How Deep Does an Engraving Need to Be?

What does it take to make a mark that outlasts everything else? We dig into the physics of engraving — why a carved groove beats any sticker or paint — and what military and aerospace standards reveal about depth, materials, and survival. From spacecraft part numbers to 75,000-year-old cave engravings, we explore the oldest technology for permanence and what it teaches us about marking our own stuff. Episode #974061 — open it directly at myweirdprompts.com/974061