Mach Memes

Physics textbooks: casually asking if you've witnessed objects traveling at 158 times the speed of sound like it's a normal Tuesday activity. For context, Mach 158 is approximately 121,000 mph or 54 kilometers per second . At that speed, a golf ball would circle the Earth in about 12 minutes and have enough kinetic energy to level a small city. The textbook's follow-up question is basically asking "Would you like to experience a thermonuclear explosion with a side of atmospheric reentry burns?" Sure, right after I finish my coffee.