Models prepare for a presentation of the creations by Ukrainian designer Jean Gritsfeldt during Ukrainian Fashion Week at the railway station in Kiev, Ukraine on September 2, 2018. The fashion event presents 2018/19 collections by Ukrainian and international designers from 01 to 05 September 2018. (Photo by Valentyn Ogirenko/Reuters)

Egyptian President Hosni Mubarak speaks to the media after talks with German Chancellor Angela Merkel at the Chancellery on April 23, 2008 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)

Musician Kirk Hammett of Metallica performs onstage during The Big 4 held at the Empire Polo Club on April 23, 2011 in Indio, California.

Lady Gaga attends the 2011 CFDA Fashion Awards at Alice Tully Hall, Lincoln Center on June 6, 2011 in New York City. (Photo by Andrew H. Walker/Getty Images)

Penelope Cruz attends the Palme d'Or Award Ceremony held at the Palais des Festivals during the 63rd Annual Cannes Film Festival on May 23, 2010 in Cannes, France. (Photo by Sean Gallup/Getty Images)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.

Christmas decoration selling during Depot Christmas Shopping on November 23, 2011 in Hamburg, Germany. (Photo by Christian Augustin/Getty Images)

Israeli police inspectors stand next to a bus damaged in an explosion March 23, 2011 in Jersalem, Israel. A bomb exploded near a crowded bus, wounding passengers in what appeared to be the first militant attack in the city in several years.