How do you know the size/maximum area of a gravity field

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Discussion Overview

The discussion revolves around understanding the size or maximum area of a planet's gravitational field. Participants explore the nature of gravitational influence, its persistence over distance, and the reasons behind the weakening of gravitational force as distance increases.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions how to determine the size or maximum area of a planet's gravity field, noting that the gravity equation involves the radius from the planet to the object but does not clarify the extent of the gravity field.
  • Another participant asserts that there is no maximum area for gravitational effects, stating that they extend indefinitely, though they become negligible with distance due to the inverse square law.
  • A participant expresses confusion about why gravitational force weakens with distance, drawing an analogy to heat from a fire and asking for clarification.
  • One response explains that the energy from a heat source spreads out over distance, leading to less energy impacting a fixed-size object, while also mentioning that gravitational effects are related to the distortion of space-time as described by General Relativity.
  • A later reply reiterates the explanation about heat and gravity, indicating that the participant found it helpful for guiding their further research.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of gravitational fields, with differing views on the concept of a maximum area and the reasons for the weakening of gravitational force with distance. The discussion remains unresolved regarding these points.

Contextual Notes

Participants express uncertainty about the underlying principles of gravity and its relationship with space-time, indicating a need for further exploration of General Relativity and related concepts.

Steven Hansel
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The title said it, how do you know the size or maximum area of a planet's gravity field can cover. The reason i asked this question because from the gravity equation the r is the radius from Mplanet and Mobject. So, that doesn't explain how big is the gravity field. Is it when the gravity force become 0?
 
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There is no maximum. The gravitational effects go forever. They may become negligible, since it decreases proportional to 1/r2, but it never completely disappears. As object A gets farther from one other object B and closer to a third object, C, the gravitational effect of C may become greater than that of B, but the effect of B is still there.
 
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Thanks for the answer, i still have one more question that i forgot to ask, why does gravitational force weakens as it get farther from a planet. I'm really confused. I also don't understand why when you get near fire it's hot and when you get away from it, you don't get any heat. thanks for answering!
 
For heat from a fire, the energy of a source gets spread out, so less of it hits another object of a fixed size as it gets farther away.
For gravity, the true answer is beyond my expertise on the subject. A mass distorts space-time in a certain way that is the subject of General Relativity.
 
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FactChecker said:
For heat from a fire, the energy of a source gets spread out, so less of it hits another object of a fixed size as it gets farther away.
For gravity, the true answer is beyond my expertise on the subject. A mass distorts space-time in a certain way that is the subject of General Relativity.
Okay, that really helped me to where i should find my answer, thanks for answering :)
 

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