Law of attraction Could you please explain that since we know Newton's law of Universal Gravitation says all masses attract each other. Thus, we humans should be attracted as well or any other daily life objects. Why is it that we don't feel that attraction to be prominent? 
 A: Lets calculate the force between $60$ kg boy and $50$ kg girl separated by $1$m (stricly speaking distance between their center of masses) in space. By Newton's law of gravity,
$$F=G\frac{M_1M_2}{r^2}$$
$$F=6.67X10^{-11}\frac{60X50}{1^2}=0.00000020010N$$
But remember, what Albert Einstein said "Gravitation can not be held responsible for people falling in love" :)
I hope the calculation explained you, why the attraction is not felt prominent.
A: Note that gravitational constant can be measured directly in the laboratory.
For example, the Cavendish experiment detects the force between two heavy metal (lead or gold or what have you) in a torsion balance.
It is only because the force is very small relative to other forces such as the pull of the rest of the earth that you do not notice it.
Note also that shape of the earth, e.g. mountains, also produce variations in earth gravity.
A: The gravitational force is proportional to the mass of each object.  The proportionality constant is incredibly small compared to other forces.  Thus, we only feel (and observe) gravity when the masses are very large (such as the earth, planets, the moon, and the sun).
