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=mc2)

• 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)

•Redshift, a phenomenon of electromagnetic waves such as light in which spectral lines are shifted to the red end of the spectrum.

The electromagnetic radiation emitted by a moving object also exhibits the Doppler effect.

RED SHIFT

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 (.05-

1cm)

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

redshift slinky lab

EVIDENCE - TAKING A CLOSER LOOK

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.

• 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 MADE DURING 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

• Characteristics of the planets in our solar system

SOLAR SYSTEM

11/15/99 NORM HERR (SAMPLE FILE)

• The Sun

• Eight Planets

• One dwarf planet

• Sixty-one satellites of the planets

• Many Comets and asteroids

SUN

11/15/99 NORM HERR (SAMPLE FILE)

• 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

MERCURY

11/15/99 NORM HERR (SAMPLE FILE)

• Orbit

• highly eccentric

• perihelion 46 million km

• aphelion it is 70 million km

• One full day-night cycle takes 179 earth days

• Temperatures vary from -173 C – 427 C

VENUS

11/15/99 NORM HERR (SAMPLE FILE)

• Volcanism

• Rotates backwards

• Dense Atmosphere

• Hot – 480 C

• 90x atmospheric pressure compared to Earth

EARTH

11/15/99 NORM HERR (SAMPLE FILE)

• Moon is 1/6 mass of earth

• period of rotation: 24 hours

• period of orbit 365.25 days

MARS

11/15/99 NORM HERR (SAMPLE FILE)

• Solid carbon dioxide is found at the poles

• Mars is known as the Red Planet

• ½ the size of Earth

ASTEROID BELT • Contains lumps of rocks and metal

• Several million asteroids

JUPITER

• Largest Planet - Jupiter contains over 70% of the mass in the solar system outside the Sun

• It is about 11 times the radius and 330 times the mass of the earth.

• 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

11/15/99 NORM HERR (SAMPLE FILE)

• 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)

URANUS

11/15/99 NORM HERR (SAMPLE FILE)

• Rolls on its axis, doesn’t spin

• Methane Atmosphere

NEPTUNE

11/15/99 NORM HERR (SAMPLE FILE)

• Wind speeds of 1000km/hour

• Ice Volcanoes

Note the apparent storms

PLUTO

• Pluto is a ‘dwarf planet’

• 1/5 the mass of Earth’s Moon

• 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

• More?