The above simulations present a classic physics thought experiment, sometimes
called a Gedanken experiment (from the German). An object is moving to the
right in a straight line with constant speed. The spaceship is
accelerating upward. The animation on the left
shows what a stationary observer would see as the rocket accelerates upward. The animation on the right shows
what an observer in the spaceship would see.
would someone in the spaceship describe the motion of the ball?
do you write the laws of the physics so that both frames are correct?
a: The motion of objects in an accelerating spaceship appears to be due to a
force. Therefore the ball appears to be accelerating downward with a constant
b: In order to get observers in the two reference frames to agree, we must
invent a force that acts on objects in the accelerating frame. Depending on the
acceleration of the spaceship, we may call this fictitious force gravity. In
fact, one cannot tell whether one is in a spaceship accelerating at 9.8 m/s2
far from the earth, or in a non-accelerating spaceship on the surface of the
Earth (ignoring rotation of the Earth and other small effects). In fact, this
equivalence between the two frames was Einsteinís starting point for general
Script Author: Mario Belloni