6 R7 i2 Y! T" P9 D% _9 U. ]dogmatism. Reading any newspaper nowadays D+ [0 q0 P( r9 y5 L/ b
is enough to show you that this work 4 r# e% C# `' z. C! L; S. h# V& vis not yet complete. But it is civilizing work, ) f( |# r& w) l& Jof which scientists are able to feel proud.