Computing as a language of Physics

Lectures presented at an International Seminar Course. Trieste, 2-20 August 1971 organised by the International Centre for Theoretical Physics, Trieste

FOREWORD
The International Centre for Theoretical Physics has maintained an interdisciplinary character in its re sear ch and training program as far as different branches of theoretical physics are concerned. In pursuance of this aim the Centre has organized extended research courses with a comprehensive and synoptic coverage in varying disciplines. The first of these on plasma physics was held in 1964; the second, in 1965, was concerned with the physics of particles; the third, in 1966, covered nuclear theory; the fourth, in 1967, and the sixth, in 1970, dealt with condensed matter and imperfect crystalline solids; the fifth, in 1969, and the seventh, in 1971, were courses on nuclear structure. The proceedings of all these courses were published by the International Atomic Energy Agency. The
present volume records the proceedings of the eighth course, held from 2 to 20 August 1971, which dealt with computing as a language of physics. Grants from the United Nations Development Programme, the Organization of American States, the International Bureau for Informatics-International Computation Centre and the DigitalEquipment Corporation made it possible for the Centre to increase the participation of scientists from developing countries. The program o f lectures was organized by Professors L. Bertocchi (Trieste, Italy), L. Kowarski (CERN), S .J . Lindenbaum (Brookhaven and New York, USA)and K. V. Roberts (Culham, UK).

Abdus Salam

CONTENTS
Part I: General Introduction
Computers and physics (IAEA-SMR-9/26) .................................................. 3
K.V. R o b e r t s
The impact of computers on nuclear science (IAEA-SMR-9/7) ......... 27
L. K o w a r s k i
Part II: Classical computational physics
Occurrence of partial differential equations in physics and the
mathematical nature o f the equations (IA E A -SM R -9 /1 4 a ) .................. 41
D .E . P o t t e r
Difference schemes and numerical algorithms (IA E A -SM R -9 /1 4 b ) . . 57
D.E. P o t t e r
Plasma physics, space physics and astrophysics
(IAEA-SMR-9/14c) .............................................................................................. 79
D.E. P o t t e r
Plasma, gravitational and vortex simulation ( IA E A -SM R -9 /1 3 ) ......... 95
R. W. Ho c k n e y
P a r t ic le - f ie ld interactions: numerical techniques and problems
(IAEA-SMR-9/13b) .............................................................................................. 109
R.W. H o c k n e y
The solution o f P o is s on 's equation (IA E A -SM R -9 /l3 c ) ......................... 119
R .W .H o c k n e y
Difference methods in fluid dynamics, with applications
(IAEA-SMR-9/17) .................................................................................................. 129
J. K i l l e e n
Application o f computers to problems o f controlled thermonuclear
r ea c to r s (IAEA-SMR-9/10) ............................................................................. 157
M.N. R o s e n b l u t h
Monte Carlo techniques in statistical mechanics (IA E A -SM R -9 /l l ) . 165
M.N. R o s e n b l u t h
A fluid transport algorithm that works (IA E A -SM R -9 /1 8 ) ...................... 171
J. P. B o r i s
Part III: Quantum Computational Physics
Statistical methods fo r bubble chamber analysis (IAEA-SMR-9/28) . 193
E. L o h rm a n n
Data p ro ce ssing for e le c tronic techniques in high-frequency
experiments (IAEA-SMR-9/25) ....................................................................... 209
S.J. L i n d e n b a um
Multi-particle high-energy reactions (IAEA-SMR-9/26) ......................... 235
S. P. R a t t i
Optical-model and coupled-channel calculations in nuclear
physics (IAEA-SMR-9/8) ................................................................................ 281
J. R a y n a 1
Computer simulation in so lid-state physics (IAEA-SMR-9/15) ............ 323
R. B u l l o u g h
The quantum computational physics o f atoms and molecules
(IAEA-SMR-9/20) ................................................................................................ 337
R.K. N e s b e t
Accurate calculation of c r o s s -s e c t ion s for non-reactive molecular
co ll is ions (IAEA-SMR-9/19) ............................................................................ 375
W.A. L e s t e r , Jr.
Part IV: Symbolic analysis
Comparative survey o f programming languages (IAEA-SMR-9/21) . . . 391
J. A. C am p b e l l
Translation of Symbolic ALGOL I to Symbolic ALGOL II
(IAEA-SMR-9/22) .............................. ............................... .................................... 485
G. K u o - P e t r a v i c , M. P e t r a v i c and K.V. R o b e r t s
Automatic Optimization o f Symbolic ALGOL programs:
I. General principles (IAEA-SMR-9/24) ............................ ...................... 491
M. P e t r a v i c , G. K u o - P e t r a v i c and K.V. R o b e r t s
The DELPHI-SPEAKEASY system (IAEA-SMR-9/16) .............................. 521
S. Co h e n
Introduction to LISP (IAEA-SMR-9/9) .............................................................. 529
D. L u r i é
Generation o f Feynman diagrams by the use of FORTRAN
(IAEA-SMR-9/12) ................................................................................................ .. 555
M. P e r r o t t e t
Computer solution of symbolic problems in theoretical physics
(IAEA-SMR-9/27) ......................... ........................................................................ 567
A. C. He a r n
Faculty and Participants 597