Saturday, November 24, 2012

Antigravity from Supergravity

 As 2013 approaches, one may be left wondering where all the marvelous 2015 inventions of Back to the Future 2 are.  It seems the motorized Nike's worn by Marty McFly do exist (as Nike Air MAGs), but as of now cost a pretty penny to purchase.  However, the shoes aren't even the coolest invention featured in the movie, as hoverboards steal the spotlight in the 1989 film.

Let's suppose hoverboards may be possible.  How will they work?  Could they be a type of antigravity device?  Antigravity turns out to be quite natural in extended supergravity theories, as pointed out by the late Joel Scherk.  The supergravity multiplet in the N=2,8 cases contains in addition to the graviton, a spin-1 vector field (graviphoton) and in the N=8 case, a graviscalar.  The graviphoton behaves like a massive photon, prone to couple with gravitational strength, and unlike the graviton may provide a repulsive (as well as attractive) force, giving rise to a type of antigravity.  Could a real life hoverboard operate using graviphoton fields?  Perhaps real life hoverboards will employ superconductor/topological insulator pairs to accomplish the needed levitation effect.  Stay tuned.

1 comment:

ThePeSla said...

Perhaps it will take something not so exotic. For example the difference in centrifugal and centripetal forces can be used to raise a mechanical device a certain height where the piston hits an edge of high impact and the other direction it is free to float. Now the question is in reality which should nature or we regard as fictitious forces. While it was impractical considering the terrain for say individual soldier use (cerca 1959) yet considered also for a larger device as a craft. If we add boosts from smaller systems on this principle perhaps the hover board can match the weigh of the surfer. ThePeSla