Acceleration does cause the formation of an event horizon, I believe, which might be considered to couple it with gravity (in an unexpected way).
On 14 February 2014 09:33, Jesse Mazer <[email protected]> wrote: > > On Thu, Feb 13, 2014 at 2:32 PM, Edgar L. Owen <[email protected]> wrote: > >> Jesse, >> >> Let me think about this, but it is NOT the observer in "free fall in a >> gravitational field" that is equivalent to acceleration. It is an observer >> RESISTING free fall (e.g. standing on the surface of the earth) that is >> equivalent to acceleration. >> > > Suppose the observer who's not moving on a geodesic path (call her Alice) > passes through the small spacetime neighborhood where the observer who IS > moving on a geodesic path (call him Bob) is defining his "local inertial > frame" (Bob's geodesic path can either by a free-fall path through curved > spacetime, or inertial motion in flat spacetime, since both qualify as > geodesics in their respective spacetimes). As Alice passes through this > region, she performs some experiment and notes the physical result. > Whatever physical elements are involved in this experiment, Bob can analyze > them too, and he should predict the SAME result even if his analysis is a > bit different--for example, if Alice is standing on a platform and lets go > of a ball, the ball will hit the platform, from Alice's point of view this > is due to a gravitational force and from Bob's point of view this is due to > the platform accelerating up towards the ball, but either way the actual > prediction is the same. So, to say that Bob should observe the same results > of any local experiment (provided he is approximating everything to first > order) regardless of whether he's moving inertially in flat spacetime or > free-falling in gravity is physically equivalent to saying Alice should > observe the same results of any local experiment (again ignoring > second-order and higher effects) regardless of whether she's accelerating > through Bob's region in flat spacetime, or passing through his region > because he's in free-fall while she is not (say, she's standing on a > platform resting on a pole embedded in the Earth below, while Bob falls > past her). > > Jesse > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
