Inference or observation? object a feels heavier then object b.

Observation!
An inference is something you can’t directly see or feel, like in this case you might *infer* that Object A is made of a more durable material because it is heavier.

On the other hand, an observation is something you can directly see or understand. In this case, you felt that Object A was heavier and knew from feeling it that it was heavier.

In conclusion; an observation is something you can directly observe, while an inference is something you make when using logic to decide something about something.

This movement is also referred to as  glacial plucking