A piece of the Soviet satellite Sputnik 4 was found in the middle of the road in front of 610 North 8th Street in Manitowoc, Wisconsin on 5 September 1962. A plaque on the sidewalk and a metal ring embedded in the road mark this historic spot.
Voyager 1 was launched from Cape Canaveral aboard a Titan-Centaur rocket on 5 September 1977. It went on to visit Jupiter and Saturn. Voyager 1 is one of five space probes currently on a solar system escape trajectory.
Thomas Edison did not invent the electric light bulb or the electric generator. What he did do was create a system that unified the two devices into a commercially viable system. The Pearl Street Station began selling electricity 51 years and 6 days after electromagnetic induction was discovered by Michael Faraday. The station was located at 255-257 Pearl Street between John and Fulton Streets in Manhattan. It operated until 1890 when it was damaged in a fire. According to a long gone ConEd webpage, a commemorative plaque was placed at the site in 1917, but I couldn’t find it. The site is a surface level parking lot between two large office buildings. I seem to remember demolition work at that location in the 2000s. I assume the plaque is in safe keeping some place awaiting the day when something more impressive than an acre of asphalt occupies that parcel of land.
Pioneer 11 made its closest approach to Saturn on 1 September 1979. It was the first space probe to visit this planet. Pioneer 11 is one of five space probes currently on a solar system escape trajectory.
Phase out of incandescent light bulbs begins (2009)
Posted Tuesday, 1 September 2026
The ban on the manufacture, importation, and sale of incandescent light bulbs of 100 W or greater went into effect in the European Union on this day in 2009. This event marked the beginning of the end for a technology that had been popular since the 1880s.
Incandescent light sources radiate energy in a range of frequencies from the infrared to the visible. (A little bit of microwave and ultraviolet leaks out as well.) The energy emitted in the visible range is the useful part. The rest is waste. For a typical incandescent light bulb, the wasted energy is greater than the useful energy. This flaw was trivial in the Nineteenth Century when the alternatives were gas and oil lamps, candles, or nothing and it was tolerated for many applications in the Twentieth Century when fluorescent tubes were just too flickery and blue.
At the dawn of the Twenty-first Century, however, reasonably economical compact fluorescent lights had managed to adequately mimic the warm glow of the old standard incandescents and throwing away precious electric energy had become an indefensible attitude. What was once the iconic representation of a brilliant idea had become a symbol of irresponsibility.
The maiden flight of Discovery (STS-41-D) was supposed to take place on 26 June 1984. Launch was aborted 4 seconds before liftoff when the computer detected an anomaly in one of the orbiter’s main engines.
Space shuttle engines turn on in stages. The main engines on the orbiter turn on first. They can be steered and powered up and down. They can also be turned off. The solid rocket boosters have one setting and one setting only — all the way on. The only way to turn them off is to use up all the fuel.
NASA replaced the errant engine and Discovery launched successfully on 30 August 1984.
The termination shock is the locus of points in space where the solar wind basically stops blowing outward from the sun and begins to drift with the background gases of interstellar space. It is one way to mark the edge of the solar system.
The two Voyager space probes were launched in 1977 to study the giant outer planets — Jupiter, Saturn, Uranus, and Neptune. They are on escape trajectories and will never return.
Distances within the solar system are frequently measured in astronomical units. One AU is equal to the average distance from the sun to the earth, about 150 million kilometers (93 million miles). Both Voyagers are currently more than 100 AU from the sun. For comparison, Jupiter is about 5 AU from the sun and Neptune is about 30 AU from the sun. Everybody’s favorite non-planet Pluto has an orbit that varies in size from about 30 AU to about 50 AU.
Voyager 2 crossed the solar wind termination shock at 83.7 AU in the southern hemisphere, 10 AU closer to the Sun than found by Voyager 1 in the north …
Voyager 1 and Voyager 2 crossed the shock and entered the heliosheath on 2004.96 (16 December 2004) at heliographic coordinates of (34.3°, 173°) and on 2007.66 (30 August 2007) at (−27.5°, 216°), respectively.
