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Cosmic Influences

Cosmic Influences. On Earth. Big Bang. Estimated to have occurred 13.7 ± 0.13 b illion years WMAP (Wilkinson Microwave Anisotrophy (variation in temperature) Probe Mapping Universe Big Bang – 3.47min. http://www.negotiationlawblog.com/Big%20Bang.jpg. Big Bang Theory:

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Cosmic Influences

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  1. Cosmic Influences On Earth

  2. Big Bang • Estimated to have occurred 13.7 ± 0.13 billion years • WMAP (Wilkinson Microwave Anisotrophy (variation in temperature) Probe • Mapping Universe • Big Bang – 3.47min http://www.negotiationlawblog.com/Big%20Bang.jpg

  3. Big Bang Theory: Leads to a point of common origin for all matter This point of common origin is where everything came into being in a single instant Because time and space originated in the Big Bang, it did not occur in any specific location of space Every point in the universe was there when the Big Bang occurred, and therefore, every point in the universe is where the Big Bang happened The cosmic microwave background radiation is the echo of the Big Bang. Concepts in Cosmology

  4. Concepts in Cosmology • Big Bang Theory: (cont) • As the universe expanded, the wave stretched-out, much like a phone cord is stretched as you walk away from the base • The stretched-out wave would be very long and have very low energy • Two scientists, A. Penzias and R. Wilson, discovered this radiation, experimental verification of the Big Bang. 2 billion years after the big bang http://apod.nasa.gov/apod/ap960907.html

  5. Concepts in Cosmology • Future of the Universe • Big Crunch: If universe is greater than the critical density, collective gravity of all the matter in the universe will stop expanding and begin to contract. • Expanding Universe: If universe less than the critical density (current scientific theory), then universe will expand forever. http://apod.nasa.gov/apod/ap080210.html

  6. Universe • Our universe is estimated to have 125 – 500 billion galaxies • The average number of stars per galaxy is given as 200 billion • Error??? • Big 2.10 min http://www.astro.uio.no/ita/nyheter/HUDF_0304/HUDF_IR_full.jpg

  7. Two Inch Universe • If the Solar System is shrunk to 2 inches in diameter, then • The nearest star is 2 football fields away • The nearest star known to have planets is 6 football fields away • The Milky Way galaxy is the size of North America http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Alpha_Centauri_relative_sizes.png/800px-Alpha_Centauri_relative_sizes.png

  8. Milky Way http://www.digitalskyllc.com • Starting with ours – the Milky Way • In a plane, the center found in the Sagittarius Arm • Silly name??? • Nyx, goddess of the night sky, dripped milk • SS in MW http://www.youtube.com/watch?v=S7GiZMVNB20&feature=related http://hubblesite.org/gallery/album/entire_collection/pr2004025a/web_print

  9. Our Solar System • Medium size sun • 8 planets • 4 rocky inner planets • 4 gas giants • 5 dwarf planets • Asteroid Belt between last rocky and first gas giant • Kuiper Belt, of which Pluto is a large member • Oort Cloud http://upload.wikimedia.org/wikipedia/commons/c/c4/Planets2008.jpg

  10. Theories of Life • SETI (Search for Extra-Terrestrial Intelligence) • Life, including intelligent life, is found everywhere in our galaxy as well as other galaxies • Rare Earth Hypothesis • Most solar systems not suitable for life, but only in narrow habitable zones http://cache.io9.com/assets/resources/2008/04/SETI.jpg

  11. R* = 10/year (10 stars formed per year, on the average over the life of the galaxy) fp = 0.5 (half of all stars formed will have planets) ne = 2 (stars with planets will have 2 planets capable of supporting life) fl = 1 (100% of these planets will develop life) fi = 0.01 (1% of which will be intelligent life) fc = 0.01 (1% of which will be able to communicate) L = 10,000 years (which will last 10,000 years) N = 10 × 0.5 × 2 × 1 × 0.01 × 0.01 × 10,000 = 10, or the number of advanced civilizations. Drake’s Equation

  12. Drake’s Equation • Huge assumptions – which will greatly change the estimated number of intelligent civilizations in a galaxy • Range from 2.31 to 10,000s http://poweroftheunknown.files.wordpress.com/2006/04/drake2.jpg

  13. Habitable Zone • Where do we look? • Not too hot • Not too cold • Just right http://www.art.com/asp/sp-asp/_/PD--10100681/SP--A/IGID--1287057/Goldilocks.htm?sOrig=CAT&sOrigID=7645&ui=04CC46E750A7403884872C1AA8D89201

  14. Habitable Zones • Greatest diversity and density of life found on our planet as we approach the equator Amphibiaweb.org/amphibian/countydata.html

  15. Habitable Zones • Only life known is Earth • Possible Mars • Possible satellites around Jupiter or Saturn • However, are those too cold • Possible when sun swells??? http://www.star.le.ac.uk/edu/Extrasolar.shtml

  16. Habitable Zones • Not only on Earth and in our solar system, but also in our galaxy • Too close to the center of the galaxy, too much radiation • Too far out on an arm, not enough radiation http://forgetomori.com/wp-content/uploads/2007/08/galactic-habitable-zone1.jpg

  17. Proof? • The only confirmation of life is on Earth • Distance to the farthest reaches of our observable universe is 46.5 billion light years • Billions of galaxies with billions of stars • Far fetched to think we are alone, but technologically intelligent life????? http://img159.imageshack.us/img159/6331/phpkahgjyamqo0.jpg

