Yourgrau P. A world without time.. the forgotten legacy of Goedel and Einstein (Basic Books, 2005)(ISBN 0465092934)(176s)_PPop_

to Mach, who carried the day on that battlefield, whether in person or in print and
whether in Vienna with Boltzmann or waging battle from afar. In 1897, in one particularly
unpleasant encounter at a meeting of the Imperial Academy of Sciences in Vienna, Mach,
following Boltzmann's talk, rose to voice his objections, declaring bluntly, "I don't believe
that atoms exist!" Boltzmann never did re- cover from such polemics, in spite of the fact
that in 1905 Einstein would deliver a terminal blow to Mach's epistemological critique of
the atomic hypothesis.
In the same year, indeed, in the same volume of the same journal, Annalen der Physik, in
which he propounded the theory of relativity, Einstein published a paper on "Brownian
motion," the random dance long observed in the behavior of microparticles, in which he
made explicit use of the hypothesis of the reality of atoms to explain this phenomenon and
to make precise and verifiable predictions about the
behavior of particles based on measurements of real, nonfictional, atoms. In the same
year, Einstein had managed to make profound physical discoveries employing both Mach's
verificationist critique of Newton (to produce the theory of relativity) and Boltzmann's
mathematical and model-theoretic realism (to produce the theory of Brown-ian motion and
establish the existence of invisible atoms). This was neither the first nor the last time
Einstein would succeed in overthrowing not just the theories but the very worldview of a
great thinker who had once been his inspiration or father figure. He would write years
later that "the scientist must appear to the systematic epistemologist as a type of
unscrupulous opportunist; he appears as a realist insofar as he seeks to describe a world
independent of the acts of perception . . . as a positivist insofar as he considers concepts
and theories justified only to the extent to which they furnish a logical representation of
relations among sensory experiences."
Boltzmann's rescue by Einstein, however, came too late. Worn down by years of verbal
battles with the ruthless Mach, Boltzmann succumbed to his wildly unstable moods. In
1906, on holiday at the Bay of Duino near Trieste, the great physicist tried once again to
take his own life, while his wife and daughters were swimming, this time by hanging. This
second attempt succeeded. A great influence, not only on Einstein, had come to a sudden
and tragic end. Ludwig Wittgenstein, who had been hoping to make a career in physics and
engineering by following Boltzmann's great model, now embarked on a new course that
would ultimately lead him, via research in aeronautical engineering in Manchester,
England, to Frege and Russell and the foundations of mathematics. Boltzmann's influence,
however, had already left its mark. The physicist's prophetic idea of describing a physical
system by locating it in a logical framework in various dimensions of physical significance
would have a profound effect not only on the future of quantum mechanics but on the
bible of the Schlick circle. For it was in Boltzmann's conception that Wittgenstein found
the germ of his idea of locating an objectóany objectóby its position in what in the
Tractatus he called "logical space." Where Boltzmann chose to lo-
cate a physical body by specifying its position in terms of a set of coordinates, three
spatial and one temporal, as well as a fifth coordinate, temperature, and a sixth, pressure,
and so on, which gave the "ensemble of possible states" of a physical system, Wittgenstein
wrote that "the facts in logical space are the world. ... A picture presents a situation in
logical space. ..."