What type of science did Thomas Edison use?

Answer 1

Edison delved into various realms of science, thermodynamics, electricity, acoustics, magnetism, etc. More importantly, Edison was probably the best exemplar of a practitioner of the scientific method:

Establish a Hypothesis

Design an experiment to test the hypothesis

Conduct the Experiment

Analyze the results

Draw a conclusion

His tireless application of this method to his "Applied Research" is famous. 'Basic Research' is conducting experiments to just learn about the nature of things. Applied Research is conducting research toward a goal, e.g. the invention of an incandescent lighting device that was practical.

My favorite quotation from Edison was in response to the question, "you've tried almost 1000 different designs and filament materials and you've failed to develop a practical light bulb; you've accomplished nothing, have you? (the term light bulb didn't exist at the time)

Edison: "On the contrary, I've discovered over 1000 ways NOT to design a light bulb?"

The point being, that the lessons he learned from his failures, guided him toward success.