Editing Confirmation holism (section)

==Underdetermination in physical theory==

By 1845 astronomers found that the orbit of planet [[Uranus]] around the Sun departed from expectations.  Not concluding that [[Newton's law of universal gravitation]] was flawed, however, astronomers [[John Couch Adams]] as well as [[Urbain Le Verrier]] independently predicted a new planet, eventually known as [[Neptune]], and even calculated its weight and orbit through Newton's theory.{{efn |name= discOfNeptune|1= From wikipedia: ''[[Discovery of Neptune]]'' <ref name="Danjon, Prof. André Director of the Paris Observatory 1946">{{cite journal | last1=Danjon |first1=André | year=1946 | title=Le centenaire de la découverte de Neptune | journal=[[Ciel et Terre]] |volume=62 |page=369 | bibcode=1946C&T....62..369D}}</ref>}} And yet neither did this empirical success of Newton's theory verify Newton's theory.

[[Le Verrier]] soon [[Perihelion precession of Mercury|reported]] that [[Mercury (planet)|Mercury]]'s [[perihelion]]—the peak of its orbital ellipse nearest to the Sun—advanced each time Mercury completed an orbit, a phenomenon not predicted by Newton's theory, which astrophysicists were so confident in that they predicted a new planet, named ''[[Vulcan (hypothetical planet)|Vulcan]]'', which a number of astronomers subsequently claimed to have seen.  In 1905, however, Einstein's [[special theory of relativity]] claimed that space and time are both [[spacetime|relative]], refuting the very framework of Newton's theory that claimed that space and time were both [[absolute space and time|absolute]].

In 1915, Einstein's [[general theory of relativity]] newly explained [[gravitation]] while precisely predicting Mercury's orbit.  In 1919, astrophysicist [[Arthur Eddington]] led an expedition to test Einstein's prediction of the Sun's mass reshaping [[spacetime]] in its vicinity.  The [[Royal Society of London|Royal Society]] announced confirmation—accepted by physicists as the fall of Newton's theory.  Yet few [[theoretical physics|theoretical physicists]] believe general relativity is a fundamentally accurate description of gravitation, and instead seek a theory of [[quantum gravity]].<ref>{{Cite web|url=https://www.preposterousuniverse.com/podcast/2019/09/09/63-solo-finding-gravity-within-quantum-mechanics/|title=63 &#124; Solo: Finding Gravity within Quantum Mechanics – Sean Carroll}}</ref><ref>http://cgpg.gravity.psu.edu/people/Ashtekar/articles/rovelli03.pdf {{Bare URL PDF|date=March 2022}}</ref> {{citation needed|date=January 2014}}