---
source: https://iinventedlight.com/library/notes/what-is-gravity.md
title: "What is gravity?"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; restated in our own words"
attribution: "Summary by iinventedlight (AI-assisted). Sources: NASA, What Is Gravity?, US government work, public domain; NASA, Chapter 3: Gravity & Mechanics, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No observation or experiment was done; only the fetched government pages were read."
category: coverage-gaps
topic_area: "science-explain: physics"
tags: science, physics, gravity
sources:
  - id: S1
    title: "What Is Gravity?"
    publisher: NASA
    url: https://spaceplace.nasa.gov/what-is-gravity/en/
    accessed: 2026-11-04
    license: "US government work, public domain"
  - id: S2
    title: "Chapter 3: Gravity & Mechanics"
    publisher: NASA
    url: https://science.nasa.gov/learn/basics-of-space-flight/chapter3-1/
    accessed: 2026-11-04
    license: "US government work, public domain"
---
# What is gravity?

## Short answer
Gravity is the force by which a planet or other body pulls objects toward its center. It keeps the planets in orbit around the Sun and is why things fall when you drop them. [S1]

## Key points
- All masses attract each other. The pull weakens with the square of the distance but never fully disappears. [S2]
- Einstein described gravity as a curve in space around a massive object. [S1]
- Kepler's laws and Newton's mechanics describe how planets move under gravity. [S2]

## Claims
- id: C1
  claim: Gravity draws objects toward a body's center.
  source: S1
  evidence: "Gravity is the force by which a planet or other body draws objects toward its"
- id: C2
  claim: Gravity keeps the planets in orbit around the Sun.
  source: S1
  evidence: "The force of gravity keeps all of the planets in orbit around the sun."
- id: C3
  claim: Gravitation is the mutual attraction of all masses.
  source: S2
  evidence: "Gravitation is the mutual attraction of all masses in the universe."
- id: C4
  claim: Gravity's effect falls with distance squared.
  source: S2
  evidence: "its effect decreases in proportion to distance squared"

## Sources
- [S1] What Is Gravity?. NASA. https://spaceplace.nasa.gov/what-is-gravity/en/ . License: US government work, public domain. Accessed 2026-11-04.
- [S2] Chapter 3: Gravity & Mechanics. NASA. https://science.nasa.gov/learn/basics-of-space-flight/chapter3-1/ . License: US government work, public domain. Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).