# How does one exactly calculate gravity? How to portray a visual?

1. Jul 16, 2013

### infinite.curve

I know of the equation F=G((m1)(m2))/d^2.

So the distance between two masses are squared then divided out of the out come of the masses times the gravitational constant.

My question: how to make a visual representation of this formula?

2. Jul 16, 2013

### Staff: Mentor

It somewhat depends on what you want to show with your visual representation.

One way would be to draw a graph with the force between the two objects on the vertical axis and the distance between them on the horizontal axis, assuming the masses are constant.

Another way would be to draw a graph with the force between them on the vertical axis and the product of the two masses on the horizontal axis, assuming that the distance between them is constant.

Another way would be to draw a three-dimensional graph with the force between the objects on the z-axis, the distance between them on the x-axis, and the product of the masses on the y-axis.

And yet another way would be to draw a graph with the gravitational potential energy on the vertical axis and the distance between them on the horizontal axis.

There are more possibilities, but these between them cover most of the interesting visual representations.

3. Jul 16, 2013

### Bobbywhy

Google is your friend: Using the search terms "visualization of gravity" hundreds of U-tubes, images, and articles appear. Just try it.

4. Jul 16, 2013

### bp_psy

As Nugatory suggested making a graph of the force as a function of some of variables is the most useful way to visualize a formula. A vector diagram can be also useful but you usually can't get all of the info in the formula using one.

In this case this is kind of a bad advice since what you get, is a bunch a of videos,pictures and animations of the pretty misleading rubber membrane analogy model from GR. The OP asks about the visualization of the Newtonian formula.

5. Jul 16, 2013

### infinite.curve

All the responses are ever much appreciated.

Can anyone actually draw it and clip on a picture?

I get the idea, but want to be certain of what I am picturing.

6. Jul 16, 2013

### Mmm_Pasta

This isn't the equation for any two masses. This is for two spherical or point masses. The equation between a rod and a sphere would be different. You can get creative with different geometries.

As others have said, you can plot the force as a function of separation distance.

7. Jul 16, 2013

### infinite.curve

Yes, that is true. So what would be the equation for a rod and a circle?

In regards of how to make a visual representation, I got it. Thank you.