WCSA - On This Day - April 25, 2021 - Bell Labs Demonstrates the First Practical Silicon Solar Cell in 1954
(Worldkings.org) Solar cells, which convert sunlight into electrical current, had their beginnings more than a hundred years ago, though early solar cells were too inefficient to be of much use. In April, 1954, researchers at Bell Laboratories demonstrated the first practical silicon solar cell.
[WorldKings – World Almanac Event 2021] – 13th anniversary of World Meningitis Day (April 24, 2008 – April 24, 2021)
(WorldKings.org) World Meningitis Day is an initiative of the worldwide Confederation of Meningitis Organizations (CoMO) which began in 2008. The goal is to spread the word about meningitis, how to spot it and what causes it. It’s also a day to promote the importance of vaccines.
(Wcsa.world) A soda fountain is a device that dispenses carbonated soft drinks, called fountain drinks. They can be found in restaurants, concession stands and other locations such as convenience stores.
[WorldKings – World Almanac Event 2021] – 26th anniversary of World Book and Copyright Day (April 23, 1995 – April 23, 2021)
(Worldkings.org) World Book and Copyright Day is a celebration to promote the enjoyment of books and reading. Each year, on 23 April, celebrations take place all over the world to recognize the magical power of books – a link between the past and the future, a bridge between generations and across cultures.
WCSA - On This Day - April 23, 2021 - The first ever YouTube video, titled "Me at the zoo", was published by user "jawed" in 2005
(Wcsa.world) YouTube is an American video-sharing website headquartered in San Bruno, California. The service was created by three former PayPal employees—Chad Hurley, Steve Chen, and Jawed Karim—in February 2005. Google bought the site in November 2006 for US$1.65 billion; YouTube now operates as one of Google's subsidiaries.
[WorldKings – World Almanac Event 2021] – 51th anniversary of Earth Day (April 22, 1986 – April 22, 2021)
(Worldkings.org) Earth Day is an annual event on April 22 to raise awareness and value of the natural environment of the Earth. In 2009, the United Nations General Assembly declared April 22 as International Mother Earth Day.
(Wcsa.world) Earth Day is an annual event celebrated on April 22. Worldwide, various events are held to demonstrate support for environmental protection. First celebrated in 1970, Earth Day events in more than 193 countries are now coordinated globally by the Earth Day Network.
WCSA - On This Day - April 21, 2021 - The first discoveries of extrasolar planets are announced by astronomer Alexander Wolszczan, in 1994
(Wcsa.world) The confirmation kicked off an explosion in extrasolar planet hunting. Astronomers have now found more than 500 planets around other suns, and are adding more all the time.
[WorldKings – World Almanac Event 2021] – 11th anniversary of Chinese Language Day (April 20, 2010 – April 20, 2021)
(Worldkings.org) The United Nations (UN) observes the UN Chinese Language Day every year on or around April 20. The contribution of Chinese literature, poetry and language in world culture is highlighted on this day.
(Wcsa.world) On April 20, 1902, Marie and Pierre Curie successfully isolate radioactive radium salts from the mineral pitchblende in their laboratory in Paris. In 1898, the Curies discovered the existence of the elements radium and polonium in their research of pitchblende. One year after isolating radium, they would share the 1903 Nobel Prize in physics with French scientist A. Henri Becquerel for their groundbreaking investigations of radioactivity.