THE BIG BANG THEORY
HOW IT ALL BEGAN….
BEFORE THERE WAS A UNIVERSE, THERE WAS..
• One single, infinitesimally small, dense and hot point • Then, for reasons that are unknown, that point, expanded with energy that is unfathomable • Time and Space began with this event
Universe started from a single point, and has been expanding ever since Expansion happened approx. 13.75 billion years ago Expansion contained all of the ENERGY in space
NOT A “BIG BANG” NOT AN EXPLOSION! • the matter is all actually standing still while space itself expands dragging the matter with it
HOW DO WE KNOW IT STARTED FROM A SINGLE POINT? • Objects are currently moving away from each other today, then, they must have been closer together yesterday, and the day before that and so on…
THE FURTHER GALAXIES ARE AWAY FROM EARTH, THE FASTER THEY ARE MOVING AWAY
• Known as Hubbles law
• Therefore, the closer these galaxies were to time of the big bang • So, information from these galaxies gives us knowledge about the beginning of time!
AS THE UNIVERSE EXPANDS, IT COOLS
Universe has cooled from 1032 degrees to 3 degrees Kelvin in 15 billion years (K = C+273)
AS THE UNIVERSE EXPANDED, IT COOLED • Energy that was released from cooling formed matter. (Matter and energy are related, E=mc 2) • The universe expanded, cooled then formed matter.
WHAT TRIGGERED THE BIG BANG? • Scientists disagree on what started the big bang: • Was it the edge of another expanding universe? • What it radiation from another big bang hitting the tiny spot that triggered it? • Was it the result of radiation from a supernova?
• No one, as of yet, knows for sure
IF WE DON’T KNOW WHAT CAUSED THE BIG BANG, DOES THAT MEAN THE THEORY IS NOT VALID? • Theories don’t try to explain everything, just what evidence is available and pertinent • the theory of Gravity doesn’t explain where mass came from • The Germ theory of disease transmission doesn’t explain where germs came from • Atomic theory doesn’t state where atoms come from
LESSON CHECK • On a separate piece of paper, do the following: • Describe how the universe was prior to the big bang • Describe why galaxies that are further away from Earth are moving faster than Earth • Describe the universe today
CREATE YOUR OWN…
BIG BANG
EVIDENCE FOR THE BIG BANG THEORY
• Red Shift of GALAXIES • Radiation left over from the Big Bang • Composition of matter in the universe
REMEMBER THE EM SPECTRUM??? • a process in which photons (energy packets) travel • do not need to travel through a medium • All types of waves travel at the speed of light
RED SHIFT
AS AN OBJECT MOVES AWAY, THE WAVELENGTH IT EMITS LENGTHENS
DOPPLER EFFECT
WHAT HAPPENS TO THE WAVELENGTH (COLOR) AS OBJECTS MOVE AWAY? (LOOKING ONLY AT THE VISIBLE PORTION OF THE SPECTRUM)
RED SHIFT The electromagnetic radiation emitted by a moving object also exhibits the Doppler effect.
•Redshift, a phenomenon of electromagnetic waves such as light in which spectral lines are shifted to the red end of the spectrum.
RED SHIFT Object moving closer light waves pushed together wavelength shorter appears blue Object moving away light waves stretched out longer wavelength appears red
What color do you think galaxies appear from earth? Object moving away, appears RED
Object moving towards, appears BLUE
RED SHIFT OF GALAXIES • Astronomers observe galaxies are all red shifted from Earth – What does this say about the galaxies in relation to Earth? • Therefore, all galaxies are moving away from earth • Therefore, the universe is expanding
WAIT A MINUTE!! WHAT IS A GALAXY!?! • a massive, system consisting of stars, stellar remnants, gas and dust and dark matter (more on dark matter later!) • Examples of galaxies range from dwarfs with as few as ten million (107) stars, to giants with one hundred trillion (1014) stars, each orbiting their galaxy's own center of mass • Galaxies are held together by gravity • Supermassive black holes reside at the center of most galaxies.
