an equal and opposite reaction."
This law is very interesting. According to this law, when you push against a wall, it also pushes back on you. However odd this may seem, it is very important to us in everyday life. If this law was not true then the force of gravity would pulls us straight to the center of the earth. I think there are enough movies out there to convince you that plummeting to the center of the earth would not be a good thing! What then keeps us from getting pulled down there? It is a force called the normal force, this is the force that pushes up from the ground on our bodies. Now, if it were not for gravity then what would happen? Well we would all go flying off the earth, again, not a good thing! So to review, Newtons third law is what keeps our feet planted on the ground when we are walking around. What a wonderful law.