 Make a list of 10 things you know about scientific theory. (5-7 Minutes) ◦ What is the definition? ◦ What are some examples? ◦ Can scientific theories change? ◦ If so, how can scientific theories change?  Prior to reviewing the answers on the next slide, make a list of information that students listed on the dry erase board in the back of the room.

 A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation. ◦ In everyday language, a “theory” is a hunch or a guess. THIS IS NOT THE CASE IN SCIENCE.

 Some theories ◦ Evolution ◦ Gravity ◦ Atomic Theory ◦ Cell Theory  Theories rely on inferences. ◦ Inferences – a conclusion that you can draw from the available evidence

 A scientific theory can change…. ◦ ONLY IF there is new evidence prompting scientists to revisit the current theory. NOW WE ARE GOING TO WATCH A TWO MINUTE VIDEO ABOUT THE BIG BANG THEORY. JUST WATCH – NO NEED TO TAKE NOTES. IT IS OKAY TO WATCH THE VIDEO TWICE.

 console#search/the big bang video  Use Chrome

Important notes to record in your journal are marked with a STAR. Information that does not have a star is provided to expand on the broad concepts presented throughout the powerpoint.

 The Big Bang Theory is the current model that describes the early development of the universe.  The universe started as a little speck of a hot, super-massive, and super dense ball.  Everything that is currently in the universe came from that one tiny speck.

 Every proton, neutron, atom, and so forth came from that hot, super-massive, and super-dense ball.  About 13.7 Billion years, BANG!!!  A violent explosion hurled the material within that ball into all directions of space.

 The universe expanded quickly after the Big Bang and continues to expand today.  As the universe expanded and cooled, things started to form. ◦ i.e. – Protons, neutrons, atoms, stars, and galaxies  All of the different elements that exist today developed from that initial ball 13.7 billion years ago.

 13.7 billion years ago – BANG! ◦ Exactly what triggered the sudden expansion remains a mystery.

 Gravity formed  Electromagnetic forces emerged  The universe was made up of fundamental particles, including quarks, electrons, photons, and neutrons

 The universe takes shape.  The protons, neutrons, and electrons come together to form elements. ◦ At this time, the universe is made up largely of helium and hydrogen, which we will learn later are two of the simplest elements in existence.

 The universe remained an enormous cloud of hot, expanding gas.  As the universe continued to cool, electrons were able to combine with hydrogen and helium.  Photons were no longer scattered. Time and distance shifted them into microwave lengths.

 Gravity amplified slight irregularities in the density of the “primordial gas.”  Even as the universe continued to expand, pockets of gas became more and more dense.  Stars were formed within these pockets.  Groups of stars became the earliest galaxies.

 Smaller galaxies merged into larger ones, forming different shapes (like spirals or spheres).  Sometimes these mergers were so violent that stars and gas collapsed into a common center, creating black holes.

 Within galaxies, stars were born while others died.  When stars die, they create enormous explosions called supernovas.  Supernovas are important to the evolution of galaxies because they distribute all of the common elements (oxygen, carbon, nitrogen) into space.  These explosions also create heavier elements such as gold, silver, and lead.

 The sun formed within a cloud of gas in the Milky Way Galaxy.  A vast disk of gas and debris that swirled around this new star formed planets, moons, and asteroids.

 Astronomers estimate that in about 3,000,000,000 years, our galaxy will be swallowed up by one of its nearest neighbors (Andromeda).  Scientists believe that depending on their pathways, these two galaxies will either merge to form one galaxy or they will destroy each other.

 console#search/the big bang video  Use Chrome

 Read articles in small groups and think about the following questions: ◦ What contribution did this person make to how we view the universe? ◦ What previous information did the person build upon and/or challenge in making the contribution? ◦ What evidence is used to challenge and support he contribution this person made? ◦ What political and social challenges, if any, did this person face when making his contribution.

 Share out information to the class regarding your scientist.  Three minutes per group.  Whole group discussion – who had the bigger influence?

 Write a letter to a Kindergartener explaining The Big Bang Theory. Be sure to use your timeline notes.  Important vocabulary to include: gravity, electromagnetic forces, supernova, stars, galaxies, scientific theory, The Big Bang

 3 things you learned about the Big Bang Theory  2 important points that will be on your test  Write one questions you still have about the Big Bang