Gravity & The Big Bang Theory THE UNIVERSE Gravity & The Big Bang Theory

All things with _________ are affected by ________________ GRAVITY All things with _________ are affected by ________________ Two objects, whether large or small, always have a gravitational force between them. Gravitational force ___________ as mass _______________. Gravitational force ___________ as distance _____________

THINK! What are two examples of gravity at work? Why is a cat easier to pick up than an elephant?

DEFINITION OF THE UNIVERSE UNIVERSE: ____________________________________________________________ ________________________________________ that exist, that have existed in the past, and that will exist in the future. We see the universe NOW as it was in the ________________ It takes time for light to travel in space. The farther away an object is, the older the light that we receive from that object. Earth is 8 light minutes away from the Sun

PROFILE OF THE UNIVERSE Age: ______________________ years old Size: Diameter of observable universe is __________________ Shape: Latest data supports a flat universe Contains: 100 billion galaxies Space is a ___________________ with no air and no air pressure Most of the universe is ________________________ Average Temperature: 2.725 Kelvin (0 Kelvin is the coldest temperature possible)

TECHNOLOGY USED TO STUDY THE UNIVERSE New technology helps scientists _______________________. ___________________________ (not affected by Earth’s atmosphere) Hubble Observatories (Earth telescopes) Mauna Kea, Hawaii ___________________________ Voyagers I and II Spacecrafts Mars Rover Scientists _________________to test theories and _______________________

Edwin Hubble discovered the universe is ________________. STUDYING THE UNIVERSE Edwin Hubble discovered the universe is ________________. Made observations of light from distant galaxies which indicated they were ___________________________________________________________ Used the ____________________________________to show moving objects show a ____________________________________ DOPPLER EFFECT: observed change in the frequency of a wave when the source or observer is moving. Shorter wavelength in front of the moving source Longer wavelengths behind the moving source RED SHIFT: an apparent shift toward longer wavelengths of light (red light) caused when a luminous object ___________________ from the observer.

THINK! What happens to waves as they get farther away from a source? (Think of a pebble dropped in a pond) Why does a siren sound higher pitched as it approaches and lower pitched after it passes and moves away?

The light source (S) is moving toward the left. RED SHIFT DIAGRAM S = light source The light source (S) is moving toward the left. The light waves in front of the light source (S) bunch up which causes the light to appear more blue (BLUE SHIFT) to the observer that the light source is approaching. The light waves behind the light source (S) spread out which causes the light to appear more red (RED SHIFT) to the observer that light source is moving away from. Observer the light source is approaching Observer the light source is moving away from

Hubble’s Law Hubble’s law is statement of correlation between the to a galaxy and it’s (recessional) which is determined by red shift.

BIG BANG THEORY _____________________________________ implies that the universe was once __________________________ Universe began in an extremely small space called the “point of singularity,” then began to rapidly expand or “explode” BIG BANG THEORY: theory that all matter and energy in the universe was ______________________________________________________ _________________________________________________________ that 10 to 20 billion years ago exploded and began ________________ _________________________________________________________ Georges Lemaitre - the Catholic priest who came up with the idea of the Big Bang

EVIDENCE SUPPORTING THE BIG BANG THEORY _______________________________________________: steady but very dim signal from all over the universe in the form of radiation at microwave wavelengths. Dim remnants of the radiation produced during the big bang (left over from the unimaginably hot explosion). ________________________________= the expansion of the universe means we can “rewind” time to when it started from a single point

THINK! What is the big bang theory (in your own words)? What is one piece of evidence that supports the big bang theory?