An electron microscope photograph shows a nano-scale F1 racing car model created by a newly developed 3D printing technique for nano structures, made available to Reuters March 29, 2012. Researchers from the Vienna University of Technology have set a new world speed record for creating 3D nano objects. The University team creates their grain of sand-size structures in just four minutes, a fraction of the time that other items have previously been printed. Making complex large 3D structures in the past would take hours or even days but with the newly developed 3D laser printer, the scientists can speed that up by a factor of 500 or in some cases 1,000 times. The process called "two-photon lithography" involves using a focused laser beam to harden liquid resin in order to create micro objects of solid polymer. The scientists said the technique could be developed to make small biomedical parts to be used by doctors.

A handout electron microscope photograph shows a nano-scale model of London's Tower Bridge.

An electron microscope photograph shows a nano-scale model of Vienna's St. Stephans cathedral created by a newly developed 3D printing technique for nano structures, made available to Reuters March 29.

Demonstrators hold signs aloft as they march during an NAACP march and rally to the Sanford Police Department for Trayvon Martin in Sanford, Fla., March 31. Sanford is the town where Trayvon Martin, 17, was shot dead on Feb. 26 after George Zimmerman, 28, a Hispanic neighborhood watch captain, believed the young man walking through the gated community in a hooded sweatshirt looked suspicious.

Trayvon Martin supporters march through the historically African American community of Goldsboro on their way to an NAACP rally in front of the Sanford Police Department on March 31, in Sanford, Fla.

Demonstrators march during an NAACP march and rally for Trayvon Martin in Sanford, Fla., March 31.

Samara Almanza (C) is assisted by (L-R) Aneesha Suresh, Aditi Bhatt, Dr. Citlali Lopez-Ortiz and Kaitlyn Pasquinelli during a dance class for children with movement disabilities in Evanston, Illinois, March 25, 2012.

Samara Almanza is assisted during the dance class.

Samara Almanza (C) is helped with her stretching by Kaitlyn Pasquinelli (L) and Ilana Feld during the dance class.

A girl watches Moon Jellies swimming in a giant cylindrical aquarium on display during the preview for "The Jellies Experience" exhibition.

Japanese Sea Nettles, the first jellies to greet visitors, are seen during the preview for "The Jellies Experience" exhibition.

A visitor photographs Japanese Sea Nettle Jellies through a viewing window during "The Jellies Experience" exhibition.

Giant cylindrical aquariums containing Moon Jellies are seen on display during the preview for the "The Jellies Experience" exhibition at the Monterey Bay Aquarium.

The first complete views of the legendary wreck: As the starboard profile shows, the Titanic buckled as it plowed nose-first into the seabed, leaving the forward hull buried deep in mud—obscuring, possibly forever, the mortal wounds inflicted by the iceberg. (Copyright 2012 RMS TITANIC, INC; Produced by AIVL, Woods Hole Oceanographic Institution)

The first complete views of the legendary wreck: Titanic's battered stern is captured overhead here. Making sense of this tangle of metal presents endless challenges to experts. Says one,

Water Spray, ca. 1940. Vintage gelatin silver, printed c. 1940, 10 x 12 inches.

Matthew Brandt, American Lake, WA C1, 2011, from the series Lakes and Reservoirs. C-print soaked in American Lake water.

Shiva at Whistle Creek, 1992. Gelatin silver print, 8 x 10 inches.

A Tibetan exile child wipes tears off her mother's face during a special ceremony for 27-year-old Jamphel Yeshi who burned himself alive as an act of protest against the visit by China's president in New Delhi.

Tibetan exiles offer prayers near the coffin containing the body of 27-year-old Jamphel Yeshi, wrapped in a Tibetan flag, inside the Tsuglakhang temple, in Dharmsala on March 30.

Tibetan exiles pray next to the burning funeral pyre of 27-year-old Jamphel Yeshi, who passed away Wednesday morning two days after he immolated himself in New Delhi.

Polar bear cub Anori cuddles with his mother Vilma at the zoo in Wuppertal, Germany, on March 29. Anori was born on Jan. 4 and has stayed in a closed enclosure with his mother for the past two months. He is the half-brother of Knut, who died in 2011.

A male Sumatran orangutan dad gets a kiss from his cub inside their enclosure at a city zoo in Moscow on March 30.

Visitors brace themselves from the rotor wash of the Marine One helicopter as President Barack Obama lifts off from the South Lawn of the White House in Washington, on March 30, as he travels to Vermont and Maine for campaign fundraising events.

