May 28

Events - Science & Technology

585 BC

A solar eclipse occurs, as predicted by the Greek philosopher and scientist Thales, while Alyattes is battling Cyaxares in the Battle of the Eclipse, leading to a truce. This is one of the cardinal dates from which other dates can be calculated. It is also the earliest event of which the precise date is known.

In 585 BC, Greek philosopher Thales predicts a solar eclipse that interrupts the Battle of the Eclipse between Alyattes and Cyaxares, leading to a truce.
Greek philosopher and scientist Thales is said to have predicted the solar eclipse of May 28, 585 BC. The eclipse occurs during the Battle of the Eclipse between the Lydian king Alyattes and the Median king Cyaxares. Stunned by the sudden darkness, the warring armies call a truce and negotiate peace. This event becomes a pivotal reference point in ancient chronology, allowing historians to anchor other dates. It is also recognized as the earliest historical event for which an exact date is known, highlighting Thales' contributions to early scientific thought.
585 BC solar eclipse Thales Alyattes Cyaxares
1936day.year

Alan Turing submits On Computable Numbers for publication.

Alan Turing submits his groundbreaking paper 'On Computable Numbers,' laying the foundation for modern computer science.
On May 28, 1936, British mathematician Alan Turing submitted his seminal paper to the Proceedings of the London Mathematical Society. In On Computable Numbers, he introduced the concept of a theoretical computing machine—now called the Turing machine—and formalized the notion of algorithmic computation. The paper addressed Hilbert’s Entscheidungsproblem by proving that no universal algorithm could decide all mathematical truths. Published in 1937, Turing’s work became the cornerstone of theoretical computer science and influenced the development of real-world computers and artificial intelligence. Today, it is regarded as one of the most important contributions to mathematics and technology in the 20th century.
1936 Alan Turing On Computable Numbers
1962day.year

The Soviet Kosmos 5 satellite is launched.

The Soviet Union launches the Kosmos 5 satellite, advancing its early space exploration efforts.
On May 28, 1962, the Soviet Union successfully launched Kosmos 5 into Earth orbit aboard a Kosmos carrier rocket. The satellite’s mission included studying the ionosphere, radiation levels, and solar activity. Kosmos 5 was part of a series of spacecraft designed to enhance scientific understanding of near-Earth space. Its instruments transmitted valuable data on atmospheric conditions and cosmic rays. The launch underscored the USSR’s commitment to space research during the height of the Space Race. Though less famous than later missions, Kosmos 5 contributed to foundational knowledge that would support future satellites and manned flights.
Kosmos 5