1. Energy

2. What types of energy are there?

3. What types of energy are there?
Nuclear
Fusion
Fission
Mechanical (Kinetic)
Potential
Gravity
Springs
Chemical
Light
Heat
Electrical

4. Essentially all energy on Earth comes from a single source

5. FUSION

6. THE SUN
Every second, the sun converts 500 million metric tons of hydrogen to helium. Due to the process of fusion, 5 million metric tons of excess material is converted into energy in each second. This means that every year, 157,680,000,000,000 metric tons are converted into energy.

7. The solar surface
Fusion

8. The Sun The sun flare  The corona during an eclipse  The aurora
Fusion

9. Nuclear Fusion
Nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus.
It is accompanied by the release or absorption of energy depending on the masses of the nuclei involved..

10. Nuclear Fusion of Protons - hydrogen cycle
The Sun derives energy from fusion of protons. There are many possibilities, but two detailed cycles were proposed.
The hydrogen cycle:
H + H  2D (+e–) + + + n 2D + H  3He +  3He + 3He  4He + 2 H net 4 H = 4He (+ 2e–) + 2+ +2  + 2 n MeV Or
Enough energy to keep a 60W light bulb on for 7 x sec
Fusion

11. Nuclear Fusion in Stars
Stars are giant fusion reactors.
Nuclear fusion reactions provide energy in the Sun and other stars. Solar energy drives the weather and makes plants grow.
Energy stored in plants sustains animal lives, ours included.
Fusion

12. Nuclear Fusion and the Sun
Sun Mass is 333,000 times that of the Earth.
The sun is a big nuclear fusion reactor, 75% H and 25% He.
Sun radius ( km) is 109 times that of the Earth (6.4e3 km).
Sun emits 3.861026 watts, ~ 8 kwatt/cm2, 1.4 kwatt/m2 reach the Earth’s atmosphere (solar constant).
1 kwatt/m2 reaches the Earth’s surface
This is the energy that drives our weather.
Fusion

13. Matter and Energy
We have been taught that “matter and energy cannot be created nor destroyed”
We now need to understand that Matter and Energy are two forms of the same thing

14. E = mc2 Matter can be changed into Energy
Einstein’s formula above tells us how the change occurs
In the equation above:
E = Energy
m = Mass
c = Speed of Light (Universal Constant)
Energy
Mass
Light
Speed

15. E = mc2 The equation may be read as follows:
Energy (E) is equal to Mass (m) multiplied by the Speed of Light (c) squared
This tells us that a small amount of mass can be converted into a very large amount of energy because the speed of light (c) is an extremely large number

16. Fusion
Fusion is a nuclear reaction whereby two light atomic nuclei fuse or combine to form a single larger, heavier nucleus
The fusion process generates tremendous amounts of energy; refer back to Einstein’s equation
For fusion to occur, a large amount of energy is needed to overcome the electrical charges of the nuclei and fuse them together

17. Fusion
Fusion reactions do not occur naturally on our planet but are the principal type of reaction found in stars
The large masses, densities, and high temperatures of stars provide the initial energies needed to fuel fusion reactions
The sun fuses hydrogen atoms to produce helium, subatomic particles, and vast amounts of energy

18. Review
Mass and Energy are two forms of the same thing; neither can be created nor destroyed but mass can be converted into energy (E = mc2)
Fission is a nuclear reaction in which a heavy atomic nucleus is split into lighter atomic nuclei
Fusion is a nuclear reaction in which 2 light atomic nuclei are combined into a single, heavier atomic nucleus

19. H-bomb Tsar 2 The Russian Tsar H-Bomb was the most powerful ever made
Nov. 1, 1952, the first H-bomb Mike tested, mushroom cloud was 8 miles across and 27 miles high;the canopy was 100 miles wide, 80 million tons of earth was vaporized. H-bomb exploded Mar. 1, 1954 at Bikini Atoll yielded 15 megatons and had a fireball 4 miles in diameter. USSR H-bomb yields 100 megatons.
Tsar 2
The Russian Tsar H-Bomb was the most powerful ever made
Fusion

20. Nuclear Fusion under Controlled Conditions
Humans had controlled fission chain reactions before testing bombs.
1952, Nov. 1. US tested the first H-bomb at Enewetak, controlled sustained fusion reactor has yet to be achieved.
High temperature and high particle density for long period of time are the conditions for fusion.
This has not yet been achieved in a context where more energy is produced than it costs to make the reaction happen
Fusion

21. Fission
Fission may be defined as the process of splitting an atomic nucleus into fission fragments
The fission fragments are generally in the form of smaller atomic nuclei and neutrons
Large amounts of energy are produced by the fission process

22. Fission
Fissile nuclei are generally heavy atoms with large numbers of nucleons
The nuclei of such heavy atoms are struck by neutrons initiating the fission process
Fission occurs due to electrostatic repulsion created by large numbers of protons within the nuclei of heavy atoms

23. Fission A classic example of a fission reaction is that of U-235:
U Neutron
2 Neutrons + Kr-92 + Ba Energy
In this example, a stray neutron strikes an atom of U It absorbs the neutron and becomes an unstable atom of U-236. It then undergoes fission. Notice that more neutrons are released in the reaction. These neutrons can strike other U-235 atoms to initiate their fission.

24. Fission
The fission process is an a natural one as a French researcher found a natural uranium reactor in Gabon, West Africa; it has been estimated to be over 2 billion years old
Fission produces large amounts of heat energy and it is this heat that is captured by nuclear power plants to produce electricity

25. Review
Mass and Energy are two forms of the same thing; neither can be created nor destroyed but mass can be converted into energy (E = mc2)
Fission is a nuclear reaction in which a heavy atomic nucleus is split into lighter atomic nuclei
Fusion is a nuclear reaction in which 2 light atomic nuclei are combined into a single, heavier atomic nucleus

26. Quiz Which nuclear process produces large amounts of energy?
A. Fission
B. Fusion
C. Both fission & fusion
D. Neither fission nor fusion

27. Quiz Fission is the process that _________ atomic nuclei. A. Combines
B. Burns up
C. Stores
D. Splits

28. Quiz
Mass may be converted into energy.
A. True
B. False

29. Quiz The fission process requires heavy atomic nuclei. A. True
B. False

30. Quiz
Name a nuclear reaction that occurs within the sun:

31. Quiz Fission is a natural process that occurs on the planet Earth.
A. True
B. False

32. Quiz
Explain this equation:
E = mc2