THE ANDROMEDA GALAXY – OUR CLOSEST NEIGHBOR – 2.5 MILLION LIGHTS YEAR AWAY
A VIEW OF 15% OF THE GALAXIES – THAT’S 3 MILLION GALAXIES REDSHIFTED
LESSON CHECK
• Take 3 minutes to discuss with your table partner how the red shift of galaxies can be used as evidence to support the theory of the big bang
COSMIC BACKGROUND MICROWAVE RADIATION • 1964 by Penzias and Wilson • a faint background glow, almost exactly the same in all directions, that is not associated with any star, galaxy, or other object
COSMIC MICROWAVE BACKGROUND RADIATION Radiation believed to be left over from the Big Bang
WHERE DOES THIS RADIATION COME FROM?
• As the universe expands, the space between the photons that the expansion created grows • As the space between the photons continues to grow, the wavelength of those photons also increases. • This wavelength is in the microwave range (.051cm)
IMAGE FROM WMAP
SOUND OF COSMIC BACKGROUND RADIATION http://Sound of Cosmic Radiation
Evidence of the big bang
Cosmic Background Microwave Radiation
LESSON CHECK
• Take 3 minutes to discuss with your table partner how cosmic background microwave radiation can be used as evidence to support the theory of the big bang
EVIDENCE - TAKING A CLOSER LOOK redshift slinky lab
COMPOSITION OF MATTER IN THE UNIVERSE • Helium • Deuterium (H-2, an isotope of hydrogen)
HELIUM IN THE UNIVERSE • By observing ultraviolet light, astronomers found helium in the early Universe. • Helium forms when deuterium fuses with another deuterium (H-2 and H-2 forming Helium) for this to happen, it must be super HOT! (around 10 billion Kelvin)
BIG BANG NUCLEOSYNTHESIS – H-2 FUSING TO FORM HELIUM
HELIUM – FROM FUSION IN STARS • Helium is formed in the core of stars during fusion • The fusion reaction releases energy in the form of photons • Stars and hydrogen bombs are the only things we know of that make helium in the today’s universe.
HELIUM MADE DURING STAR FORMATION • 1960: spectroscopic studies of stars showed that the helium accounted for 20-30% of the mass of stars, the rest (70-80%) being mostly hydrogen. • However, 24% of the matter in the entire universe is due to Helium…star formation of Helium couldn’t account for all that Helium! • Some, if not most, of the helium must have existed before star formation.
HELIUM WAS MADE DURING THE BIG BANG • physicists calculated that roughly 1/4 of mass was converted into helium during the big bang, while the rest remained as hydrogen. • 1970s: spectroscopic studies of other galaxies have confirmed that the majority of the observed helium did exist before any star formation.
DEUTERIUM IN THE UNIVERSE
• 1973: studies of absorption spectra of nearby stars showed that interstellar medium (material between stars) contains deuterium.
DEUTERIUM – AN ISOTOPE OF HYDROGEN H-2
• Deuterium, unlike helium, is not produced in stars at all. • In stars, deuterium quickly fuses to make Helium • At temperatures above about one million degrees K, deuterium breaks down into protons and neutrons.
• Astronomers in the early 1970s realized that no known process in the present universe could have produced deuterium.
DEUTERIUM IN THE UNIVERSE
• At the time of the big bang, temperatures and densities were lowered so quickly, there would have been no time for the deuterium to break down, so the deuterium present to day could have only formed during the big bang.
HELIUM AND DEUTERIUM
• the abundance of helium and existence of deuterium provide strong evidence that the universe began with a hot, violent expansion consistent with the big bang model.
THE MYSTERY OF DARK MATTER – THIS IS NOT ORDINARY MATTER! • Today astronomers believe that around three quarters of the mass of the Universe consists of dark matter, a substance quite different from the ordinary matter that makes up atoms and the familiar world around us. • Dark matter only interacts with gravity, which means it neither reflects, emits or obstructs light (or indeed any other type of electromagnetic radiation). Because of this, it cannot be observed directly. • Dark matter remains a mystery today!
THE BIGGER MYSTERY: DARK ENERGY • Hubble studies of the expansion rate of the Universe have found that the expansion is actually speeding up. • Astronomers have explained this using the theory of dark energy, as a sort of negative gravity that pushes the Universe apart ever faster. • Dark energy is an even bigger mystery than dark matter!
