What is the difference between magic and science?

I was watching the movie trailer for Thor a few days ago. The movie is based on the comic book series by Marvel. I don't know much about the series, but I thought this line from the movie was interesting:

"...you ancestors called it magic, you call it science. I come from a place where they are one and the same."

What is the difference between magic and science?

When Thor says "science" I think he is not referring to the study of patterns found in the natural world, but the manipulation of physical laws in the universe. He is referring to engineering: manipulating the physical world to perform work.

There are many historical accounts of people groups encountering other societies with more advanced  technologies and labeling them magic. Usually these people groups were wiped out, colonized, assimilated or enslaved by the more advanced societies. To use a rather silly example: the gun was called "the thunder stick" by the savages in many Hollywood flicks.

From a single individual's perspective the difference between magic and "science" (engineering) is merely in the ability to understand the model or idea that explains the work. If the individual must ask themselves, "Do I understand the underlying physics of what happened?" The answer to this question will cause them to categories the event as either magic or engineering.

How do scientists categorize phenomenon that they don't understand? They don't use the word "magic" (no way), but in effect that is what it is to them until they can understand it. Many scientists get defensive when the topic of the supernatural is brought up. In my opinion it is not so different in theory than the "magic" that they are trying to understand in their work. 


When does a scientist stop thinking and noodling over a problem that he doesn't understand?