1. Time…and distance Moon: Mars: Sun: Pluto: 212,000 miles 48,000,000 miles 93,000,000 miles 3.6 billion miles

2. Milky Way Galaxy > 100 billion suns 60,000 light years wide Earth Nearest star? Alpha Centauri: 4.3 light years or 25 trillion miles

3. Galaxy Clusters Hubble telescope estimates >125 billion galaxies Nearest? Andromeda 2 million light years away For every grain of sand on Earth, there are a million stars.

4. Geologic Time Scale

5. How do you determine ages? How to determine ages 1.Relative age dating. Comparing the age of one thing relative to something else. 2. Absolute age dating. Using analytical techniques to determine the real age of an object.

6. Superposition Sediments accumulating on top are younger than those below.

7. Cross-Cutting Rocks which cross-cut are younger than those they cut.

8. Unconformity Sediment deposition, followed by a period of eroison, then more sediment deposition. End result? A time gap.

9. Age Placing

10. Grand Canyon

11. Canyon Ages

12. Layers on Mars

13. Index Fossils Organisms which lived only during a specific period of time.

14. Correlation Same rock layers, correlated over vast distances Same rock types, ages, fossils, etc.

15. Continental Drift Correlation was used during the development of the continental drift theory, years ago.

16. Absolute Age Dating Relative age dating placed rock layers into a specific order. Radiometic age dates were used to determine the age of the rock layers and verify the ordering.

17. The Atom Atom: In the nucleus, there are protons (+) and neutrons (neutral charge) Surrounding the nucleus are negatively charged electrons - used for bonding with other atoms to form molecules Atomic number = number of protons in the nucleus Atomic weight = # protons + # neutrons Isotope: Same number of protons, different number of neutrons

18. Radioactivity Some isotopes are unstable. These will “decay” to stable isotopes called daughter products. As isotopes decay, they give off subatomic particles + heat Radiation

19. Nuclear Fuel Rods To build a nuclear reactor, what you need is some mildly enriched uranium. Typically, the uranium is formed into pellets with approximately the same diameter as a dime and a length of an inch or so. The pellets are arranged into long rods, and the rods are collected together into bundles. The bundles are then typically submerged in water inside a pressure vessel. The water acts as a coolant. In order for the reactor to work, the bundle, submerged in water, must be slightly supercritical. That would mean that, left to its own devices, the uranium would eventually overheat and melt. To prevent this, control rods made of a material that absorbs neutrons are inserted into the bundle using a mechanism that can raise or lower the control rods. Raising and lowering the control rods allow operators to control the rate of the nuclear reaction. When an operator wants the uranium core to produce more heat, the rods are raised out of the uranium bundle. To create less heat, the rods are lowered into the uranium bundle. The rods can also be lowered completely into the uranium bundle to shut the reactor down in the case of an accident or to change the fuel.

20. Nuclear Meltdown Chernobyl, Ukraine: 1986 Explosion released 200 times more radiation than the Hiroshima and Nagasaki bombs combined.

21. Chernobyl plume

22. Contaminated Areas

23. Sarcophagus

24. Alpha Emission

25. Beta Emission

26. Electron Capture

27. Examples Unstable isotope Stable daughter product

28. Half Life Half life: Over a given period of time, half the parent isotope decays into its daughter product.

29. Examples Uranium 238 to Lead 206: 4.5 billion years Uranium 235 to Lead 207: 713 million years Thorium 232 to Lead 208: 13.9 billion years Rubidium 87 to Strontium 87: 50 billion years Potassium 40 to Argon 40: 1.5 billion years

30. Mineral Examples Zircon Common in granites Zr+Si+O Trace amounts of Th & U Link to radon Radium->Radon->Polunium Radon half life: 3.8 days EPA action level: 4 picocuries per liter

31. Carbon 14 Dating Half-life: 5730 yrs Live organisms maintain a fixed amount of C-14 C-14 decays to N-14 after death.