US President Barack Obama, under the watchful eye of the Secret Service, departs the aboard Marine One from the South Lawn of the White House in Washington, DC, on March 30. President Obama will spend the day campaigning in Vermont and Maine.

U.S. President Barack Obama waves to visitors as he walks towards the Marine One on the South Lawn prior to his departure from the White House March 30, in Washington, DC. Obama was traveling to Vermont and Maine for campaign events.

Israeli mounted policemen move crowds of Palestinian protesters during a demonstration marking Land Day in the east of the city on March 30, outside the old city of Jerusalem, Israel. Land Day, which began in 1976, marks the day Israeli forces killed six Palestinians during a protest against Israeli occupation of what Palestinians consider to be their land.

Israeli border police officers use pepper spray as they detain an injured Palestinian protester during clashes on Land Day after Friday prayers outside Damascus Gate in Jerusalem's Old City on March 30.

Members of the Hamas security forces prevent Palestinian protesters from reaching the border between Israel and the northern Gaza Strip, after a protest marking Land Day in Beit Hanun, on March 30.

A Palestinian girl holds her mother and cries during a demonstration marking Land Day in the east of the city on March 30, outside the old city of Jerusalem, Israel.

A Palestinian youth climbs over a fruit stall as an Israeli mounted policeman disperses hundreds of Palestinian protesters during a demonstration marking Land Day in east Jerusalem on March 30. Demonstrators waving huge Palestinian flags gathered for Land Day, sparking scuffles with hundreds of Israeli police who were seen beating some of the crowd, an AFP correspondent said.

Palestinians scuffle with Israeli policemen during a demonstration marking Land Day in east Jerusalem on March 30.

Israeli police officers detain an injured Palestinian protester during clashes on Land Day, after Friday prayers outside Damascus Gate in Jerusalem's Old City March 30. Israeli security forces fired rubber bullets, tear gas and stun grenades to break up groups of Palestinian stone-throwers on Friday as annual Land Day rallies turned violent. Police said they made five arrests at Damascus Gate.

Palestinian boys look to the direction of the Lebanes-Israeli border during a Palestinian rally to mark Land Day, in the southern Lebanese village of Arnoun, Lebanon, on Friday March 30. More than 3,000 Lebanese and Palestinians gathered outside the Crusader-built Beaufort castle 9 miles from Israel. Lebanese security forces kept them from moving any closer to the border. March 30 is traditionally marked by Israeli Arabs as "Land Day," a time of protests against the alleged confiscation of Arab-owned lands by Israel.

A worker cleans a shop stormed by demonstrators following clashes between police and protesters after a general strike in Barcelona, Spain, on March 30. The Spanish government prepared to approve on Friday a new austerity budget that hundreds of thousands protested against this week in sometimes violent demonstrations.

A man leaves a bank stormed by demonstrators following clashes between police and protesters after a general strike in Barcelona, Spain, on March 30. The Spanish government prepared to approve on Friday a new austerity budget that hundreds of thousands protested against this week in sometimes violent demonstrations.

A Carslon Wagonlit Traves employee is seen through a broken window on March 30, in Barcelona, Spain. Violent clashes between demonstrators and riot police in the past 24 hours has left scores injured and led to 74 people being detained.

A security guard stands next to a Starbucks coffee shop stormed by demonstrators during clashes between police and protesters after a general strike in Barcelona, Spain, on March 30. The Spanish government prepared to approve on Friday a new austerity budget that hundreds of thousands protested against this week in sometimes violent demonstrations.

An Afghan carries a bundle of wood in Nahr-i Sufi near the DHQ (Char Dara District Police Headquarter) in the province of Kunduz on March 30. The Afghan economy has always been based on agriculture, despite the fact that only 13 percent of its total land is arable and just eight percent is currently cultivated.

A view shows damaged buildings in the old city of Homs March 30, 2012.

A damaged car is seen in front of a damaged building in the old city of Homs, Syria, March 30.

Damaged buildings line a street filled with rubble in the old city of Homs, Syria, March 30, 2012.

A damaged vehicle is seen next to a damaged building in Al Qasseer city, near Homs, Syria, March 28.

Models present creations made of chocolate, at a fashion show on the occasion of the 'Salon du Chocolat' in Zurich, Switzerland.

A model receives the last touch-ups before presenting a creation at the first Salon du Chocolat.

Doves are seen inside a dress made of chocolate.

A model presents a dress made of chocolate.