This article is a tribute to Phillip Anderson, who passed away on March 29, 2020. Besides his pioneering works in condensed-matter physics, he also wrote extensively on the theme of reductionism and multiscale physics.
To understand an extensive, complex physical system, thinkers break it up into smaller components and try to understand the properties of the most minor microscopic components. This method helps us understand many complicated things around us, and has helped us solve a lot of real-world problems. But it does not help us understand certain phenomena, such as turbulence in fluids. A different way of thinking, a method that considers the physical system as a whole is needed in such cases. This method is called the multiscale analysis.