Originally Posted by
Vessbot
He's moving backward. His (body) groundspeed could not be in the positive unless he's running toward the tail at greater than 500 knots.
Originally Posted by
Jet_Fan
no, it's -499 because he is facing the tail. If he stops it goes back to -500. If he turns to face the cockpit while stationary it goes from -500 to +500 almost instantly.
You're adopting a frame of reference which changes orientation with the person. The only way you can make sense of any of this is with a constant, non-accelerated frame of reference.
the airliner is flying East at 500 knots. the passenger is walking toward the tail at one knot, he is still moving East at 499 knots. He's not moving west merely because he's facing west.
While I obviously think Brecrow's theory is fallacy, I have to agree with him that the analogy the two if you are using here is just as flawed.