Physical Science

1. Universe Slides subject to change Physical Science

2. Job 38 14 Where were you when I laid the Earth’s foundation? 31 Can you bind the beautiful Pleiades? Can you loose the cords of Orion? 32 Can you bring forth the constellations in their seasons or lead out the Bear with its cubs?

3. Celestial Sphere North Celestial Pole North Pole Celestial Equator Equator South Pole South Celestial Pole

4. The Sun: Our Nearest Star

5. Sun Diameter: 109 Earths Mass: 333,000 Earths Density: Avg. 1.4 g/cm3 Sun exists as a plasma, and is not solid. Gravity: 27.9 g Solar Day: 25 days

6. Solar and Heliospheric Observatory ESA/NASA Collaboration

7. Sun Temperature 15,000,000 K 6,000 K 50,000 K 1,000,000 K • Nuclear reaction at Core • Bright visible surface “Photosphere” • Thin layer of hotter gas “Chromosphere” • White halo “Corona” • Sun is hotter as you rise above the surface.

8. Sun's Power Nuclear fusion of hydrogen into helium in its core. Normally (at Earth temperatures) hydrogen nuclei (protons) repel each other. At Sun's core, T =15,000,000 K, protons collide with such energy they fuse. Energy released as hydrogen goes through several steps to become stable helium.

9. Nuclear Fusion • Every second in the sun’s interior mass is converted to energy: • hydrogen (H) → helium (He) + energy • 6.0x1011 kg H → 5.96x1011 kg He + energy • Enough fuel to last another five billion years.

10. Solar Flares Charged particles in the midst of intense magnetic fields. Photo March 18, 2013 by NASA Solar Dynamics Observatory

11. Sunspots Cooler areas on the sun (T ≈ 4600 K). NASA

12. Sunspots Sunspot intensity cycles every 10-11 years. Emitted radiant energy varies with sunspot activity. Significant influence on Earth’s climate.

13. Effect of Sunspots Red curve illustrates solar activity. Black curve, Earth's average temperature. Over last 100 years,average global temperature has increased by approx 0.7 °C. Earth’s climate is closely associated with Solar activity – correlates with colder temperatures. Science, 254, 698-700, 1991

14. 2009 had 260 spotless days 2010 had 51 spotless days, 2011 had 2 spotless days Since then there have been sunspots every day. www.almanac.com/sunspotupdate Today’s Activity

15. Climate Change

16. Stars Like the Sun, other stars are massive, luminous balls of plasma. Most stars between 0.1 and 5 solar masses. Size is a balance of thermal and radiant pressure outward, and gravity inward. Once regarded by astronomers as a small and relatively insignificant star, our Sun is now thought to be brighter than about 85% of the stars in the Milky Way galaxy.

17. Measure Star Brightness • More negative the number, the more bright ! • Apparent magnitude of the Sun is −26.74, and the mean apparent magnitude of the full moon is −12.74. The Sun is the brighter of the two objects. • The apparent magnitude of Sirius is −1.44, and the apparent magnitude of Polaris is 1.97. Sirius is the brighter of the two stars. • Hubble Space Telescope can see stars of magnitude 30.

18. Star Magnitude Scale Sky Map

19. Star Distances • 1 light year—the distance light goes in one year—approx. six trillion miles. • 1 light year = 9.46x1015 meters. • Closest star to us: Proxima Centauri (4.3 light years). • Keep in mind it only takes 8 minutes for light to come from the Sun to Earth. • About 17 hours from Earth to Voyager 1 (125 AU from Sun)

20. View of Stars Long photo exposure of stars from Oregon. Center of concentric circles is Polaris, the “North Star” at the North Celestial Pole. Polaris is 431 light years from Earth.

21. Big Dipper Polaris Venus East West Jupitor Uranus Orion Betelgeuse Sirius 5:00 am 9/22/12

22. Big Dipper Polaris Venus Jupitor East West Uranus Orion Betelgeuse Sirius 6:00 am 9/22/12

23. Big Dipper Polaris Uranus Sun East West Jupitor Venus Orion Betelgeuse Sirius 7:00 am 9/22/12

24. Ursa Major Ursa Minor The Little Bear Ursa Major The Great Bear

25. Big Dipper The Big Dipper is formed by seven major stars within Ursa Major. • In the U.S. this group of seven stars is called the “Big Dipper.” UK and Ireland, the “Plough.” American Indians referred to it as a bear and three cubs. • In 19th century, runaway slaves would follow the “drinking gourd” to head north and freedom.

26. Where is Polaris in the Sky? Find the Big Dipper within Ursa Major. Two end stars point to Polaris, approximately seven lengths. Polaris is in the handle of Little Dipper (Ursa Minor).

