What keeps the stars apart?

Discussion in 'Physics & Math' started by Quantum Quack, Jul 8, 2004.

  1. Quantum Quack Life's a tease... Valued Senior Member

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    When we look into the night sky we see amazing uniformity. We look at distant glaxies and again there is s certain uniformity.

    The question is, given that there are so many stars, why we don't see many collisions between stars?

    Another question would be, if someone can enlighten us, what is the smallest recorded distance betweeen at least two stars?

    Is it possible that gravity is also repulsive, when two stars are considered?

    Both repulsive and attractive in such a ratio that allows our stars to remain apart?

    Care to discuss?
     
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  3. Pete It's not rocket surgery Registered Senior Member

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    Stellar collisions are very rare, except in dense stellar systems.
    • There is so much space in between that close approaches are rare.
    • Gravitational attraction means that as two stars approach, they move faster, meaning that a very precise hit is necessary, otherwise they'll just sling around each other.
    • We haven't been looking for very long

    Contact binary
    There is also evidence of stellar collisions in the past (this is an old article - there are more recent ones).
     
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  5. Jolonar Being of intellect. Registered Senior Member

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    We don't see many collisions because they are so far away. Not to mention that they are in a biosynchronous orbit around the center of the galaxy. Thus, very few occurr due to the rotational speed of the galaxy and the gravity that holds them all together yet repells them from one another.

    57Km between the coronas. That is to the nearest Km. (Stable)

    Yes. Two opposing mater stars can be repulsed by the metals withing the core of each one. They are basically giant magnets in a sense.

    Hmmmm.... That's a hard one. Can anyone answer this?

    Sure. What are you opinions and theories?
     
    Last edited: Jul 8, 2004
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  7. Quantum Quack Life's a tease... Valued Senior Member

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    The line of thought I am exploring at present is teh contention that gravity is a self governing force.
    By this I mean that gravity is self mitigating.

    As we know gravity is not an absolute force. In that it's attraction is not absolute ( singularity) and what I am interested in is what allows gravity not to be absolute?

    Obviously if the gravity was absolute the universe would be one mass and not dispersed as it is.

    Now, I accept that gravity and space time may very well be the same thing and wonder if the time aspect affords this mitigation of gravitational strengths?
    BTW I am not posing any new theory and am just exploring this universal dynamic a little.
     
  8. Quantum Quack Life's a tease... Valued Senior Member

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    also BTW thanks Pete for those links......
     
  9. Quantum Quack Life's a tease... Valued Senior Member

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    This I find remarkable......you say stable......care to expand on this?
     
  10. eburacum45 Valued Senior Member

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    Originally Posted by Quantum Quack

    Is it possible that gravity is also repulsive, when two stars are considered?


    Oh yes? What are mater stars? and how repulsive is this magnetism? Even if it counteracts gravity to some extent magnetism is a different phenomenon to gravity.
    Gravity is never repulsive.

    The only reason stars do not collide is that they are very, very small, and space is very big.
    Mind bogglingly big.
     
  11. Quantum Quack Life's a tease... Valued Senior Member

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    Maybe I am wrong but if one works out the chance of collision due to the numbers of stars involved I think would normally state that the probability would be very high. Intuitive so.

    However apart from Pete's input about clusters ( dense stellar systems) it seems that the galaxies, including ours is defying that intuitive probability.

    There seems to be ( intuitive ) a relationship that is more than just attraction between the stars. Earlier in another thread the possibility that light acts as a break or repulsive force.....any thoughts on this?
    I know that the amount of force light presents is so small but I feel it is somewhat under rated in it's strength ( intuitive)
     
  12. Hypercane Sustained Winds at Mach One Registered Senior Member

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    Stellar collisions are rare. Like the others said, space is very big and the stars are just very small. Ever wonder why there are very few comets making its elliptical orbit around the sun? Because comets belong in the Oort Cloud, and how comets end up in here is because when a passing star comes nearby the gravitational wave from the star pushes at least a few rocks from the Oort Cloud and most of them doesnt make it into the inner solar system because most of them were caught by any of the gas giants gravity.

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  13. John Connellan Valued Senior Member

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    No, it doesn't matter how big space is or how small the stars are, they don't collide because the distances between the stars are usually phenomenal.
     
  14. Quantum Quack Life's a tease... Valued Senior Member

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    The thing is,
    "if gravity is only attractive then surely in time the stars would come together"
     
  15. John Connellan Valued Senior Member

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    The galaxy as a whole probably IS coming together is it?!
     
  16. beta Registered Senior Member

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    Hmmm. Lets not get too hasty here. Consider this scenario.
    Two stars are both in free fall in the same straight line trajectory towards a distant black hole. The stars are at different separation distance from the BH, therefore the star closest to the BH 'falls' faster than the star that is further from the BH.
    If I were an observer on one of these stars, I would see the other star being 'repelled' from the star I'm on. Since I'm inertial, I could then conclude that gravity can also be repulsive

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  17. Hypercane Sustained Winds at Mach One Registered Senior Member

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    Indirectly it could be repulsive.
     
  18. fadingCaptain are you a robot? Valued Senior Member

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    1. Distances between stars/galaxies/clusters are immense.

    2. Something is pushing galaxies away from each other at increasing rates.
     
  19. Brandon9000 Registered Senior Member

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    You might, but the correct conclusion would be that both stars are being attracted by the black hole's gravitational field, and that one is experiencing a stronger force because it's closer. The gravitational force between two pieces of matter is always attractive.
     
  20. Crisp Gone 4ever Registered Senior Member

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    Also remember that on a local galactic scale, everything rotates pretty much like in a solar system (the planets also don't collide, do they?), which is an additional reason why stars don't just "fall" towards eachother.
     
  21. Hypercane Sustained Winds at Mach One Registered Senior Member

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    1. Yes it is.

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    2. The Cosmological Constant, better yet, Dark Energy.
     
  22. beta Registered Senior Member

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    Thats one conclusion, not necessarily the only or correct one. I'm an inertial observer, therefore my observation is equally valid.
     
  23. hyperdog Registered Senior Member

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    You would see the other star receding, but you would also see the black hole approaching at a faster rate, leading you to conclude that the distance between the other star and the black hole is decreasing. Thus, black holes suck.
     

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