Physics last quarter

• PYTHAGORAS

  ·       Around 500 B.C., most Greeks believed that the Earth was round, not flat. It was Pythagoras and his pupils who were first to propose a spherical Earth.
• ANAXAGORAS

  ·       In 500 to 430 B.C., Anaxagoras further supported Pythagoras' proposal through his observations of the shadows that the Earth cast on the Moon during a lunar eclipse. The shadow reflected was circular.
• ARISTOTLE

  ·       Around 340 B.C., Aristotle listed several arguments for a spherical Earth which included the positions of the North Star, the shape of the Moon and the Sun, and the disappearance of the ships when they sail over the horizon
• NORTH STAR,

  It was believed to be in fixed position in the sky. However, when the Greeks traveled to places nearer the equator, like Egypt, they noticed that it is closer to the horizon.
• OBLATE SPHEROID

  The shape of the Earth. It has bulging equator and squeezed poles
• EUDOXUS

  ·       Eudoxus proposed a system of fixed spheres. He believed that the Sun, the moon, the five known planets and the stars were attached to these spheres which carried the heavenly bodies while they revolved around the stationary Earth.
• ARISTARCHUS

  Aristarchus is the very first Greek to profess the heliocentric view. The word helios means sun; centric means centered. This heliocentric view considered the sun as the center of the universe
• Heliocentrism: the astronomical model in which the Earth and planets revolve around the Sun
• Geocentrism: any theory of the structure of the solar system (or the universe) in which Earth is assumed to be at the center of it all.
• ERATOSTHENES

  The first successful attempt to determine the size of the earth was made by him. He did this by applying geometric principles. He observed the angles of the noonday sun in two Egyptian cities that were almost opposite each other- Syene in the south and Alexandria in the north
• CLAUDIUS PTOLEMY

  ·       He believed that the earth was the center of the universe. His Ptolemaic Model claimed that the planets moved in a complicated system of circles. This geocentric model also became known as the Ptolemaic System.
• HIPPARCHUS

  ·       Hipparchus is considered as the greatest of the early Greek astronomers. He observed and compared the brightness of 850 stars and arranged them into order of brightness or magnitude. He developed a method for predicting the times of lunar eclipses to within a few hours. Aside from this, he also measured the length of the year to within minutes of the modern value.
• EXAMPLES OF ASTRONOMICAL PHENOMENA BEFORE THE ADVENT OF TELESCOPES

  ·       NEW MOON

  ·       WAXING CRESENT

  ·       FIRST QUARTER MOON

  ·       WAXING GIBBIUS

  ·       FULL MOON

  ·       WANING GIBBOUS

  ·       THIRD QUARTER

  ·       WANING CRESCENT
• GNOMON

  ·       shadows that the gnomon casts, they were able to observe that the sun rises in the eastern part of the sky, reaches its highest point in midday, and sets in the western part of the sky.
• MOON

  ·       A moon, also called a satellite, is a relatively small object that is orbiting around a planet.

  ·       Just like the Earth, half of the moon is always lit by sunlight and the other half is in shadow.

  ·       It takes our moon about 29.5 days to complete one cycle of phases (from full Moon to full Moon).
• Moon: A natural object that orbits a larger object.
• Eclipse: when one celestial body such as a moon or planet moves into the shadow of another celestial body
• Solar eclipse: a type of eclipse that occurs when the Moon passes between the Sun and Earth, and the Moon fully or partially blocks the light from the Sun.
• Gibbous: the figure of the moon that is more than half full, looking swollen on one side
• Crescent: the figure of the moon that appears as a curve with pointy ends
• Waning: shrinking; describes the moon when the illuminated portion is decreasing
• Waxing: growing; describes the moon when the illuminated portion is increasing
• Planet: In the solar system, a planet is a large round object that orbits the Sun and has cleared out most of the other objects in its orbit.
• Solar System: The Sun and all of the planets, comets, etc. that revolve around it.
• LUNAR ECLIPSE

  ·       The lining up of the earth, moon, and sun produces a lunar eclipse when the moon passes into the shadow of the earth.

  ·       MES
• SOLAR ECLIPSE

  ·       solar eclipse occurs when the moon’s shadow falls on the earth.

  ·       EMS
• CELESTIAL SPEHERE

  ·       celestial bodies can be described as diurnal motion, annual motion, and precession of the equinoxes.
• DIURNAL MOTION

  ·       Diurnal motion is the apparent daily revolution of the celestial sphere around the celestial poles as a direct effect of the Earth’s rotation on its axis.
• PRECESSION OF THE EQUINOXES

  ·       sun revolves around the ecliptic, it intersects the celestial equator twice during a year at two points. These points are called the equinoxes: vernal and autumnal.
• ANNUAL MOTION

  ·       Annual motion is the apparent yearly movement of the stars as observed from Earth
• ARISTOTLE’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  ·       VERTICAL MOTION Vertical motion is referred to as natural motion. In a natural motion, the object will move and will return to its natural state based on the object's material or composition - earth, water, air, and fire.
• ARISTOTLE’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  ·       HORIZONTAL MOTION An object moving in a violent motion requires push or pull to maintain horizontal motion. Motion continues only so long as there is an applied force to an object. When the force is removed, motion stops.
• ARISTOTLE’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  PROJECTILE MOTION Aristotle believed that the projectile motion of an object is parallel to the Around until it is the object's time to all back into the Around
• GALILEO’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  ·       VERTICAL MOTION ● In the absence of a resistance, objects would all not depending on their weight, but in the time it falls.
• GALILEO’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  ·       HORIZONTAL MOTION ● An object in motion, is unimpeded, will continue to be in motion, and an external force is not necessary to maintain the motion. In the Earth’s surface is very flat and extended infinitely, objects that are pushed will not be impeded.
• GALILEO’S CONCEPT OF VERTICAL MOTION, HORIZONTAL MOTION, AND PROJECTILE MOTION

  PROJECTILE MOTION Galileo believed that a projectile is a combination of uniform motion in the horizontal direction and uniformly accelerated motion in the vertical direction