one thing you do when you Killing is Dying. Killing can be used for Fun. 
Observation is derived from Observer. Observation is related to Scientific. Scientific is related to Physics. Physics is related to Slope. 
Dying <--HasSubevent-- Killing --UsedFor--> Fun 
Observer <--DerivedFrom-- Observation <--RelatedTo--> Scientific <--RelatedTo--> Physics <--RelatedTo--> Slope 