Force

==Development of the concept==
Philosophers in [[Classical antiquity|antiquity]] used the concept of force in the study of [[statics|stationary]] and [[dynamics (physics)|moving]] objects and [[simple machine]]s, but thinkers such as [[Aristotle]] and [[Archimedes]] retained fundamental errors in understanding force. In part, this was due to an incomplete understanding of the sometimes non-obvious force of [[friction]] and a consequently inadequate view of the nature of natural motion.<ref name="Archimedes">{{cite book |last=Heath |first=Thomas L. |author-link=Thomas Heath (classicist) |url=https://archive.org/details/worksofarchimede029517mbp |title=The Works of Archimedes |via=[[Internet Archive]] |access-date=2007-10-14 |year=1897 }}</ref> A fundamental error was the belief that a force is required to maintain motion, even at a constant velocity. Most of the previous misunderstandings about motion and force were eventually corrected by [[Galileo Galilei]] and [[Sir Isaac Newton]]. With his mathematical insight, Newton formulated [[Newton's laws of motion|laws of motion]] that were not improved for over two hundred years.<ref name=uniphysics_ch2/>

By the early 20th century, [[Albert Einstein|Einstein]] developed a [[theory of relativity]] that correctly predicted the action of forces on objects with increasing momenta near the speed of light and also provided insight into the forces produced by gravitation and [[inertia]]. With modern insights into [[quantum mechanics]] and technology that can accelerate particles close to the speed of light, [[particle physics]] has devised a [[Standard Model]] to describe forces between particles smaller than atoms. The [[Standard Model]] predicts that exchanged particles called [[gauge boson]]s are the fundamental means by which forces are emitted and absorbed. Only four main interactions are known: in order of decreasing strength, they are: [[strong force|strong]], [[electromagnetic force|electromagnetic]], [[weak force|weak]], and [[gravitational force|gravitational]].<ref name=FeynmanVol1>{{cite book |last1=Feynman |first1=Richard P. |last2=Leighton |first2=Robert B. |last3=Sands |first3=Matthew |title=The Feynman lectures on physics. Vol. I: Mainly mechanics, radiation and heat|year=2010|publisher=Basic Books|location=New York|isbn=978-0465024933|edition=New millennium |title-link=The Feynman Lectures on Physics |author-link1=Richard Feynman |author-link2=Robert B. Leighton |author-link3=Matthew Sands}}</ref>{{rp|((2–10))}}<ref name=Kleppner />{{rp|79}} [[High energy physics|High-energy particle physics]] [[observation]]s made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental [[electroweak]] interaction.<ref name="final theory"/>