Ancient Persian Freezers —- The Yakhchals
Today in the modern world we take freezers, and the frozen results of freezers for granted. But in ancient times, cold drinks, frozen desserts, and chilled tropical cocktails were a luxury unknown to most people. However the idea of artificially freezing goods is nothing new. As far back as 400 BC, the ancient Persians built special freezers called yakhchals. Yakhchals were large buildings used for storage of ice and foodstuffs during the hot Persian summers. Typically they were around 60 feet tall, and had a large subterranean storage space dug out from under it. The Yakhchal itself was made from a special type of mud clay called sarooj which was composed of clay, sand, lime, goat hair, egg whites, and ash mixed in a special proportion which made it extremely resistant to heat transfer. In other words the inside stayed cool, while heat from the outside was prevented from entering the building because of the thick insulated walls. This combined with the subterranean storage ensured that whatever goods were stored in the pit stayed cool, as temperatures below ground level are usually around the 60 to 65 degree Fahrenheit range. However, these designs were not what made a yakhchal a freezer. There was one other brilliant design feature which ensured that the yakhchal would stay frosty all year long.
At the top of the dome was a small hole, or series of small holes called windcatchers. Typically windcatchers were pointed in the direction of the prevailing winds. Due to its conical shape there was always a negative pressure gradient inside the yakhchal. According to Bernoulli’s Law air flow at a high pressure will always move toward areas of low pressure. Thus air from the outside was constantly flowing through the yakhchal. In addition, according to Venturi’s Principal, whenever air flows through a small hole, the smaller the hole, the greater the speed of the flow. The small hole, or series of holes of the yakhchal ensured that air passed into it at great flows. What resulted was a great amount of outside air entering into the yakhchal at high speeds. While the air itself wasn’t cool, the flows at which it was being entrained into the yakhchal created temperatures that were below freezing. Typically the windcatchers were cut in such a way that the incoming jet of air would be directed onto the storage pit.
The ancient Persians primarily used their yakhchals for storing ice and foodstuffs. During the summer, Persian nobles often enjoyed a frozen treat called faloodeh (pictured above), which is made from thin noodles with syrup made from sugar and rose water, then flavored with lemon, lime, fruits, almond, pistachio, and other flavorings. Due to the Persian’s freezing technology, faloodeh (which is still popular today) goes down in history as one of the first frozen desserts. The practice of building and using yakhchals continued up to the 20th century, when they were eventually replaced with modern freezers and refrigerators.
Ancient technology can be really cool…
But brown folks were backwards and technologically incompetent.
UM THIS IS AMAZING
Bully messes with karate champ. [video]
The source video is very, very worth watching. A few things to point out:
The young woman in the dark coat is continually trying to escape from the man. She has spoken to him, she’s pulled away, she’s even tried to walk away before he dragged her back. She hit him as a last resort but it didn’t do anything, he just got more aggressive.
The girl in the white jacket was walking by, recognized that a bad situation was happening, stopped, and intervened. At 0:28 she calls the man out, and continues to call him out until he breaks off attacking the young woman in the dark coat and turns his aggression on her. At which point she defends herself—and then she escorts the young woman in the dark coat safely away.
This is a hero.
Bringing this back.
three flavours cornetto trilogy
Each film in the trilogy is connected to a Cornetto ice cream, with a Cornetto of the appropriate flavour appearing in each film. Shaun of the Dead features a strawberry-flavoured Cornetto, which signifies the film’s bloody and gory elements, Hot Fuzz includes the blue original Cornetto, to signify the police element to the film, and The World’s End features the green mint chocolate chip flavour in a nod to aliens and science fiction. While the first two films include appearances of the ice cream itself, the last incorporates only the appearance of the wrapper.
Gertie the Dinosaur was released in 1914 by Windsor McCay. It was the first film to use some animation techniques such as keyframes and tracing paper, and was the first film to feature a dinosaur.
100 years later and we have come a long way in animation technology as well as scientific knowledge of dinosaurs. Hollywood has featured dinosaurs in popular science fiction movies, and BBC has published many documentary-style films about prehistoric life. In December 2013, BBC released a reboot of their popular Walking with Dinosaurs documentary with a new 3D film.
Happy centennial, Gertie!
GERTIE THE DINOSAUR IS EXACTLY 100 YEARS OLD TODAY!
A young Jewish refugee with her Chinese playmates. Shanghai, China (x)
Between 1933 and 1941, it is estimated that 20,000 Jews escaped persecution by fleeing to the Chinese port of Shanghai. Shanghai was one of the few places in the world that would accept Jewish refugees at this time, Japan being another.
i am furious that i am just now learning about this important fact.
Because it has nothing to do with the USA being the superhero and saving all the Jews
Sept. 12, 1992: Dr. Mae Jemison Becomes First African American Woman in Space
On this day in 1992, Dr. Mae Jemison became the first African American woman to travel through space. She served as Mission Specialist aboard Space Shuttle Endeavour on STS-47.
WTCI’s Alison Lebovitz discusses the legacy of the first woman of color to travel beyond the stratosphere on “The A List with Alison Lebovitz.” Watch the interview here.