why is space weightless

[taylrl]

At what point does the effect of earths gravity become zero, and why is it such? Surely at all points in space you should be able to feel some effect (albeit negligable) of gravity. If the effect of gravity does actually become zero, then is there a formula linking the distance you feel zero gravity at, to the mass of a body? I think I might have studied such a formula at school, but i cant remember it.

 

Why isnt the moon on a collision course with earth?

[gcol]

There are, I believe, several points of null gravity in our solar system. They are called Lagrange points. The one between earth and moon is point 5.

[taylrl]

so what is it that causes these lagrange points?

 

Ill just google it

[Klaynos]

so what is it that causes these lagrange points?

 

Ill just google it

 

 

Gravity from the moon cancells out the gravity from the earth' date=' the point is still affacted by gravity from the sun and everything else.

 

There is a formula linking gravity and the mass of objects:

 

[math']g= - \frac {GM} {r^2}[/math]

Note:

[math]g=\frac F m[/math]

[insane_alien]

Force of gravity = 0 when the distance is infinite. in a word, never. ever.

[YT2095]

no matter Where you go in this universe you`ll Never escape gravity. it simply does Not vanish over distance, it only gets reduced to very low levels, it`s never "Gone" per se.

[gcol]

This question is being dismissed too airily. Try this:

"WMAP Observatory_Lagrange Points", fromNASA.

[swansont]

This question is being dismissed too airily. Try this:

"WMAP Observatory_Lagrange Points"' date=' fromNASA.[/quote']

 

But that's not an answer to the original question that was asked, and the other three responses were, so I don't think the original question was being dismissed at all. The followup simply hadn't been addressed yet.

 

Lagrange points are solutions where the gravitational force goes to zero when solving for the three-body solution (in this case) involving the sun, moon and earth, in the approximation that the sun is fixed (you can't solve the three-body problem exactly). There are five points that go to zero, though IIRC three of them are points of unstable equilibrium.

[gcol]

I grovel:embarass:

[swansont]

I grovel:embarass:

 

No need. Nothing inherently wrong, IMO, in wanting to see that a reasonable question gets answered. You just have to have a little patience .

[gcol]

1.

I guess I was possibly mistaken in assuming that points of null gravity could be thought of as no gravity, a couple of posters having categorically stated that wherever you go in our galaxy/universe, You cannot escape the effect of it. But if null does means zero, and there must be a rather large number of these points............ Or perhaps there is just one point in the universe, even dynamic, which is the null of total gravitic effects?

2.

Within the site I referenced, there seemed good indications as to the history and calculation of these points.

[s pepperchin]

This question is why physics makes a point to distinguish between mass and weight.

[silkworm]

This question is why physics makes a point to distinguish between mass and weight.

 

Because mass and weight are entirely different things. The weight of an object changes with the acceleration it feels (F=ma), and an object will weigh less on a small planet than it will on a larger planet if it has the same mass. Mass can not be created or destroyed and most be conserved. Weight is a force that changes with acceleration.

[[Tycho?]]

Because mass and weight are entirely different things. The weight of an object changes with the acceleration it feels (F=ma), and an object will weigh less on a small planet than it will on a larger planet if it has the same mass. Mass can not be created or destroyed and most be conserved. Weight is a force that changes with acceleration.

 

Mass can be created or (more easily) destroyed by converting it to energy, like in nuclear reactions.