Feeling Gravity?

Most recent answer: 07/06/2012

Q:
According to Newton's law of gravitation, every objectin the universe attracts each other which is directly proportional to their masses and invrsely proportional to their distance between them. But I dont feel any attraction of any object except earth. Why?
- Razin Shaikh (age 13)
Navsari,Gujarat,India
A:
Actually, you don't feel the attraction to the earth either. If you were free-falling in the earth's field, it wouldn't feel any different than free-falling in a stronger or weaker field. What you feel is the pressure from the floor or a chair or whatever is getting in the way of the free-fall.

It's true that the earth is the main source of the field here. So the earth's gravity accounts for almost all of the strength that those other forces (floor, chair,...) need to make you not keep falling toward the earth. The reason the other fields are weaker is simply that the other objects are much farther away. The strength of the field falls off as the inverse  square of the distance to the distant object.


Mike W.

(published on 07/06/2012)