hidden momentum

{{Short description|Physics concept}}

In special relativity, hidden momentum or hidden mechanical momentum is the mechanical momentum (mass times velocity) that is unaccounted for by Newtonian mechanics. The concept of "hidden momentum" has been used in answering "paradoxes" in electromagnetism and other problems, including the Shockley–James paradox,{{cite journal|last1=Boyer|first1=Timothy H.|journal=Phys. Rev. E|date=7 January 2015|volume=91|issue=1|title=Classical interaction of a magnet and a point charge: The Shockley-James paradox|page=013201|doi=10.1103/PhysRevE.91.013201|pmid=25679727|arxiv=1408.3742|bibcode=2015PhRvE..91a3201B|s2cid=3752475}} the Mansuripur paradox,{{cite journal|last1=Griffiths|first1=David J.|last2=Hnizdo|first2=V.|journal=American Journal of Physics|date= June 2013|volume=81|issue=8|title=Mansuripur's paradox|pages=570–574|doi=10.1119/1.4812445|arxiv=1303.0732|bibcode=2013AmJPh..81..570G|s2cid=119277926}} and the Aharonov–Casher effect.{{cite journal|last1=Mansuripur|first1=Masud|journal=IEEE Transactions on Magnetics|date=April 2014|volume=50|issue=4|title=The Lorentz Force Law and its Connections to Hidden Momentum, the Einstein–Laub Force, and the Aharonov–Casher Effect|pages=1–10|doi=10.1109/TMAG.2013.2291817|arxiv=1404.3261|bibcode=2014ITM....5091817M|s2cid=1819434}}