1818day.year
French physicist Augustin Fresnel submits his prizewinning "Memoir on the Diffraction of Light", precisely accounting for the limited extent to which light spreads into shadows, and thereby demolishing the oldest objection to the wave theory of light.
Augustin Fresnel publishes his groundbreaking "Memoir on the Diffraction of Light", resolving key objections to the wave theory of light.
In 1818, French physicist Augustin Fresnel submitted his prizewinning "Memoir on the Diffraction of Light" to the French Academy of Sciences. Fresnel’s work provided a precise mathematical explanation for the phenomenon of diffraction and showed how light waves bend around obstacles. His theory addressed long-standing objections to the wave model of light that had been championed by Huygens. By demonstrating the limited spread of light into shadows, Fresnel’s findings offered strong experimental support for wave optics. This memoir played a crucial role in the shift from Newton’s corpuscular theory to the dominance of wave theory. Fresnel’s equations and methods remain foundational in modern optics and photonics. His contributions paved the way for later discoveries in electromagnetic wave propagation and interference.
1818
Augustin Fresnel
1851day.year
Annibale de Gasparis discovers asteroid 15 Eunomia.
Italian astronomer Annibale de Gasparis discovers the asteroid 15 Eunomia, one of the largest bodies in the asteroid belt.
On July 29, 1851, Annibale de Gasparis, working at the Observatory of Naples, identified a new asteroid that would be designated 15 Eunomia. Eunomia is one of the brightest and largest asteroids in the main belt, measuring approximately 250 kilometers in diameter. De Gasparis’s discovery added to our understanding of the growing population of minor planets orbiting between Mars and Jupiter. The asteroid’s name derives from Eunomia, the Greek goddess of law and order, reflecting the naming tradition of classical mythology. Observations of Eunomia have provided valuable data on asteroid composition, rotation, and orbit. Today, it remains a key object of study in planetary science and asteroid family classification.
1851
Annibale de Gasparis
asteroid
15 Eunomia
1957day.year
The International Atomic Energy Agency is established.
On July 29, 1957, the International Atomic Energy Agency (IAEA) was established to promote peaceful uses of nuclear energy.
Created under the United Nations framework, the IAEA was tasked with fostering safe, secure, and peaceful nuclear technologies across member states. Headquartered in Vienna, the agency began operations with a mandate to inspect nuclear facilities and verify compliance with non-proliferation agreements. It served as a global forum for scientific collaboration, offering technical assistance and setting safety standards. The IAEA’s founding marked a milestone in international cooperation, aiming to prevent the spread of nuclear weapons while advancing power generation and medical applications. Over time, the agency has played a key role in major nuclear inspections and disaster responses worldwide.
1957
International Atomic Energy Agency
1958day.year
U.S. President Dwight D. Eisenhower signs into law the National Aeronautics and Space Act, which creates the National Aeronautics and Space Administration (NASA).
On July 29, 1958, U.S. President Dwight D. Eisenhower signed the National Aeronautics and Space Act, creating NASA.
Responding to the Soviet Union’s Sputnik launch, the National Aeronautics and Space Act consolidated America’s civilian space efforts into the National Aeronautics and Space Administration. Officially replacing the NACA, NASA began operations on October 1, 1958, under the leadership of its first administrator, T. Keith Glennan. The agency was charged with coordinating space exploration, aeronautical research, and missile development for peaceful purposes. Its establishment fueled the space race, leading to historic missions including Project Mercury and the Apollo moon landings. NASA’s foundation remains a cornerstone of the United States’ achievements in space science and technology.
1958
Dwight D. Eisenhower
National Aeronautics and Space Act
National Aeronautics and Space Administration
1985day.year
Space Shuttle Challenger launches on STS-51-F. The shuttle ends up in a lower orbit then planned due to an engine failure during ascent.
Space Shuttle Challenger embarked on mission STS-51-F on July 29, 1985, and managed an engine failure to complete its objectives in a lower orbit.
On July 29, 1985, NASA's Space Shuttle Challenger lifted off from Kennedy Space Center for mission STS-51-F, also known as Spacelab 2. Shortly after ascent, one of its three main engines experienced a shutdown due to a turbopump failure. Despite this setback, the crew successfully adjusted their flight plan and continued the scientific experiments aboard the Spacelab module. The mission achieved most of its research objectives, including studies in astronomy, astrophysics, and materials science. Ground controllers monitored shuttle performance closely and provided in-flight troubleshooting support. STS-51-F demonstrated NASA's growing expertise in handling in-flight anomalies and reinforced the shuttle's capability as a versatile orbital laboratory.
1985
Space Shuttle Challenger
STS-51-F
2005day.year
Astronomers announce their discovery of the dwarf planet Eris.
Astronomers announced the discovery of Eris, a distant dwarf planet larger than Pluto, reshaping our understanding of the solar system.
On July 29, 2005, Mike Brown and his team at the Palomar Observatory revealed the discovery of a new trans-Neptunian object.
Initially designated 2003 UB313, the object was later named Eris after the Greek goddess of discord.
Eris’s size, slightly exceeding that of Pluto, prompted astronomers to reconsider the definition of a planet.
This discovery directly led the International Astronomical Union to introduce the "dwarf planet" category in 2006.
Eris follows an elliptical orbit taking it far beyond Pluto, with a highly inclined path around the Sun.
Its identification expanded our knowledge of the Kuiper Belt and the diversity of bodies in the outer solar system.
2005
Eris
2021day.year
The International Space Station temporarily spins out of control, moving the ISS 45 degrees out of attitude, following an engine malfunction of Russian module Nauka.
The International Space Station lost attitude control, spinning 45 degrees after a thruster malfunction on Russia’s Nauka module.
On July 29, 2021, the Nauka multipurpose laboratory module’s engine test malfunctioned, triggering unplanned firings.
The ISS was pushed 45 degrees off its normal orientation, disrupting solar power and communications.
Mission control teams in Houston and Moscow collaborated to stabilize the station using Russian and US thrusters.
No crew members were harmed, but scientific experiments experienced temporary interruptions.
The event raised concerns about integration testing of new modules on orbiting platforms.
Russian space agency engineers later identified software calibration errors as the culprit.
2021
International Space Station
Nauka