History of Physics

The discipline of science that shades the most light on the
structure of the world and also the most advanced one is
undoubtedly none other than Physics. Hence, it is much
needed to have some basic ideas of not only what the
up-to-date development of physics is but also how we came to
think in that way and how the whole of modern physics is
attached with its history.
In fact, the history of this science begins with Galileo, but in
order to understand his work it will be well to see what was
thought before his time. The ancient scholars whose ideas were
mainly taken from that of Aristotle used to believe that different
laws for terrestrial bodies and that of celestial bodies persisted
side by side at the same time. They even believed the same
holds true for living and dead matter as well. The four basic
elements according to them were that of air, water, fire and
earth – Among them the heaviest ones were the water and
earth while air and fire were believed to be lighter.
 
Earth and water had a natural downward motion, fire and air
upward motion. There was no idea of one set of laws for
different types of things or everything that matters; there was
no science of changes in the movements of bodies. Galileo and
Descartes, in a bit lesser degree compared to Galileo —
introduced the fundamental principles and concepts which
formed the foundation stone for physics until as long as the
present century we are in.
 
The ancient scholars worked hard to put forward the theory
that there exists one set of laws which holds true for living as
well as dead matter. Among them, Galileo conceptualized two
fundamental principles which actually made the discipline of
mathematical physics came into being: Law of parallelogram
and that of inertia. This law of inertia is now known as
Newton's first law of motion which is good enough to precisely
calculate the motion of different matter with respect to each
other, hence using the laws of dynamics.
 
Technically, the principle of inertia puts forward the idea that
causal laws of physics should be denoted in terms of
acceleration, i.e. a change of velocity in amount or direction or
both which was found in Newton's law of gravitation. From the
law of inertia, it is seen that the causal laws of dynamics
should be differential equations of the second order, though this
form of statement could not be made until Leibnitz and
Newton had developed the infinitesimal calculus.
 
The work of majority of the students on the mathematical side
of physics can be explained with Newton's set of principles. The
very basic equations of motions or the ideas of dynamics and
that of inertia, momentum, mass and acceleration were applied
by Newton to large bodies like the Earth and the Moon for
explaining their structure and the universe's motion.