Let's say Alice is a PhD student who's well into the research phase of a PhD. She's got a nice exciting project she enjoys, a helpful supervisor, she's making good progress. And then there's a big discovery. She's excited about the new discovery, she wants to work on it, and her current project suddenly doesn't seem so interesting anymore. Real life example: suppose Alice is a Chemistry PhD student from the late 1980s working in condensed matter, and the big discovery is cold fusion.
Can Alice ditch her project to work on the new discovery? What if the new discovery is in an area that is not her supervisor's specialization? I'm also curious whether Alice can make this switch if she's a professor (as opposed to PhD student).
My guess would be that it's hard for Alice to do this as a PhD student even if there's another supervisor available, because she would have to start over again and therefore take longer to graduate (running into funding issues). It'd also be an administrative hassle especially if she has to change departments (Chemistry to Physics in example above - the fields are related, but not that related). If Alice is a professor then she would presumably be stuck, because she's got to work on her grants. She could apply for new grants related to the big discovery, but it would be a while before she can work on it. Am I correct?