Hi Manuel. On your next post (last post at this moment):
You say: "This doesn't necessarily mean that his hand would become visible, "
Why not? The sand is visible so why not the hand.
And of course then his whole body since, as you say yourself, a physical hand out of phase with it's body would be very hard to explain. So then we are back at : if he shows up, some people will be in trouble. Most likely Courtney and crew.
Unless of course we're talking holograms. The whole setup of Harvey, crew and craft could very well be a projected hologram in scalar energy, so only visable to paranormally gifted individuals, like the people at Farsight.
So no problems with different planets and different gravity.
Then you ask:" So what happens to the air that's in the place of the hand? Will it be pushed away?"
In one of the recent FS viewings Intysam saw a teleportation gadget in which beings from far away could 'materialise'. I've always wanted to know how that works. Same question. Does the incoming body automatically remove what is there in the form of molecules/radiation? That would cause quite a 'bang'. Or is the spot cleaned up first so there is 'nothing' there anymore. In which case it is impossible for Harvey to materialise on the beach without such a gadget as Intysam descibes (in Antarctica I think).
Then you say: "They manage to manipulate a minor thing, like flipping a card or pushing a light switch. But this would mean their body must become tangible, even if it's just for half a second."
In the 'paranormal literature' we find many examples of that. Of a 'double' that extends out of the body and 'does things', like lifting tables of influencing electricity. It's not that they materialise for half a second but that a subtler form of energy (as I said a combination of yin [Earth] and yang [sun] energy, see Costa Danaos: 'The Magus of Java', a person that I have met and can vouch for) is augmented to such an extend that it can influence denser vibrations/matter.
In that case no air molecules are displaced, it's just another form of matter next to 'our matter' influencing matter. So no real 'materialisations' and as you say: telekinesis.
Moving a pencil would prove nothing since so many 'magicians' can do waaaaay more interesting stuff that can fool anybody. It would downplay FS to 'an act'.