h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I was reminded whilst reading this about the 'exciting' physics lessons I participated in at school. Either we were very bored or very sad individuals, but we somehow managed to work out the speed of light in furlongs per fortnight... oh dear...

Furlongs per fortnight? Genius! What's the speed of light then, according this? I'm very intrigued...

Sam

I really can't believe I've just done this...

The speed of light is equal to:

1,802,617,499,785 furlongs/fortnight

(to the nearest furlong...)


natalie

Thats the sort of pace I could live life at, furlongs per fortnight. So much more relaxed than miles per hour.

I've got a funny feeling that today is an historic one because I'm absolutely sure that the phrase 'furlongs per fortnight' will eventually work its way into the common lexicon, denoting not only an actual measurement, but also a thinly veiled riposte (a harking back to older times if you like) at our pace-obsessed lives. As Ghandi once said, 'There's more to life than increasing its speed'.

Natalie, you've done us all a great service.. furlongs per fortnight - what wonderful turn of phrase - I now have an actual unit of measurement that measures the pace I work.

Furlongs per fortnight... furlongs per fortnight... I love it. Thank you. Another tea break, anyone?

Sam

When I was at university, we had a night service you could call for counselling. In order to keep the staffers from being too bored, they would also field other reference questions if there were no urgent problems on another line. Someone got them to calculate the speed of light in furlongs per fortnight through whiskey (different refractive index) for them. They were really bored...

Yours,
Jake

Agghhhhh! And the answer was? Well? Well? I'm on the edge of me seat here?

What a great day it's been on site.

An attoparsec is a bit more than an inch, and a microfortnight is about a seconds. Thus an attoparsec per microfortnight is about 1"/sec.

...and pi seconds is approximately a nanocentury!

That quote came from the "fortune" program on UNIX, and I'm fairly sure this is also where the phrase "furlongs per fortnight" came from, as in (I'm quoting from memory, may be only approximate):

"The number you need will always be expressed in the least convenient units, for example furlongs per fortnight"

Anyone else remember seeing this?

I had definitely heard of "furlongs per fortnight" long before this conversation. I don't remember if it was from the Unix fortune(1) though.

I did once know how fast hair grows: in angstroms per second!

I found out recently that it's one of Finagle's laws (or Murphy's? I don't remember). Being given thee least convenient units, that is.

For those of us interested in the speed of light through whiskey in furlongs/fortnight posed by Mr. Cogito, the speed actually (assuming the conversion previously stated is sound) is 1,287,583,928,420 give or take 5 furlongs/fortnight (darned calculators only having 12 significant places!!!!!)

The utterly unoriginal, uncelebrated but still curiously strong
-Deuce.

Fantastic, mindblowing, funny. But enough about me.

What about the tog? I remember duvets having tog ratings. Do they still? Higher the tog, cosier the duvet.

It seems to be a British and American unit for thermal resistance, though only used in the context of textitles.

The SI unit of it is m²K/W, and the tog is a power of ten of this:

1 tog = 0.1 m²K/W (meter*meter*Kelvin/Watt)

It seems to be a part of culture. In some countries thermal resistance is only used for building materials. It's like with the weather forecast: In some countries rain probablility and wind chill temperature are very common whilst in other countries they are of very rare use.

The VMS operating system still has some system parameters (such as TIMEPROMPTWAIT (the amount of time the system waits for the operator to enter the date and time at bootup if the hardware system clock is invalid)) which are measured in an obscure (and therefore typical DEC) unit of 'Microfortnights'. A microfortnight is 1.2096 seconds.

Remember, PI seconds is a nanocentury, near enough (0.451% difference).

dum dum dum duuuummmmmmmmm..... Origin of furlongs per fortnight:

The Contributions of Edsel Murphy to the understanding of the behaviour of inanimate objects.


Abstract - Consideration is given to the effects of the contributions of Edsel Murphy to the discipline of electronics. His law is stated in both general and special forms. Examples
are presented to corroborate the author's thesis that the law is universally applicable.

I. INTRODUCTION
IT HAS LONG BEEN the consideration of the author that the contributions of Edsel Murphy, specifically his general and special laws delinating the behaviour of inanimat objects, have not been fully appreciated. It is deemed that this is, in large part, due to the inherent simplicity of the law itself.

lt 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 greate appreciation of Edsel Murphy, his law, and its ramifications 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:
l+1~ 2 (1)
where ~ 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 demonstratton. However. Cohen has made it clear that the broader scope of Murphy's general law obviously takes precedence.

To show the all-pervasive nature of Murphy's Law, the author offers a small sample of the application of the law in electronics engineering.

