Steven Weinberg. c( L0 x; q& F7 R& T4 d" e* J
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Steven Weinberg is in the Department of Physics, 3 m+ {# w2 b F0 Y2 ithe University of Texas at Austin, Texas 78712, - D& q! Q* |4 ` w) m4 w/ @0 o3 p, KUSA. This essay is based on a commencement talk + X6 J2 z5 ~7 F; C! I- \given by the author at the Science Convocation at* t; M/ J' P0 p) v
McGill University in June 2003. ; m; t# C2 O* L) E- O. x W! m, P2 S* ?* dWhen I received my undergraduate degree — about a hundred years 4 U8 ~& k2 M+ V- ~ago — the physics literature seemed to me a vast, unexplored ocean, $ A7 \7 P( }5 _( U8 n: u- B7 E Zevery part of which I had to chart before beginning any research of my own. How+ K4 G! W" D, U- E
could I do anything without knowing everything that had already been done?* w& \7 M7 @4 w! }, A4 e% w
Fortunately, in my first year of graduate school, I had the good luck to fall into the7 J% N0 |- w" M" O& g
hands of senior physicists who insisted, over my anxious objections, that I must start 5 C+ V, N6 o% l: g5 c& {& wdoing research, and pick up what I needed to know as I went along. It was sink or& z0 Z; o, `2 S# c" u
swim. To my surprise, I found that thisworks. I managed to get a quick PhD — 5 R6 H2 ^( h# n/ nthough when I got it I knew almost nothing about physics. But I did learn one big . T* q; u5 ?" w- M1 g% mthing: that no one knows everything, and you don’t have to . o' [" `# n; _& S$ E' h
5 d, j: [! k- I8 b
Another lesson to be learned, to continue ' {4 T* U1 @' ?4 dusing my oceanographic metaphor, is that ; O& ~3 @6 A6 [while you are swimming and not sinking you7 R' ?( L' [# i7 O6 ]. s
should aim for rough water. When I was $ }- V* w; P$ k( H Y ~teaching at the Massachusetts Institute of : v; D- e. e- U! Z* `" uTechnology in the late 1960s, a student told# w7 l! I }( D; N3 w& i1 Y \
me that he wanted to go into general 9 R5 S0 E- s5 b3 r" C& Brelativity rather than the area I was working% N( w. I1 d# h* ~/ y* e
on, elementary particle physics, because/ B$ O5 }! z% l- R
the principles of the former were well 8 D+ ]) `; r) G. N& l7 o Qknown, while the latter seemed like a mess( h1 l6 t, W7 X
to him. It struck me that he had just given! V' y% D% s# w: P! p# [
a perfectly good reason for doing the opposite.9 ^/ `) E1 S5 W8 w/ @ T& G. q
Particle physics was an area where% v7 a3 K h: V, D1 V
creative work could still be done. It really was ) `, B7 X0 I6 Z* g) l- g4 `a mess in the 1960s, but since that time the 9 e' B5 f. B$ L- W* V4 y e( `work of many theoretical and experimental5 R6 c/ b; P+ Z$ n/ H$ Y) v {! }
physicists has been able to sort it out, and " r* I$ |2 f5 a4 h$ ?* yput everything (well, almost everything)/ \ T) I* s A* q- I+ S
together in a beautiful theory known as & r0 a5 R: f0 L$ \the standard model.My advice is to go for the . V* y7 @+ l5 ~2 lmesses — that’s where the action is. & z) M7 v% Z6 _/ L3 f% q 6 Y4 ^$ {7 a) U0 s9 }+ DMy third piece of advice is probably the. \& s2 k5 ?; I) D) E% l
hardest to take. It is to forgive yourself for% x% v% S$ r" l6 E9 f5 D! N
wasting time. Students are only asked to3 c* Z% N6 p: Y+ z& z6 S; X
solve problems that their professors (unless) K+ e5 @8 C( P9 P
unusually cruel) know to be solvable. In2 H; L" E$ B% Y5 z6 u
addition,it doesn’t matter if the problems are # X* s5 J2 l) K' E9 @2 Zscientifically important — they have to be % n2 ]# N: f g1 ~solved to pass the course. But in the real ) f* o& ~ I! Hworld, it’s very hard to know which problems & y# e1 t. v. ~) _6 [2 K# Dare important, and you never know whether ' M+ L' {3 c: ^+ V/ ~6 sat a given moment in history a problem is 0 w- q0 E% Z4 O8 V9 h% O! ?7 R+ A8 Z4 |solvable. At the beginning of the twentieth8 q/ i' N& C/ ?" Z* ^* s5 X5 g
century, several leading physicists, including* d& o5 p% h$ L5 m: [
Lorentz and Abraham, were trying to work; c3 b9 B$ F- A4 l) b
out a theory of the electron. This was partly1 d7 c0 z7 }; e
in order to understand why all attempts to$ ]8 x0 U8 ]; L, b! G9 n" V
detect effects of Earth’s motion through the `4 Z6 O* t4 U) y7 r" ^ether had failed. We now know that8 f$ ^, z4 N' z* `
they were working on the wrong problem.: u8 Q: L. \* @1 G! I+ Q& B0 r
