With a partner on page 55 create a definition for what is a: Theory Write 2 examples Click here for videoClick here for video flow chart

Scientific Theory A scientific theory is an explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable descriptions of the real world.

Formation of the Universe The Big Bang Theory (BBT) (BBT)

Red Shift Shift of wavelengths of light towards the red end of the spectrum; happens as a light source moves away from us (Earth). Red shift is related to the Doppler Effect: Change in frequency of a wave for an observer moving relative to its source click for video click for video Shift of wavelengths of light towards the red end of the spectrum; happens as a light source moves away from us (Earth). Red shift is related to the Doppler Effect: Change in frequency of a wave for an observer moving relative to its source click for video click for video

Red Shift Visual

Hubble’s Law The farther away a galaxy is, the faster it is moving away from us. Used Red Shift data to come to this conclusion. The farther away a galaxy is, the faster it is moving away from us. Used Red Shift data to come to this conclusion.

Expanding Universe What’s the Big Deal!? - If we study this expansion we can determine: ~How the universe formed ~Age of universe ~Could support idea of galaxy formation; material stayed in clumps then pulled together over time

Expanding Universe Visual

Extra Help org/science/cosmology- and-astronomy/universe- scale-topic/big-bang- expansion-topic/v/red-shift org/science/cosmology- and-astronomy/universe- scale-topic/big-bang- expansion-topic/v/red-shift

Doppler Effect See how the wavelength is compressed due to movement of the car. This works similarly with light as it moves away from Earth. See how the wavelength is compressed due to movement of the car. This works similarly with light as it moves away from Earth.

Background Radiation Called Cosmic Microwave Background Radiation (CMB) ‘Left over’ thermal radiation from Big Bang This has been observed and is nearly uniform throughout the entire universe Background Radiation Called Cosmic Microwave Background Radiation (CMB) ‘Left over’ thermal radiation from Big Bang This has been observed and is nearly uniform throughout the entire universe

CMB Visual

CMB Radiation CMB so uniform it is nearly impossible to explain where else it could have come from By studying CMB we have identified the Universe to be about 13.7 billion years old CMB so uniform it is nearly impossible to explain where else it could have come from By studying CMB we have identified the Universe to be about 13.7 billion years old

Evidence for BBT Red Shift Expansion of the Universe CMB Uniform radiation throughout the Universe Red Shift Expansion of the Universe CMB Uniform radiation throughout the Universe

Review-- Write In Notebook 1. How did Hubble determine that the universe is expanding? 2. How do astronomers determine the composition of distant stars? 3. What is the significance of the idea that the universe is expanding?

Big Bang Balloon Activity Title : Big Bang Balloon Activity Purpose: To model the expansion of the universe over time Procedure: See Handout Title : Big Bang Balloon Activity Purpose: To model the expansion of the universe over time Procedure: See Handout

Big Bang Balloon Activity Data Table: Galaxy Distance from Home Galaxy over time Time 1Time 2Time 3Time 4Time 5 Home Galaxy Galaxy A Galaxy B Galaxy C Galaxy D Galaxy E

Big Bang Balloon Activity Conclusion: answer the following questions in your notebook, under the heading “Conclusion.” Be sure to use complete sentences. 1. How did the distance from the home dot to each of the other galaxies change each time you inflated the balloon? 2. Did the galaxies near home or those farther away appear to move the greatest distance? Conclusion: answer the following questions in your notebook, under the heading “Conclusion.” Be sure to use complete sentences. 1. How did the distance from the home dot to each of the other galaxies change each time you inflated the balloon? 2. Did the galaxies near home or those farther away appear to move the greatest distance?

Big Bang Balloon Activity Conclusion: answer the following questions in your notebook, under the heading “Conclusion.” Be sure to use complete sentences. 3. How does this activity help to explain how the big bang could have happened? 4. How could you use this model to simulate the “Big Crunch” a time when all the galaxies might collapse in on themselves? What would you do to your balloon? Conclusion: answer the following questions in your notebook, under the heading “Conclusion.” Be sure to use complete sentences. 3. How does this activity help to explain how the big bang could have happened? 4. How could you use this model to simulate the “Big Crunch” a time when all the galaxies might collapse in on themselves? What would you do to your balloon?