From our roots in ancient Greece until now, human ingenuity and persistence have formed the basis for communication, energy, scientific knowledge, and education. It is not that a specialized discipline is detrimental to finding solutions, but that a degree in a specific area is not what necessarily leads to new ideas and solutions to new problems. It is our desire to learn and explore and understand that gives us the ability to innovate and explain some very interesting subjects. So, what do we need to be amateur scientists and discover new and interesting material? I would offer the desirability of the following three elements in the search for answers: Curiosity, observation, and diligence.
I can only speak for myself for how I find new areas of interest and examination. First, I have no boundaries as to what can be discovered, even if it has been discovered before. I have no problem with reinventing the wheel if I learn in the process. Second, I have my eyes open and watch the world around me with great interest. It might be people, animals, items in the dollar store, or almost anything in sight. And third, and most of all, I expect failure. I certainly don't seek failure but I accept it as a part of the process. And, I fail a lot! There are exceptions to all of the rules as everyone knows. I recently posted on the Odds n' Ends page an entry called "This experiment is for the Birds" based on curiosity, observation, and the diligence to make the gadget to test my hypothesis. It worked the first time and that was a pleasant surprise. But, if it had failed, I would have tried another idea. It seems that the brain is an endless processor and there is always something to try.
There is a good article about the world of tinkerers mostly in the 20th century in Popular Science and the Scientific American. There is also an internal link to the archives in PS. The article written by Mark Frauenfelder is at Boing Boing here. The complete Amateur Scientist CD is reviewed on my page on Science and technology under "Amateur Scientist" in the archive.
If you are an inveterate tinkerer and hacker, keep on hackin, and if you are not, maybe its time to start. Just an observation...