1. WE ARE MADE OF STAR DUST
It all started with the Big Bang (a scientific theory) 13.7 b.y.a. Hydrogen and Helium were formed.

2. Are we truly made up of stardust or where are all the elements formed?
So what IS Star dust?
Elements = chemical elements that we find on the periodic chart. It starts with the tiny H (hydrogen) . Check out your periodic chart!
Are we truly made up of stardust or where are all the elements formed?
In Big Bang (H, He)
In Stars
In Supernovae and Novae Explosions
( Man-made elements –not found in our bodies or nature)

3. All these main elements in our body were created in space
All these main elements in our body were created in space! And then some!

4. Stars create chemical elements through fusion – the same elements we find on Earth.
Recipe for Fusion:
1.Take some small elements.
2. Let them be pulled into the center by gravitational force.
3. Apply LOTS of pressure
3. Apply HIGH HIGH heat.
4. The nuclei of protons and neutrons will combine and form one nucleus.
5. The electrons will match in number the protons and electrons.
6. The “left overs” (positrons, neutrons) and energy (gamma rays) escape.
(excellent article)

5. What are the elements formed in a star?
The smallest elements are formed from what into what? _______  ______
The largest element formed in a star are _______ .
Our sun may be too small to produce all these elements. True/False?
Do stars produce the most abundant elements organisms need? Yes/No? What are they? ____ _____ _______ _____

6. Larger elements get formed as part of nova and supernova events
A nova or supernova is the explosion of a huge dying star’s contents.
Lots of pressure, lots of heat
Lots of larger elements are formed.
Which ones? List some by consulting your periodic chart: __________________
(excellent article)

7. Orion’s Horsehead Nebula
Q: What IS a Nebula??
Q: Where in a Nebula do new Stars get born?
Orion’s Horsehead Nebula
A: Nebulae are clouds of gas and dust made up of chemical elements (H, He, O, C, Fe ..) that were created shortly after the big bang or are left-overs from violent supernovae explosions.
A: In areas where dust and gas condense further, new star and solar systems are born out of this material.
 How is this nebula picture created? Painstakingly.

8. What is a nebula made up of?
Nebulas consist of mostly ____ and ____ elements, but there is a whole smorgasbord of other elements in them as well.
These elements are part of the ____ and ______ that make the nebula look like a cloud.
Only (dense/loose) _______ regions of nebula can “give birth” to new stars.
As these regions rotate (like eddies) and condense further, matter meets and forms larger structures.

9. As material rotates and condensed, two things happened: 1
As material rotates and condensed, two things happened: 1. Motion forms a disk 2. The speed of rotation increased, hurling the heavier materials into the center where they heated up and up.

10. The Solar system – the sun and the nine planets – started off as a spinning cloud composed of its nebula’s gas and solid grains of ice and rock.
When the sun formed, its heat evaporated the icy grains near it, leaving only rock that grew into our small rocky planets. Further out, the icy grains survived, next to some rock, and the planets that formed attracted extra gas to be built into our gas giants

11. Review Q: HOW did your Solar System develop?
Why is there no ice near the sun but far out by the gas giants?
Why is there no gas by the terrestrial planets?
Why does our planet have liquid water (and ice and water vapour) but the others don’t?

12. We Are Made of Stardust Big Bangs produced the H and He.
Stars form chemical elements (He, C ..) through fusion in their center.
At the end of their life stars explode and free these elements that get collected into nebulae.
Nebulae are nurseries of new stars and solar systems now contain these elements.
Our solar system also “inherited” these elements. So when Earth formed, these elements were its building blocks.
And we humans, earthlings, are made up of just these same elements ( H, He, C .. ) made once upon a time and put into the nurseries of stars, the nebulae..
Cycling of Matter recycles these elements – our stardust – over and over again.
We are made of Stardust – we are components of the Universe.

13. Recycling = Renewal
Matter (elements in gas or dust form and other components) in the Universe are recycled through formation of stars and supernova events that produce the nursery for new stars. Where these stars produce new matter and explode and so it goes on and on for a while.
Recycling of Matter in our biosphere is equally important, as the next slide demonstrates.

14. Cycling of Matter ensures that our elements – stardust get reused
Primary producer
Non-living things
Water
Carbon dioxide
Nutrients
Sunlight
Primary consumer
Decomposer
Secondary consumer

15. How does light get produced?
The sun produces light through fusion.
The moon and other shiny things reflect light that is produced from another source.
Most light bulbs produce light through incandescence or fluorescence.

16. How the Sun produces light.
H+ Atoms
Fusion He +
Light and Other Energy
H+ Atoms

17. Earth Earth’s Light is Reflected light
Earth, our moon and close objects are lighted up by the sun where and when it shines on it (our daytime!).

18. Incandescent lights
Light is produced by heating up a wire with electricity until it is white hot.
90 % of the energy transformed as heat. Only10% of the total energy is transformed as light.

19. Fluorescent lights
The Fluorescent lights work because a ballast gives a high initial voltage to start an arch within the tube. The current is then reduced to just maintain the electric arc. In the lamp the electric arc between the two electrodes excites atoms of mercury present in the gas fill in the lamp, causing electrodes in the mercury atoms to absorb energy and then release it in the form of ultraviolet (UV) radiation.
This UV light then strikes the phosphorus coating the inside of the lamp tube which “Fluoresces” , producing visible light.

20. Glow in the Dark Stuff
Photons (light particles) are absorbed by phosphors and released at a slow rate, after the light source has been removed.
The two chemicals used today are Zinc Sulfide and Strontium Aluminate.

21. The Sun produces as part of fusion far more than just Light: it produces lots of Energy!
2 H+ Atoms
1 He +
Energy
2 H+ Atoms

22. The Sun (a star) produces the Whole ELECTROMAGNETIC SPECTRUM = energy!

23. Elements in the Sun: 4 hydrogens fuse to 1 Helium atom and energy.

24. Going further: Thermonuclear Reactions in the Sun

25. Summary of Solar Fusion Reactions
1H1 +
1H1
1H2 +
1e0 +
Energy
1H1
2He3
1H2 +
+ gamma radiation + Energy
2He3
2He3 + +
2He4
+ P + P + Energy

26. THE SUN: A PERFECT FUEL FOR LIFE ON OUR BLUE BEAUTY

28. Can we run out of energy? Yes, should the sun no longer shine.

29. THE END