Life on earth

Discussion in 'Biology & Genetics' started by timojin, Sep 29, 2017.

  1. DaveC426913 Valued Senior Member

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    Our whole universe was in a hot, dense state. Then nearly fourteen billion years ago expansion started (wait)...
    The earth began to cool, the autotrophs began to drool, Neanderthals developed tools. We built a wall (we built the pyramids).
    Math, science, history, unraveling the mysteries that all started with the big bang. (Hey!)
     
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  3. timojin Valued Senior Member

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    To my understanding the quarks have a very short life, according to cern experiments, and at that time if so the volume of the universe would be very large since they are subatomic particles . Than the other question what have taken place to break the atoms into subatomic particles to increase such volume .
    "almost like anti-gravity pushing things apart." what do know about that ? You adding other factors to be questioned .
     
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  5. timojin Valued Senior Member

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    How did the universe got hot ? How could it get dense since as temperature increase the volume of the gas expands ?
     
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  7. James R Just this guy, you know? Staff Member

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    It just started that way.

    We're talking about the big bang here. Nobody knows what happened before the big bang (if there even was a "before").

    Also, the big bang was not an expansion like expanding gas in space. Rather, it was an expansion of space(time) itself.

    To give you an example, every proton or neutron contains 3 quarks. Protons and neutrons are stable particles*. The quarks they contain are stable.

    There were no atoms until a long time after the big bang. The universe was far too hot to allow atoms to form.

    We know about inflation because it's the accepted way to explain a number of observations about the universe that otherwise cannot be explained. Initially it was a controversial theory, but it is now well accepted by cosmologists.

    Remember: cosmological models are constructed to model real-world observations of the universe. Scientists aren't just making stuff up at random. A scientific theory is not the same as a vague idea or hypothesis somebody dreamed up.

    ---
    * At least, neutrons bound in a nucleus are stable. Isolated neutrons tend to decay after a few minutes.
     
  8. timojin Valued Senior Member

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    I am familiar of the composition of a proton ,
    In nature things are stable in low state of energy , If there where quarks and other subatomic particles, there must have been protons and neutrons to exide or to destabilize them to release the components. Otherwise where do they come from ?
    If this subatomic particles combine again energy will be released and the atoms formed will experience high temperature they will expand and show an increase in volume . So what is necessary to reduce the volume so the atoms will combine to form gas molecules . Somehow the temperature have to be decreased in order for larger masses.
    Somehow I don't by the theory of the big bang, there are to many questions.
     
  9. exchemist Valued Senior Member

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    Yeah, you see, when the Bang part fragments, the n goes off and you get left with a Bag.
     
  10. exchemist Valued Senior Member

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    ....along with a lot of blue smoke.
     
  11. Yazata Valued Senior Member

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    If by "fragmentation" you mean the initial 'big-bang', the 'universe' (the observed space-time-matter continuum) is currently estimated to be about 14 billion years old. The Earth is believed to be about 4.5 billion years old. So the universe was apparently nearly 10 billion years old when the Earth first appeared.

    My layman's understanding is that the big bang story seemingly wants us to hypothesize/believe that the universe began in a singularity without spatial dimensions, at a mathematical point essentially or something like it (very small). And the conservation of energy idea suggests that all the energy currently present in the entire universe (billions of galaxies) was initially present in that one point. So we would seem to be talking about energy densities approaching infinity. Then it hypothetically expanded much faster than the speed of light (cosmic 'inflation') which would have reduced the energy density dramatically. The idea seems to be that various kinds of particles kind of crystalized as the universe suddenly cooled (they call it 'symmetry breaking').

    Or at least that's how I picture it. I'm not a physical cosmologist or anything close to one.

    As you can perhaps intuit from my tone, I'm a little skeptical about this story (I'm skeptical about everything), but big-bang cosmology nevertheless seems to be the best contemporary cosmological myth that I know of at the moment and I accept its truth provisionally.

    I'm not sure what this has to do with life on Earth.
     
  12. timojin Valued Senior Member

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    Commonly the opening starts one way and evolves into something different . That is what happen.
     
  13. Janus58 Valued Senior Member

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    In its earliest state, matter and energy were indistinguishable and even the fundamental forces were merged into one force. This changed as the universe expanded and cooled and the forces separated. This allowed for quarks to form, but initially they were too energetic to bind together into neutrons and protons. That didn't happen until the universe had expanded and cooled more.
    All your "questions" are due to your ignorance of, and misconceptions on the subject. As such, whether or not you buy into the big bang model is of no consequence.
     
  14. DaveC426913 Valued Senior Member

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    Sure but you're pretty much asking to start from Square One and have us cover 9.7 billion years before we even get to the actual topic.

    Can it not be taken as a given that atoms formed, and clumped into stars and planetesimals, including the essential elements that life requires?

    Indeed. This is off-topic. This should be its own thread.
     
  15. Gawdzilla Sama Registered Senior Member

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    Serial yeah-buts have because.
     
  16. DaveC426913 Valued Senior Member

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    This does not parse.
     
  17. timojin Valued Senior Member

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    This is

    I know I am ignorant. but please ,, this hand waving supposed to satisfy an individual reader ? What makes this more credible than creation ?
    So I am an Infidel of your theory which is not very realistic.
     
  18. exchemist Valued Senior Member

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    It is more credible because it is an extrapolation of theories in physics that are based on observational evidence.
     
  19. Gawdzilla Sama Registered Senior Member

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    Me either. What did you do to my post.

    And don't blame the oxycontin.
     
  20. DaveC426913 Valued Senior Member

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    No. If you want to learn stuff, you should be reading books, where you get in-depth knowledge.
    This is a place where you can bring the questions you have from your reading to get clarification.
     
  21. James R Just this guy, you know? Staff Member

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    Yazata:

    This is the description from our current best model of what was going on at the big bang. Unfortunately that model (from general relativity) is a classical model, and physicists recognise that as such it is very unlikely to be able to correctly describe what was going on when the universe was tiny.

    The upshot of this is that you'll be hard pressed to find a cosmologist who actually thinks there was an infinite-density singularity at the big bang. It's better to think of that description as a kind of limit or approximation, which glosses over some rather important details that we are yet to work out.

    The same kind of thing applies to describing black holes, by the way. The thing to remember is that wherever the word "singularity" is used by physicists, it usually means a place where the mathematical description "blows up" in some way that is probably unphysical.

    To give you an idea using a solved problem: when Schrodinger came up with the first general relativistic description of a black hole, there were concerns about an apparent singularity at the event horizon of the hole, where time seemed to dilate infinitely according to the equations. However, that turned out to be more of a mathematical problem - the singularity was "removable" in various ways , such as changing to an alternative set of spacetime coordinates. That is, the apparent singularity turned out to be an artifact of the model, rather than anything with disasterous physical implications.
     
  22. timojin Valued Senior Member

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    I am not entitled to ask questions, just read to be indoctrinated . I am a subscriber to science journal and other Journals for over 10 years. I was the president of local section of the electrochemical society and a member of the American chemical society. Many people who write books they want to set the pattern their way .
     
  23. DaveC426913 Valued Senior Member

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    How is that different from many people who post on forums?

    The only difference between books and forums is that you're getting us to do your homework for you.
     

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