1676day.year
The Danish astronomer Ole Rømer presents the first quantitative measurements of the speed of light.
In 1676, Danish astronomer Ole Rømer presented the first quantitative measurements of the speed of light.
Ole Rømer analyzed the eclipses of Jupiter's moon Io to study light's behavior.
He observed discrepancies in the timing of these eclipses from Earth.
From these anomalies, he deduced that light travels at a finite speed.
Rømer's calculations marked the first experimental estimate of light's velocity.
His work laid the groundwork for future breakthroughs in optics and physics.
This milestone changed scientific views on the nature of light.
1676
astronomer
Ole Rømer
presents
measurements
speed of light
1783day.year
In Paris, Jean-François Pilâtre de Rozier and François Laurent d'Arlandes make the first untethered hot air balloon flight.
In 1783, Jean-François Pilâtre de Rozier and François Laurent d'Arlandes made the first untethered hot air balloon flight in Paris.
Pilâtre de Rozier and d'Arlandes lifted off from the Jardin des Tuileries.
Their Montgolfier balloon flight marked humanity's first free flight by air.
They soared over Paris for about 25 minutes, covering around 5 miles.
The flight demonstrated the potential of lighter-than-air aviation.
Their pioneering venture paved the way for modern ballooning and flight exploration.
This achievement captured public imagination and advanced aeronautical science.
1783
Jean-François Pilâtre de Rozier
François Laurent d'Arlandes
hot air balloon
1877day.year
Thomas Edison announces his invention of the phonograph, a machine that can record and play sound.
In 1877, Thomas Edison announced his invention of the phonograph, the first machine to record and play sound.
Edison unveiled the phonograph in his Menlo Park laboratory.
The device used tinfoil-wrapped cylinders to capture sound vibrations.
Listeners heard recorded voices and music played back for the first time.
This breakthrough revolutionized audio recording and entertainment.
The phonograph laid the foundation for the modern music industry.
Edison's innovation transformed communication and sound reproduction.
1877
Thomas Edison
phonograph
1905day.year
Albert Einstein's paper that leads to the mass–energy equivalence formula, E = mc², is published in the journal Annalen der Physik.
Albert Einstein publishes his landmark 1905 paper in Annalen der Physik, introducing the mass–energy equivalence principle, E=mc².
As part of his annus mirabilis, Einstein’s 1905 publication laid the theoretical foundation for understanding how mass and energy are interchangeable. Presented in Annalen der Physik, the paper redefined classical physics and paved the way for the development of nuclear energy. The equation E=mc² revealed that even small amounts of mass could yield immense energy, influencing future research in quantum mechanics and relativity. This breakthrough remains one of the most famous and fundamental concepts in modern science.
1905
Albert Einstein
mass–energy equivalence
1953day.year
The Natural History Museum, London announces that the "Piltdown Man" skull, initially believed to be one of the most important fossilized hominid skulls ever found, is a hoax.
The Natural History Museum in London reveals that the Piltdown Man skull is a forgery, ending decades of scientific debate.
On November 21, 1953, researchers at the Natural History Museum announced that the Piltdown Man fossil, once heralded as a missing link in human evolution, was a hoax. Using fluorine analysis and microscopic examination, scientists determined that the skull belonged to a modern human, while the jaw came from an orangutan. The exposed forgery discredited leading theories based on the find and embarrassed the scientific community. The Piltdown hoax underscored the need for rigorous verification methods in paleontology. The discovery reshaped the study of human ancestry and remains a cautionary tale about confirmation bias.
1953
Natural History Museum, London
Piltdown Man
skull
1969day.year
The first permanent ARPANET link is established between UCLA and SRI.
The inaugural permanent ARPANET connection is activated between UCLA and SRI.
On November 21, 1969, engineers at the University of California, Los Angeles (UCLA) and the Stanford Research Institute (SRI) established the first enduring node-to-node ARPANET link, marking a critical step toward the modern Internet. This permanent connection replaced earlier experimental links and enabled continuous data exchange for research projects. The advancement demonstrated the practical viability of packet-switched networks and laid groundwork for future protocols. Over the following months, additional nodes joined, forming a growing research network. ARPANET's success spurred academic and military interest in interconnected computing.
ARPANET
UCLA
SRI
2019day.year
Tesla launches the SUV Cybertruck. A gaffe occurs during the launch event when its "unbreakable" windows shatter during demonstration.
Tesla unveiled the futuristic Cybertruck SUV, but the demonstration faltered when its so-called unbreakable windows cracked on stage. The viral mishap contrasted sharply with the vehicle’s bold design.
On November 21, 2019, Tesla CEO Elon Musk introduced the much-anticipated Cybertruck at a live event in Los Angeles. Boasting a radical angular design and stainless steel shell, the electric pickup aimed to redefine automotive aesthetics. To prove its strength, Tesla engineers hurled a metal ball at the truck’s windows—only for the glass to crack unexpectedly. The onstage blunder stunned the audience and quickly went viral online. Musk recovered by quipping that the test had simply set a new baseline for improvement. Despite the embarrassment, the Cybertruck secured hundreds of thousands of preorders within days. The launch highlighted Tesla’s daring innovation while reminding the world of the perils of live demonstrations in today’s connected age.
Tesla
SUV
Cybertruck