Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: Why and what is gravity?

Learn more physics!

Most recent answer: 02/05/2016
Q:
I keep seeing the term "force" used in explanations to measure or describe gravity, but can't find what creates this force. Is gravity the measure of friction from protons passing through an objects mass in course with a large objects magnetic lines of flux? If not what are the elements that create the "force" being felt? I am not a student looking for a homework question, just a retired electronics technician who is curious. Thanks.
- Lucien Levasseur (age 46)
San Diego, CA, USA
A:

Hello Lucien,

You ask some very serious questions. 

We know quite a bit about gravity, at least it's properties.   Every object that has mass exerts a force on other objects that have mass.  We know that the force between two objects that have have mass falls off as the square of the distance between them and is proportional to the product of the two masses.  These facts allow us to understand and calculate the orbits of the planets around the sun and orbit of the moon around the earth.   But why does such a force exist?   We don't know.  

Same thing with electricity and magnetism.   We know that there exist positive and negative charges and their attractive and repulsive forces that act similarly to that of gravity although with much greater strength.  Also we know that a moving electric charge will create a magnetic field. 

Same thing with the strong nuclear forces that allow nuclei to form, with even greater strength. 

Maybe some day a brilliant physicist will come up with a grand theory of everything that will put it all together.  Don't hold your breath.

LeeH


(published on 02/05/2016)

Follow-up on this answer.