Page 364 - Encyclopedia Of World History Vol IV

science—overview 1665

In questions of science, the authority of a thousand
is not worth that humble reasoning of a single
individual. • Galileo Galilei (1564–1642)

example was the inductivist turkey, who observed care- inadequate as historians of science became aware of the
fully how, each day, her bipedal servants provided food extent to which scientists, too, could cling to outdated
at a particular time; unfortunately, in mid December, theories or tweak their theories to avoid falsification.
just as the turkey was about to formulate the general Despairing of finding any decisive proof of the truth of
hypothesis that food would always appear at the same scientific theories, some philosophers of science gave up.
time, her servants killed her and cooked her for Christ- The historian Thomas Kuhn (1922–1996), impressed by
mas.) As a result, conclusions based on induction are the subjectivity and partisanship of real science, argued
always subject to modifications, sometimes of the most that the main defining feature of modern science was sim-
fundamental kind, as new observations become avail- ply that scientists within each scientific discipline seemed
able. Thus, by carefully observing the position and to agree about the discipline’s core ideas. Sciences, he
motion of distant galaxies, using work on variable stars argued, were organized around paradigms, or core ideas,
by Henrietta Leavitt (1868–1921), Edwin Hubble such as Newton’s laws of motion, or the theory of natu-
(1889–1953) showed that the universe, far from being ral selection. Once firmly established these were rarely
stable and eternal, is in fact expanding. subjected to the rigorous testing procedures Popper had
Early in the twentieth century, the British-Austrian taken for granted; on the contrary, there was a powerful
philosopher Karl Popper (1902–1994) proposed what element of faith in the work of most scientists most of the
he hoped was a more reliable apology for science. He time. Paradoxically, Kuhn argued that it was this faith in
argued that science advances through a process of “falsi- a core idea that explained the effectiveness of scientific
fication.” As he pointed out, even if it is impossible to research. Unlike historians, who cannot agree about the
prove the truth of any theory reached by induction, it is fundamental laws by which their discipline works, scien-
possible to prove that some theories are wrong. So Pop- tists commit to a certain body of theory and this, he
per argued that science should be trusted not because its argued, explains why they conduct research in a more
conclusions are true in any absolute sense, but because it coordinated and more effective way than historians. For
consisted of theories that had been tested rigorously and example, biologists, working within the paradigm of
had not yet been proved wrong. The best known exam- natural selection, know that any observation appearing to
ple of a falsifiable idea is perhaps the claim put forward threaten the fundamental principle of natural selection is
by Albert Einstein (1879–1955) that gravity affected important, so such problems attract many researchers,
light, a claim he suggested could be tested by seeing if the and eventually their work can lead to new insights that
light from distant stars was bent as it passed behind the usually support the core paradigm.
sun. The claim was successfully tested in 1919 during a But not always. In extreme cases, he conceded, the
solar eclipse, but what interested Popper was that Ein- accumulation of new data and new ideas may lead to the
stein’s claim was risky: It could have been proved false. overthrow of an existing paradigm. In the late nine-
Popper argued that ideologies such as Marxism and dis- teenth century, most physicists assumed the existence of
ciplines such as history did not count as sciences because an “ether,” a universal medium within which all physical
they did not generate hypotheses that were precise processes took place. Unfortunately, experiments on the
enough to be falsified. Marxism was simply too rubbery: speed of light by the U.S. researchers Albert Michelson
When it was pointed out that the socialist revolution pre- (1852–1931) and Edward Morley (1838–1923), seemed
dicted by Marx had failed to materialize, Marxists simply to show that the ether did not exist—the speed of light
shifted their ground and changed the anticipated date of was uniform in all directions, whereas the existence of an
the revolution. ether ought to have slowed light beams traveling against
Unfortunately, even Popper’s attempts to distinguish the ether’s flow. It was these anomalies that led Einstein
science from other forms of knowledge were shown to be to suggest that the Newtonian paradigm had to be