Laws (various) (2)

Laws relating to Assembly

  1. If a project requires n components, there will be n-1 components available.
  2. Interchangeable parts won't.
  3. Components that must not and cannot be assembled improperly will be.
  4. The most delicate component will be dropped.
  5. The construction and operation manual will be discarded with the packing material. The garbage truck will have picked it up five minutes before the mad dash to the rubbish can.
  6. The necessity of making a major design change increases as the assembly and wiring of the unit approach completion.
  7. THE LAW OF SELECTIVE GRAVITATION: A dropped tool will land where it will do the most damage.
  8. A component selected at random from a group having a 99% reliability will be a member of the 1% group.
  9. Tolerances will accumulate unidirectionally toward maximum difficulty of assembly.
  10. The availability of a component is inversely proportional to the need for that component.
  11. If a particular resistance is needed, that value will not be available. Furthermore, it cannot be developed with any series or parallel combination.
  12. After an instrument has been assembled, extra components will be found on the bench.

Laws relating to wiring, test and operations

  1. Any wire cut to length will be too short.
  2. Milliammeters will be connected across the power source, voltmeters in series with it.
  3. The probability of an error in the schematic is directly proportional to the trouble it can cause.
  4. Identical units tested under identical conditions will not be identical on the final test after being buried under other components and wiring.
  5. A self starting oscillator won't.
  6. A crystal oscillator will oscillate at the wrong frequency -- if it oscillates at all.
  7. A p-n-p transistor will be found to be an n-p-n.
  8. A fail-safe circuit will destroy others.
  9. If a circuit cannot fail, it will.
  10. A transistor protected by a fast-acting fuse will protect the fuse by blowing first.
  11. Probability of failure of a component is inversely proportional to the ease of repair or replacement.
  12. A KEY RULE OF STARFLEET OPERATIONS: Some idiot has left open the number two impulse vent.(Check the position of all switches, knobs, and dials before turning on a piece of equipment. Both you and the equipment will live longer.)

Laws concerning trouble-shooting

  1. After the 24th cabinet-to-chassis screw has been removed to replace the under chassis fuse, it will be observed that the line cord plug has become disengaged from the a.c. receptacle.
  2. After the 24th cabinet-to-chassis screw has been replaced, the driver tube will be found under the schematic on the bench.
  3. The bleeder resistor will quit discharging the filter capacitors as the operator reaches into the power supply enclosure.

SATTINGER'S LAW - It works better if you plug it in.
THE LAW OF THE PERVERSITY OF NATURE - You cannot successfully determine beforehand which side of the bread to butter.
ZYMURGY'S FIRST LAW OF EVOLVING SYSTEM DYNAMICS - Once you open a can of worms, the only way you can recan them is to use a larger can. (Old worms never die; they just worm their way into larger cans.)
OSBORN'S LAW - Variables won't, constants aren't.


  1. Given any problem containing N equations, there will be N+1 unknowns.
  2. The object or bit of information most needed will be least available.
  3. The device requiring service or adjustment will be least accessible.
  4. In any human eneavor, once you have exhausted all possibilities and failed, there will be one solution, simple, obvious, and highly visible to everyone else.
  5. Badness comes in waves.

Notebook of Lazarus Long


  1. No matter what result is anticipated, there is always someone willing to fake it.
  2. No matter what the result, there is always someone eager to misinterpret it.
  3. No matter what happens, there is always someone who believes it happened according to his pet theory.

FINAGLE'S CREED - Science is Truth; don't be misled by facts.

THE FINAGLE FACTOR - (Sometimes called the SWAG(Scientific Wild-Assed Guess) Constant) That quantity which, when multiplied by, divided by, added to, or subtracted from the answer which you got, yields the answer you should have gotten. [note] Items such as 'Finagle's Constant' and the more subtle 'Bougerre Factor' are loosely grouped, in mathematics, under constant variables, or, if you prefer, variable constants. Finagle's Constant, a multiplier of the zero-order term, may be characterized as changing the universe to fit the equation. The Bougerre (pronounced 'bugger') Factor is characterized as changing the equation to fit the universe. It is also known as the 'Soothing Factor'; mathematically similar to the damping factor, it has the characteristic of dropping the subject under discussion to zero importance. A combination of the two, the Diddle Coefficient, is characterized as changing things so that universe and equation appear to fit without requiring a change in either.

FINAGLE'S COROLLARY - On a seasonally adjusted basis, there are only six months in a year. If mathematically you end up with the wrong answer, try multiplying by the page number.

IGGY'S RULE OF SCIENTIFIC ADVANCES - All scientific discoveries are first recorded on napkins or tablecloths. Engineering advances are drawn inside matchbook covers. Keep supplies of them handy at all times.

Rules of the Lab

  1. When you don't know what you're doing, do it neatly.
  2. Experiments must be reproduceable, they should fail the same way each time.
  3. First draw your curves, then plot your data.
  4. Experience is directly proportional to equipment ruined.
  5. A record of data is essential, it shows you were working.
  6. To study a subject best, understand it thoroughly before you start.
  7. To do a lab really well, have your report done well in advance.
  8. If you can't get the answer in the usual manner, start at the answer and derive the question.
  9. If that doesn't work, start at both ends and try to find a common middle.
  10. In case of doubt, make it sound convincing.
  11. Do not believe in miracles---rely on them.
  12. Team work is essential. It allows you to blame someone else.
  13. All unmarked beakers contain fast-acting, extremely toxic poisons.
  14. Any delicate and expensive piece of glassware will break before any use can be made of it.(Law of Spontaneous Fission)

The Ten Commandments of Statistical Inference

  1. Thou shalt not hunt statistical inference with a shotgun.
  2. Thou shalt not enter the valley of the methods of inference without an experimental design.
  3. Thou shalt not make statistical inference in the absence of a model.
  4. Thou shalt honour the assumptions of thy model.
  5. Thy shalt not adulterate thy model to obtain significant results.
  6. Thy shalt not covet thy colleagues' data.
  7. Thy shalt not bear false witness against thy control group.
  8. Thou shalt not worship the 0.05 significance level.
  9. Thy shalt not apply large sample approximation in vain.
  10. Thou shalt not infer causal relationships from statistical significance.