This document discusses important ancient contributors to the study of science from 636 BC to AD 170. It outlines the key discoveries and theories of Thales of Miletus, Pythagoras, Democritus, Aristotle, Aristarchus of Samos, Archimedes of Syracuse, Hipparchus of Nicaea, and Claudius Ptolemaeus, including their work in astronomy, physics, and early scientific method. It then introduces some founders of modern science from the 15th to 17th centuries, including Copernicus, Tycho Brahe, Kepler, Galileo, Bacon, and Newton, highlighting their revolutionary developments in astronomy, physics, optics, and mathematics.

1. Earth Science

2. Science
- branch of knowledge or study dealing with a
body of facts or truths systematically arranged
and showing the operation of general laws.
- systematic knowledge of the physical or material
world gained through observation and
experimentation.
- knowledge, as of facts or principle, knowledge
gained by systematic study.
Beginning:

3. ANCIENT CONTRIBUTORS IN THE
STUDY OF SCIENCE

4. Thales of Miletus
(636-546 B.C.)
- founder of Greek science.
- a great thinker, he started the studies
and observations of the sky although
he believed that the earth is flat.

5. - he was the first to conclude that the
moon shines from light reflected from
the sun and to accurately predict lunar
and solar eclipses.
Pythagoras
(580-500 B.C.)

6. - first to recognize that the morning
and evening stars are one and the
same heavenly body.
- he named it “Aphrodite”, from the
name of the Greek goddess of love
and beauty known now as planet
Venus.
- he was the first to teach that the
earth is spherical and discover the
relationship between the pitch of

7. the sound and the length of the
vibrating string.
- most famous for a theorem in
Geometry that bears his name
Pythagorean Theorem, states the
square of the hypotenuse of a right
triangle equals the sum of the
squares of the other two sides.

8. Democritus
(460-370 B.C.)
- hypothesized the universe is made
up entirely of minute particles
called atoms, which according to
him, are invisible, unchangeable
and indestructible.

9. Aristotle
(460-370 B.C.)
- was the most prolific scientist of
ancient Greece.
- he wrote 150 volumes in all fields of
study and excelled in two fields –
logic and biology.

10. - his systematic treatment of logic is
standard for students until today.
- in biology–he was the first to make
systematic classification of animals.
Aristarchus of
Samos
(310-230 B.C.)

11. - was the first to correctly
hypothesize the the earth turns on
its axis and revolves around the
Sun, anteceding Copernicus by
more than 1500 years.
- he used the method of ratio and
proportion in his calculations of the
sizes of the Sun and the Moon.

12. Archimedes of
Syracuse
(287-212 B.C.)
- considered the “greatest scientist
and mathematician of ancient
times.”
- he studied floating bodies and the
various properties of geometric
figures.

13. - was the first to correctly
hypothesize the earth turns on its
axis and revolves around the Sun,
anteceding Copernicus by more
than 1500 years.
- he used the method of ratio and
proportion in his calculations of the
sizes of the Sun and the Moon.

14. - he also discovered the laws of
governing levers.
- Hipparchus of
- Nicaea
- V (146-127 B.C.)

15. - one of the greatest Greek
astronomers of antiquity.
- he constructed a very systematic
model of the heavens and made
more accurate determination of the
sizes of the Sun and Moon and
their distances from earth.

16. Claudius
Ptolemaeus or
Ptolemy of
Alexandria
(A.D. 100-170)
- considered the “greatest
astronomer of antiquity.”

17. - he wrote his famous book,
Almagest where he explained
his theory of planetary motion
and described in detail the
motion of the planets around
the Earth.
- he advocated the geocentric
theory which placed the
stationary earth at the center

18. of the universe with the sun,
the planets, the Moon and the
stars orbiting around it in
perfect circles at equal rates,
except for the planets.
- although proven incorrect 1500
years later by Copernicus,
Kepler and Newton.

19. - his attempts for accuracy and
precision of details is a model
for subsequent scientists to
emulate.

20. FOUNDERS OF MODERN SCIENCE

21. Nicalaus Copernicus (1473-1543)
- Polish astronomer who proposed that
the planets have the Sun as the fixed point
to which their motions are to be referred;
that Earth is a planet which, besides
orbiting the Sun annually, also turns once
daily on its own axis; and that very slow,
long-term changes in the direction of this
axis account for the precession of the
equinoxes.

22. - This representation of the heavens is
usually called the heliocentric, or
“Sun-centred,” system - derived from the
Greek helios, meaning “Sun.”
Tycho Brahe (1546-1601)
- Danish astronomer whose work in
developing astronomical instruments and
in measuring and fixing the positions
of stars paved the way for future
discoveries.

23. - His observations - the most
accurate possible before the
invention of the telescope included
a comprehensive study of the solar
system and accurate positions of
more than 777 fixed stars.
Johannes Kepler (1571-1630)
- German astronomer who discovered
three major laws of planetary motion,
conventionally designated as follows:

24. a. the planets move in
elliptical orbits with the Sun at one
focus
b. the time necessary to traverse any arc
of a planetary orbit is proportional to
the area of the sector between the
central body and that arc (the “area
law”)
c. there is an exact relationship between
the squares of the planets’ periodic
times and the cubes of the radii of their
orbits (the “harmonic law”)

25. Galileo Galilei (1564-1642)
- Italian natural philosopher, astronomer,
and mathematician who made
fundamental contributions to the
sciences of motion, astronomy,
and strength of materials and to the
development of the scientific method.
- His formulation of (circular) inertia,
the law of falling bodies,
and parabolic trajectories marked the
beginning of a fundamental change in
the study of motion.

26. - His insistence that the book of nature
was written in the language
of mathematics changed natural
philosophy from a verbal, qualitative
account to a mathematical one in
which experimentation became a
recognized method for discovering the
facts of nature.

27. - His discoveries with the telescope
revolutionized astronomy and paved the
way for the acceptance of
the Copernican heliocentric system, but
his advocacy of that system eventually
resulted in an Inquisition process against
him.

28. Roger Bacon (1220-1292)
- English Franciscan philosopher and
educational reformer who was a
major medieval proponent of
experimental science.
- studied mathematics, astronomy,
optics, alchemy, and languages.
- He was the first European to describe in
detail the process of making gunpowder,
and he proposed flying machines and
motorized ships and carriages.

29. - Displayed a prodigious energy and zeal
in the pursuit of experimental science.
Isaac Newton (1642-1727)
- English physicist and mathematician,
who was the culminating figure of the
scientific revolution of the 17th century.
In optics, his discovery of
the composition of white
light integrated the phenomena
of colours into the science of light and

30. laid the foundation for modern physical
optics.
- In mechanics, his three laws of motion,
the basic principles of modern physics,
resulted in the formulation of the law of
universal gravitation.
- In mathematics, he was the original
discoverer of the infinitesimal calculus.