How mass attracts other mass

We are shown in science programs on TV that mass distorts space in such a way that two or more masses seem to attract each other. The geodesic lines bend towards the earth but don't quite touch it as they bend back again. How does this make two or more masses attract each other?

All answered here..

https://en.wikipedia.org/wiki/Geodesics_in_general_relativity

don't forget that spacetime has it's own geodesic lines, as does the earth, and all things surrounding....

Thanks, Ghozer. The reference was interesting but how many of us understand such maths? Are you saying that gravity bends the geodesics of both masses so that each mass tries to move along a new geodesic, one that intersects the other mass's geodesic? If so then the reason why masses do so is just a fact, not something we can give a reason for, isn't it?

Get a lump of lead and put a light marble next to it say a millimetre away.

Come back to it in a year and the distance will be the same.

Most people are less attracted to larger masses.

Get a lump of lead and put a light marble next to it say a millimetre away.

 

Come back to it in a year and the distance will be the same.

Wow. You really need to get an education.

Read some science books, and do some of the simple experiments yourself - it won’t harm you I promise. Unless all science is a conspiracy dreamt up by our lizard overloads?

Get a lump of lead and put a light marble next to it say a millimetre away.

 

Come back to it in a year and the distance will be the same.

Do the trivially simple maths and you'll understand why.

Get a lump of lead and put a light marble next to it say a millimetre away.

 

Come back to it in a year and the distance will be the same.

I assume that the "light" refers to the weight of the marble due to the effect of "gravitational attraction" of the Earth on mass of the marble.

I assume therefore that the experiment is taking place near the Earth.

I predict that large mass of lead and a small mass of the marble will fall at the same acceleration and hit the ground at the same time.

Unless of course you have introduced another factor like a table to put them on. In that case I predict that the "gravitational effect" will contribute to causing a "frictional force" between the objects and the table.

The "gravitational force" attracting the two masses is not large enough to overcome the "frictional force" and so preventing their movement.

Your prediction: "Come back to it in a year and the distance will be the same." is correct in these special circumstances.

I also predict that these two objects placed in "space" as far as possible from the influence of other masses and with the same or zero velocity relative to each other would move towards each other at a predictable acceleration dependant on their masses.

Yes Annie Bynnol, but why is your last paragraph correct? Masses do not generate gravity like boiling kettles generate steam for example. Nor like torches generate light. Gravity doesn't radiate out of masses.

---------- Post added 28-04-2018 at 20:02 ----------

Do the trivially simple maths and you'll understand why.

Can't you explain it without using the smokescreen of advanced maths?

Thanks, Ghozer. The reference was interesting but how many of us understand such maths? Are you saying that gravity bends the geodesics of both masses so that each mass tries to move along a new geodesic, one that intersects the other mass's geodesic? If so then the reason why masses do so is just a fact, not something we can give a reason for, isn't it?

well think about it logically..

as the mass is attracted to each other (or whatever else) the lines will also move/change as the mass moves, you need to look into quantum field fluid dynamics and how the quantum field affects the movement of geodesic lines...

they always follow a parabolic arc with the centre point of the curvature being at the centre point of the mass.

He didn't say to drop them to be fair, so I assume he was placing them on a flat surface and hoping to disprove gravity by the fact that the marble doesn't roll towards the lead.

This is of course due to insufficient force being applied to overcome it's friction.

---------- Post added 28-04-2018 at 22:20 ----------

 

Can't you explain it without using the smokescreen of advanced maths?

The maths to calculate the scenario that the conspiracy nut suggested is not complex nor a smokescreen, it's simple and demonstrable.

It doesn't explain WHY gravity exists, but maths can't explain why something, it just explains how something.

---------- Post added 28-04-2018 at 22:22 ----------

It's like asking WHY the weak nuclear force exists, or electromagnetism. I doubt there is a WHY, a why implies that it's for a reason which leads you down all sorts of ridiculous reasoning paths about prime movers, which themselves are circular and unresolvable. These forces simply are, they describe the behaviour we can see, to the best of our understanding there isn't and can't be a why.

Most people are less attracted to larger masses.

Roman Catholics are attracted to Masses.