Please note that kethcup is referred to as a “pseudoplastic” substance. Also note that the article leaves out the best way of getting ketchup out of the bottle, which was taught to me by someone who doesn’t even like ketchup. It’s hard for me to explain in writing, but you can’t just shake it in the air freely. You hold one arm steady, and let the arm with the bottle hit that arm, and you let physics happen. Someone make a video.