You are standing on a scale in an elevator. suddenly you notice your weight decreases. what do you conclude? you are standing on a scale in an elevator. suddenly you notice your weight decreases. what do you conclude? the elevator is accelerating downwards. the elevator is accelerating upwards. the elevator is moving at a constant velocity upwards. your diet is working. the elevator is moving at a constant velocity downwards.

Imagine someone would cut the cable of the elevator. The elevator, the scale and the person inside would be in free fall and that person would be "weightless". So I would conclude the elevator is accelerating downwards.

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.