Evolution of physics
Dr Hameed A Khan
Physics is the most basic of all sciences and its importance in our
everyday life cannot be emphasized enough. In order, to capture the true
picture of physics’ contribution to improving mankind’s quality of life,
one must take a journey back in time and follow the road to the
evolution of science and technology in general and physics in
particular. Early traces of the evolution of science can be dated back
to the 7th century BC-Greek era; however, those of technology are
difficult to identify. It is often said that technology came before
science, because mankind in its primitive ways pursued methods of
repetitive hit and trial until a way was found to satisfy the requisite
need. The mother of all inventions, need, led man to do technology long
before he could or would do science. It is for this reason that some
historians and technologists go to the extent of stating that the wheel,
which is considered to be the invention that fueled the S&T evolution,
was invented by technology and not science.
After the Greeks, history experienced the era of the Romans, who were
more focused on technology than science and, therefore, this period
experienced a little progress in the realms of science itself. During
the period of ‘After Jesus’, the Chinese made noteworthy contributions
to science and technology (papermaking, gunpowder), and then came the
era of the Muslims. The Muslims helped spreading the influence of
science from the Mediterranean eastward into Asia, where it picked up
contributions from the Chinese and the Hindus, and westward as far as
Spain, where Islamic culture flourished in Córdoba, Toledo, and other
cities. Though little specific advances was made in the realms of
physics, the Muslims ensured preservation of Greek science and kept it
alive during this period. The much preserved and patronized science kept
by the Muslim world made possible the revival of learning in the West,
beginning in the 12th and 13th century. During this period, the Muslims
experienced their downfall, not only in terms of their dominance in the
world, but also in terms of their dominance in science. The Mongols
destroyed Baghdad, which was one of the centres of Muslim scientific
literature and civilization. Though the Turks continued to patronize
science, much of the libraries and books preserved by the Muslim world
no longer existed. In the year 1453, Istanbul also fell to the Turks.
During this period, the intellectual community of the Muslims
(especially those who spoke Latin) fled to Western Europe, more
specifically Italy and then on to Greece. With their comfort in
communication, they helped spread scientific knowledge in European
languages across the western part of the continent. Some of the books of
Muslim scholars and scientists were even translated into Latin and other
European languages.
During the dark and middle ages of Europe, the Church was in control of
the State, and religion guided the society to abide and follow what was
divine decree without questioning. As the norms of these ages promoted
nothing but blind following, the culture of science in Europe could not
develop, as science dwells purely on query. During the period of
renaissance, the control of the church weakened and people started
questioning religious and societal beliefs. In this environment,
scientific queries were also re-generated, which marked the beginning of
an era of progress and development in science and its realms.
The physics of Newton during his era is considered to be remarkable in
the true sense of the word. It is from here that the foundations of
modern science and modern physics were grounded. The full explanation of
celestial and terrestrial motions was not given until 1687, when Newton
published his Principia [Mathematical Principles of Natural Philosophy].
This work, the most important document of the Scientific Revolution of
the 16th and 17th centuries, contained Newton’s famous three laws of
motion and showed how the principle of universal gravitation could be
used to explain the behavior not only of falling bodies on the earth but
also planets and other heavenly bodies. To arrive at his results, Newton
invented one form of an entirely new branch of mathematics, the calculus
(also invented independently by G. W. Leibniz), which was to become an
essential tool in much of the later development in most branches of
physics.
The journey of science that originated in mystery, passed through
astrology and astronomy, moved on from geocentric to heliocentric
descriptions of the solar system, gone from circular to elliptic orbits
of the planets, progressed from kinematics to dynamics and finally
reached the grand synthesis of Newton and classical mechanics. In the
17th century, focused and specific interrelationships between science
and technology. Watt invented the steam engine in 1765. By the end of
the 19th century, the interaction and inter-linkage of scientific
discovery and industrial revolution had materialized. The period of
early 18th century up till early 20th century is appropriately denoted
as the time when the foundations of modern science were laid. During
these 200 years or so, science moved from Newton on to Einstein, from
macrocosmos on to microcosmos and from classical physics to quantum
physics.
The key characteristics of this era include critical observations,
ingenious experiments, unique insight and patient incremental
understanding, which ultimately led to amazing and unorthodox synthesis
and suggestions. This was an era of gradual evolution, intermittent
revolution through discoveries, independent development of fundamental
modern scientific fields, as well as intertwined and interlinked
progression of cross-disciplinary realms. During this time-frame,
science was led by innovation breeding innovation, which materialized
the establishment of the broadest laws of science.
It was quite clear by the beginning of the 20th century that the most
fundamental entities of nature are not atoms. It is indeed a great
achievement of mankind to have uncovered the secrets of the inner
structure of the atom. Near to the end of the 19th century, scientists
realized that classical mechanics had its limitations and was unable to
explain a number of upcoming phenomena. Quantum physics and light quanta
evolved due to the resolution of the new phenomena regarding emission
and absorption of electromagnetic radiation by matter.
In 1905, Einstein used the quantum theory to explain the photoelectric
effect, and in 1913 Niels Bohr again used it to explain the stability of
Rutherford’s nuclear atom. In the 1920s, the theory was extensively
developed by Louis de Broglie, Werner Heisenberg, Wolfgang Pauli, Erwin
Schrödinger, P. A. M. Dirac, and others; the new quantum mechanics soon
became an indispensable tool in the investigation and explanation of
phenomena at the atomic level. Special relativity has unified the
concepts of mankind regarding mass and energy, by showing the
equivalence of both. The discovery of nuclear fission by Otto Hahn and
Fritz Strassmann (1938) and its explanation by Lise Meitner and Otto
Frisch provided a means for the large-scale conversion of mass into
energy, in accordance with the theory of relativity, and triggered as
well the massive governmental involvement in physics that is one of the
fundamental facts of contemporary science. The growth of physics, since
the 1930s, has been so great that it is impossible in a survey article
to name even its most important individual contributors.
Among the areas, where fundamental discoveries have been made more
recently are solid-state physics, plasma physics, and cryogenics, or
low-temperature physics. Out of solid-state physics, for example, have
come many of the developments in electronics (e.g., the transistor and
microcircuitry) that have revolutionized much of modern technology.
Another development is the maser and laser (in principle the same
device), with applications ranging from communications and controlled
nuclear fusion experiments, to atomic clocks and other measurement
standards.
The writer is a Scientist Emeritus, PAEC, Islamabad. |