  18. Back to Earth • What cosmic influences can impact (literally) the Earth? • Meteors • Asteroids • Comets • Sun • Moon • Earth http://prehistoricsillustrated.com/images_kc/earth_impact.jpg

  19. Asteroid Belt • Total mass smaller than our moon (but much of the mass lost) • 26 large and millions of small asteroids • Ceres largest, now classified as a minor planet http://www.arcadiastreet.com/cgvistas/ceres_100a.htm http://www.semp.us/_images/biots/Biot443PhotoA.jpg

  20. Oort Cloud • Outer reaches of our solar system from Kuiper Belt to ~50,000AU! • Billions of comets http://astro.berkeley.edu/~conor/ay250/pluto.html

  21. Sun Flare • Medium yellow star • ~10 billion life span • Primarily hydrogen with some helium • Converts ~8 tons of matter per second to energy E = mc2 http://apod.nasa.gov/apod/ap051005.html

  22. Size 1 Size 2

  23. Energy Output • Sun produces so much energy, that one second is equivalent to the the current energy used by world for 500,000 years • Most of the energy is x-ray, ultraviolet, visible, and infrared plus subatomic and charged particles http://dawn.artov.rm.cnr.it/img/spectrum.jpg

  24. Gravity • From Newton to Einstein • Spacetime and Gravity

  25. Earth in Space • Earth protected by magnetic fields • Generated in outer liquid iron/nickel core • Earth protected by atmosphere • Screens gamma rays, x-rays and most ultraviolet rays http://lpmpjogja.diknas.go.id/kc/e/earth_files/earth-24.jpg

  26. Energy to Earth • What day is this? • Spring Equinox • Summer Solstice • Fall Equinox • Winter Solstice • Seasons 5.53 min http://ccrc.unh.edu/~stm/AS/Common/Suns_Rays.JPG

  27. Solar Incidence of Angle • Light travels in a straight line • The curvature of the Earth forms the Incidence of Angle • The same amount of energy is spread over a larger area http://openlearn.open.ac.uk/file.php/2805/S250_3_002i.jpg

  28. Solar Radiation • Solar radiation • X-ray – blocked by atmosphere • Ultraviolet – mostly blocked by atmosphere • Visible – permeates, partially blocked by clouds • infrared – permeates http://mangalorean.com/circle/images/articles/20061130green4.jpg

  29. Albedo • Albedo is the fraction of solar energy reflected from the Earth back into space • a measure of the reflectivity of the earth's surface • Light soils, heavily vegetated areas have a high albedo • Dark soils, open areas have a low albedo • Ice, especially with snow on top of it, has a high albedo • Water is much more absorbent and less reflective, and has a low albedo http://media-2.web.britannica.com/eb-media/41/112541-004-926AB193.gif http://www.esr.org/outreach/glossary/albedo.gif

  30. Human Activity • All organisms change their environment – not just humans • Impact relating to lowering the albedo: • Pollution on ice and snow • Asphalt and cities • Clear cut or slash and burn http://www.mth.msu.edu/~ivanov/SatelliteP/Big/worldtradecenter_nyc800.jpg http://www.ncar.ucar.edu/assets/images/arctas_diagram.jpg

  31. Seasons and Sunlight • What is the solar angle of incidence for the equator for the globe on the left? • 90° • 66.5° • 47° • 43° • The globe on the left represents: • Summer Solstice • Winter Solstice • Equinox and cannot tell if it is the spring or fall • Not enough information http://www.physicalgeography.net/fundamentals/images/earth_sun_angles.gif

  32. Seasons and Sunlight • What is the solar angle of incidence for the equator for the globe on the right? • 90° • 66.5° • 47° • 43° • The globe on the right represents: • Summer Solstice • Winter Solstice • Equinox and cannot tell if it is the spring or fall • Not enough information http://www.physicalgeography.net/fundamentals/images/earth_sun_angles.gif

  33. Direction of Rotation A B • If you are looking down at the North Pole, does the earth spin • Counterclockwise • Clockwise http://www.flutrackers.com/forum/attachment.php?attachmentid=1512&d=1176083504

  34. Eccentricity • 100,000 year cycle • Winter in North at Perihelion, and therefore shorter than summer • Low eccentricity of 0.005 • High eccentricity of 0.058 • Mean eccentricity of 0.028 • Present eccentricity 0.017 • Moving towards low centricity - warming Perihelion Aphelion http://en.wikipedia.org/wiki/File:Eccentricity_half.svg

  35. Obliquity • Tilt of the Axis • 41,000 year cycle • Minimum tilt is 21.1º • Maximum tilt is 24.5º • Currently at 23.5º • Tilt is decreasing - cooling http://upload.wikimedia.org/wikipedia/commons/6/61/AxialTiltObliquity.png

  36. Precession • Wobble like a top • Completes the wobble every ~21,000 years • Other “north stars, Thuban in Draco and Vega in Lyra • Top 10 sec • Both 33 sec http://stardate.org/images/gallery/d_procession.jpg

  37. Milankovitch Cycles • These three cycles, in combination, can alter climate • Eccentricity • Obliquity • Precession • Milankovitch 2.38 min http://www.cgd.ucar.edu/research/highlights/section/milankovitch.jpg

  38. Questions?

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