Dashing the dream of ideal ‘invisibility’ cloaks for stress waves

Some have dreamt of the perfect cloak to make buildings impervious to stress waves caused by bombs, earthquakes or other calamities. Sorry, researchers are now dashing the dream. But there’s still hope. They also say it’s possible to make imperfect, real-world cloaks that will actually do some good by adding significant partial protection against some common earthquake waves.