
                          THE CONTRIBUTIONS OF
                              EDSEL MURPHY
                         TO THE UNDERSTANDING OF
                             THE BEHAVOR OF
                            INANIMATE OBJECTS



                ABSTRACT - CONSIDERATION IS GIVEN
                TO THE EFFECTS OF THE CONTRIBUTIONS 
                OF EDSEL MURPHY TO THE DICIPLINE OF
                ELECTRONICS ENGINEERING.  HIS LAW IS
                STATED IN BOTH GENERAL AND SPECIAL FORM.




                    1.  INTRODUCTION

     IT HAS LONG BEEN THE CONSIDERATION OF THE AUTHOR THAT THE 
CONTRIBUTIONS OF EDSEL MURPHY, SPECIFICALLY HIS GENERAL AND SPECIAL
LAWS DELINEATING THE BEHAVIOR OF INANIMATE OBJECTS, HAVE NOT BEEN 
FULLY APPRECIATED.  IT IS DEEMED THAT THIS IS, IN LARGE PART, DUE TO
THE INHERENT SIMPLICITY OF THE LAW ITSELF.
     IT IS THE INTENT OF THE AUTHOR TO SHOW BY REFERENCES DRAWN FROM
THE LITERATURE, THAT THE LAW OF MURPHY HAS PRODUCED NUMEROUS COROLLARIES.
IT IS HOPED THAT BY NOTING THESE EXAMPLES, THE READER MAY OBTAIN A
GREATER APPRECIATION OF EDSEL MURPHY, HIS LAW AND ITS RADIFICATIONS
IN ENGINEERING AND SCIENCE.

     AS IS WELL KNOWN TO THOSE VERSED IN THE STATE-OF-THE-ART, MURPHY'S
LAW STATES THAT  "IF ANYTHING CAN GO WRONG, IT WILL"  OR TO STATE IT
IN MORE EXACT MATHEMATICAL FORM:
                           1 PLUS 1 X$ 2
WHERE X$ IS THE MATHEMATICAL SYMBOL FOR  HARDLY EVER.
     SOME AUTHORITIES HAVE HELD THAT MURPHY'S LAW WAS FIRST EXPOUNDED
BY  H. COHEN, WHEN HE STATED THAT  "IF ANYTHING CAN GO WRONG, IT 
WILL --- DURING THE DEMONSTRATION."  HOWEVER, COHEN HAS MADE IT CLEAR
THAT THE BROADER SCOPE OF MURPHY'S GENERAL LAW OBVIOUSLY TAKES PRE-
CEDENCE.
     TO SHOW THE ALL-PERVASIVE NATURE OF MURPHY'S WORK, THE AUTHOR 
OFFERS A SMALL SAMPLE OF THE APPLICATION  OF THE LAW IN ELECTRONICS
ENGINEERING.



                      2.  GENERAL ENGINEERING

2.1  A PATENT APPLICATION WILL BE PRECEDED BY ONE WEEK BY A SIMILAR
     APPLICATION MADE BY AN INDEPENDENT WORKER.

2.2  THE MORE INNOCUOUS A DESIGN CHANGE APPEARS, THE FURTHER ITS
     INFLUENCE WILL EXTEND.


2.3  ALL WARRANTY AND GUARANTEE CLAUSES BECOME VOID UPON PAYMENT
     OF INVOICE.

2.4  THE NECESSITY OF MAKING A MAJOR DESIGN CHANGE INCREASES AS THE
     FABRICATION OF THE SYSTEM APPROACHES COMPLETION.

2.5  FIRMNESS OF DELIVERY DATES IS INVERSELY PROPORTIONAL TO THE
     TIGHTNESS OF THE SCHEDULE.

2.6  DIMENSIONS WILL ALWAYS BE EXPRESSED IN THE LEAST USUABLE TERM.
     VELOCITY, FOR EXAMPLE, WILL BE EXPRESSED IN FURLONGS PER FORTNIGHT.

2
2.7  AN IMPORTANT INSTRUCTION MANUAL OR OPERATING MANUAL WILL HAVE
     BEEN DISCARDED BY THE RECEIVING DEPARTMENT.

