Let us assume that the present does not make any recognizable sounds when shaken (
meow splat - the present now contains a dead kitten). Let us furthermore assume that the internal state of the present does not change, so that any measurements can be repeated.
I will consider it cheating to unwrap the present, or shine any form of light, rays or particles through the present. Not many people has x-ray or neutron scattering devises available anyway. - and obviously it is cheating to squeeze the present.
What can be measured?
- Size and shape of wrapping(hey mom ... my wish elephant will not fit in here)
- The mass
- Position of center of mass
- Moment of inertia tensor
- Vibrational resonance
- Magnetic resonance
- Thermal radiation
If the seven scalars in mass, position of center of mass and moment of inertia tensor were measured, what could be said about the shape and mass distribution of the present?
If vibrational or magnetic resonance were measured, what could be said about the shape and materials of the present?
Would the thermal radiation not just depend on the temperature of the wrapping? what if the room temperature were dropped, then the present would heat the wrapping depending on the heat capacity, and thermal conductance. -but can it be used for anything?
This question has been heavily edited to correct my previously mistakes, and reflect my progress. THANK YOU for the answers already given.