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  • Original caption: "View of the Earth as seen by the Apollo 17 crew traveling toward the moon.
  • Space exploration in the past five decades has turned the low orbit of our planet into a hovering junkyard, a mix of dead satellites and discarded rocket hardware. This space garbage — euphemistically referred to as “space debris” — isn’t just an eyesore for visiting space aliens; it also poses a serious hazard to space shuttle missions, as well as the International Space Station. This junk isn’t just floating in space, it’s hurtling around the earth at 18,000 mph. A collision could have devastating consequences. It was exactly this scenario that NASA scientists feared this week, when it was reported that astronauts on the station might have to evacuate due to a possible collision with a piece of an old Soviet satellite. Luckily, the astronauts got good news today that the space station was safe from space junk. It was a close call, though; because it was deemed too late for NASA to move the station, the crew had taken shelter in the Russian Soyuz before receiving the all-clear today. The UN passed a set of space-debris guidelines in 2007, but obviously more serious action needs to be taken to confront this issue.
  • Transcript

    • 1. The Gaia Hypothesis
      Mariana Botero
      IE- MGEC
      Data Management and Information Design
    • 2. Gaia
      Gaia in Greek meant earth, land or mother
      In Greek mythology, Primal Goddess of Earth, of the order of Mother Titan or Great Titan
      Symbolized Mother Nature or Earth Mother
    • 3. Holism
      Holism: Idea that all properties of a system cannot be explained by component parts alone, but as a whole
      Developed by Aristotle in the Metaphysics, “the whole is different from the sum of its parts”
    • 4. Gaia Theory or Feedback Loop Theory
      Homeostasis: equilibrium, balance
      Different processes contribute to overall equilibrium
      Biomass makes conditions on the planet hospitable through surface temperature, atmospheric composition, and ocean salinity
      Feedback consisted of the Earth supporting Life, and Life supporting the Earth
    • 5. Surface Temperature
      Global surface temperature has remained constant, despite a 25-30% increase in the energy provided by the Sun
      Example of the Earth maintaining conditions hospitable for Life
    • 6. Atmospheric Composition
      Atmosphere: 79% nitrogen, 20.7% oxygen, 0.03% carbon dioxide
      Methane should not exist; combustible in an oxygen atmosphere
      Remains constant, should be unstable
      Stability can only be maintained through removal or production by living organisms
      Example of Life maintaining conditions optimal for Earth
    • 7. Ocean Salinity
      Constant at 3.4% for a long time
      Cells require salinity but do not tolerate above 5%
      River salts should have raised salinity much higher
      Stability maintained through influence of organic processes
    • 8. Volcanic Activity
      Produces CO2 in atmosphere, then goes through cycle where used by algae and released on ocean floor, increasing clouds
      • Thus, controls surface temperature, cools planet, and aids precipitation for plant life
    • Daisyworld Model
      Mathematical model for illustrating Gaia Hypothesis feedback mechanisms
      Daisies represent albedo
      Black – absorb light and warm the planet
      White – reflect light and cool the planet
      Planet temperature regulated back to optimum, even when model increased radiation
    • 9. Real Application
      Simple homeostatic mechanisms generally accepted (i.e. when atmospheric CO2 rises, biomass increases and thus removal of more CO2)
      Lovelock attributed this to systemic Darwinian evolution; creatures that improve their environment for survival do better than those that damage the environment
    • 10. Criticism I- Meaning of Life
      Critics said a criteria of life is the ability to reproduce
      Lovelock defined life as self-preserving system of feedback loops
      Instellar travel and carrying conditions of life elsewhere could signify planetary spore
    • 11. Criticism II - Theological
      Gaia acted intentionally, purposefully
      Lovelock said intentionality was metaphorical, no religious implications
      Theory criticized for having theological connotations and not scientific enough
    • 12. Radicalism Surrounding Theory
      Extended holistic lifeform to galaxies, “we are made of stardust. Life in inherent in nature”
      Fires, metals, crystals as living organisms
      Is it possible then to have non-life?
      Gaia Movement- political branch concerned with how humans might live more sustainably within “living system”
      Earth is conscious and part of universal evolution, a single organism
      Mystical and metaphysical interpretations
    • 13. Defense
      Gaia not an organism, but the interaction among organisms
      Planet behaves as a physiological system in certain limited ways
      Surface of the planet regarded as alive
      “Gaia is just a symbiosis as seen from space”
    • 14. Ecological Science
      Modified Gaia Theory agrees with science that Earth is the ultimate object of ecological study
      Earth System Science studies interactions between biota, oceans, geosphere and atmosphere
      Concern common to both of human modification to global environment and implications for Life and human well-being
    • 15. Climate Change
      4 Conclusions:
      Earth System a single, self-regulating system with complex interactions and feedbacks
      Anthropogenic changes are clearly identifiable beyond natural variability
      These changes have multiple effects that affect the Earth System in complex ways
      The nature of changes now occurring simultaneously, their magnitudes and rates, are unprecedented
    • 16. Uninhabitable Planet
      Lack of respect of humans for Gaia is testing capacity for homeostasis (damage to rainforests, reduction of biodiversity, greenhouse gas emissions, warming oceans, etc.)
      Activities are eliminating negative feedbacks and increasing global warming positive feedbacks
      By 2040, 6 billion inhabitants will have been affected or killed by floods, droughts, and famine
      A 4o temperature rise will eliminate 90% of life on the planet
      Lovelock believes it is too late to repair damage, “we are about to take an evolutionary step and my hope is that the species will emerge stronger”
    • 17. Gaia Spore
      Carl Sagan said that from cosmic point of view, “space probes have character of a planet preparing to go to seed”
      Biosphere will multiply in future by colonizing other planets
      Humankind will be the primer for Gaia´s reproduction
      Human interstellar exploration, colonization, and terraforming other planets may be Gaia´s spore