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History of Universe (Baez timeline)

  1. Sep 30, 2004 #1

    marcus

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    Baez posted this timeline last week, its up to date
    and it has big bang temperatures and cosmology stuff
    as well as evolution of life on earth stuff

    and it also has projected history sever billion years into future
    so it is a pretty good timeline, hope you check it out and
    have some reactions

    http://math.ucr.edu/home/baez/timeline.html
     
  2. jcsd
  3. Oct 1, 2004 #2

    Chronos

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  4. Oct 1, 2004 #3

    selfAdjoint

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    Very neat. I was fascinated by some of the life history. Who knew that grass was just a little older than apes? And birds go so far back?
     
  5. Oct 3, 2004 #4
    I like Baez timeline, but he forgot to mention the Hadron era and the lepton era, both occurring before the starting of the radiation era
     
  6. Oct 5, 2004 #5

    Nereid

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    Not so fast! According to this site, grasses are between 55 and 70 million years old, with clear 'grass pollen' in the fossil record from 60 million years ago. However, it does seem clear that dinosaurs didn't eat grass!

    For those PF readers who don't already know, the 'grasses' include rice, wheat, and maize, and domesticated animals depend partly or wholly on grasses. Among the implications of increased levels of CO2 are the extent to which C3 plants will lose out to C4 ones (CAM plants aren't relevant here?); how many economically important grasses are C3 species?

    It's also a little disappointing to see that Baez ignores the Chinese development of the printing press (at least 400 years before Gutenberg).
     
    Last edited: Oct 5, 2004
  7. Oct 5, 2004 #6

    selfAdjoint

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    The Chinese press was important to the Chinese, but the European press was one of the things that led to the European exploration/plundering/colonizing expeditions, which led to the modern world.
     
  8. Oct 6, 2004 #7
    Please do not expect a mathematical physicist to get his details on human history 100% correct.
     
  9. Oct 6, 2004 #8

    Phobos

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    I was thinking of creating a similar timeline. Looks like he beat me to it.
     
  10. Oct 8, 2004 #9
    I'm very confused because I have examined a large quantity of timelines, and they seem to disagree in the ciphers, so in these times of "precision cosmology", it seems like a bad disease that we are not able to agree in the instants that things occurred.
    Example: according to www.fact-index.com/t/ti/timeline_of_the_big_bang.html the lepton era occurred from 1 s until 3 min. after Big Bang. But according to www.physics.gmu.edu/classinfo/astr103/CourseNotes/Html/Lec09/Lec09_pt2_cosmologyModern.htm it happened from 10-4 to 1 sec. after Big Bang. Similar disagreements can be found for the hadron era in different timelines. Some timelines mention the quark era, but others no. Some mention the electroweak era, but others no. Chronos link mentions both the Planck era, and the quantum gravity era, but I don't know how to differentiate between these two. I'd like a common consensus, history interests me also, you can never say that the Russian revolution happened in 1941 for example! :mad:
     
    Last edited: Oct 8, 2004
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