Why a helium balloon flies backwards when you hit the brakes

How can algae microbots deliver drugs for bladder cancer? Why does a helium balloon fly backwards when you hit the brakes in a car? Does the Sun make ash? Will removing your gallbladder affect your cholesterol? Is there a symbiotic relationship between spiders and antelopes? Can cloud seeding affect rainfall? What causes restless legs? Why are global sperm counts dropping? And what holds the…