27. Sirius Brightest star in the sky, magnitude −1.4. Bright because it is relatively close, 8.6 lightyears, and hot (10,000 K vs Sun 6,000 K). Find it by following the “belt of Orion” southward. • Known as the "Dog Star", in its constellation, Canis Major (Big Dog). Faithful dog of Orion the Hunter.

28. Betelgeuse Betelgeuse (“beetle-jooz”) is a red supergiant star approaching end of its life cycle. Ninth brightest, reddish tinge. 641 light years away. Located in constellation Orion. Near the belt. If put in place of our Sun, would reach to Jupiter. Hubble telescope, Visible

29. End of a Star’s Life The future of Betelgeuse—In larger stars, nuclear fusion continues until the heavier core has grown so large that it can no longer support its own mass. This core will suddenly collapse. The shockwave formed by this sudden collapse causes the rest of the star to explode in a supernova. Most of the matter in the star is blown away by the supernova explosion

30. Nebulae Crab Nebula first observed 1731. Corresponds to bright (6x Venus) supernova recorded by Chinese and Arab astronomers in AD 1054. At center is the Crab Pulsar, a rotating neutron star roughly 20 km in diameter. ρ=1014 g/cm3 Pulsar blinks light, 30 times per second. Crab Nebula 6,300 ly – Hubble

31. Edwin Hubble • Up to the early 1900’s the Milky Way was considered the universe. • Edwin Hubble collected data from Mt. Wilson Observatory, and announced in 1925 that there were other galaxies beyond the Milky Way (in particular the Andromeda Galaxy) • His announcement changed our view of the universe. Mt Wilson Webcam

32. Andromeda Spiral Galaxy - Amateur Telescope

33. Andromeda Galaxy Andromeda Spiral Galaxy - Hubble Nearest Galaxy to Milky Way

34. The Hubble Space Telescope is named in honor of Edwin Hubble.

35. Galaxies A galaxy is a massive system consisting of stars, gas and dust, and “dark matter.” Range from ten million to one trillion stars, average 100 billion. Stars orbit a common center of mass. Our Sun is one of the stars in the Milky Way galaxy. Classified according to their shape, elliptical, spiral, starburst, ...

36. Milky Way Galaxy • Milky Way spiral galaxy. • Sun is on the “Orion” arm. • 100,000 ly in diameter. • 200 billion stars. • One of a cluster of 40 galaxies called the Local Group. Includes Andromeda Galaxy. • Artist concept→ Artist concept

37. M104 Sombrero Galaxy - Hubble , Visible

38. Nearby Spiral Messier 81 Galaxy, 12 million light-years - NASA Spitzer Space Telescope, Infrared

39. A Full Ring Galaxy - NASA Hubble

40. Black Hole A Black Hole is at the center of each galaxy, and its size correlates to the size of each galaxy. A black hole is a place in space where the gravity is so strong that nothing—not even light—can escape it. This is not a black hole. This is a Black Hole

41. Observable Universe 100 billion galaxies in the observable universe. Approximately 100 billion stars in each galaxy. Galaxies range from 3 to 300,000 light years in diameter. “Dark matter” is an invention to explain why galaxies rotate as if they are much heavier than they appear. Unseen mass. Galaxy may be up to 90% dark matter.

42. Red Shift • Light from stars moving away from Earth • Dark lines from absorption of specific light colors by the gases in the Sun’s photosphere. • H and He. Lower Frequencies • Doppler effect • Stellar Doppler effect

43. Universe Is Expanding Formulated in 1929 based on Hubble’s additional measurements from Mt. Wilson. Most cited evidence for the “Big Bang” model of the universe. Sometimes the energy for this expansion is called “dark energy.” Not understood. • Hubble’s Law (1929): “The redshift in light coming from distant galaxies is proportional to their distance.”

44. Big Bang Cosmological model of the universe Supported by all lines of scientific evidence and observation. Essential idea is that the universe has expanded from a primordial hot and dense initial condition at some finite time in the past and continues to expand. Extrapolation of the expansion of the universe backwards in time helps fix a date ~ 13 billion years ago.

45. Mote of Dust • 1990 Voyager photo taken as Voyager exits Solar System. • Earth is 4 billion miles away.

46. Compare Carl Sagan’s view of Earth http://obs.nineplanets.org/psc/pbd.html With God’s: Isaiah 45:18 “For this is what the LORD says— he who created the heavens, he is God; he who fashioned and made the earth, he founded it; he did not create it to be empty, but formed it to be inhabited.” Romans 5:8 But God demonstrates his own love for us in this: While we were still sinners, Christ died for us. Earth and Moon seen from Mars by MGS on 8 May 2003