The world I am working on is a soft science fiction realm dressed up in the trappings of magic and the occult. A world where there are loosely defined scientific principles behind the rituals and relics of effective spell casting. Lycanthropy is believed to be nanite-actualized lunacy. Vampirism is explained as a side effect of an anemia cure gone wrong. I'm aiming at the soft spot, where the characters are living in world of infinite possibilities, but are still holding out hope that their faith in science will save them.
Which leads me to question...
I'm looking for a whimsical, semi-scientific "explanation" for demon summoning, and I would prefer that it involve time travel. Either fetching demons from the past, from an age before science destroyed the faith-base which fueled their existence, or from the future, from the chaos which is waiting for us once science inevitably falls apart.
So is there a relationship between either the circle, the pentagram or the candles and any of the modern theories of time travel?