Gravity range?

[iAmSchrodinger'sCAT]

Is there a range of gravity? Like, is there a point in which you wont be affected by the gravity of an object?

Edited April 11, 2011 by iAmShrodinger'sCAT

[Janus]

No, Gravity is infinite in range.

[ydoaPs]

While the range is technically infinite, the strength of the force decreases proportionately with r^-2, so there is an effective range.

 

[math]|F|=|ma|[/math]

[math]|F|=|G\frac{Mm}{r^2}|[/math]

[math]|ma|=|G\frac{Mm}{r^2}|[/math]

[math]|a|=|G\frac{M}{r^2}|[/math]

[math]|r^2|=|G\frac{M}{a}|[/math]

[math]|r|=|\sqrt{G\frac{M}{a}}|[/math]

 

Now, to find the effective range for whatever mass you're analyzing, you just need to pick an acceleration due to gravity that you define as having negligible effect. Notice that as acceleration tends toward zero, the effective range tends toward infinity.

[iAmSchrodinger'sCAT]

Thank you this helps me a lot

[lemur]

While the range is technically infinite, the strength of the force decreases proportionately with r^-2, so there is an effective range.

 

Now, to find the effective range for whatever mass you're analyzing, you just need to pick an acceleration due to gravity that you define as having negligible effect. Notice that as acceleration tends toward zero, the effective range tends toward infinity.

My question with this is always if you had two objects and nothing else in the universe - if one object moved away from the other at escape velocity or greater, would it continue increasing its distance from the other object to infinity, or would it curve into a spiral whose expansion approached zero? If the spiraling would occur, you could say that gravity doesn't just have an effective range but that its range is determinant of spacetime expansiveness, no?