The new, twenty-first edition of the freely
downloadable physics textbook, as usually without
any commercial interest whatsoever, is available on
http://www.motionmountain.eu Almost 1500 pages lead through the whole of physics, from
mechanics to relativity, electrodynamics, thermodynamics,
quantum theory, nuclear physics, astrophysics and
unification. Over hundred new figures and tables, and
numerous explanations have been added, with many
examples from animals, plants and machines.
The twenty-first edition now explains why the speed of
light is too slow to speculate with success on the stock
exchange, adds the second-level bear fur colour puzzle and
the young mother puzzle, presents the nearest place with
a pressure permanently lower than that of the atmosphere,
adds the puzzle about the horse and the snail on a rubber,
tells more about metamaterials, adds some simple chemical
puzzles, presents what incredible things on atomic layers
one can discover using a pencil and sticky tape, tells
more on biological rhythms and clocks, explains how to
observe the rotation of the Earth in any classroom after
two seconds of observation, shows an electric effect
observed on many playgrounds, shows the beauty of bursting
soap bubbles and bouncing tennis balls, explains how it is
possible to observe the motion of single, isolated
electrons, gives more details on the shape of the proton,
and tells how to build the simplest possible radio
control system.
The first 360 pages are available also in French, due to
the great work of Benoit Clenet, and can be downloaded from
the bienvenue page.
A wiki open to everybody now keeps track of misprints
and suggestions.
Enjoy the reading!
Christoph Schiller
Forum 
