MOTION MOUNTAIN

326 10 classical physics in a nutshell
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the universe – was unknown when Michelson, who later even earned the Nobel Prize in
physics, gave his speech. Indeed, not only was general relativity still unknown; above all,
quantumtheory still needed to be discovered.
Many physicists in Michelson’s time knew that important changes in the description
of nature were necessary. Michelson had overlooked three contradiction between
electrodynamics and nature for which he had no excuse. First of all, we found above
that clocks and metre bars are necessarily made of matter and necessarily based onelectromagnetism.
But as we saw, classical electrodynamics does not explain the stability
and properties of matter and atoms. Matter is made of small particles, but the relation
betweentheseparticles,electricityandthesmallestchargesisnotclear.Ifwedonotunderstand
matter, we do not yet understand space and time, since we defined space and
timeusingmeasurementdevices made of matter.
Secondly, Michelson knew that the origin of no colour observed in nature is described
by classical electrodynamics. Classical electrodynamics can only explain colour differencesandcolourchanges,butitcannotdescribeabsolute
colour values.
Worse, Michelson overlooked a third aspect: the classical description of nature does
not allow us to understandlife.The abilities of living beings – growing, seeing, hearing,
feeling, thinking, being healthy or sick, reproducing and dying – are all unexplained by
classical physics. In fact, all these abilities contradict classical physics.
At the end of the nineteenth century, the progress in technology due to the use of
electricity, chemistry and vacuum technology allowed better and better machines and
apparatuses to be built. All were built with classical physics in mind. In the years between
1890 and 1920, these classical machines completely destroyed the foundations of classical
physics. Experiments with these apparatuses showed that matter is made of atoms of
finite and constant size, that electrical charge comes in smallest amounts, that there is a
smallest entropy value, a smallest angular momentum value and a smallest action value
in nature, and that particles and light behave randomly. In short, precise experiments
show that in nature, the existence of the infinitely small is wrong in many cases: many
observables come inquanta. Like an old empire, the reign of classical physics collapsed.
Classical physics doesnot describe nature correctly at small scales.
In summary, understanding light, matter and its interactions, including life itself, is
the aim of the upcoming parts of our ascent of Motion Mountain. And to understand life
we need to understand the size, shape, colour and material properties of all things. And
this understanding takes place at small scales. More specifically, in order to understand
light, matter and life, we need to study particles. A lot is still left to explore. And this
exploration will lead us from wonder to wonder.
Motion Mountain – The Adventure of Physics copyright © Christoph Schiller June 1990–November 2015 free pdf file available at www.motionmountain.net