A Somali police officer arrests a suspected rebel member of the al Qaeda-affiliated al Shabaab among beach goers in Mogadishu. Al Shabaab claimed responsibility for today's pre-dawn attack on a Kenyan university campus near the Somali border. The following gallery examines who is al Shabaab. Here: Somali police officer (R) arrests a suspected rebel member (L) of the Al Qaeda-affiliated al Shabaab among beach goers at the Lido beach north of Somalia's capital Mogadishu March 23, 2012. (Photo by Feisal Omar/Reuters)

In this January 31, 2014 file photo released by the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), shows residents of the besieged Palestinian camp of Yarmouk, queuing to receive food supplies, in Damascus, Syria. That year, the U.N. was able to deliver food to about five percent of people in besieged areas including Yarmouk, while today estimates show the organization is reaching less than one percent. (Photo by UNRWA via AP Photo)

Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

Bryan Berg was introduced to card-stacking by his grandfather at the age of 8. He is a self-taught artist in all of the techniques he uses today. Berg's freestanding card structures are based on a grid-like arrangement, which Berg tested in a structural engineering lab to support 660 lbs per square foot―using no tape, no glue, no folding, and no tricks.

Jason Arnold, project manager from solarcentury walks between lines of solar panels erected at Weighbridge, Wheal Jane, Baldhu on July 7, 2011 near Truro, England. A ceremony was held today to mark the connection of the 1.4kw solar farm, which on a 6.2 acre plot is the first in the South West and biggest in the UK to date, using 5,680 panels. (Photo by Matt Cardy/Getty Images)

Paintings are moved on a stand at the “London Art Fair” on January 18, 2012 in London, England. The fair includes over 100 different stands featuring work by well known 20th century British artists and showcases some of the best emerging talent in the art world today. The show runs until January 23, at Business Design Centre in Islington. (Photo by Dan Kitwood/Getty Images)

Natsumi Hayashi is a Japanese artist known for her fixation with levitating. Two years, ago, the photographer began posting portraits online of herself floating in mid-air. The magical project – titled “Today's Levitation” – is the subject of a playful survey of her year-long obsession with flying.