THE SOLAR SYSTEM

100 yds 13 yd 2.5 yd Earth 93 million Jupiter – 485 mill Pluto – 3.7 bill SCALE: If the Solar System was a Football Field In Dayton And the nearest star, Proxima Centuri (24 trillion mi) is 385 mi away!

SCALE OF PLANETS AND SUN

Galaxy – 100 Billion Stars

OUR GALAXY – THE MILKY WAY EDGE ON VIEW

A SPIRAL GALAXY - TOP DOWN VIEW

DEFINITIONS 1)Atom – the smallest particle that retains all the given properties of an element. 2)Element – a substance that cannot be broken down into a simpler substance by ordinary chemical or physical processes 3)Atomic Structure – protons (+), neutrons ( ) & electrons (-)

DEFINITIONS 4) Universal Forces : a) Nuclear Force – Strong & Weak Strong Force binds protons & neutrons together in the atomic nucleus. Attraction only operates on a tiny scale. Weak force complex. b) Electromagnetic – Binds electrons (-) to nucleus (+). Attracts & repels, operates at larger distances. c) Gravity – Attractive force between any objects that have mass. Weakest force, but operates at all distances.

DEFINITIONS 5) Energy Derived from Atoms a) Fission: Nuclear Reactors b) Fusion: How Stars Burn

HOW ENERGY COMES TO EARTH

HOW FAR AWAY ARE GALAXIES? HOW DO WE MEASURE SUCH GREAT DISTANCES?

Planet hunters have found two worlds roughly the mass of Neptune, each orbiting a star within 30 light-years of our solar system. The discoveries pushed the limit of current search technology, revealing worlds never seen outside our solar system. Together they suggest is it just a matter of time before objects much like Earth are detected. Artist’s Conception

The planets were found using a Doppler-shift method that notes a wobble in a star caused by the gravity of the orbiting planet. Artist’s Conception

SCOPE OF THE UNIVERSE How do we measure & study it? 1)Unit of measure – the light-year The distance that light travels in a year 186,000 mi/sec X 86,400 sec/day X 365 days/year = 5.9 trillion miles = 1 light year 2) How do we actually measure great distances? Phenomenon of Parallax

MEASURING DISTANCE WITH PARALLAX

ORIGIN OF THE UNIVERSE: THE BIG BANG What is the Evidence? 1)Red Shift of light & Doppler Effect 2)Primordial Background Radiation

THE DOPPLER EFFECT

THE DOPPLER EFFECT: THE REDDER GALAXIES ARE MOVING AWAY FASTER AND ARE MUCH FARTHER AWAY

Scientific Method 1)Define Problem. How did the Universe Originate? 2) Collect Data, Make Observations. Doppler Effect shows that all galaxies are moving outward, away from Earth and that the farther a galaxy is away, the faster it is moving. 3) Formulate Hypothesis. The universe began as an infinitely hot, dense, point of energy that explodes – THE BIG BANG! Matter and space are created as universe expands and accelerates outward.

Scientific Method 4) Test Hypothesis. Collect more data a) Black Body Radiation. Radiation left over from the Big Bang. Discovered and fits predicted intensity curve. b) Primordial Helium. Scientists predicted that the Big Bang should have created approximately 75% hydrogen and 25% helium. But, fusion in stars should create more helium. So, the older a star, the more helium it should contain. Our Sun – 28% Helium; Older Stars – 29 –30% Helium 5) Corroborate or Dispute Hypothesis? a) Corroborate – A good Theory b) Dispute – Must modify/change hypothesis. IN SCIENCE NOTHING IS EVER 100% TRUE! ALWAYS KEEP TESTING YOUR THEORIES!

THE PERIODIC TABLE OF THE ELEMENTS If the early universe was all Hydrogen & Helium, how did all the other elements originate?

HOW DO STARS BURN? FUSION

THE LIFE AND DEATH OF STARS

HOW DID OUR SOLAR SYSTEM FORM?

What features of our solar system would a good theory of it’s origin have to explain?

FORMATION OF OUR SOLAR SYSTEM

p.26-27a Forming the solar system, according to the nebula hypothesis: A second- or third- generation nebula forms from hydrogen and helium left over from the big bang, as well as from heavier elements that were produced by fusion reactions in stars or during explosion of stars. The nebula condenses into a swirling disc, with a central ball surrounded by rings.

p.26-27b The ball at the center grows dense and hot enough for fusion reactions to begin. It becomes the Sun. Dust (solid particles) condenses in the rings. Dust particles collide and stick together, forming planetesimals.

p.26-27c Gravity reshapes the proto-Earth into a sphere. The interior of the Earth separates into a core and mantle. Forming the panets from planetesimals: Planetesimals grow by continuous collisions. Gradually, an irregularly shaped proto-Earth develops. The interior heats up and becomes soft.

p.26-27d Soon after Earth forms, a small planet collides with it, blasting debris that forms a ring around the Earth. The Moon forms from the ring of debris.

p.26-27e Eventually, the atmosphere develops from volcanic gases. When the Earth becomes cool enough, moisture condenses and rains to create the oceans.

p.26-27

A NEBULA

Comet Shoemaker-Levy hits Jupiter in 1994

THE HISTORY OF THE UNIVERSE AFTER THE BIG BANG