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THE BIG BANG THEORY. What is the Big Bang Theory?. ?. The Big Bang Theory. * A small disclaimer: the Big Bang theory is taught just as that, a theory. I am not trying to change your beliefs in any way, I am just simply stating some observations made by some really smart people!.
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The Big Bang Theory * A small disclaimer: the Big Bang theory is taught just as that, a theory. I am not trying to change your beliefs in any way, I am just simply stating some observations made by some really smart people!
VOCABULARY REVIEW Explain the difference between a: HYPOTHESIS LAW HYPOTHESES THEORY
What is the Big Bang Theory? • The theory that the universe violently expanded in a single event called the big bang. • Occurred 10-20 Billion years ago. • The universe has been expanding since.
Notes of Concern! • It is believed that all matter and radiation was packed into a primeval fireball no larger then the period at the end of this sentence. • There was no “bang” or “explosion”, it is just a term. • Since there was no space prior, the big bang was more of an unfolding of space and matter from a very small region. Also time as we know it started.
As a review: What was created at the onset of the Big Bang? • Matter (Something that has mass and takes up space.) • Energy ( ex. Radiation /Light ) • Time (A condition which has a past, present and future.) • Space (What the universe filled in.)
How it all began-The first second • In one-millionth of a second after the Big Bang the Universe was a hot, seething mass of radiation and exotic particles. • This mass expanded and cooled, forming protons, neutrons and electrons (Subatomic particles).
Minutes Later…….. These subatomic particles grouped together forming the first atoms of hydrogen and helium.
After several billions of years… Gravity caused clouds of gas to collapse, forming planets, stars, and galaxies.
And today… The present day Universe continues to expand today. Galaxies and stars are continuing to move away from one other.
EVIDENCE FOR THE BIG BANG http://youtu.be/kZ0KBFoYH7c
The observed movement of matter within the universe. • The relative amounts of certain chemical elements (types of atoms) in the universe. • The existence of cosmic radiation detected by modern day telescopes.
COSMIC RADIATION http://www.youtube.com/watch?v=hcds5Ob59Dg
Astronomy and Motion Lab Parts #1 , #2 , #3
Scientists have been studying motion for over 2300 years! Artistotle, Aristarchus, Ptolemy, Copernicus, Brahe, Galileo, Kepler, Newton & Hubble
Lets review some vocabulary first… Force- A push or pull that can cause an object to speed up, slow down, or change direction
Speed- The rate (how fast) at which an object moves. Does not keep track of direction. Speed = Distance Example: 75 mph Time Average Speed = Total Distance Total Time Example: 440 miles = 55 miles/hr or 55mph 8 hrs
Velocity • Velocity - The speed and direction of an object’s motion. The rate at which an object changes its position. • Direction can be: up/down, left/right, to/from , East, West, North or South. • Example: 65 mph EAST • Average Velocity= Change position or displacement / Time
Acceleration Acceleration is the rate at which an object changes it’s velocity. It is a rate of a rate! You are accelerating if there is a … change in speed change in direction change in BOTH speed and direction Acceleration = Change in Velocity Time Units of measure: most likely meters/second2 or km/hr/sec or mi/hr/sec
If we observe a ball free falling without air resistance we would see that the ball falls: • Accelerating objects are constantly changing their velocity
Try this… • Acceleration has nothing to do with going fast, you can be going very fast and not be accelerating? True or False • If you slow down at a stop sign and start again are you accelerating? • If you rotate in a circle are you accelerating? • If you slow down at a corner & turn, are you accelerating?
Acceleration Answers • Acceleration has nothing to do with going fast, you can be going very fast and not be accelerating? True • If you slow down at a stop sign and start again are you accelerating? YES • If you rotate in a circle are you accelerating? YES • If you slow down at a corner & turn, are you accelerating? YES
Astronomy and Motion Lab Parts #4 , #5
Newton’s First Law Law of Motion • In regards to motion all matter has 2 states: At Rest or Moving An object in motion tends to stay in motion with the same speed unless acted upon by an unbalanced force. • Things keep doing what they are already doing!
Inertia is the resistance an object has on it’s state of motion. Inertia is Newton’s First Law or Law of Motion Inertia is a property of matter. The greater your mass then the greater your inertia. Inertia
Try this… • If I slide a book across the table why does it stop at the rest position? • Is force required to keep an object going? • An astronaut throws a rock in space far from friction & Earth’s gravity. What will happen? • If you stop a car suddenly what happens to a 80 lb child compared to a 200 lb man?
Inertia Answers • If I slide a book across the table why does it stop at the rest position? Friction, The book would continue in motion with the same speed and direction forever in the absence of friction or gravity. • Is force required to keep an object going? No • An astronaut throws a rock in space far from friction & Earth’s gravity. What will happen? The rock would not stop but continue in motion in the same direction. • If you stop a car suddenly what happens to a 80 lb child passenger compared to a 200 lb man passenger? The seat belt would be the external force that would stop them as the body wants to go forward. The more mass you have the harder the force would be to stop the object or person.
What is happening here? • The ball wants to continue in motion (inertia) but forces are acting upon it to change its direction. • Gravity • Air resistance or friction
Momentum • Inertia depends on mass • Momentum depends on mass and speed. • Momentum is Inertia in Motion! • A masscan have momentum only when its moving. • Momentum = mass X velocity P = mv
Momentum’s relationship with mass & velocity • Momentum is directly proportional to mass or is dependent upon mass. • Mass increases then momentum increases. • Momentum is also dependent on velocity. • Velocity or speed increases then momentum increases.
Try this… • If velocity decreases what happens to momentum? • If you were going to be hit by a vehicle both traveling at the same speed which one would you prefer… a Mini Cooper or a Hummer? Why?
Momentum answers: • If velocity decreases what happens to momentum? decreases • If you were going to be hit by a vehicle both traveling at the same speed which one would you prefer… a Mini Cooper or a Hummer? Why? Mini Cooper because the vehicle with less mass has less momentum.
Astronomy and Motion Lab Part#6
Hubble’s Law • The Universe is expanding and still expanding according to Edwin Hubble. • He discovered in 1929 using spectroscopy that galaxies are moving away from us in proportion to their distances from us.
Visible Light • Visible light is the light you can see. • ROYGBV • When all the waves are together they make white light. • Spectroscopy uses only visible light from objects in space
Each color has a different wavelength Violet has the shortest wavelength Red has the longest wavelength Spectroscopy
Hubble’s Red Shift Discovery • Hubble examined the light from stars in the distant galaxies, he found that the pattern of spectral lines of the elements were shifted toward the red end of the spectrum. • Red Shift = Objects that are moving away • Blue Shift = Objects that are moving toward us
Hubble observed the spectral lines shifting toward the red end of the spectrum, thereby concluding that the universe is expanding.
Doppler Effect • When an object is moving away from us, any energy waves emitted will be stretched out to form longer, lower energy waves. Any object moving towards us would produce the opposite effect—shorter, higher energy waves. Thus, a siren is louder when it is moving toward you and is emitting short, high energy waves.
So how can we determine the makeup of our universe? We use a spectrocope!
Chemical Make-up Since, according to this theory, all matter was created at the Big Bang, the Universe today retains an imprint of its initial cosmic mixture. Astronomers can analyze a stars chemical make-up and the ratio of hydrogen to helium. The amounts of these gasses agree with what the Big Bang theory predicts.
How do we determine the presence of cosmic radiation? We use modern day telescopes!