Thanks to some more inquiries as to “how some magic was absorbed into science”, here we have some quick history. It may be relevant to gaming if you happen to using a historical setting.
Before you had “science” humans had a great mass of learned behaviors – also known as rituals. Some worked, some did not. The human brain is very good at picking out patterns – even if the “pattern” is simply a minor coincidence in a set of random data and really isn’t there.
Many rituals worked to some extent – but were the result of more-or-less random tinkering and word of mouth; mix the right herbs in a bowl inscribed with spells, heat them while breathing the fumes and chanting a prayer to the gods, and drink them when you had certain symptoms, and you’d often feel better.
A lot of the effect was often psychological; the brain does run the body, and the “placebo” effect is very real. Use a charm to give you confidence, and it will work as long as you believe it.
That often made the parts that actually did something that wasn’t purely psychological (the right herbs and the heating in water part perhaps) pretty hard to sort out from the parts that didn’t – the chanting and the inscription on the bowl. The fumes? Who knows? That might help with some things, and not with others.
“Science” began when people started trying to methodically sort out the parts that had a real, physical, effect from the parts that didn’t. Along the way, it started trying to explain HOW the bits that worked worked.
That was very hard, and took a very long time.
In hindsight, it also led to a new division; “Science” covered all the bits that worked. “Magic” covered all the stuff that didn’t and – for a time – all the rituals which still included elements that did not work with the stuff that did.
Scientists, of course, are still desperately looking for things that work and can’t be explained; there’s no better way to get fame and grants and respect as a scientist than to come up with some new Science. The notion that scientists would want to surpress something like that is one of the most absurd fantasies around.
By the age of enlightenment, “Magic” had pretty much come to mean “Stuff that people often do and believe in which does not actually work”. It was what was left over from humanities accumulated mass of rituals once all the science had been extracted.
Occasionally it meant “con artist” – but, as far as we can tell, a lot of people who thought they possessed various special powers were sincere in their beliefs.
These days it mostly falls under “fictions” and “superstitions” (fictions that a fair number of people actually believe in) – although, having examined a lot of such material from a wide variety of traditions, a substantial percentage really falls under “gibberish”.
In fictional productions – first in plays and stories, and later with widespread printing and the advent of popular fiction, “Magic” acquired more meanings – “Plot Device”, “Blatant absurdity that works in the fictional setting”, and “stuff that we’re going to pretend works in reality”.
It acquired yet another meaning along the way – going from “things that are unexplained” to “things I don’t personally see how are done” – and thus tricksters and stage performers became magicians and their arts became “magic tricks”. The “tricks” part is important though; very few people really consider such things to be genuine “magic”.
It also acquired a more unfortunate connotation along the way – “Mental Illness”. “Magical Thinking” is a normal part of the human condition – but it’s also heavily involved in schizophrenia, obsessive-compulsive disorders, and many other mental disorders.
After physics went from rules of thumb to mathematical theories about forces and particles it also came to mean “something that produces a demonstratable result but which cannot be explained within the current boundaries of physics”. Unfortunately, no actual examples of that have been seen for quite some time – gravely disappointing scientists, who would like the recognition and grant money that would come with exploring and explaining some new physics. Still, if we’re really, REALLY, lucky perhaps neutrinos really can travel faster than light.
With the advent of role-playing games games, and more technically-oriented fiction writers, “Magic” also came to mean “a fictional system of natural laws which do not exist in reality but which – in the setting – allow various effects to be produced”.
That, of course, is a (fictional) branch of rule-of-thumb engineering, and has as little to do with classical magic as a chili recipe has to do with a cave painting designed to ensure success in hunting (presuming that is indeed what at least some of them were for). We still call it “magic”, but our games are essentially “lets pretend” with rules – and so we’re entitled to call it what we want. That privilege goes with “lets pretend”.