According to Terminator 2: Judgement Day, the military-designed artificial intelligence system called Skynet became self-aware on 29 August 1997 at 2:14 AM and turned against its creators on what became known as Judgement Day. According to Terminator 3: The Rise of the Machines, this event occurred on 19 April 2011 at 8:11 PM. All times are assumed Eastern Daylight because that’s where I live.
Michael Faraday discovers electromagnetic induction (1831)
Posted Saturday, 29 August 2026
Entry from Faraday’s lab notebook dated 29 August 1931.
I have had an iron ring made (soft iron), iron round and ⅞ths of an inch thick, and ring six inches in external diameter. Wound many coils of copper round, one half of the coils being separated by twine and calico; there were three lengths of wire, each about twenty-four feet long, and they could be connected as one length, or used as separate lengths. By trials with a trough each was insulated from the other. Will call this side of the ring a. On the other side, but separated by an interval, was wound wire in two pieces, together amounting to about sixty feet in length, the direction being as with the former coils. This side call b.
Charged a battery of ten pairs of plates four inches square. Made the coil on b side one coil, and connected its extremities by a copper wire passing to a distance, and just over a magnetic needle (three feet from wire ring), then connected the ends of one of the pieces on a side with battery: immediately a sensible effect on needle. It oscillated and settled at last in original position. On breaking connection of a side with battery, again a disturbance of the needle.
Date: 29 August 1949
Code name: RDS-1 (РДС-1), Reaktivniy dvigatel’ Stalina (Реактивный Двигатель Сталина), "Stalin’s Jet Engine"
Type: plutonium fission
Yield: 10–20 thousand tons of TNT
Location: Semipalatinsk, Kazakhstan
The Soviet Union exploded its first nuclear weapon near Semipalatinsk, Kazakhstan on this day in 1949. It was a plutonium fission device similar in design and yield to the test device detonated near Alamogordo, New Mexico and the aerial bomb dropped on Nagasaki, Japan in the summer of 1945. The Soviet code name for the device was “Stalin’s Jet Engine” (Реактивный Двигатель Сталина).
Voyager 2 made its closest approach to Neptune on 25 August 1989. It is the only space probe to have visited this planet so far. Voyager 2 is one of five space probes currently on a solar system escape trajectory.
Voyager 2 made its closest approach to Saturn on 25 August 1981. It was the second space probe to have visited this planet. Voyager 2 is one of five space probes currently on a solar system escape trajectory.
Canopus: First French thermonuclear weapon test (1968)
Posted Monday, 24 August 2026
Date: 24 August 1968 (8:30 AM Tahiti Time)
Code Name: Canopus
Type: two-stage fusion
Yield: 2.6 million tons of TNT
Location: Fangataufa Atoll, French Polynesia
Voyager 2 launched from Cape Canaveral, Florida aboard a Titan-Centaur rocket on 20 August 1977. It visited Jupiter in 1979, Saturn in 1981, Uranus in 1986, and Neptune in 1989. It passed the termination shock (the point where the solar wind slows abruptly to subsonic speed) in 2007. Voyager 2 original mission was to explore the outer planets, but it is now essentially an interstellar space probe.
Sputnik 5 was launched on 19 August 1960 with the dogs Белка (Belka), which means squirrel, and Стрелка (Strelka), which means arrow, 40 mice, 2 rats and a variety of plants on board. The spacecraft returned to earth the next day and all animals were recovered safely.
An hour and thirty-one minutes after launch, my pressure altimeter halts at 103,300 feet. At ground control the radar altimeters also have stopped on readings of 102,800 feet, the figure that we later agree upon as the more reliable. It is 7 o’clock in the morning, and I have reached float altitude.
