Re: [math-fun] Black Hole Binaries can eject relativistic normal stars
At 11:49 AM 12/1/2014, Mike Stay wrote:
Frederic Pohl's book _The World at the End of Time_ includes this as a major plot point.
Cool! I'll have to try to find this book.
On Mon, Dec 1, 2014 at 11:43 AM, Henry Baker <hbaker1@pipeline.com> wrote:
FYI -- Apparently, just like planets & planetoids can be ejected from solar systems, regular stars can be ejected from a system of binary black holes.
I presume that "living" in a planetary system of such a star would provide time dilation relative to the rest of the universe. Of course, the event which accelerated the star in the first place might a) strip the star of all/most of its planets; or at least b) kill all life on any such planets that do manage to escape with the star.
"In the context of astro-biology, SHS could spread life beyond the boundaries of their host galaxies [26, 27]."
I forgot to say that one implication of b) is that since time is moving relatively slowly on the accelerated star, if all life is killed when the star is accelerated, there won't be much time for life to evolve on the accelerated star planetary system. So you now need 3 compounded miracles: for life to have already evolved on the star prior to ejection; for the star to be involved in a binary black hole system; and for life to survive the ejection. Good luck with that...
Relativistic time dilation isn't a big deal for most ejected stars: With velocity measured in c=1 units, the factor is sqrt(1-v^2). For small v this is about 1 - (v^2)/2; if v = .1, the effect is half a percent. Even when v = .5, the ratio is .86603, with a slowdown of 13%. There's also an insignificant speedup, from no longer being in the galaxy's gravity well. Rich ------ Quoting Henry Baker <hbaker1@pipeline.com>:
At 11:49 AM 12/1/2014, Mike Stay wrote:
Frederic Pohl's book _The World at the End of Time_ includes this as a major plot point.
Cool! I'll have to try to find this book.
On Mon, Dec 1, 2014 at 11:43 AM, Henry Baker <hbaker1@pipeline.com> wrote:
FYI -- Apparently, just like planets & planetoids can be ejected from solar systems, regular stars can be ejected from a system of binary black holes.
I presume that "living" in a planetary system of such a star would provide time dilation relative to the rest of the universe. Of course, the event which accelerated the star in the first place might a) strip the star of all/most of its planets; or at least b) kill all life on any such planets that do manage to escape with the star.
"In the context of astro-biology, SHS could spread life beyond the boundaries of their host galaxies [26, 27]."
I forgot to say that one implication of b) is that since time is moving relatively slowly on the accelerated star, if all life is killed when the star is accelerated, there won't be much time for life to evolve on the accelerated star planetary system. So you now need 3 compounded miracles: for life to have already evolved on the star prior to ejection; for the star to be involved in a binary black hole system; and for life to survive the ejection. Good luck with that...
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