1822day.year
French physicist Augustin-Jean Fresnel, in a "note" read to the Academy of Sciences, reports a direct refraction experiment verifying David Brewster's hypothesis that photoelasticity (as it is now known) is stress-induced birefringence.
In 1822, Augustin-Jean Fresnel reported experimental proof of stress-induced birefringence, advancing the study of photoelasticity in optics.
On September 16, 1822, French physicist Augustin-Jean Fresnel presented to the Academy of Sciences a groundbreaking experiment on light behavior in stressed materials. Building on David Brewster’s hypothesis, Fresnel demonstrated that certain materials exhibit birefringence when under mechanical stress, a phenomenon later called photoelasticity. He detailed how polarized light split into two beams with different velocities, revealing internal stress patterns. This discovery not only confirmed theoretical predictions but also opened new methods for studying material properties. Photoelasticity became an essential tool in engineering and materials science for visualizing stress distribution. Fresnel’s work solidified his reputation as a leading pioneer in wave optics.
1822
Augustin-Jean Fresnel
Academy of Sciences
David Brewster
photoelasticity
birefringence
1955day.year
A Soviet Zulu-class submarine becomes the first to launch a ballistic missile.
In 1955, a Soviet Zulu-class submarine achieved the first-ever underwater launch of a ballistic missile.
During the height of the Cold War, the Soviet Navy modified a Zulu-class submarine to carry and fire a ballistic missile. On this day, the vessel successfully conducted the first submerged missile launch, demonstrating a new dimension of nuclear deterrence. This milestone forced major naval powers to reconsider submarine stealth tactics and anti-submarine warfare. The achievement presaged the future of strategic submarine-based nuclear arsenals. It also spurred the United States to accelerate its own Polaris submarine missile development. The test highlighted the evolving balance of power at sea and marked a turning point in naval nuclear strategy.
Zulu-class submarine
ballistic missile
1959day.year
The first successful photocopier, the Xerox 914, is introduced in a demonstration on live television from New York City.
The Xerox 914 becomes the world's first successful commercial photocopier, unveiled live on television.
In a groundbreaking live demonstration from New York City on September 16, 1959, Xerox introduced the 914, the first commercially successful plain-paper photocopier. Developed by Chester Carlson and perfected by the Haloid Company, the machine could produce clear copies in seconds, revolutionizing document reproduction. Businesses quickly embraced the technology, leading to rapid growth in office productivity and transforming administrative operations worldwide. The Xerox 914's success laid the foundation for modern office equipment industries and cemented Xerox's reputation as a technological innovator. Its influence extended beyond business, impacting education, law, and government record keeping.
1959
Xerox 914
1961day.year
The United States National Hurricane Research Project drops eight cylinders of silver iodide into the eyewall of Hurricane Esther. Wind speed reduces by 10%, giving rise to Project Stormfury.
Experimentation with cloud seeding during Hurricane Esther reduces wind speeds and sparks the Project Stormfury initiative.
As part of the United States National Hurricane Research Project on September 16, 1961, scientists dropped eight cylinders of silver iodide into the eyewall of Hurricane Esther. The seeding experiment unexpectedly reduced the storm's wind speed by approximately 10 percent, offering the first glimpse of potential hurricane modification. This success led to the formal launch of Project Stormfury, a long-term program aimed at mitigating hurricane intensity. Researchers over the next decade conducted multiple field tests in the Atlantic, refining cloud seeding techniques. While later studies cast doubt on the effectiveness of such interventions, Project Stormfury remained a landmark effort in weather control and atmospheric science history.
1961
Hurricane Esther
Project Stormfury
1961day.year
Pakistan establishes its Space and Upper Atmosphere Research Commission with Abdus Salam as its head.
Pakistan establishes its Space and Upper Atmosphere Research Commission under Abdus Salam, laying the groundwork for the nation's space program.
On September 16, 1961, Pakistan formally founded the Space and Upper Atmosphere Research Commission (SUPARCO) with Nobel laureate Abdus Salam as its first chairman. The commission was tasked with advancing national capabilities in rocketry, space research, and satellite technology. Under Salam's leadership, early projects focused on meteorological studies and sounding rocket launches. SUPARCO's establishment marked Pakistan's entry into the global space race and its ambition to develop indigenous space science expertise. Over the ensuing decades, the agency expanded its mandate to include satellite development, remote sensing, and international collaboration. The formation of SUPARCO reflects the broader postcolonial drive for scientific autonomy and technological progress.
Space and Upper Atmosphere Research Commission
Abdus Salam
1975day.year
The first prototype of the Mikoyan MiG-31 interceptor makes its maiden flight.
The first prototype of the Soviet Mikoyan MiG-31 interceptor makes its maiden flight, demonstrating cutting-edge supersonic air defense technology.
On September 16, 1975, test pilot Viktor Pugachyov flew the inaugural prototype of the Mikoyan MiG-31 at Zhukovsky airfield near Moscow. Designed to replace the MiG-25 'Foxbat,' the MiG-31 featured advanced radar systems and powerful engines to intercept high-speed targets. Its maiden flight lasted approximately 40 minutes, during which engineers evaluated handling and avionics. The aircraft could reach speeds over Mach 2.8 and operate at altitudes above 20,000 meters. Development of the MiG-31 cemented its role as a backbone of Soviet air defense and it remains in service today. The successful flight marked a leap forward in Cold War-era aviation technology.
Mikoyan MiG-31
1996day.year
Space Shuttle Atlantis is launched on STS-79 to dock to the Russian space station Mir.
Space Shuttle Atlantis launched on mission STS-79, becoming the first shuttle to dock with the Russian space station Mir and strengthening international cooperation in space.
STS-79 marked a key milestone in US-Russian space collaboration during the Shuttle–Mir program.
Launched on September 16, 1996, Atlantis carried a multinational crew and supplies to Mir.
The shuttle successfully docked with the Russian space station, enabling crew exchange and joint scientific experiments.
Astronauts Shannon Lucid and John Blaha swapped places, extending the US presence aboard Mir.
The mission demonstrated complex rendezvous techniques and long-duration habitat resupply.
STS-79 helped lay the groundwork for later cooperation on the International Space Station.
It showcased the potential for peaceful partnership in space exploration.
1996
Space Shuttle Atlantis
STS-79
Mir