Good news for khaki-clad men plagued by speckled staining of their trousers from urine splash back: physicists may have found the optimal splash-suppressing design for a urinal insert, thereby creating a “urine black hole.” Urine gets in, but it can’t get back out.
“Since the mid-19th century, both enlisted and fashion-conscious owners of khaki trousers have been plagued by undesired speckle patterns resulting from splash back while urinating.”