PHYSICAL SCIENCE

• Astronomy


  A natural science that deals with the study of celestial objects and phenomena
• Astronomy


  • Uses Mathematics, Physics and Chemistry in order to explain the origin and evolution of celestial objects and phenomena
• Types of terrestrial motion

  • Diurnal - daily rotation of Earth on its axis
  • Annual Motion - yearly revolution of Earth around the Sun
  • Precession of Equinoxes - wobbling of Earth every 36,000 years due to gravitational pull of Sun and Moon
• Rotation


  Earth rotating on its own axis, producing the 24-hour day
• Revolution


  Earth revolving around the Sun, producing the 365-day year
• Equinox


  An event in which a planet's subsolar point passes through its equator, when both the Northern and Southern Hemisphere experience roughly equal amounts of daytime and nighttime
• Equinoxes


  • March equinox - vernal (spring) equinox
  • September equinox - autumnal equinox
• Geocentric models


  • Assume Earth is the center of the universe
• Heliocentric models


  • Assume the Sun is the center of the universe
• Early models of the universe

  • Thales - Earth is a disk floating on water
  • Anaximander - Earth is a cylinder with curved surface
• Geocentric models


  • Pythagorean - Earth is round, heavenly bodies move in circles
  • Plato - Universe is perfect and unchanging, planets move in circular orbits
  • Eudoxus - Uses concentric spheres for sun, moon and planets
  • Aristotle - Uses buffering spheres and Prime Mover
  • Ptolemy - Complex epicyclic model with epicycles and deferents
• Heliocentric models


  • Philolaus - "Pyrocentric" model with fire at center
  • Aristarchus - Sun-centered model with planets in circular orbits
  • Copernicus - Earth spins on axis and revolves around Sun
• Tycho Brahe


  • Accurately measured and recorded positions of Sun, Moon and planets for 20 years
  • In his model, Sun orbits Earth while other planets orbit Sun
• Galileo Galilei


  • Observed mountains and craters on Moon, sunspots, 4 moons of Jupiter, phases of Venus with telescope
• Johannes Kepler


  • Inherited Brahe's data and formulated 3 laws of planetary motion
• Kepler's 3 laws of planetary motion

  • Law of Ellipses - Planets move in ellipses with Sun at one focus
  • Law of Equal Areas - Planets cover equal areas in equal times
  • Law of Harmonies - Orbital period is proportional to size of orbit
• Perihelion


  Closest point of a planet's orbit to the Sun
• Aphelion


  Farthest point of a planet's orbit from the Sun
• Major zones of the solar system

  • Inner System - Very hot, can have Iron Silicate, Molten, and Heliosal Desert planets
  • Habitable Zone - Where Earth is, can have Terrestrial, Over-Industrialized, and Transition Desert planets
  • Asteroid Belt - No planets, just asteroids
  • Outer System - Gas giants, can have Hypertonic Gas Giant, Grass Gas Giant, and Equatorial Ring planets
  • Kuiper Belt - Ice Dwarf and Dense Turbulent planets
• Newton's Laws of Motion

  Fundamental principles that describe the relationship between an object and the forces acting upon it
• Universal Gravitation


  The force by which a planet or other body draws objects toward its center
• Isaac Newton

  Renowned researcher and key figure in the development of modern physics, made significant contributions to optics, astronomy, and physics, and is remembered as one of the greatest scientists of all time
• Isaac Newton's lifespan


  January 4, 1643 - March 31, 1727
• Isaac Newton


  • Formulated the three laws of motion, which explain how objects move in response to forces
• Motion

  Change with time of the position or orientation of a body
• Types of motion

  • Translational
  • Rotational
• Translational motion

  A motion in which all the points of a body move uniformly in a single direction
• Rotational motion


  The motion of an object around a circular path, in a fixed orbit
• Inertia


  A tendency of a body to resist any change in its state of rest or uniform motion
• Newton's First Law (Law of Inertia)

  An object in motion will remain in motion, and an object at rest will remain at rest, unless acted upon by an unbalanced force
• Inertia at rest

  A tendency of a body to resist any change in its state of rest
• Inertia of motion


  A tendency of a body to resist the change in its state of uniform motion
• Inertia in one direction

  The tendency of a body or object to oppose any change in the direction of the motion
• Newton's Second Law


  Net force is equal to mass times acceleration
• Newton's Third Law (Action and Reaction)


  When two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction
• An apple falling from a tree


  Inspired Sir Isaac Newton's theory of gravity
• Gravity


  The force by which a planet or other body draws objects toward its center
• Newton's Law of Universal Gravitation

  Every particle attracts every other particle in the universe with force directly proportional to the product of the masses and inversely proportional to the square of the distance between them
• Position vs. Time graph

  Visually represents an object's motion by showing how its position changes over time
• Important descriptions for Position vs. Time graph


  • Position - location of an object
  • Velocity - changes the position of an object per unit time
  • Acceleration - how quickly or slowly changing the position of an object or velocity
  • Distance Scalar - how far the distance between the object to one another is, with no specific direction
  • Displacement vector - tells you how much the object's position has changed, including both distance and direction
  • Slope - at any given time, indicates the velocity of the object