CRUEL NATURE: a relativistic tragicomedy
		N. David Mermin

Reproduced by permission from N. D. Mermin, Boojums all the Way Through,
Cambridge University Press, 1990.  The play previously appeared in Space
and Time in Special Relativity, McGraw-Hill, 1968 and in Physics Today,
May 1983.


Cast of Characters
A
Friend of A
B
G
Chorus of Relativists

A one-act relativistic tragicomedy set in otherwise empty space.

A, surrounded by his clocks and meter sticks, is talking with his friend.

Friend of A:
	Tell me, good A, is it then truly so
	That you are in a state of perfect rest?
A:	I am, sir. I move not.  My state of rest
	Is true and absolute.
F:				Is it then so
	Your meter sticks do span a meter's length?
A:	Not one jot more nor less, sir, I confess,
	Provided they maintain their state of rest.
F:	How much, sir, in an honest hour's good time
	Will these, your clocks, have measured on their dials?
A:	Faith, sir, an honest hour!  No more, no less,
	While they remain with me, at perfect rest.
F:	And will each of your clocks, regardless of
	The distance 'twixt them, read the same true time
	Upon their dials, all in that sweet relation
	That does befit fine clocks: Synchronization?
A:	This too is so (once more the truth you've guessed!)
	Of all my clocks that, with me, are at rest.
F:	Your rhymes improve at couplet's grace's expense.
A:	Blank verse is not my business.  Get thee hence.
F:	A thousand pardons, sir!  I did but jest
	And did not think it would disturb your rest.
A:	My rest is perfect, absolute, and true.
F:	In that case, gentle A, do you maintain
	That clocks and meter sticks that pass you by
	With uniform velocity (say v)
	Fail to to be synchronized, slow down, and shrink
	As it is written in Lorentz's Rules?
A:	Just so, good friend, just so.  You speak the truth.


B now floats uniformly into view, seated in the center of an immense
network of clocks and meter sticks.


F:	Look you!  Who comes now?
A:				  That is Mr. B,
	Approaching us with constant speed (say v).
	Look how his clocks do fail to synchronize,
	Take longer than a second to describe
	A second's passage, while his meter sticks
	Do shrink in the direction of his motion,
	All in accordance with my lovely rules.(*)

-----
(*) Which in this book are called Lorentz's Rules.

F:	Welcome most hearty, B, to A's domain.
B:	Nay, warmest welcome to both you and A
	As you progress toward my ancestral home.
F:	How fare your many clocks and meter sticks?
B:	Now and fore'er, sir, they are just and true.
	My clocks are in harmonious accord
	And in a second's time do indicate
	The passage of a perfect passing second.
	My meter sticks extend one meter's length
	From end to end.
F:			  Hear you that, A?
A:					    I do.
	The man has lost his wits.  He does not know
	That he it is who moves, while I stand still.
	Ergo the knave is fully unaware
	That all his clocks and meter sticks behave
	As it is written in Lorentz's Rules,
	Failing to keep true time and span true length
	To that extent precise and mathematick
	As do my rules require for one who moves
	Past me with his velocity.
F:				   Poor fool!
	But now he passes by you and will see
	By swift comparison, experimental,
	Of his askew equipment with yours true,
	That his is deep in error.
A:				   No, alack!
	You overestimate the wisdom of
	The man.  So deep has he enmeshed himself
	In folly, so fully does he deem himself
	At rest, that he believes that my Loren-
	Tz's Rules describe the sticks and clocks at rest
	With me!
F:		 A double folly's double woe!
	But yet methinks there consolation be
	In doubleness.  The saving point is this:	
	If to his false-deemed state of rest erroneous
	He adds a further concept incorrect
	And vile, by his most wrongful application
	Of your Lorentz's Rules, which we both know
	Describe the strange distortions of things moving
	Past him who is at rest (and such are you),
	If, as I say (for I have lost the thread
	Of my intent) he wrongfully applies
	Your special rules, assuming they are his,
	Then marry, by this double error gross
	(Wrongly to deem himself at rest, and worse,
	Wrongly to think that he can use your Rules)
	Does he not double chance of contradiction
	Which will his fault correct, his mind inform,
	When he observes your instruments of measure
	So just and true (due to their state of rest)?
A:	His second folly does abet his first
	And by compounding, save it.  Had he thought
	Himself at rest and not as well believed
	My own Lorentz's Rules, his too to use,
	His error, by th'impending confrontation
	Of swift advancing B and my true tools
	Of space and time, would manifest become
	To B himself, forced to this recognition
	By contradiction stark and merciless.
	Howe'er because he uses my own Rules
	As if 'twere he at rest, and I who moved
	Along with my true clocks and meter sticks,
	The inconsistencies that should inform
	His intellect of its sad misconception
	And jar it like a ringing clarion call
	To certain knowledge of those clear distortions
	His many clocks and meter sticks are heir to
	By virtue of their motion, he poor fool
	Is able to account for in a way
	That masks the inconsistencies and bars
	Sweet ministering contradiction from
	The portals of his mind.  He simply blames
	The facts that should destroy his sleep dogmatic
	On the fictitious shrinkage, slowing down,
	And lack of that sweet quality we deem
	Most excellent in clocks: Synchronization,
	That he in his most vain, deluding use
	Of my Lorentz's Rules assigns to my
	Most wrongfully malignèd instruments.
	To his misfortune, Nature, arch deceiver
	So made the world that his delusions, two,
	Will learn from this encounter nothing new.
	Each doth confirm the other's false surmise.
	So was it e'en with C and X and Y.
	So shall it be when G and H come by.
	I rage against such cruel deceit in vain;
	Harsh Nature has decreed it.
F:	(to B, now very close)		Look you, sir:
	The clocks and meter sticks of outraged A!
	Perceive they argue not the same as yours!
B:	Of course they don't: His meter sticks do shrink,
	His clocks are slow, nor are they synchronized;
	While my sticks measure distance absolute,
	My clocks record Time's true and even tread,
	Each, though apart, my other clocks do prove.
	This is because, quite simply, I don't move.
A:	Alas, poor B!  Nature conspires against him.
B:	Alas, poor A!  He thinks that I be mad,
	When all too well I know the madness lies
	In him.  So has it been with Y and C
	And X; with G and H, so shall it be.


B passes by A and recedes into the distance.

F:	O wicked Nature, to conspire 'gainst B
	That all his gross and lamentable follies
	Most undetectable thy tricks have rendered.
A:	Sadder still, but for delusions twain
	He hath a most incisive, cogent brain.
	Alas, poor B! And C! And X! and G!
B:	(from afar) Alas, poor A! And X! And G! And C!
G:	(coming into sight) Alas, poor A and B! And X! And C!


Chorus of Relativists:
	Such sorry discord need not be
	If Absolutists had more sense:
	So right in all their measurements,
	So mad in their philosophy.