February 13

Galileo’s publication of Dialogue on the Two Chief World Systems had drawn papal scrutiny for defending Copernican theory. Summoned by the Inquisition, he traveled to Rome under the watchful eyes of church authorities. During his trial, Galileo faced charges of heresy for advocating that the Earth revolved around the Sun. Despite his attempts at moderation, he was forced to recant his support for heliocentrism. His sentence included house arrest and the prohibition of teaching or publishing on the topic. The trial became a landmark conflict between emerging scientific inquiry and ecclesiastical authority. Galileo’s ordeal influenced later debates on academic freedom and the scientific method.

During tests of incandescent filaments, Edison noted that heated rods emitted streams of charged particles into a vacuum. This effect, thermionic emission, later underpinned the development of vacuum tubes for amplification and electronics. Edison’s meticulous laboratory records documented the behavior of electrons in a low-pressure environment. Although he did not immediately commercialize the phenomenon, his findings paved the way for radio transmitters and early computers. Thermionic emission became a cornerstone of 20th-century electrical engineering.

On February 13, 1960, France detonated Gerboise Bleue in the Algerian Sahara, achieving a yield of approximately 70 kilotons. The test at the Reggane test site made France the fourth nation after the US, USSR, and UK to wield nuclear weapons. President Charles de Gaulle saw the detonation as essential for French independence in defense. Gerboise Bleue's success marked the beginning of France's force de frappe nuclear deterrent. The test sparked international criticism and concerns over environmental and human health impacts. Subsequent tests continued until 1996, when France signed the Comprehensive Nuclear-Test-Ban Treaty.

On February 13, 2004, the Harvard–Smithsonian Center for Astrophysics announced the discovery of BPM 37093. Located over 50 light-years away, this white dwarf star has a carbon-oxygen core that has crystallized into a massive diamond-like structure. Scientists estimated the 'diamond' portion weighs around 10 billion trillion trillion carats—making it the largest known. The star was affectionately called 'Lucy' after The Beatles' song 'Lucy in the Sky with Diamonds'. This finding provided direct evidence of white dwarf crystallization, confirming theoretical predictions about stellar evolution. The discovery offers insight into how stars cool and the future fate of our own Sun. It marked a milestone in astrophysics, demonstrating the creative power of telescopic observations.

On February 13, 2012, the European Space Agency conducted the maiden flight of the Vega rocket from the Guiana Space Centre in Kourou. Designed to carry small to medium payloads, Vega expanded Europe's launch capabilities beyond heavy Ariane and light Soyuz rockets. The successful launch placed a dummy payload into low Earth orbit, validating Vega's performance. Vega's reliability and cost-effectiveness opened new markets for commercial and scientific satellites. This milestone bolstered Europe's autonomous access to space and diversified its launcher family. Since then, Vega has become a key tool for climate monitoring, Earth observation, and technological demonstrations.