Their orbital speed is irrelevant. All that matters is that their speed relative to each other and to the station is zero. There was simply nothing there to cause tension in the line. Also, if the line was "sliding" along her leg, she would have immediately reached down and grabbed it, since a failure to do so would have killed both of them. But she made no such immediate move, therefore it's obvious it wasn't sliding.
Of course, the vast majority of people know very little about physics.
Thus, with our ignorance, we are free to completely enjoy this great film without any science-related hesitation.
Robert R said:
I would argue that most people would notice this physics error but in the end not care due to the overwhelming majority of physics that Gravity did get right.
I view it differently than both of you. I don't know the physics AND I don't think physics is the key issue in the scene.
Yes the scene bothered me as I think the timing/editing screwed up this scene. The guy seemed to let go at a point it became completely unclear that he HAD to. Now, I, the viewer 'leaves the film' thinking that what happened didn't connect to what I saw. They just overplayed their hand or in short, they went several seconds too long before he disconnected.
Terrific film in my view but I thought they mucked that moment up, big time.