At that time, no one could have developed a # ~+ P7 E3 @8 ?$ W {4 ]successful theory of the electron, because) Y# b& O# W8 U( ]0 j
quantum mechanics had not yet been# k6 H& T: `+ ^
discovered. It took the genius of Albert 3 `, U) y7 _5 n n6 ZEinstein in 1905 to realize that the right , b* c' x3 Z& Z) i. [problem on which to work was the effect 1 \- t$ Y% f( U7 V! x5 V( Vof motion on measurements of space and) Y7 U% {: J5 I$ r% `
time. This led him to the special theory of `( |( C9 u9 X. N9 O
relativity. As you will never be sure which0 u v: b# P( k7 J
are the right problems to work on, most 2 M7 H& m% o" J5 O4 o \of the time that you spend in the laboratory; c: q& y- }, n3 M4 p( X
or at your desk will be wasted. If you want5 R$ x5 W3 q3 y- B. {9 R' V
to be creative, then you will have to get used ) a' ^: A& l' h* @& M3 w# cto spending most of your time not being- ?) w ?: ~/ c3 W. X
creative, to being becalmed on the ocean of 8 f" h. ~' P2 u( d, \- Cscientific knowledge. - |( A; M0 Q* b) \ 3 B; M( f- d8 u) v: E" e! FFinally, learn something about the history / @' J1 b' p' v6 u8 Cof science,or at a minimum the history of your9 w# _; \1 t) h: n# R# H7 w8 ^
own branch of science. The least important* S2 ?* E) v. O( h
reason for this is that the history may actually# V% x6 m. k7 W
be of some use to you in your own scientific $ T& d l$ b) o; \work. For instance, now and then scientists: f: e* p. F A3 z0 [6 t- s( h
are hampered by believing one of the oversimplified! B9 l# r+ }& T/ }! w. j% S' f: w. @
models of science that have0 V2 G0 c1 {; H* A5 O
been proposed by philosophers from Francis 7 q) O' W( ]# C( O v4 kBacon to Thomas Kuhn and Karl Popper.9 e6 f0 ] R0 k( A! _) h/ z' I
The best antidote to the philosophy of science9 w( ?" S+ d2 M3 E2 b0 M
is a knowledge of the history of science.! t5 z: e5 k+ Y
More importantly, the history of science 2 {# t4 T3 y% b# U, i3 Gcan make your work seem more worthwhile! R w+ y" ^; A3 X% l
to you. As a scientist, you’re probably not 9 ?8 X2 q& I1 i) {% @3 m1 L, U! f3 xgoing to get rich. Your friends and relatives5 P" @9 C6 M3 n; ^, Z9 t1 K
probably won’t understand what you’re2 a' z y0 S: p0 ]3 r
doing.And if you work in a field like elementary ~+ h. Q4 e( S h' k b* I
particle physics, you won’t even have the* ~" ]9 X( e7 P+ b8 T/ F; ?: q
satisfaction of doing something that is 9 j* D v6 I8 Y4 {/ G+ G& Uimmediately useful. But you can get great 5 }- p# G9 u: d: `, Y+ c7 |7 ~ f% Ksatisfaction by recognizing that your work in 2 o M8 r) Y! O; }science is a part of history. . b) E* L: i4 n* C' Y ?- a/ A! x) t+ H5 ?
Look back 100 years, to 1903. How0 b; }4 e% H+ ]3 l! T1 J, b
important is it now who was Prime Minister1 ` o& L3 w! ^! o8 P+ p5 [6 f
of Great Britain in 1903, or President of the 2 u( f0 L3 L0 c+ V; xUnited States? What stands out as really 2 Z+ h: e7 S9 A7 m1 r/ K0 _7 Simportant is that at McGill University, - P% K5 J! |. k e& s, YErnest Rutherford and Frederick Soddy were! Q# ]& @' X* q ^8 r1 n% w
working out the nature of radioactivity. 7 |1 m+ h, H6 N0 QThis work (of course!) had practical applications,2 ]( r4 L' ~" ^
but much more important were its8 S2 o- a6 x8 [; ]7 r, K
cultural implications. The understanding of : Y) {5 Z6 \+ D: @% g- l# X4 Eradioactivity allowed physicists to explain " p* f. m& r" s5 U/ y) nhow the Sun and Earth’s cores could still be * Z- U# E$ s' ]8 fhot after millions of years. In this way, it" B- Z' S: |" `
removed the last scientific objection to what 5 g9 A& ?; x, e1 m J/ P# i" {many geologists and paleontologists 1 l3 _; L# b2 ?- r3 Vthought was the great age of the Earth and . i( Q7 B U- T( u- Ithe Sun.After this,Christians and Jews either 5 J2 H! r- m8 ?( t7 Dhad to give up belief in the literal truth of # _- A7 L/ d3 Q5 Hthe Bible or resign themselves to intellectual$ }, q5 H8 V3 w! r1 Y1 w
irrelevance. This was just one step in a& w1 p& p9 l! d; G% J/ P
sequence of steps from Galileo through# r/ a: I% |, [2 {
Newton and Darwin to the present that,time0 J4 D8 _ T6 V/ H
after time,has weakened the hold of religious) K A, |6 v" H
dogmatism. Reading any newspaper nowadays 7 ~. t+ N: Q" z9 R" Bis enough to show you that this work, m! P1 h- N$ [* m: p, n, o
is not yet complete. But it is civilizing work, . X/ |. o" q1 r/ ^; [of which scientists are able to feel proud.