Copernicus and others had found a fault with the Greek model of the universe,
namely that the Earth rotated about the Sun. Galileo confirmed with his telescope
that indeed, Venus had shadows, confirming that it orbited the Sun, and
presenting evidence that the planets as they might be called, were as round as
the moon. Furthermore, Kepler following Tycho Brahe’s confirmations of
cosmological data, presented laws which explained planetary motion around the
sun in terms of the ellipse. Suddenly, there was no reason to believe that a
heliocentric system was refutable by anything remaining within the Aristotelian

Isaac Newton famously observed an apple falling to the ground, and had a Eureka
moment in which the Earth and the Moon were suddenly mixed together by a
single gravitational law.

Newton proposed a law of Universal Gravitation which explained the attraction of
the Moon to the Earth in terms of the masses of the two bodies::

Newton also proposed Three Laws of Motion which were: [A] Every object in a
vacuum maintains the same state of motion unless influenced from the outside; [B]
Force equals mass times acceleration; [C] For every reaction there is an equal and
opposite reaction::

Combining the two sets of laws, Newton could explain Kepler’s laws, which were:

[A] Orbits are ellipses; [B] In terms of the area around the foci, planets sweep out
equal areas in equal times; [C] Because ellipses are so standardized, there is a
relationship between the ratio of one ellipse and another, when both are

Based on Newton it could be determined for instance, that binary systems and
binary stars are possible, in which two celestial bodies are offset in a mutually
included orbit.

Newton believed in a trinity of matter, motion, and energy, a materialist universe in
which particles were indivisible and permanent, impossible to break by any
means;  This was the beginning of a new era of science in which Space and Time
were utterly absolute and distinct aspects of the universe. Time was one-
dimensional, knowledge was two-dimensional, and space was three-dimensional;
the universe was encapsulated.

Amongst Newton's accomplishments was an optic theory in which he proposed
that light consists of particles, which became a basis for atomics;

Within some time, scientists began research on the basic components of the
universe, which they said were atoms, indivisible particles corroborated from
Newtonian physics:

Each atom had at least three components, and no more than three types:

Electrons, with a negative charge, orbit at a “valence” from the center;

Protons, positively charged particles, are contained within the nucleus;

Finally, Neutrons, neutral particles, are bound to the protons by a kind of glue,
creating the nucleus

Together with these three elements of the atom, any type of chemical substance
could be constituted;

This model continued to have undisputed prevalence until the work of Albert
Einstein and Relativity, at which point the universe began to look more complex
once again.
PHI 398
Ultimate Nature of the Universe