LESSON CHECK
• Take 3 minutes to discuss with your table partner how the composition of the universe can be used as evidence to support the theory of the big bang
READING ASSIGNMENT: FLEX BOOK: CHAPTER 1 AND 2
THE ORIGIN OF THE SOLAR SYSTEM - THE NEBULAR THEORY
Collapsing Clouds of Gas and Dust •1 billion years after the Big Bang
•Clouds of gases (Helium and Hydrogen) and dust begin to clump together and collapse – called a NEBULA
CLOUD BEGINS TO CONTRACT… • Force of gravity is greater than gas pressure, so cloud begins to contract • The cloud is initially spinning slowly. • Due to angular momentum, the cloud spins faster as it contracts.
THE SPINNING NEBULA FLATTENS… • Force of gravity, gas pressure and rotation
CONDENSATION OF PROTOSUN AND PROTOPLANETS • Instabilities in collapsing rotation cloud cause local regions to contract. (Due to gravity) • Protosuns and protoplanets become the sun and planets in our solar system
CENTRAL BULGE CONTINUES TO COLLAPSE • Gravity causes bulge to continue to collapse
• Temperatures inside bulge get extremely hot – several million degrees • Hydrogen begins to fuse to form helium which releases enormous amounts of energy a star (our sun) is born
NEBULAR HYPOTHESIS OF SOLAR SYSTEM FORMATION.
From start to finish, it took something like 10 million years to form the sun and planets from a collapsing cloud of gas, and this is not very long at all!!
HUBBLE SPACE TELESCOPE PICS
THE MILKY WAY GALAXY
THE MILKY WAY GALAXY
THE FATE OF THE MILKY WAY
READING ASSIGNMENT: FLEX BOOK: CHAPTER 3
READING ASSIGNMENT: FLEX BOOK: CHAPTER 4
OUR SOLAR SYSTEM
AGENDA •
Where is our solar system
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Characteristics of the planets in our solar system
SOLAR SYSTEM The Sun
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Eight Planets
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One dwarf planet
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Sixty-one satellites of the planets
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Many Comets and asteroids
NORM HERR (SAMPLE FILE)
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SUN • 75% hydrogen and 25% helium by mass • Sun converts hydrogen to helium in its core • Differential rotation • equator the surface rotates once every 25.4 days • near the poles it's as much as 36 days
• Core conditions • temperature is 15.6 million Kelvin • pressure is 250 billion atmospheres
NORM HERR (SAMPLE FILE)
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MERCURY
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Orbit • highly eccentric • perihelion 46 million km • aphelion it is 70 million km
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One full day-night cycle takes 179 earth days
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Temperatures vary from -173 C – 427 C
NORM HERR (SAMPLE FILE)
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VENUS •
Volcanism
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Rotates backwards
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Dense Atmosphere
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Hot – 480 C
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90x atmospheric pressure compared to Earth
NORM HERR (SAMPLE FILE)
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EARTH •
Moon is 1/6 mass of earth
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period of rotation: 24 hours
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period of orbit 365.25 days
NORM HERR (SAMPLE FILE)
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MARS •
Solid carbon dioxide is found at the poles
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Mars is known as the Red Planet
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½ the size of Earth
NORM HERR (SAMPLE FILE)
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ASTEROID BELT •
Contains lumps of rocks and metal
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Several million asteroids
JUPITER
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Largest Planet - Jupiter contains over 70% of the mass in the solar system outside the Sun
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It is about 11 times the radius and 330 times the mass of the earth.
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Jupiter is not a solid body, but instead is a ball of gas and liquid (mostly hydrogen and helium)
Great Red Spot
63 Moons
Takes 12 years to rotate around the Sun
SATURN
• Gas giant. • Strong surface winds (1500 mile/hour). • Less dense than water.
• Has rings made up of ice, dust and rocks • 29 years to rotate one time around the Sun • Atmosphere is Helium
• Has 60 moons – Titan is its largest (larger than Mercury)
NORM HERR (SAMPLE FILE)
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URANUS •
Rolls on its axis, doesn’t spin
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Methane Atmosphere
NORM HERR (SAMPLE FILE)
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NEPTUNE •
Wind speeds of 1000km/hour
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Ice Volcanoes
Note the apparent storms NORM HERR (SAMPLE FILE)
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PLUTO •
Pluto is a ‘dwarf planet’
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1/5 the mass of Earth’s Moon
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Orbit is inclined 17deg to the ecliptic, so it goes farther above and below the plane than of the other planets
HOW CAN WE REMEMBER THE ORDER OF THE PLANETS? •
My Very Educated Mother Just Served Us Nine Pizzas
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More?
