Okay, so maybe not invisible, but transparent is pretty darn close. And maybe only plastic. But we’re closer than we were before—for this post’s purposes, at least! Need a scientific explanation for cloaking? Look no further, I gotchu. 😉
Researchers have found a way to make materials that are normally opaque to sound waves completely transparent. Their system involves placing acoustic relays at strategic locations so that sound waves can propagate at a constant amplitude — regardless of what may lie in their path. This method could eventually be used to make it possible to hide objects like submarines.
Source: Sound-waves: Making opaque materials totally transparent — ScienceDaily