SLIFSCI

• A thought-out explanation for observations of the natural world that has been constructed using the scientific method, and which brings together many facts and hypotheses.

  Theory
• The scientific study of the stars, planets, and other natural objects in space.

  Astronomy
• A vast space that comprises trillions of galaxies and everything that exists; it includes space and dark matter.


  Universe
• Are vast cosmic islands of stars, gas, dust, and dark matter held together by gravity.

  Galaxy
• A form of energy that includes radio waves, microwaves, X-rays and gamma rays, as well as visible light.

  Electromagnetic Radiation
• God created the universe and everything that is in it. (Book of Genesis)

  Creationism
• The *currently accepted theory* of the origin and evolution of the universe. The universe *expanded from a tiny, dense and hot mass* to its present size and much cooler state.

  The Big Bang Theory by Georges Lemaitre
• Edwin Hubble supported the Big Bang Theory and states that the age of the universe is 13.8 Billion years.
• Evidences of the Big Bang Theory

  
  

  1. the redshift;
  2. abundance of hydrogen, helium, and lithium;
  3. cosmic microwave background radiation
• Developed to explain several puzzles with the Big Bang theory. It states that the early Universe *expanded exponentially fast* for a fraction of a second after the Big Bang.

  Inflation Theory by Alan Guth
• States that the universe is *expanding and will contract* once all the energy after the Big Bang is used up.

  Oscillating Universe Theory by Richard C. Tolman
• States that the universe is *constantly expanding while maintaining its average density*, matter being continuously created to form new stars and galaxies at the same rate that old ones become unobservable due to increasing distance and velocity of recession.

  Steady State Theory by Fred Hoyle, Thomas Gold, and Hermann Bondi
• Any of the natural pathways by which essential elements of living matter are circulated.

  Biogeochemical Cycle
• The term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical aspects of each cycle.
• Biology. Life. Living things. These cycles all play a role in the *lives of living things*. The cycles might limit the organisms of Earth or they might happen along side, changing the environment.

  "BIO"
• Earth. Rocks. Land. This refers to the *non-living processes at work*. Oxygen cycles through many systems. It's in you and plants for the 'bio' part of the cycle. Oxygen might also wind up in rocks.

  "GEO"
• Molecules. Reactions. Atoms. *All cycles include these small pathways*. Complete molecules are not always passed from one point to the next. Sometimes *chemical reactions* take place that changes the molecules and locations of the atoms.

  "CHEMICAL"
• Elements move through the atmosphere. Main reservoirs are the atmosphere and the ocean.

  Gas Cycles
• Elements move from land to water to sediment. Main reservoirs are the soil and sedimentary rocks.

  Sedimentary Cycles
• Minerals are the building blocks of rocks.
• Mineralogists use the criteria to determine whether a material is classified as a mineral or not.
• Mineral's color may change depending on the surface.
• The color of mineral in powdered form

  Streak
• The mineral's resistance to scratching

  Hardness
• This rates the hardness of minerals by their ability to scratch softer materials.

  Mohs Hardness Scale
• The mineral's resistance to being broken and fractured.

  Cleavage
• It is the ideal shape of crystal faces.

  Crystalline structure or habit
• Ability to allow light to pass in a mineral.

  Diaphaneity
• How light is reflected off a surface on a mineral

  Luster
• Describes the mineral's reaction to stress.

  Tenacity
• A mineral turns into powder.

  Brittleness
• A mineral can be flattened by pounding with a hammer.

  Malleability
• A mineral can be stretched into wire.

  Ductility
• Minerals are bent but they remain in the new position.

  Flexible but inelastic
• Minerals are bent and they revert back to their original position

  Flexible but elastic
• The ability of minerals to be sliced by a knife.

  Sectility
• Processes occurring on the Earth's surface and that generally reduces relief.

  Exogenic Process
• What is under degradation in the exogenic process?

  Weathering, Erosion, Mass Wasting, Transportation
• What is under aggradation in the exogenic process?

  Deposition
• Mechanical weathering or physical weathering is the breakdown of rocks into pieces without any change in its composition. In this process, the size and shape of rocks changes.