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I need help to a project!

  1. May 29, 2012 #1
    Now my teacher told me that i and a few classmates that we have to make a project about the law of gravity aplying to the stars orbiting the galaxy and how it affects the celectial bodies within the galaxy... Also The Galaxy's Gravity affecting the stars...
    Can someone give me a few ideas...
    If someone can help would be most grateful

    Dark Universe..:smile:
    Last edited: May 29, 2012
  2. jcsd
  3. May 29, 2012 #2
    i suggest you to do a casestudy of the gravity of stars & its effects on surroundings all through its life ( i.e from birth to death of the star ) .
    Last edited by a moderator: May 30, 2012
  4. May 29, 2012 #3
    Thanks for the advice...
    But i need ideas. I can study on my own, alright,
    But if i'd wanted to do so i wouldn't ask for help on PF...
    Last edited by a moderator: May 30, 2012
  5. May 29, 2012 #4
    And what about the galaxy's gravity? that's also included...
    Last edited by a moderator: May 30, 2012
  6. May 30, 2012 #5


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    Staff: Mentor

    Could you be a little more specific with what the project is about?
  7. May 30, 2012 #6
    In general about the law of gravity...
    -who invented it at first (that i know)
    -How it works...
    -how it causes objects to orbit around other objects of more mass...
    -a few equations to prove it...
    -How the gravity holds in one piece the galaxy...
    -How it influenced matter to clump together and form the galaxy itself... etc, etc...
  8. May 30, 2012 #7
    Pretty sure you do! :biggrin:

    Pretty sure no one does. Not yet. The cause of gravitation is a mystery hoped to be explained by the graviton.

    To be precise, this doesn't happen. What actually happens is both the objects revolve about their common center of mass. To start, look up binary stars. Observations and details of these stars will be a good idea for your project.

  9. May 30, 2012 #8
    You can't really prove anything in physics. All you can do is fail very badly to disprove something. Almost all (edit: all, sorry) observations haven't gone against the current understanding of Gravity, General Relativity. (Note that some observations clearly go against one of GR and QM, as combining them results in utter mathematical nonsense, let alone observational nonsense.) So it's some observations that have "proven" it.

    Well, it's an attractive force. Lots of stuff in close proximity with each other will get attracted to each other and basically ... yea.

    Sorry if this sounds rude, that is not my intention.
    Last edited: May 30, 2012
  10. May 30, 2012 #9


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    Science Advisor

    This is a bit off topic, but this is just wrong. We have NO observations where a quantum theory of gravity is necessary for a correct description, and ALL observations we have made are in agreement with GR. Now, the ones which are quantum in character simply are dominated by nongravitational effects such that the correction from including GR is much much smaller than the measured errors. Nevertheless, there is still no disagreement.
  11. May 30, 2012 #10
    You ought to compare and contrasts Newton's conception of gravity with Einstein's.
  12. May 30, 2012 #11


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    Staff: Mentor

    You should be able to explain most of this using the rules for classical Newtonian gravity. However if you want to be more accurate then you would need to delve into General Relativity which is MUCH more complicated. Pretty much everything you need to know about gravity can be found here: http://en.wikipedia.org/wiki/Gravitation (Or on the other pages linked to from this article)

    As for ideas, it seems like you already have the idea you need, you just need to write it out and explain all the above. (Which is your job, not ours. We cannot do your work for you.)
  13. May 31, 2012 #12
    True Story Bro...:tongue::approve:
  14. May 31, 2012 #13
    For the galaxies - you would be a star if you included the strange way the spiral arms rotate. Find out why scientists have been puzzled by galaxy rotation and orbital speed of distant (from the center) objects compared to more central objects.
  15. May 31, 2012 #14
    I suggest you to do a bit on stellar evolution.Often people find it fascinating , you can be extensive about it as much as you wish to. Try to understand the process rather than just making a slide or two on it.
    Start with the newton's law of gravity(cover centripetal force,etc) , make a slide or two stating it's significance , stellar evolution , Black hole , collapse of newton's laws for specific cases.
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