Current Events

  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.
  • Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 ...Read more

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    Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows

    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field. For more information about this study, see the press release from the European Synchrotron Radiation Facility.
  • Ocean Volcanic Rocks Contain Samples of Recycled Crust
    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials fr...Read more

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    Ocean Volcanic Rocks Contain Samples of Recycled Crust

    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature. Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now. For more information about these results, see the press release from the Carnegie Institution.
This image shows how one artist has drawn the Big Bang. The Big Bang is a theory that explains the origins of the Universe through a massive explosion.
Click on image for full size
Windows original.

The History of the Universe

The theory that best explains the current universe is the Big Bang theory. This theory states that, in the beginning, the universe was all in one place. All of its matter and energy were squished into an infinitely small point, a singularity. The laws of physics which applied at that instant are not understood at all. Something unknown caused the universe to explode, and thus began the expansion that we see today.

The early universe was small, so everything happened very quickly compared to the timescales on which events happen for the present universe. At the start, the universe was very small and dense. This stage was called the primordial fireball. For the first second, only elementary particles, such as protons, neutrons, and electrons, could exist. But the universe quickly cooled and expanded. For about the next 500,000 years, electromagnetic radiation (light) was the most important thing in the universe and hence this time was known as the radiation era. When the universe had cooled to the point where the simplest atoms (hydrogen) could form, radiation no longer dominated and matter took over. The cosmic microwave background radiation was produced at this time. So began the matter era in which the universe exists now.

So how old is the universe? There is much debate over the current age of the universe among astrophysicists. But everyone agrees that it is somewhere between 10 and 20 billion years old.

Last modified May 6, 2008 by Randy Russell.

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