earth sci- universe

• Galaxies- A large group of stars, gas, and dust bound

  together by gravity
• Dark matter - Matter that has gravity but does not emit

  light, Has Attractive Gravity, Formed of Particles and it Binds the Universe and its about 23-27% of the entire universe
• Dark energy - Source of anti-gravity, Counteracts gravity and causes the universe to expand, Non-particulate and its about 68-73% of the entire universe

  - Has Repulsive Gravity

  - Tears the Universe
• Baryonic matter - Ordinary matter consisting of protons,

  neutrons, and electrons - Comprises atoms, planets, stars, galaxies and+

  other bodies and its about 4-4.6% of the entire universe
• Light year - Distance that a light can travel in a year
• what is the age of universe? 13.8 billion Years Old
• What stars become after they have

  exhausted nuclear fuel - White dwarf
• Neutron star - Celestial object of very small radius and very

  high density

  • Composed predominantly of closed packed

  neutrons
• Protostar - Earthly stage of star resulting from the

  gravitational collapse of gases
• Edwin hubble - First that proved the universe is expanding

  • Proved there is a direct relationship between

  the speeds of distant galaxies and their

  distances from Earth
• Who Announced significant discovery of

  "red-shift" - Edwin hubblee
• Planetary nebula - Ringshaped nebula formed by an

  expanding shell of gas around an aging star
• Thermonuclear reaction - Nuclear Fusion Reaction responsible for the energy produced by stars
• Hubble's Law - Dominant motion in the universe is the

  smooth expansion

  • "The distant galaxies we see in all directions

  are moving away from Earth"
• Black Hole - Region of space having a gravitational field

  so intense that no matter or radiation can

  escape
• Red shift - Increase in wavelength: decreased in

  frequency and moving away
• BLUE SHIFT -Decreased in wavelength: increased in

  frequency and moving closer
• Cosmic microwave backround - Remnant heat left over from the Big Bang

  • Arno Penzias and Robert W. Wilson in 1964

  using WMAP spacecraft

  • Big Bang theory predicts that the early

  universe was a very hot place and that as

  it expands, the gas within it cools
• Doppler effect - Apparent frequency of a sound changes

  due to the relative movement of the source

  and/or observer
• Objects moving toward you appear Blue but if objects moving away appear Red
• Ancient egypt - Believed in many gods and myths which

  narrate that the world arose from an infinite

  sea at the first rising
• CENTRAL AFRICA -People of Kuba in Central Africa tell the story

  of a creator god Mbombo (Bumba) who (in

  immense stomach pain) vomited the stars,

  sun, and moon
• India- Gods sacrificed Purusha (primal man) whose

  head, feet, eyes, and mind became the sky,

  earth, sun, and moon (respectively)
• Nebula- composed of gases (hydrogen) and dust
• Stellar evolution - process of star formation
• stars - are the building blocks of galaxy
• most abundant elements of the universe is Hydrogen, Helium, Lithium
• Hubble Space Telescope was named after

  Edwin Hubble
• Orion arm - Sun and entire solar system location
• Steady state model - Suggests that the universe is always expanding in a constant average density
• Big bang theory - Started from a tiny dense and hot mass to its present size and much cooler state
• Big bang theory rest on two ideas which is - General relativity and Cosmological principle
• Homogeneous – every point is equivalent
• Isotropic – every direction is equivalent
• Asteroid belt - Circumstellar disc located between the orbits of Mars and Jupiter
• Kuiper belt - Comprises numerous rocky or icy bodies a few meters to hundreds of kilometers in size
• Oort cloud - Marks the outer boundary of the solar system and is composed mostly of icy objects
• Terrestial planets - have High densities

  ● Thin or no atmospheres

  ● Rotate slowly

  ● Rocky materials such as silicates, iron, and

  nickel of high melting points
• Jovian Worlds - have

  ● Low densities

  ● Thick atmospheres

  ● Rotate rapidly
• Collision or Encounter Hypothesis- What hypothesis that is Assumption is that the Sun was formed before the planets. - The gravitational attraction of closely passing

  star of blast of a nearby supernova

  • Explosion drew out a filament of solar material

  that condensed to form the planets.