Jump to content

Gravity range?

Featured Replies

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.

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?

Archived

This topic is now archived and is closed to further replies.

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.