The document provides an overview of cosmological theories and astronomers throughout history. It discusses Ptolemy's geocentric model, Aristarchus and Copernicus proposing heliocentric models, Tycho Brahe's observations, Galileo discovering Jupiter's moons and sunspots, Kepler's laws of planetary motion, Newton's law of universal gravitation, Gamow's Big Bang theory, Hubble confirming other galaxies, the steady state theory, and old earth creation theory accepting the age of the Earth but questioning evolution.

1. Submitted by: URETA, Renee D.
BS Biology 2

2. THE
UNIVERSE
As the totality of everything
that exists, including
all matter and energy, the p
lanets, stars, galaxies, and
the contents of intergalactic
space.

3. PTOLEMY ARISTARCHUS COPERNICUS BRAHE
SELECT
AN
ASTRONOMER
TO
BEGIN
GALILEI KEPLER NEWTON

4. CLAUDIUS PTOLEMY
Ptolemy is most famous for his
contribution to astronomy, which is in
his 13-book work called the Almagest.
The Ptolemaic system of astronomy placed
the Earth at the center of the universe
and explained all the observed motions
of the Sun, Moon, planets, and stars
with a system of uniform circular
motions.
Ptolemy borrowed heavily from the
previous work of Hipparchus.
The Ptolemaic astronomical system was
wrong, but it was a good enough
scientific model to last over 1400 years
until the time of Copernicus.

5. PTOLEMY’S
SOLUTION

6. ARISTARCHUS OF
SAMOS Aristarchus (310 BC -230 BC)

was a famous Greek
mathematician and astronomer,
popular for his theories
regarding the heliocentricity of
our solar system.
 He was the first to say that the
Sun, and not the Earth, was the
center of our universe. This
theory brought him ridicule
during his lifetime.
 Aristarchus was one of the first
astronomers to calculate the
relative sizes of the Sun, the
Moon and the Earth.

7. NICOLAS COPERNICUS
 The Universe was Earth
centered.
 His theory answered the
fact that the planet’s sizes
were different throughout
the year and the fact that
the orbits of the planets
were irregular now and
then would be explained.
He wrote his theory in a
book, De Revolutionibus
Orbium Coelestium (On
the Revolutions of the
Heavenly Spheres)

8. TYCHO  Tycho's major works include De Nova et Nullius
Aevi Memoria Prius Visa Stella ("On the New
BRAHE and Never Previously Seen Star) (Copenhagen,
1573); De Mundi Aetherei Recentioribus
Phaenomenis ("Concerning the New
Phenomena in the Ethereal World) (Uraniburg,
1588); Astronomiae Instauratae
Mechanica ("Instruments for the Restored
Astronomy") (Wandsbeck, 1598; English tr.
Copenhagen, 1946); Astronomiae Instauratae
Progymnasmata ("Introductory Exercises
Toward a Restored Astronomy") (Prague 1602).
 His observations were not published during his
lifetime. Johannes Kepler used them but they
remained the property of his heirs. Several
copies in manuscript circulated in Europe for
many years, and a very faulty version was
printed in 1666. At Prague, Tycho hired
Johannes Kepler as an assistant to calculate
planetary orbits from his observations. Kepler
published the Tabulae Rudolphina in 1627.
Because of Tycho's accurate observations and
Kepler's elliptical astronomy, these tables were
much more accurate than any previous tables.

9. GALILEO  in 1609, instrument put together by a
GALILEI lens-grinder in Holland, he constructed
the first complete astronomical telescope.
 Galileo discovered that the moon, shining
with reflected light, had an uneven,
mountainous surface and that the Milky
Way was made up of numerous separate
stars.
 In 1610 he discovered the four largest
satellites of Jupiter, the first satellites of a
planet other than Earth to be detected.
He observed and studied the oval shape
of Saturn (the limitations of his telescope
prevented the resolving of Saturn's rings),
the phases of Venus, and the spots on the
sun. His investigations confirmed his
acceptance of the Copernican theory of
the solar system; but he did not openly
declare a doctrine so opposed to
accepted beliefs until 1613, when he
issued a work on sunspots.

10. JOHANNES KEPLER
 Johannes Kepler 1571-
1630
 Worked for Tycho
Brahe, inherited his
data
 Heliocentric model (29
years!)
 Found orbit shapes by
observation from
different points in
Earth’s orbit

11. KEPLERS 3 LAWS:
 Orbit of every planet is an ellipse with the sun at one of
the foci. Thus, Kepler rejected the ancient Aristotelean
and Ptolemaic and Copernican belief in circular motion.
 A line joining a planet and the sun sweeps out equal
areas during equal intervals of time as the planet travels
along its orbit. This means that the planet travels faster
while close to the sun and slows down when it is farther
from the sun.
 The squares of the orbital periods of planets are
directly proportional to the cubes of the semi-major
axes (the "half-length" of the ellipse) of their orbits. This
means not only that larger orbits have longer periods,
but also that the speed of a planet in a larger orbit is
lower than in a smaller orbit.

12. ISAAC NEWTON
 Gravity, Newton’s
other great
contribution, is one
of the four
fundamental forces
in the universe.

13.  Because of Galileo’s
work, Newton knew
that an object fell to
the Earth at a rate of
about 9.8 meters
(32 feet) per
Newton’s Third Law of
second. Thus “the
Motion : every force exerted
apple [that] fell from by one object on another is
the tree” fell to the equal to a force, but
Earth at about this opposite in direction,
rate. exerted by the second
object on the first (every
reaction has an equal but
opposite reaction).

16. GEORGE
GAMOW
 During the War, when all the
American nuclear physicists were
involved in the Manhattan
project, Gamow worked on the
problem of the cosmic origin of
the elements, which he
proposed to solve, in 1948, by
what is now called the Big Bang
theory.
 He wrote books on atomic
physics for the general public,
such as The Creation of the
Universe (1952), and for young
people, such as Mr. Tompkins
Explores the Atom (1944)

17. OPEN
UNIVERSE

18. EDWIN HUBBLE
• American astronomer who
profoundly changed the
understanding of the
universe by confirming the
existence of galaxies other than
the Milky Way. He also
considered the idea that the loss
in frequency—the redshift—
observed in the spectra of
light from other galaxies
increased in proportion to a
particular galaxy's distance from
Earth. This relationship became
known as Hubble's law.

20. Bondi, Gold, Hoyle
The steady state theory of Bondi and Gold
was inspired by the circular plot of the
film Dead of Night, which they had
watched together. Theoretical calculations
showed that a static universe was
impossible under general relativity, and
observations by Edwin Hubble had shown
that the universe was expanding. The
steady state theory asserts that although
the universe is expanding, it nevertheless
does not change its appearance over
time; it has no beginning and no end.

21. CREATION
THEORY
Old Earth creation theory asserts that God
did create the universe, but includes the idea
that Genesis is not a literal description
of creation. This branch
of creation theory accepts scientific dating of
the Earth and the physical universe, but
questions evolution theory. Old Earth
creationism can be separated into three
different categories, including gap, day age,
and progressive creationism. Each category
accepts God as the creator of the physical
universe, but supports different views
concerning the processes involved in
creating the world as we know it.