Hocus Pocus: The Distance Between Magic to Science

    Arthur C. Clarke, famous science fiction and science fact writer, once said that "Any sufficiently advanced technology is indistinguishable from magic".
     Although stories told about witches primarily exist from what is, in the West, often called "the Dark Ages", the underlying problem continues to exist. Someone -- especially a social loner who is doing something not considered "normal" -- has knowledge and experience beyond that of others. If it is useful, they may be allowed to exist to be used by others. That is, they allow it to be used until something bad happens and they use the target of their fear and ignorance as a scapegoat and attack them.
     Hanging on my waist, I have a device that has computational power much greater that that of a 1951/52 UNIVAC that occupied an entire room 65 years ago. If you took that same smartphone and presented it in the town of Salem, Massachusetts 325 years ago, you could look forward to being on the non-preferred side of the Witch Trials.  However, if you took the smartphone back to 1952, most of the technology would be totally unexplainable. Depending on your audience, they would declare it to be an amazing fake, a stage device, or -- yes, magic. Very few would believe that it was real but you most likely would not be subject to being burned at a stake.
      Science consists of building upon previously discovered knowledge. Any jump in knowledge is typically met with suspicion. Einstein's theory of general relativity was a jump in understanding. It took years to be accepted and the "in-between" steps are still being proven even unto this day (2017 Nobel Prize being given for detection of "gravitational waves"). Leonardo Da Vinci was sufficiently wise to keep most of his ideas and discoveries isolated within his journals. His public face was largely concerned with his works of art for the Church and the rich. Since it didn't happen, we cannot know for certain, but I suspect that if he had succeeded in building, and demonstrating, a functional flying machine it would have had, at best, very mixed reactions from the Church and public.
     The split in perception between science and magic works both directions. Something that would be considered "commonplace" within current society (even if really understood by only a small subsection of the people) would be considered "magic" in the past. When people envision things in the future, it is often classified into "science fiction" UNLESS it is some ability or behavior that does not have an obvious basis in current science. Flying cars are science fiction. Functional "spells" are magic.
     Current, scientifically acceptable, spells are called algorithms. They piece together various simple instructions into logical frameworks and decision networks and come out with a "game App" or a "streaming video App" or a "communal workspace App". All of these would have been considered magic in the past. I will make the guess that there are a lot of things, about which we speculate as magic, that will also become commonplace in the future. In order for applications (Apps) to work, however, the convenient microcomputer/smartphone must also be present. Will it be true that, in order for Harry Potter's spells to become valid that some other foundation device must be created?
     What ideas of the future would you classify as magic? Do you see scientific paths to have them realized? What ideas would be the most inexplicable if sent to the past?