Added a few words to clarify that this was not a new invention or known technology but re-popularised. Also changed entrepreneur to billionaire as Musk is far more famous for having money than making it, in 2025.
[[File:Hyperloop all cutaway.png|thumb|Concept art of hyperloop inner workings|265x265px]]
'''Hyperloop''' is a proposed high-speed [[transport]]ation system for both passengers and freight.<ref>{{cite web |last=Simon |first=Joanna |url=https://wagner.nyu.edu/rudincenter/2017/02/primer-hyperloop-travel-how-far-future |title=A Primer on Hyperloop Travel: How far off is the Future? |publisher=[[Rudin Center for Transportation Policy & Management]], [[New York University]] |access-date=2024-05-24}}</ref> The concept was recently re-popularised by entrepreneurbillionaire [[Elon Musk]] in a 2013 [[white paper]], where the hyperloop was described as a transportation system using capsules supported by an [[air bearing|air-bearing surface]] within a low-pressure tube.<ref name="Alpha SpaceX" /><ref>{{cite journal |last1=Premsagar |first1=Smriti |last2=Kenworthy |first2=Jeffrey |date=2022 |title=A Critical Review of Hyperloop (Ultra-High Speed Rail) Technology: Urban and Transport Planning, Technical, Environmental, Economic, and Human Considerations |journal=[[Frontiers in Sustainable Cities]] |volume=4 |doi=10.3389/frsc.2022.842245 |doi-access=free|bibcode=2022FrSC....4.2245P }}</ref> Hyperloop systems have three essential elements: tubes, pods, and terminals. The tube is a large, sealed [[Vacuum#Vacuum-driven machines|low-pressure system]] (typically a long tunnel). The pod is a coach at [[atmospheric pressure]] that experiences low [[Drag (physics)|air resistance]] or friction inside the tube<ref name="mechsite2019092">{{cite web |last1=Opgenoord |first1=Max M. J. |title=How does the aerodynamic design implement in hyperloop concept? |url=https://mechanicalsite.com/446/how-does-the-aerodynamic-design-implement-hyperloop-concept |url-status=usurped |archive-url=https://web.archive.org/web/20191003205826/https://mechanicalsite.com/446/how-does-the-aerodynamic-design-implement-hyperloop-concept |archive-date=3 October 2019 |access-date=16 September 2019 |website=Mechanical Engineering |publisher=MIT - Massachusetts Institute of Technology}}</ref><ref>{{cite journal |last1=Lang |first1=Alex J. |last2=Connolly |first2=David P. |last3=de Boer |first3=Gregory |last4=Shahpar |first4=Shahrokh |last5=Hinchliffe |first5=Benjamin |last6=Gilkeson |first6=Carl A. |date=2024 |title=A review of Hyperloop aerodynamics |journal=Computers & Fluids |volume=273 |pages=106202 |doi=10.1016/j.compfluid.2024.106202}}</ref> using [[Maglev|magnetic propulsion]] (in the initial design, augmented by a [[ducted fan]]). The terminal handles pod arrivals and departures. The hyperloop, in the form proposed by Musk, differs from other [[Vactrain|vactrains]] by relying on residual air pressure inside the tube to provide lift from [[Aerofoil|aerofoils]] and propulsion by fans; however, many subsequent variants using the name "hyperloop" have remained relatively close to the core principles of vactrains.<ref>{{Cite web |last=Garfield |first=Leanna |title=15 remarkable images that show the 200-year evolution of the Hyperloop |url=https://www.businessinsider.com/history-hyperloop-pneumatic-tubes-as-transportation-2017-8#in-1799-inventor-george-medhurst-proposed-an-idea-to-move-goods-through-cast-iron-pipes-using-air-pressure-in-1844-he-built-a-railway-station-for-passenger-carriages-in-london-that-relied-on-pneumatics-until-1847-1 |access-date=2024-12-08 |website=Business Insider |language=en-US}}</ref><ref>{{Cite web |date=March 25, 2021 |title=Timeline: tracing the evolution of hyperloop rail technology - Rainway-Technology |url=https://rail.nridigital.com/future_rail_mar21/hyperloop_rail_system_timeline}}</ref>
Hyperloop was teased by Elon Musk at a 2012 speaking event, and described as a "fifth mode of transport".<ref name="PandoDaily Hyperloop">{{cite web |title=Pando Monthly presents a fireside chat with Elon Musk |url=https://pando.com/2012/07/12/pandomonthly-presents-a-fireside-chat-with-elon-musk/ |website=pando.com |publisher=PandoDaily |access-date=15 July 2017 |date=13 July 2012 |archive-date=16 July 2017 |archive-url=https://web.archive.org/web/20170716135721/https://pando.com/2012/07/12/pandomonthly-presents-a-fireside-chat-with-elon-musk/ |url-status=live}}</ref> Musk released details of an alpha-version in a [[white paper]] on 22 August 2013, in which the hyperloop design incorporated reduced-pressure tubes with [[pressurized]] capsules riding on [[air bearing]]s driven by [[linear induction motor]]s and [[axial compressor]]s.<ref name="gm20130822" /> The white paper showed an example hyperloop route running from the [[Los Angeles]] region to the [[San Francisco Bay Area]], roughly following the [[Interstate 5 in California|Interstate 5]] corridor.<ref name="Alpha SpaceX" /> Some transportation analysts challenged the cost estimates in the white paper, with some predicting that a hyperloop would run several billion dollars higher.<ref name="NYT-Bilton" /><ref name="AJE" /><ref name="HuffPoAstronomical" />
