NEW YORK, NY - SEPTEMBER 22: A replica of PalmyraÕs Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford UniversityÕs Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

NEW YORK, NY - SEPTEMBER 22: A replica of Palmyra's Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford University's Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

NEW YORK, NY - SEPTEMBER 22: A replica of Palmyra's Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford University's Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

NEW YORK, NY - SEPTEMBER 22: A replica of PalmyraÕs Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford UniversityÕs Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

NEW YORK, NY - SEPTEMBER 22: A replica of PalmyraÕs Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford UniversityÕs Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

NEW YORK, NY - SEPTEMBER 22: A replica of PalmyraÕs Arch of Triumph is displayed in City Hall park on September 22, 2016 in New York City. Archeologists at Oxford UniversityÕs Institute for Digital archeology created a two-thirds scale model of the 1,800 year-old Palmyra Arch that was destroyed by Islamic State militants in Syria. The arch was made of made of Egyptian marble built using 3D printing technology. (Photo by Justin Sullivan/Getty Images)

This NASA Earth Observatory image obtained September 22, 2016 show some glaciers observed from the HU-25A Guardian aircraft on September 2, 2016, showing the Brückner and Heim glaciers where they flow into Johan Petersen Fjord in southeastern Greenland. Greenland's highly unstable ice sheet is melting more than seven percent faster than previously thought, scientists said this week after discovering a hotspot beneath the Earth's crust that was distorting their calculations. The study in the journal Science Advances raises concern about the increasing impact of melting ice on sea level rise, since Greenland is the second largest ice sheet in the world after the one in Antarctica. / AFP PHOTO / NASA Goddard / Jeremy HARBECK / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / JEREMY HARBECK/NASA GODDARD" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS ==TO GO WITH AFP STORY-"Greenland ice melting faster than thought"== JEREMY HARBECK/AFP/Getty Images

SALISBURY, ENGLAND - SEPTEMBER 14: Part of the collection of rare and valuable books is seen as it is open to members of the public visiting the library at Salisbury Cathedral on September 14, 2016 in Salisbury, England. Starting this month, the cathedral is offering the general public access to the library for the first time with organised guided tours. Although the room housing the library at Salisbury Cathedral was built in 1445 the origins of the library stretch back much further and still contains a large collection of books that were created by the scribes of the old cathedral in the late 11th century which constitutes the largest collection of manuscripts of the Norman period still with its original owner. Today the Library holds approximately 8,000 volumes dating from the ninth century to the present day, with the majority of books being theological and literary texts with further examples of a wide range of other subjects including science, mathematics and medicine. (Photo by Matt Cardy/Getty Images)