you are likely to find Potato in/at/on Soil. Soil is related to Dirt. you are likely to find Dirt in/at/on Closet. you are likely to find Rifle in/at/on Closet. 
Physics is related to Theory. Theory is related to Experimental. 
Potato --AtLocation--> Soil <--RelatedTo--> Dirt --AtLocation--> Closet <--AtLocation-- Rifle 
Physics <--RelatedTo--> Theory <--RelatedTo--> Experimental 