Astronomy
BY: Nick Wilson, and John Travis
Early Astronomers/Nicolaus Copernicus
Copernicus(1500's) reinvented the Heliocentric Model. The
heliocentric model had greater depth than simply an improvement to
solve retrograde motion, it also had social and political consequences.
Heliocentric theory questioned the authority of the most revered wise
men of the ancient world and the outcry over his ideas had little to
due with the impersonal concern for truth. By placing the Sun at the
center of the Solar System, Copernicus forced a change in our
worldview.
Tycho Brahe
Tycho Brahe (1580's) was astronomy's 1st true observer. He built the
Danish Observatory (using sextant's since telescopes had not been
invented yet) from which he measured positions of planets and stars
to the highest degree of accuracy for that time period (1st modern
database). He showed that the Sun was much farther than the Moon
from the Earth, using simple trigonometry of the angle between the
Moon and the Sun at 1st Quarter.
Johannes Kepler
Kepler (1600's) a student of Tycho who used Brahe's database to
formulate the Laws of Planetary Motion which corrects the problems
of epicycles in the heliocentric theory by using ellipses instead of
circles for orbits of the planets.The formulation of a highly accurate
system of determining the motions of all the planets marks the
beginning of the clockwork Universe concept, and another paradigm
shift in our philosophy of science.
Galileo Galilei
Galileo Galilei (1564-1642) The Italian physicist and astronomer first
used a telescope from lenses he made himself, at the beginning of the
17th Century. The telescope was 30X. In 1609, he made a drawing of
the moon for the world to see. Again, he stated that the Sun was the
center of the universe, for this he was persecuted for going against the
Church. The Inquisition forced him to repeal his discoveries in order
avoid torture. He also discovered sun spots and Jupiter's 4 satellites.
Isaac Newton
Isaac Newton (1643-1727) at the University of Cambridge, developed
the laws of gravity. He coined the now famous term "and to every
action there is always an equal and opposite or contrary,
reaction." Newton also determined the moon's effect on the tides. He
also discovered that the prism seperated light's component colours,
which added to the study of stars through spectral analysis.
Edwin Hubble
1924- Edwin Hubble (1889-1953) discovered
that our Milky Way was not the
center of the universe, but rather only one galaxy in among billions.
He calulates the distance to the Andromeda and Triangulum 'nebulas'.
He also measures the redshift of the spectra of the galaxies and states
that the universe is expanding.
Geocentric Model
The Geocentric Model sets Earth as the center of the universe. The
theory that the Earth was the center and not the sun was long accepted
worldwide before Nicolaus Copernicus discovered the sun was the
center.
Heliocentric Model
The Heliocentric Model sets the sun as the center of the universe.
When Copernicus first told people the sun was the center of the
universe no one would accept this and he was hated by many people.
This is now the modern day model of the universe.
Ptolemaic System
The Ptolemaic System is the theory that the Earth stands motionless at
the center of the Earth, and everything revolves around it. This is the
basis for the Geocentric Model, and was long beleived to be true.
About 20% of Americans still think this is true.
Cycle Of The Moon
1. New (also called the Dark Moon) - not visible
2. Waxing Crescent
3. First Quarter - commonly called a "half moon"
4. Waxing Gibbous
5. Full - we can see the entire illuminated portion of the moon
6. Waning Gibbous
7. Third Quarter - another "half moon", but the illuminated part is
opposite of the First Quarter
8. Waning Crescent
9. New - back to the beginning
Terrestrial Planets
The four closest planet to the Sun - Mercury, Venus, Earth, and Mars
- they are called terrestrial planets because they have hard, rocky
surfaces.But generally speaking they are all small, rocky bodies (lots
of minerals made of the elements silicon,
oxygen, aluminum, magnetism, sulfur, and iron) within its
atmospheres.
Jovian Planets
The four Jovian Planets are Jupiter, Uranus, Saturn, and Neptune. These
planets are mostly gas. Jovian planets are sometimes called a gas giant.
Refracting Telescopes
A refracting telescope is a form of optical telescope that uses a lens as
its objective to form an image. Although large refracting telescopes
were popular in the 19th century, the reflecting telescope was used for
most research.
Reflecting Telescopes
Reflecting telescopes use two mirrors to reflect light from an object to
create an image. This telescope was used for most research purposes
instead of the refracting telescope.
Radio Telescopes
Radio telescopes use a radio antenna and is involved in radio
astronomy. They use the radio wave frequency of the electromagnetic
spectrum to collect data. These telescopes don't have to worry about
light pollution unlike the reflecting and refracting telescopes.
How Do Space Rocks Impact Earth
A space rock (meteor, meteorite, meteoroid) that hits the Earth can
create craters in the ground. If it hits something whatever it hit will
probably be destroyed.
Electromagnetic Spectrum
The Electromagnetic Spectrum is the range of all possible frequencies
of Electromagnetic Radiation. It extends from low frequencies like
radio waves to gamma radiation.
Basics Of The Sun
● The sun rotates around its axis once in about 27 days
● The sun is the center of the universe
● The suns surface is about 6,000 degrees F on the surface
● The core is over 15,000,000 degrees F
● The suns radius about 696,000 kilometers across, the equivalent to
109 Earths
● You can fit about 1,000,000 Earths inside the sun
Space Probes
Space Probes are used to study space without having to use people.
They are used to research the moon, planets, stars, and whatever else
that scientists feel needs to be researched.