This book presents a set of low-cost physics experiments, making use of the new technologies available (data collection and analysis systems by computers, Internet, video, commercial electronics, smartphones, etc.), while highlighting the methodological aspects of physics and science in general. The projects are aimed at university students of science and engineering, although some may be used in high schools.The experiments would enable students to answer the questions: How do we know this? Why do we believe in that? These questions illustrate the nature of scientific thinking process.This book is complemented by the site www.fisicarecreativa.com, where several of the projects presented here were carried out by students from different universities. We hope it can be used as an innovative STEM learning tools.