Locard’s Exchange Principle

Have you ever heard of the forensic science theory known as Locard’s Exchange Principle? Named after the "Sherlock Holmes of France," the French criminologist Emile Locard, this theory suggests that when a person enters a room, they will inevitably pick something up and leave something behind, often without realizing it.

Modern technology, including the invention of microscopes, has confirmed the truth of this principle. While it’s particularly useful for detectives, it's also a valuable way to reflect about our own interactions with others. As we navigate life, we are…