MOTION MOUNTAIN

296 9 concepts, lies and patterns of nature
Do observations take time?
An observation is an interaction with some part of nature leading to the production of
a record, such as a memory in the brain, data on a tape, ink on paper, or any other fixed
pattern applied to a support.The necessary irreversible interaction process is often called
writing the record. Obviously, writing takes a certain amount of time; zero interaction
time would give no record at all. Therefore any recording device, including our brain,
always records sometime average of the observation, however short it may be.
In summary, what we call a fixed image, be it a mental image or a photograph, is always
the time average of a moving situation. Without time averaging, we would have no fixed
memories. On the other hand, any time averaging introduces a blur that hides certain
details; and in our quest for precision, at a certain moment, these details are bound to
become important.The discovery of these details will begin in the upcoming part of the
walk, the volume that explores quantum theory.
In the final part of our mountain ascent we will discover that there is a shortest possibleaveraging
time. Observations of that short duration show so many details that even
the distinction between particles and empty space is lost. In contrast, our concepts of
everyday life appear only after relatively long time averages. The search for an averagefreedescriptionofnatureisoneofthebig
challengesofouradventure.
Is induction a problem in physics?
“Nurgesetzmäßige Zusammenhänge sind
denkbar.*
LudwigWittgenstein, Tractatus, 6.361” “Thereisatradition ofopposition between
adherentsofinductionandofdeduction.Inmy
viewit would bejustassensibleforthetwo
endsofaworm toquarrel.
Induction is the usual term used for the act of making, from a
AlfredNorthWhitehead”
small and finite number
of experiments, general conclusions about the outcome of all possible experiments performedin
otherplaces,or at othertimes.In a sense,it is thetechnical termfor sticking
outone’sneck,whichisnecessaryinevery scientific statement. Universal statements,includingtheso-called‘laws’andpatternsofnature,relyoninduction.Inductionhasbeen
a major topic of discussionfor sciencecommentators.Frequently one finds the remark
that knowledge in general, and physics in particular, relies on induction for its statements.Accordingtosome,inductionisatypeofhiddenbeliefthatunderliesallsciences
butatthesametimecontrastswiththem.
Toavoid wasting energy, we make only a few remarks.The first can be deduced from
a simple experiment. Try to convince a critic of induction to put their hand into a fire.
Nobody who honestly calls induction a belief should conclude from a few unfortunate
experiences in the past that such an act would also be dangerous in the future... In short,
somehow induction works.
A second point is that physical universal statements are always openly stated; they are
* ‘Onlyconnexions that aresubjecttolaw arethinkable.’
Motion Mountain – The Adventure of Physics copyright © Christoph Schiller June 1990–November 2015 free pdf file available at www.motionmountain.net