Editing Newton's laws of motion (section)

===General relativity===
[[General relativity]] is a theory of gravity that advances beyond that of Newton. In general relativity, the gravitational force of Newtonian mechanics is reimagined as curvature of [[spacetime]]. A curved path like an orbit, attributed to a gravitational force in Newtonian mechanics, is not the result of a force deflecting a body from an ideal straight-line path, but rather the body's attempt to fall freely through a background that is itself curved by the presence of other masses. A remark by [[John Archibald Wheeler]] that has become proverbial among physicists summarizes the theory: "Spacetime tells matter how to move; matter tells spacetime how to curve."<ref name="Wheeler">{{Cite book|last=Wheeler|first=John Archibald|url=https://books.google.com/books?id=zGFkK2tTXPsC&pg=PA235|title=Geons, Black Holes, and Quantum Foam: A Life in Physics|date=2010-06-18|publisher=W. W. Norton & Company|isbn=978-0-393-07948-7|language=en|author-link=John Archibald Wheeler}}</ref><ref>{{Cite journal|last=Kersting|first=Magdalena|date=May 2019|title=Free fall in curved spacetime—how to visualise gravity in general relativity|journal=[[Physics Education]] |volume=54|issue=3|pages=035008|doi=10.1088/1361-6552/ab08f5|bibcode=2019PhyEd..54c5008K |s2cid=127471222 |issn=0031-9120|doi-access=free|hdl=10852/74677|hdl-access=free}}</ref> Wheeler himself thought of this reciprocal relationship as a modern, generalized form of Newton's third law.<ref name="Wheeler" /> The relation between matter distribution and spacetime curvature is given by the [[Einstein field equations]], which require [[tensor calculus]] to express.<ref name=":7" />{{Rp|page=43}}<ref>{{Cite book|last=Prescod-Weinstein|first=Chanda|url=https://www.worldcat.org/oclc/1164503847|title=The Disordered Cosmos: A Journey into Dark Matter, Spacetime, and Dreams Deferred|date=2021|publisher=Bold Type Books|isbn=978-1-5417-2470-9|location=New York, NY|oclc=1164503847|author-link=Chanda Prescod-Weinstein}}</ref>

The Newtonian theory of gravity is a good approximation to the predictions of general relativity when gravitational effects are weak and objects are moving slowly compared to the speed of light.<ref name=":6" />{{Rp|page=327}}<ref>{{Cite book|last=Goodstein|first=Judith R.|url=https://www.worldcat.org/oclc/1020305599|title=Einstein's Italian Mathematicians: Ricci, Levi-Civita, and the Birth of General Relativity|date=2018|publisher=American Mathematical Society|isbn=978-1-4704-2846-4|location=Providence, Rhode Island|pages=143|oclc=1020305599|author-link=Judith R. Goodstein}}</ref>