2.8  SUGGESTIONS MADE BY THE VALUE ANALYSIS GROUP WILL INCREASE COSTS
     AND REDUCE CAPABILITIES.

2.9  ORIGINAL DRAWINGS WILL BE MANGLED BY THE COPING MACHINE.



                        3.  MATHEMATICS

3.1  IN ANY GIVEN MISCALCULATION, THE FAULT WILL NEVER BE PLAIN IF
     MORE THAN ONE PERSON IS INVOLVED.

3.2  ANY ERROR THAT CAN CREEP IN WILL.  IT WILL BE IN THE DIRECTION
     THAT WILL DO THE MOST DAMAGE TO THE CALCULATION.

3.3  ALL CONSTANTS ARE VARIABLES.

3.4  IN ANY GIVEN COMPUTATION, THE FIGURE THAT IS MOST OBVIOUSLY
     CORRECT WILL BE THE SOURCE OF ERROR.

3.5  A DECIMAL WILL ALWAYS BE MISPLACED.

3.6  IN A COMPLEX CALCULATION, ONE FACTOR FROM THE NUMERATOR WILL
     ALWAYS MOVE INTO THE DENOMINATOR.


                         4.  PROTOTYPING AND PRODUCTION

4.1   ANY WIRE CUT TO LENGTH WILL BE TOO SHORT.

4.2   TOLERANCES WILL ACCUMULATE UNIDIRECTIONALLY TOWARD MAXIMUM
      DIFFICULTY OF ASSEMBLY.

4.3   IDENTICAL UNITS TESTED UNDER IDENTICAL CONDITIONS WILL NOT BE
      IDENTICAL IN THE FIELD.

4.4   THE AVAILABILITY OF A COMPONENT IS INVERSELY PROPORTIONAL TO
      THE NEED FOR THAT COMPONENT.

4.5   IF A PROJECT REQUIRES (N) COMPONENTS, THERE WILL BE (N-1) UNITS
      IN STOCK.

4.6   IF A PARTICULAR RESISTANCE IS NEEDED, THAT VALUE WILL NOT BE
      AVAILABLE.  FURTHER, IT CANNOT BE DEVELOPED WITH ANY AVAILABLE
      SERIES OR PARALLEL COMBINATION.

4.7   DROPPED TOOL WILL LAND
      WHERE IT CAN DO THE MOST DAMAGE.  (ALSO
      KNOWN AS THE LAW OF SELECTIVE GRAVITATION.)

4.8   A DEVICE SELECTED AT RANDOM FROM A GROUP HAVING 99 PERCENT
      RELIABILITY, WILL BE A MEMBER OF THE 1 PERCENT GROUP.

4.9   WHEN ONE CONNECTS A 3 PHASE LINE, THE PHASE SEQUENCE WILL BE WRONG.

4.10  A MOTOR WILL ROTATE IN THE WRONG DIRECTION.

4.11  THE PROBABILITY OF A DIMENSION BEING OMITTED FROM A PLAN OR
      DRAWING OF IMPORTANCE.

4.12  INTERCHANGEABLE PARTS WON'T.

4.13  PROBABILITY OF FAILURE OF A COMPONENT, ASSEMBLY, SYSTEM OR SUB-
      SYSTEM IS INVERSELY PROPORTIONAL TO THE EASE OF REPAIR OR 
      REPLACEMENT.

