A concept illustration of the world's first forest in the sky, the Bosco Verticale green twin towers currently under construction in Milan, Italy. Towering over the city skyline the world's first forest in the sky will be a sight to behold. With tree equal to one hectare of forest spanning 27 floors these 365 and 260 foot emerald twin towers will be home to an astonishing 730 trees, 5,000 shrubs and 11,000 ground cover plants. (Photo by Boeri Studio)

A prototype of a new nano spaceship is displayed during a press conference held by Israel's Space IL organisation on December 8, 2011 in Ehud, Israel. Israeli President Shimon Peres participated in the event unveiling Space IL's latest prototype nano spaceship with the aim of launching a Israeli robotic spacecraft that will land on the moon and raise funds for scientific education in Israel. (Photo by Ilia Yefimovich/Getty Images)

A Chinese shopper sleeps on a bed in the showroom of the IKEA store on July 6, 2014 in Beijing, China. Of the world's ten biggest Ikea stores, 8 of them are in China to cater to the country's growing middle class. The stores are designed with extra room displays given the tendency for customers to make a visit an all-day affair. Store management does not discourage shoppers from sleeping on Ikea furniture, even marking them with signs inviting customers to try them out. (Photo by Kevin Frayer/Getty Images)

In this July 10, 2014 photo, Chris Minore, of Orange, Conn., performs the under chop technique at the Adirondack Woodsmen's School at Paul Smith's College in Paul Smiths, N.Y. Eighteen young students in matching gray sports shirts took part recently in a weeklong crash course on old-school lumberjack skills such as sawing, chopping, ax throwing, log boom running and pole climbing. (Photo by Mike Groll/AP Photo)

An elephant mahout (trainer) lies on his elephant his feet resting on its ears as it rests and eats prior to opening day's play at the King's Cup Elephant Polo Tournament 2014 held near Bangkok, in Samut Prakan province, Thailand, 28 August 2014. The annual charity tournament runs until 31 August and involves 51 elephants who normally live on the streets and are used for begging. Sixteen competing elephant polo teams from 40 different nations take part in the charity event directed at raising funds to improve the lives of the elephants and elephant conservation in general. (Photo by Barbara Walton/EPA)

A box of 36 coloured pencils as photographed in a studio with an illustrative price tag of $115 (US dollars), equivalent to the Bs. 725 (bolivars) that it costs on average to purchase in Caracas at the official exchange rate of 6.3 bolivars per dollar, in Caracas September 29, 2014. Venezuela's economic crisis has led to some shocking and surreal price distortions that hit people's buying power dramatically. (Photo by Carlos Garcia Rawlins/Reuters)

The moon illuminates the snow-covered Concordia, the confluence of the Baltoro and Godwin-Austen glaciers, near the world's second highest mountain the K2 (8,000 meters) in the Karakoram mountain range in Pakistan September 6, 2014. While other parts of Pakistan and northern India were flooded, Concordia in the Karakoram mountain range was covered with a seasonally unusual amount of snow. Geographically, Pakistan is a climbers paradise. It rivals Nepal for the number of peaks over 7,000 meters and is home to the world's second tallest mountain, K2, as well as four of the world's 14 summits higher than 8,000 meters. (Photo by Wolfgang Rattay/Reuters)

A man tries to photograph the interior of the driver's cab belonging to Eurostar's new Siemens e320 train at St Pancras station in central London, November 13, 2014. Eurostar, the company that runs passenger trains through the Channel tunnel between London and Paris, said it would buy seven additional e320 trains from Siemens for about 300 million pounds ($473 million). The company placed an order for 10 new trains in 2010, the first of which is due to enter commercial service next year, enabling the company to add new routes. (Photo by Andrew Winning/Reuters)