Leanna Arcila, 7, is licked by Watson, a therapy dog with the Pawtucket police department, as she receives her COVID-19 vaccination from Dr. Eugenio Fernandez at Nathanael Greene Elementary School in Pawtucket, R.I., Tuesday, December 7, 2021. Even as the U.S. reaches a COVID-19 milestone of roughly 200 million fully-vaccinated people, infections and hospitalizations are spiking, including in highly-vaccinated pockets of the country like New England. (Photo by David Goldman/AP Photo)

Today is what is known as the equilux and it happens when day and night are equal and occurs a few days before the spring equinox, and a few days after the autumn equinox. What appears to be a floating leaf is actually a stray sticking to a wet car windshield in a park in Scaggsville, Maryland on September 25, 2024. Today sunrise was at 7:02am and sunset took place at 7:02pm. The green and orange colored leaf (about half for each color) seems to represent the transition from Summer to Fall. (Photo by Michael S. Williamson/The Washington Post)

These are the ambitious plans which suggest skyscrapers of the future may house an entire city. The Endless City project is an award-winning proposal by sure Architecture, who propose turning skyscrapers into complete ecosystems. London is the proposed city for the mixed-use tower – which would feature huge ramps linking different sections of the structure. The company, whose design won the SkyScrapers and SuperSkyScrapers Competition, insist the structure would be a great space-saver in dense cities which have previously spread outwards rather than upwards. (Photo by Caters News)

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)

A gaucho is unseat by a wild horse during the annual celebration of Criolla Week in Montevideo, March 30, 2015. Throughout Easter Week, “gauchos”, the Latin American equivalent of the North American cowboy, from all over Uruguay and neighboring Argentina and Brazil will visit Montevideo to participate in the Criolla Week to win the best rider award. The competition is held from March 29 to April 5 this year. (Photo by Andres Stapff/Reuters)

Female Naval Academy plebes perform push ups with a twelve foot log on top of them during the annual Sea Trials May 17, 2016 at the Naval Academy in Annapolis, Maryland. The Naval Academy freshman class endures 14 hours of rigorous physical and mental challenges during the annual Sea Trials training exercise as part of the culmination of their freshman year at the academy. (Photo by Win McNamee/Getty Images)

Manchester United goalkeeper Emily Ramsey celebrates with team mates Millie Turner and Jackie Groenen after winning the penalty shoot out at the FA Women's Continental League Cup match between Manchester United and Manchester City at Leigh Sports Village on November 19, 2020 in Leigh, England. Sporting stadiums around the UK remain under strict restrictions due to the Coronavirus Pandemic as Government social distancing laws prohibit fans inside venues resulting in games being played behind closed doors. (Photo by Visionhaus)

Frenchman Georges Speicher drinks as he starts riding down the Col de l'Aubisque during the 18th stage of the Tour de France between Tarbes and Pau. on July 17, 1933. Speicher finished second beaten by Spanish winner Learco Guerra to retain his overall leader's yellox jersey on his way to winning the Tour de France. (Photo by France Presse Voir/AFP Photo)