Aristotle believed that heavy objects fall faster than lighter objects due to air resistance slowing lighter objects. Galileo attempted to disprove this by showing that in a vacuum, all objects fall at the same rate regardless of mass. Newton further developed these ideas by inventing calculus and proposing his three laws of motion. By the late 19th century, classical physics appeared complete through theories like Newtonian mechanics and electromagnetism. However, experiments by Michelson-Morley and Planck revealed phenomena that could not be explained classically, showing that classical physics broke down at small scales and high speeds.

1. • The idea of phenomena of falling objects put forward by Aristotles that
heavy objects fall faster than lighter object stating
that the speed at which something falls actually
depends on its weight.
• no one disagrees with Aristotle, most people are comfortable with the idea
of ​​Aristotle falling faster that's what they've been seeing for almost 2000
years.
• Aristotle's rules for falling objects remained unchallenged until a new
scientist attempted to prove him wrong.
• In the year 1599 an Italian scientist named Galileo attempted to prove
Aristotle wrong, Galileo believed the only reason heavy objects fall faster is
because air resistance slows down lighter objects and that if air resistance
could be reduce, they would both fall at the same accelerate

2. • 100 years ago Isaac Newton is popularly remembered as the
man who saw an apple fall from a tree, and was inspired to
invent the theory of gravity, so that he generalized the
results of Galileo’s experiment before.
• If you have grappled with elementary physics then you know
that he invented calculus and the three laws of motion upon
which all of mechanics is based.
• More fundamentally, Newton's mathematical approach has
become so basic to all of physics that he is generally
regarded as the father of the clockwork universe: the first,
and perhaps the greatest, physicist.

3. • Throughout the seventeenth, eighteenth, and nineteenth
centuries, in the century multitude of major discoveries and
physical theories have been developed,
• near the turn of the 20th century, Newton’s theoried on
classical mechanics had been joined with Maxwell’s classical
electromagnetism and Carnot’s Thermodynamic,
• it seemed like we knew just about all there was to know
about physics,

4. • The universe appeared to be completely deterministic.
Meaning that if we could know the precise location
and momentum of every particle in a system, as well
as the laws that govern their motion, we could know
that system’s state any moment in the past or future .

5. • if we had such information for every particle in the universe we could
know everything about the universe including how it began dan how
it would end.

6. • It was around this time that some cracks began to form in
the deterministic world view through a series of perplexing
discoveries

7. • Two cracks mentioned by Lord Kelvin in his famous lecture in the 1900 identified two
urgent problems for 19th physics he called (“clouds”) of “the theory of heat and light”.
• two“clouds” as he puts it: the relative motion of the ether with respect to massive
objects, and Maxwell-Boltzmann’s theorem on the equipartition of energy.
• michelson invented the interferometer for the purpose of discovering the effect of the
earth's motion on the observed velocity. Together with Professor EW Morley using an
interferometer, it was shown that light travels at a reference constant speed in all inertial
systems. The experiment compare to speed of light in perpendicular direction in the
attempt to detect the relative motion of matter through ether, and the result was
negative, that’s mean there was no significant difference between the speed of light in
the direction of movement through the presumed ether an the speed of right angle
• Plank said that The wavelength (i.e. color) of radiant energy emitted by a blackbody
depends on only its temperature, not its surface or composition. And and introduce the
term quantization, he said Energy is quantized in some systems. Yang tidak dapat
dijalaskan dalam fisika klasik

8. • Through of a series of perplexing discoveries, we quickly realized that
classical physics just work fine for most earthly phenomena, it’s break
down when looking at the realm of the very small like subatomic
particles, as well as the realm of very fast like things moving close to
the speed of light