<span>Villi are hair-like structures covered with epithelial cells measuring 1.5 mm that line the mucous inner membrane of the small intestine. The epithelial cells of the villi contain microvilli and are responsible for the absorption of nutrients. Being so small and numerous, they effectively increase the absorptive surface area of the small intestine. When the surface area increases, this is the time they absorb the nutrients.
As for plants' root hair cells, they receive nutrients through osmosis. Root hair cells are adapted for this by having a large surface area to speed up osmosis. The absorbed water and minerals are transported through the roots to the rest of the plant where it is used for different purposes: It is a reactant used in photosynthesis.
As we can see, both of them utilize increasing their surface area.</span>
        
             
        
        
        
One of the methods used widely to calculate the distance of nearby or closer objects in astronomy is Parallax. The distance of the stars are usually expressed in light years but the unit of distance is parsec or parallax second.  
                                          1 Parsec = 3.26 light years
Astronomers are not able to measure the parallax of a star that is a million light years away because the star is too far and the distance with which the start appears to move is too less to be calculated accurately.