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Relative motion and mass

  1. Dec 17, 2013 #1
    Well, relativity says whatever moves, it's volume shrinks and mass increases (as observed).
    So if i am traveling at 99% c with respect to a massive neutron star, do that star become a black hole for me?
  2. jcsd
  3. Dec 17, 2013 #2


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    No. Because the source of gravity isn't just mass, but the stress energy tensor. The way you interact with the neutron star is going to be different, but it's not going to turn into a black hole. The relativity aspect isn't lost. You can consider the problem from neutron star's perspective, and derive your trajectory. You will follow that same trajectory relative to neutron star from your own perspective.
  4. Dec 17, 2013 #3


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  5. Dec 17, 2013 #4


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    If I am traveling at 99.999999999% c with respect to you, do you become a black hole for me? :wink:
  6. Dec 17, 2013 #5


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