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Astronomy
Question | Answer |
---|---|
Kepler's 1st law of Planetary Motion | The orbit of each planet about the Sun is an ellipse with the Sun at one focus |
Newton | Built the first reflecting telescope (1668) |
Copernicus | Published heliocentric theory of the Universe (1543) |
Galileo | Used telescope for astronomical purposes and discovers 4 Jovian moons, Moon's craters, and Milky Way Galaxy (1609) |
Ptolemy | Suggested geocentric theory of the universe in work Mathematike Syntaxis (140 BC) |
Brahe | Discovered a supernova in the constellation Cassiopeia (1572) |
Aristarchus | Suggested the Earth revolves around the Sun. He provided the first estimate of Earth-Sun distance (280 BC) |
Eratosthenes | Measured the circumference of the Earth with surprising accuracy (240 BC) |
Hipparchus | Developed first accurate star map and star catalogue with over 850 bright stars (130 BC) |
First Solar/Lunar calendars | 2000 BC in Egypt and Mesopotamia |
Julian Calendar | Purely solar calendar implemented in the Roman Empire (45 BC) |
Hans Lippershey | Spectacle maker invents telescope (1608) |
Kepler | Created the 3 laws of Planetary Motion (1609 - 1619) |
Kepler's 2nd law of Planetary Motion | As a planet moves around its orbit, it sweeps out equal areas in equal times. This tells us that a planet moves faster when it is closer to the Sun (near perihelion) than when it is farther from the Sun (near aphelion) in its orbit. |
Newton's Laws | 3 Laws of Motion and the Universal law of gravitation |
Newton's Laws of Motion | 1) In the absence of a net force, an object moves with constant velocity 2) a net force affects an object's motion. Force = rate of change in momentum or force = mass X acceleration 3) For any force, there is always an equal and opposite reactive force. |
Newton's Universal law of Gravitation | The force of gravity (Fg) between two objects given by the formula Fg = G(M1M2/d2) |
Drake Equation | Lays out the factors that play a role in determining the number of communicating civilizations in our galaxy. |
Circles within circles | Ancient Greek theory that the earth was the center of the Universe and all planets moved in perfect circles around Earth. |
Heliocentric | Belief that the sun is the center of the Universe |
Geocentric | Ancient belief that the Earth is the center of the Universe |
Conservation of energy | Energy (including mass-energy) can be neither created nor destroyed, but can only change from one form to another |
Conservation of momentum | In the absence of net force, the total momentum of a system remains constant |
Conservation of angular momentum | in the absence of net torque (twisting force), the total angular moment of a system remains constant |
Azimuth | Direction around the horizon from due north, measured clockwise in degrees |
Astronomy | The study of the Universe and movement of the planets |
Astrology | The study of the movement of the stars and how their alignment affects people's lives |
Stars in Milky Way | 100 Billion |
Stars in the entire Universe | 100 Billion X 100 Billion = 10,000,000,000,000,000,000,000 or 10^22 |
Speed of Light | 300,000 km per sec |
Size of the Earth | Earth = tip of a ballpoint pen Sun = size of a grapefruit |
Distance to the Sun | 1 AU or 150,000,000 km |
Distance to the moon | 4 days from the earth |
Age of the Solar System | 13.7 Billion Years |
Ecliptic | Apparent movement of the sun and stars across the sky |
Zenith | 90 degrees above the horizon (straight up) |
Azimuth | left to right direction |
Mass | amount of particles in a given space |
Acceleration due to gravity | The acceleration of a falling object which is designated by g = 9.8 m/s squared |
Energy | what makes matter move; kinetic, potential, radiative |
Astronimical Units (AU) | The average distance (semimajor axis) of the Earth from the Sun which is about 150 million km |
Light Year | Distance light travels in one year which is 9.45 trillion km (9.46 x 10^14) which = 300,000 km/sec |
Rotation | The spinning of an object around its axis |
Revolution | The orbital motion of one object around another |