Hello all. I'm a long time reader and a first time poster. I should start by saying that I am not a physicists or a physics student and am studying it merely out of curiosity so please forgive any ambiguous terms I may use that are not standard. I came up with a sort of thought experiment to do with classical or special relativity. It is my understanding that to an observer in a closed environment such as a train there is no experiment that can betray uniform velocity. However acceleration can be detected. This makes intuitive sense when we think about how it feels to travel in an actual train. But consider an observer in a closed box in outer space. Say that all of a sudden a star were to manifest itself from nothing some distance from this box. Suddenly there will be a force imparted on this box from the gravity of the star and it will be accelerated towards the star. Is there anyway to detect this occurrence? That is, does the has the box's inertial frame of reference change? Intuitively it seems that this isn't detectable since everything inside the box is being accelerated at the same rate. (Doesn't free fall feel the same as 0 gravity?) Yet relativity states that acceleration is detectable. I'm pretty certain my confusion stems from a fundamental misunderstanding of relativity but I'm not sure where I've gone wrong. Any help would be greatly appreciated.