This is a guess, but I suspect it depends on what you're trying to do.
Although I've heard of levitation as a concept, I've read very few accounts of people actually managing to do it. So while I can't logically say that it's impossible, I will say that at least certain laws of Newtonian physics do seem to be applied fairly heavily and consistently.
I feel that one of the major laws in existence, is the concept that the physical universe has to behave in such a way that, while magick can be possible, Richard Dawkins still has to be able to believe that he's right. So normally, I think that probably the sorts of results you'll get, are things which can be seen to be synchronistic or defy statistical odds, on a subtle level, but not to a point where an atheist wouldn't be able to look at the scenario, and at least semi-plausibly say that magick doesn't exist. There's a related theory in quantum physics these days, which suggests that the results of at least some experiments, may be influenced by the intentions/desires of the operator, which sounds suspiciously like magick to me. (IMG:
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As one example, I regularly summon a servitor which Phil Hine wrote about, called GOFLOWOLFOG, to help reduce my waiting time when I'm standing in supermarket queues. This servitor was created for the purpose of breaking up queues and getting them moving, hence his name.
Does the servitor work? It does seem according to my own subjective observation, that people can start moving more quickly, and cashier people can start scanning items more quickly, after the servitor has been called, and this also seems consistent. However, it's still not something where Richard Dawkins, if I told him about that, wouldn't be able to look at the entire idea and entirely plausibly say that it was rubbish.