MOTION MOUNTAIN

310 9 concepts, lies and patterns of nature
to gravity, because it classifies the observed accelerationsaaccording to distance to the
central bodyrand to its massM; indeed such a description sees each specific case as
an example of a general pattern. The habit of generalizing is one reason for the often
disturbing dismissiveness of scientists: when they observe something, their professional
training usually makes them classify it as a special case of a known phenomenon and
thus keeps them from being surprised or from being exited about it.
A description is thus the opposite of a metaphor; the latter is an analogy relating an
observation with anotherspecial case; a description relates an observation with ageneral
case, such as a physical theory.
“Felixquipotuit rerumcognoscerecausas,
atquemetusomnis etinexorabile fatum
subjecitpedibusstrepitumque acherontisavari.
Vergilius*”
Reason, purpose and explanation
“DerganzenmodernenWeltanschauung liegt
dieTäuschungzugrunde,daßdiesogenannten
NaturgesetzedieErklärungen der
Naturerscheinungenseien.**
LudwigWittgenstein, Tractatus, 6.371”
Compare the following two types of questions and answers:
1. Why are the leaves of most trees green? Because they absorb red and blue light.
Why do they absorb those colours? Because they contain chlorophyll. Why is chlorophyll
green? Becauseall chlorophylltypescontain magnesiumbetween four pyrrole
groups, and this chemical combination gives the green colour, as a result of its
quantum mechanical energy levels. Why do plants contain chlorophyll? Because this
is what land plants can synthesize. Why only this? Because all land plants originally
evolved from the green algae, who are only able to synthesize this compound, and
not the compounds found in the blue or in the red algae, which are also found in the
sea.
2. Why do children climb trees, and why do some people climb mountains? Because of
the sensations they experience during their activity: the feelings of achievement, the
symbolic act to go upwards, the wish to get a wider view of the world are part of this
type of adventure.
The two types of ‘why’-questionsshowthegeneraldifferencebetweenreasonsandpurposes(althoughthedetailsofthesetwotermsarenotdefinedinthesamewaybyeverybody).
A purpose or intentionis a classification applied to theactions of humans or animals;
strictly speaking, it specifies the quest for a feeling, namely for achieving some
type of satisfaction after completion of the action. On the other hand, a reason is a spe-
* ‘Happy he who can know the causes of things and who, free of all fears, can lay the inexorable fate and
the noise of Acheron to his feet.’ Georgica,book II, verses 490 ss.) Publius Vergilius Maro (b. 70 Mantua,
d.19bce Brindisi),thegreatRoman poet,isauthor oftheAeneid.Acheronwastherivercrossedbythose
whohadjustdiedandwereon theirwaytotheHades.
** ‘Thewholemodern conception of the world is foundedon the illusion that the so-called laws of nature
aretheexplanations ofnatural phenomena.’
Motion Mountain – The Adventure of Physics copyright © Christoph Schiller June 1990–November 2015 free pdf file available at www.motionmountain.net