From ketchup to quicksand, non-Newtonian fluids have long fascinated and puzzled scientists. Unlike ordinary fluids, their ...

If you’ve ever whacked the bottom of a ketchup bottle to get that tasty tomato goop flowing, you’ve put some serious physics to work. Ketchup is a non-Newtonian fluid. So are toothpaste, yogurt, ...

The knife easily leaves swirls in the spread. rimglow/iStock via Getty Images Plus Those Transportation Security Administration requirements are drilled into every frequent flyer’s head: You can carry ...