uhh I wouldn't recommend sending out mass emails to random professors. they will take you seriously if you have good background knowledge of their research. use some information you've learned already in classes and then look up some papers pertaining to the subject, and read about it. actually grasping the concepts behind the papers is the hardest part of this. when you feel confident enough, email some researchers doing work in the field at your university (personal faculty web pages give lots of info) and introduce yourself.
i'm also pretty sure most science professors at major institutions have research of their own (those who teach and don't do research aren't usually called professors, but lecturers), and when they teach classes they may also integrate some of their research into their lectures, which may be a start if you end up on good terms with the professor.