26 April - Srinivasa Ramanujan death anniversary

 

Srinivasa Ramanujan, passed away on 26 April 1920, was an Indian mathematician who lived during the British Rule in India. Though he had almost no formal training in pure mathematics, he made substantial contributions to mathematical analysis, number theory, infinite series, and continued fractions, including solutions to mathematical problems considered to be unsolvable. Ramanujan initially developed his own mathematical research in isolation: "He tried to interest the leading professional mathematicians in his work, but failed for the most part. What he had to show them was too novel, too unfamiliar, and additionally presented in unusual ways; they could not be bothered". Seeking mathematicians who could better understand his work, in 1913 he began a postal partnership with the English mathematician G. H. Hardy at the University of Cambridge, England. Recognizing the extraordinary work sent to him as samples, Hardy arranged travel for Ramanujan to Cambridge. In his notes, Ramanujan had produced groundbreaking new theorems, including some that Hardy stated had "defeated completely", in addition to rediscovering recently proven but highly advanced results

26 April - Tansen death anniversary

 

Tansen, passed away on 26 April 1589, was a prominent figure of Hindustani classical music. Born in a Hindu family, he learned and perfected his art in the northwest region of modern Madhya Pradesh. He began his career and spent most of his adult life in the court and patronage of the Hindu king of Rewa, Raja Ramchandra Singh, where Tansen's musical abilities and studies gained widespread fame. This reputation brought him to the attention of the Mughal Emperor Akbar, who sent messengers to Raja Ramchandra Singh, requesting Tansen to join the musicians at the Mughal court. Tansen did not want to go, but Raja Ramchandra Singh encouraged him to gain a wider audience, and sent him along with gifts to Akbar. In 1562, about the age of 60, the Vaishnava musician Tansen joined the Akbar court, and his performances became a subject of many court historians.

26 April - The Chernobyl disaster

 

The Chernobyl disaster was a catastrophic nuclear accident that occurred on April 26, 1986, at the Chernobyl Nuclear Power Plant in the city of Pripyat, in the former Ukrainian Soviet Socialist Republic, part of the Soviet Union at the time.

The disaster occurred during a late-night safety test in Reactor Number 4 of the Chernobyl power plant. Due to a combination of design flaws, operational errors, and inadequate safety protocols, a sudden power surge led to a series of explosions, resulting in a massive release of radioactive material into the atmosphere.

The immediate aftermath of the explosion led to the deaths of two plant workers, and the ensuing fire and radioactive fallout had devastating consequences for the surrounding area and beyond. The radioactive cloud spread over large parts of Europe, contaminating vast areas with dangerous levels of radiation.

The Chernobyl disaster is considered the worst nuclear accident in history in terms of both casualties and environmental impact. It resulted in widespread health problems, including radiation sickness, cancer, and birth defects, among the affected populations. The disaster also had significant social, economic, and environmental consequences, leading to the evacuation and abandonment of entire towns and regions surrounding the Chernobyl power plant.

Called the world's worst-ever civil nuclear incident, it is one of only two nuclear energy accidents rated at seven—the maximum severity—on the International Nuclear Event Scale, the other being the 2011 Fukushima nuclear disaster in Japan. The initial emergency response, together with later decontamination of the environment, involved more than 500,000 personnel and cost an estimated 18 billion roubles—roughly US$68 billion in 2019, adjusted for inflation.