4.14  IF A PROTOTYPE FUNCTIONS PERFECTLY, SUBSEQUENT PRODUCTION UNITS
      WILL MALFUNCTION.

4.15  COMPONENTS THAT MUST NOT AND CANNOT BE ASSEMBLED IMPROPERLY
      WILL BE.

4.16  A DC METER WILL BE USED ON AN OVERLY SENSITIVE RANGE AND WILL
      BE WIRED IN BACKWARDS.

4.17  THE MOST DELICATE COMPONENT WILL DROP.

4.18  GRAPHIC RECORDERS WILL DEPOSIT MORE INK ON HUMANS THAN ON PAPER.

4.19  IF A CIRCUIT CANNOT FAIL, IT WILL.

4.20  A FAIL-SAFE CIRCUIT WILL DESTROY OTHERS.

4.21  AN INSTANTANEOUS POWER SUPPLY CROWBAR CIRCUIT WILL OPERATE
      TOO LATE.

4.22  A TRANSISTIR PROTECTED BY A FAST-ACTING FUSE WILL PROTECT THE
      FUSE BY BLOWING FIRST.

4.23  A SELF-STARTING OSCILLATOR WON'T.

4.24  A CRYSTAL OSCILLATOR WILL OSCILLATE AT THE WRONG FREQUENCY.....
      IF IT OSCILLATES.

4.25  A PNP TRANSISTOR WILL BE AN NPN.

4.26  A ZERO-TEMPERATURE-COEFFICIENT CAPACITOR USED IN A CRITICAL
      CIRCUIT WILL HAVE A TC  OF  -750PPM/C.

4.27  A FAILURE WILL NOT APPEAR UNTIL A UNIT HAS PASSED FINAL
      INSPECTION.

4.28  A PURCHASED COMPONENT OR INSTRUMENT WILL MEET IT'S SPECIFICATIONS
      ONLY LONG ENOUGH TO PASS INCOMMING INSPECTION.

4.29  IF AN OBVIOUSLY DEFECTIVE COMPONENT IS REPLACED IN AN INSTRUMENT
      WITH AN INTERMITTANT FAULT, THE FAULT WILL APPEAR AFTER THE
      INSTRUMENT IS RETURNED TO SERVICE.

4.30  AFTER THE LAST OF 16 MOUNTING SCREWS HAS BEEN REMOVED FROM AN
      ACCESS COVER IT WILL BE DISCOVERED THAT THE WRONG ACCESS COVER
      HAS BEEN REMOVED.

4.31  AFTER AN ACCESS COVER HAS BEEN SECURED BY 16 SCREWS IT WILL BE
      DISCOVERED THAT THE GASKET HAS BEEN OMITTED.

4.32  AFTER AN INSTRUMENT HAS BEEN FULLY ASSEMBLED, EXTRA COMPONENTS
      WILL BE FOUND ON THE BENCH.

4.33  HERMETIC SEALS WILL LEAK.


                           5. SPECIFICATIONS AND COSTS


5.1  SPECIFIED ENVIRONMENTAL CONDITIONS WILL ALWAYS BE EXCEEDED.

5.2  ANY SAFTY FACTOR SET AS A RESULT OF PRACTICAL EXPERIENCE WILL BE
     EXCEEDED.

5.3  MANUFACTURERS SPEC SHEETS WILL BE INCORRECT BY A FACTOR OF 0.5
     OR 2.0 DEPENDING ON WHICH MULTIPLIER GIVES THE MOST OPTIMISTIC
     VALUE.  FOR SALESMEN'S CLAIMS THESE FACTORS WILL BE 0.1 OR 10.0.

5.4  IN ANY GIVEN PRICE ESTIMATE COST OF EQUIPMENT WILL EXCEED
     ESTIMATE BY A FACTOR OF 3.

5.5  IN SPECIFICATIONS, MURPHY'S LAW SUPERSEDES OHM'S.



     IN SOME CASES THE SOURCE MATERIAL WAS MISPLACED DURING PREPERATION
OF HIS PAPER.  IN ACCORDANCE WITH THE LAW, THESE MISPLACED DOCUMENTS
WILL TURN UP ON THE DATE OF PUBLICATION OF THIS PAPER.

     THE MAN WHO DEVELOPED ONE OF THE MOST PROFOUND CONCEPTS OF THE
20TH CENTURY IS PRACTICALLY UNKNOWN TO MOST ENGINEERS.  HE IS A
VICTIM OF HIS OWN LAW.  DESTINED FOR A SECURE PLACE IN THE ENGINEERING
HALL OF FAME,  SOMETHING WENT WRONG.
     HIS REAL CONTRIBUTION LAY NOT MERELY IN THE DISCOVERY OF THE LAW
BUT MORE IN IT'S UNIVERSALITY AND IT'S IMPACT.  THE LAW ITSELF THOUGH
INHERENTLY SIMPLE HAS FORMED A FOUNDATION ON WHICH FURURE GENERATIONS
WILL BUILD.
     IN FACT,  THE LAW FIRST CAME TO HIM IN ALL OF IT'S SIMPLICITY WHEN
HIS BRIDE-TO-BE INFORMED HIM OF THE IMPENDING BIRTH OF AN HEIR TO THE
FAMILY FORTUNES.

