Feather and Bowling Ball

A question here for the physicists among us:

There is the question which asks: If you drop a bowling ball and a feather on the moon (meaning a perfect vacuum), which hits the ground first? The obvious answer is that they will both hit the ground at the same time because there is no air resistance and the acceleration due to gravity will affect them both the same way.

However, I thought that I had heard that in fact, due to some aspect of Relativity that I don't understand, the feather would actually hit the ground fractionally before the heavier object. Is this true?


  • there's a practical issue with this experiment; presumably you mean dropped from the same height.

    but what does that mean?

    If the centres of gravity are equal height above the moon and the feather is flat, the size of the bowling ball will mean it hits first.

    but if the nearest point of the objects are equal height; ie the bottom of the ball and edge of the feather, then the COG of the ball is a bit further away from the moon, indicating it would have slightly less force acting on it.

    relativity? not sure.

  • Irrespective of the shapes of the objects, I was under the impression that for some reason the lighter object would actually fall faster - abeit imperceptibly.

    This would appear to be wrong because a heavier object could be considered simply to be a collection of lighter objects which were joined together. I therefore wondered if it had something to do with the way space time was 'curved' less around the lighter object.

    I will have to do some digging...

  • The force-mass ratio should be the same, indicating the same acceleration.

    There might be some weird lateral motions affecting the trajectories, but in terms of downward accelerations they should be equal.

  • Haven't got Apple but can't find anything about this on the Internet although I have found information about other inconsistencies between the general Theory of Relativity and Newtonian mechanics.

  • I'd be interested to know the result if anyone does find a confirmed answer.

  • If you drop them separately, the bowling ball with hit imperceptibly sooner. Although the bowling ball and the feather may fall to the moon at the same rate, the moon will fall towards the bowling ball faster than towards the feather.

  • agreed. but if they're dropped simultaneously?

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