View source for Fundamental force

{{Merge|Standard Model|discuss=Talk:Fundamental force#Merge}}
There are four '''fundamental forces''', sometimes called '''fundamental interactions'''.  The [[force]]s are called ''fundamental'' because there is no simpler way for [[physicist]]s to understand what the forces do or how they do it (their [[wikt:action|action]]). They are called [[wikt:interaction|interaction]]s because the action of one object on another is matched by a [[reaction]] from the other. 

We feel the effects of [[gravity]] and [[electromagnetism]] all the time.
* The [[gravitational force]] is described by [[Einstein|Einstein's]] [[general theory of relativity]] and is understood to be due to the ''curvature'' of [[spacetime]] by the [[mass]] of [[matter]]. 
* The [[electromagnetic force]] is due to [[electric charge]]. Charge causes electric force and movement of charge causes [[magnetism|magnetic force]].

The strong and weak interactions are forces at the smallest distances and explain [[nuclear physics|nuclear]] interactions.
*The [[strong force]] binds [[protons]] and [[neutrons]] together and also keeps the [[atomic nucleus|nuclei]] of [[atoms]] together. 
*The [[weak force]] causes [[beta decay]]. 

A complete description of the forces requires advanced [[physics]]. The [[Standard Model]] explains 
three of these forces (electromagnetism, the weak force, and the strong force). Most [[physicist]]s think that these become a single force under very high [[temperature]]s. This idea is known as the [[grand unification theory]].<ref>Franklin, Allan; Fischbach, Ephraim 2016. ''The rise and fall of the fifth force: discovery, pursuit, and justification in modern physics''. 2nd ed, Springer. ISBN 978-3319284125</ref>

==From the future to the past==
In the future, new forces may explain [[dark energy]] and [[dark matter]]. We may also get a [[Theory of everything]] that explains the four known fundamental forces. Even if we first ''unify'' the three forces of the Standard Model, we may continue to think of those forces as fundamental. This is what happened when [[theoretical physicist]]s unified electromagnetism and the weak interaction with 
[[electroweak]] [[theory]].

<!--{{Editor-note}}|It might make sense to keep this backward-looking history, even after the past has been added to.-->
*Once nuclear force was explained by color charge, it was seen not to be fundamental.
*Nuclear force was a theory to explain how photons could stay close together in the nucleus when their like electric charge would make them move apart, if not overcome by a stronger force.
<!--Not working on this for the time being
*[[General relativity]]
*[[Special relativity]] and [[Lorentz transformation]]
*[[Radiation]] [[Blackbody radiation]] and the quantum [[photon]]
*Light and Radio 
*[[Maxwell's equations]] Electricity and Magnetism and the implied constant speed of light
*[[Newtonian physics]] understands gravity as a force
*[[Renaissance]]: [[Galileo Galilei]] and the [[Principle of relativity]]
*[[Medieval]] and [[ancient philosophy]] had no understanding of a force as we understand them today.
*[[Human being]]s [[evolve]]d in a world where only gravity and electromagnetism can be felt directly.
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== References ==
{{reflist}}

[[Category:Force]]


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