II. GENERAL ENGINEERING
II.1. A patent application will be preceded by one week by a similar application made by an independent worker.
II.2. The more innocuous a design change appears, the further its influence will extend.
II.3. All warranty and guarantee clauses become void upon payment of invoice. II.4. The necessity of making a major design change increases as the fabrication of the system approaches completion.
II.5. Firmness of delivery dates is inversely proportional to the tightness of the schedule.
II.6. Dimensions will always he expressed in the least usable term. Velocity, for example. will be expressed in furlongs per fortnight.
II.7. An important Instruction Manual or Operating Manual will have been discarded by the Receiving Department.
II.8. Suggestions made by the Value Analysis group will increase costs and reduce capabilities.
II.9. Original drawings will be mangled by the copying machine.

III MATHEMATICS
III.1. In any given miscalculation, the fault will never be placed if more than one person is involved.
III.2. Any error that can creep in, will. It will be in the direction that will do the most damage to the calculation.
III.3. All constants are variables.
III.4. In any given computation, the figure that is most obviously correct will be the source of error.
II.I5. A decimal will always be misplaced.
III.6. In a complex calculation, one factor from the numerator will always move into the denominator.

IV. PROTOTYPING AND PRODUCTION
IV.1 Any wire cut to length will he too short.
IV.2. Tolerances will accumulat unidirectionally toward maximum difficulty of assembly.
IV.3. Identical units tested under identical conditions will not be identica in the field.
IV.4. The availability of a component is inversely proportional to the need for that component.
IV.5. If a project requires n components, there will be n-1 units in stock.
IV.6. If a particular resistance is needed, that value will not be available. Further, it cannot be developed by available series or parallel combination.
IV.7. A dropped tool will land where it can cause the most damage. (Also known as tae law of selective gravitation
IV.8. A device selected at random from a stock having 99% reliability will be a member of the 1% group.
IV.9. When one connects a 3-phase line, the 2nd phase will be wrong.
IV.10 A motor will rotate in the wrong direction
IV.11 The probability of a dimension being omitted on a plan or drawing is directly proportional to its significance.
IV.12 Interchangeable parts won't
IV.13 Probability of failure of a component, assempby, subsystem, or system is inversely proportional to the ease of repair or replacement.
IV.14 If a prototype functions perfectly, subsequent production models will malfunction.
IV.15 Components that must not and can not be assembled incorrectly will be.
IV.16 A deraeter will he used on an overly sensitive range and will be wired in backwards.
IV.17. The most delicate component will drop.
IV. 18. Graphic recorders will deposit more ink on humans than on paper.
IV.19. If a circuit cannot fail, it will.
IV.20 A fail-safe circuit will destroy others.
IV.21 An instantaneous power-supply crowbar circuit will operate too late.
IV.22 A transistor protected by a fast-acting fuse will protect the fuse by blowing first.
IV.23 A self-starting oscillator won't.
IV.24 A crystal oscillator will oscillate at the wrong frequency — if it oscillates.
IV.25. A pnp transistor will be an npn
IV.26. A zero-temperature-coefficient capacitor used in a critical circuit will have a TC of -750 ppm/C.
IV.27 A failure will not appear till a unit has passed Final Inspection.
IV.28. A purchased component or instrument will meet its specs long enough, and only long enough, to pass
IV.29. If an obviously defective component is replaced in instrument with an intermittent fault, the fault will reappear after the instrument is returned to service
IV.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.

IV.31 After an access cover has been secured by 16 hold-down screws, it will be discovered that the gasket has been omitted.
IV.32. After a unit has been fully assembled, extra compunerts will be found on the bench.
IV.33. Hermetic seals will leak.

V SPECIFYING
V.1 Specified environemental conditions will alway be exceeded.
V.2. Any safety factor set as a result of practical experience will be exceeded.
V.3. Manufacturers' spec sheets will be incorrect by a factor of 0.5 or 2.0, depending on which multiplier gives the most optimistic valac. For salesmans' claims, these factors will be 0.1 or 10.0.
V.4. In an instrument or device characterized by a number of plus-or-minus errors, the total error will be the sum of all errorsadding in the same direction.
V.5. In any given price estimate, cost of equipment will exceed estimate by a factor of 3
V.6. In specifications, Murphy's Law supersedes Ohm 's.

The man who developped one of the most profound concepts of the the 20th, century is practically unknown 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 its universality and in its impact. The law itself, though inherently simple, has formed a foundation on which future generaitons will build. In fact, the law first came to him in all its simplicity when his bride-to-be informed him of the impending birth of ann heir to the fmaliy fortune