Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Yi Arias, a CORE crew member in an upbeat mood at COVID-19 mass-vaccination of healthcare workers taking place at Dodger Stadium in Los Angeles, California, U.S., January 15, 2021 (Photo by Irfan Khan/Pool via Reuters)

The May Queen during the Beltane Fire Festival in Edinburgh, Scotland on April 30, 2022. A dynamic reinterpretation of an ancient Celtic celebration of the return of summer, the festival is centered around the story of the May Queen and the Green Man, and the lighting of the Beltane bonfire, symbolic of purification, healing and new life. Edinburgh's Beltane celebrations are the largest of their kind in the world with around 250 volunteer performers and thousands of spectators. (Photo by Jane Barlow/PA Images via Getty Images)

Thor, Virginia Tech College of Engineering, Robotics and Mechanisms Laboratory, tries to connect the hose to a firehose connection during the hose task at the Homestead-Miami Speedway, Friday, December 20, 2013, in Homestead, Fla. (Photo by Alan Diaz/AP Photo)

“I started photography in June 2009. At the time, I was searching for a way to express both the rigorous scientist and the creative artist in me. There are few hobbies that let these two approaches work together, so I really was enthusiastic about it: I am now spending all my free time studying various techniques, contemplating others' fantastic work, and of course, making pictures”. – Christophe Kiciak. Photo: “The Hero”. (Photo by Christophe Kiciak)

Two dogs sent into outer space by the Soviet Union after their safe return to earth. They spent 22 days in orbit. (Photo by Central Press/Getty Images). 22nd March 1966

“SpaceShipOne was a suborbital air-launched spaceplane that completed the first manned private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mothership was named “White Knight”. Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million”. – Wikipedia

Photo: A chase plane follows SpaceShipOne after it reached a height of 62 miles in the first non-governmental flight to leave the Earth's atmosphere on June 21, 2004 in Mojave, California. SpaceShipOne spacecraft was carried to a height of 50,000 by the twin-turbojet high-altitude research aircraft, “White Knight”, where it was launched for its final climb. The space effort was funded by Microsoft co-founder Paul Allen and headed by aerospace engineer Burt Rutan. (Photo by Jim Campbell-Pool/Getty Images)