At zero count I step into space. No wind whistles or billows my clothing. I have absolutely no sensation of the increasing speed with which I fall.
Though my stabilization chute opens at 96,000 feet, I accelerate for 6,000 feet more before hitting a peak of 614 miles an hour, nine-tenths the speed of sound at my altitude. An Air Force camera on the gondola took this photograph when the cotton clouds still lay 80,000 feet below. At 21,000 feet they rushed up so chillingly that I had to remind myself they were vapor and not solid.
For most skydivers, the acceleration experienced while falling is not constant. As a skydiver’s speed increases, so too does the aerodynamic drag until their speed levels out at a typical terminal velocity of 55 m/s (120 mph). Air resistance is not negligible in such circumstances. The story of Captain Kittinger is an exceptional one, however. At the float altitude where his dive began, the Earth’s atmosphere has only 1.5% of its density at sea level. It is effectively a vacuum and offers no resistance to a person falling from rest.
The acceleration due to gravity is often said to be constant, with a value of 9.8 m/s2. Over the entire surface of the Earth up to an altitude of 18 km, this is the value accurate to two significant digits. In actuality, this "constant" varies from 9.81 m/s2 at sea level to 9.75 m/s2 at 18 km. At the altitude of Captain Kittinger’s dive, the acceleration due to gravity was closer to 9.72 m/s2.
Given this data it is possible to calculate the maximum speed of Captain Kittinger during his descent. First we will need to convert the altitude measurements. To save calculation time we will only convert the change in altitude and not each altitude. Given that he stepped out of the gondola at 102,800 feet, fell freely until 96,000 feet, and then continued to accelerate for another 6,000 feet; the distance over which he accelerated uniformly was…
102,800 − 96,000 + 6,000
= 12,800 feet
12,800 feet
1,609 mm
1
5,280 feet
= 3,900 m
It’s now just a matter of choosing the correct formula and plugging in the numbers.
v0 =
0 m/s
a =
9.72 m/s2
∆s =
3,900 m
v =
?
v2 =
v02 + 2a∆s
v =
√(2a∆s)
v =
√(2(9.72 m/s2)(3,900 m))
v =
275 m/s
This result is amazingly close to the value recorded in Kittinger’s report.
614 mile
1,609 m
1 hour
= 274 m/s
1 hour
1 mile
3,600 s
As one would expect the actual value is slightly less than the theoretical value. This agrees with the notion of a small but still non-zero amount of drag.
A widespread power outage that affected parts of Michigan, Ohio, Ontario, Pennsylvania, Maryland, New York, New Jersey, Connecticut, and Massachusetts began at approximately 4:10 PM on 14 August 2003. By 4:13 PM 55 million people in the US and Canada were without electric power. This is sometimes thought of as the "Third New York City Blackout". The first was in 1965 and the second in 1977.
Comet Swift-Tuttle closest approach to Earth (2126)
Posted Friday, 14 August 2026
Comet Swift-Tuttle will pass very close to the earth on 14 August 2126, but it will not strike the earth or the moon as earlier calculations suggested. No dangerously close encounters are probable before the year 4479 when there is a one in a million chance (literally) the comet will collide with earth.
Comet Swift-Tuttle last visited the inner solar system in 1992. It was not easy to see and there are very few photographs of it. The visit prior to that is when it was named after its discoverers Lewis Swift and Horace Tuttle. That was in 1862 — approximately 20 years before astrophotography really got started. Thus, there are no images to go with this post.
The "ammonia maser atomic clock" was first operated on 12 August 1948 and was publicly demonstrated in January 1949. Since it used ammonia it was technically a "molecular clock". The publicity photo on the right shows Edward (E.U.) Condon (left), Director of the National Bureau of Standards, holding a model of an ammonia molecule and Harold Lyons (right), the inventor. The electric clock on top of the atomic clock is a prop.
First Color Image of the Viking Lander 2 Site
