2151
Life before the invention of AutoCAD. An overview of historical photos before the advent of computer-aided design and drafting software (1950-1980) [read more: buff.ly/3lfr6T6]
2152
These excerpts from a 1980 documentary about Czech animator Karel Zeman show how some of Karel’s special effects were achieved in the movies he made between 1947 and 1980
[full video + read more: buff.ly/3LAKWnn]
2153
In this video by QuantumBoffin, an experiment demonstrates the total internal reflection of light inside a glass block. An angular scale is used to measure the critical angle and determine the refractive index of the glass [full video: buff.ly/3eDRoNG]
2154
When researchers found this kind of mysterious underwater 'crop circles', they did not know the cause. Then, they proved to be amazing artwork made by pufferfish to attract and win a mate [source and full video: bit.ly/2p5JBLk]
2155
The black leopards of the Malaysian Peninsula may look like they have uniform dark coats, but hidden cameras with infrared light reveal a surprise: The black cats sport the characteristic leopard spots within their dark-hued coats [read more: buff.ly/2vj67bP]
2156
The vaquita is a rare species of porpoise endemic to the northern part of the Gulf of California. It's the most endangered cetacean in the world. A 2019 estimate reported that a maximum of 22 and a minimum of 6 vaquita porpoises remain buff.ly/2J7gem2
2157
This classic video show a LEGO TECHNIC functional Model of a Bridge Girder machine SLJ 90032 Wowjoint
[full video, Wolf Zipp: buff.ly/3eCoy1Z]
2158
A quite effective visual explanation of the checker shadow illusion [read more: buff.ly/2He9KRw] [source and verification: buff.ly/31LyhYv]
2159
Irukandji syndrome is induced by the sting of certain box jellyfish. Unless immediately treated, victims can die, but a symptom of the syndrome is a feeling of "impending doom": victims are so certain they will die, they beg their doctors to kill them: buff.ly/3Byzbfq
2160
An analemma is a diagram showing the position of the Sun in the sky, as seen from a fixed location on Earth at the same mean solar time, as that position varies over the course of a year. This one has been taken by Yiannis Efremidis with 46 photos in 2017 ow.ly/Vy6M30njNY4
2161
The Dakota fire pit is an efficient, simple fire design where the fire burns from the top downward, drawing a steady, laminar stream of fresh air from the air hole as it burns, achieving near complete combustion with little or no seen smoke [read more: buff.ly/3eAjeKo]
2162
This is the piano that Steinway & Sons has unveiled when celebrated its 600,000th piece: 'The Fibonacci' features the iconic spiral and is made out of Macassar Ebony [read more: buff.ly/2EQ34XO]
2163
The nuclear accident that occurred on March 10, 1956, when a B-47 Stratojet carrying two plutonium cores was lost over the Mediterranean. Despite an extensive search, the plane and its cargo was not located and its fate remains unknown today [read more: buff.ly/2ERjn6T]
2164
A demonstration of how the horizontal component of velocity remains constant
[explanation: ow.ly/2WX930oetjg]
2165
The heliosphere is the outermost layer of the Solar System and protects the planets from powerful cosmic events like supernovae. This artist’s visualization shows its possible shape
[read more: buff.ly/3mCBkhn]
[source: buff.ly/3UkkVyn]
2166
Super agile and balanced, Direct Drive's Diablo is the world first wheeled-leg transformable robot powered by 6 direct-drive motors. Ah, and it can moonwalk
[source, full video: buff.ly/3qwLBy9]
2167
One of the biggest concentrations of bioluminescence in Marina del Rey, California.
A species of photosynthetic dinoflagellates is the cause of these impressive displays
[read more: buff.ly/3Dp4v1C]
[📹 Patrick Coyne: buff.ly/3RIRhkp]
2168
In the rain forests of Borneo, a caterpillar builds a tent-like structure that enables it to eat out of the sight of predators by cutting a section of a leaf and folding it along its tiny natural hinges
[📹 BBC Earth: buff.ly/3U3ktEr]
2169
This lenticular post card simulates the prop from “Back to the Future" and it was created for the 35th anniversary of the movie [source, read more: buff.ly/3xl69x7]
2170
Lindsey Swierk documented that the water anole can breathe under water for long periods of time to avoid predators through an underwater respiration system using a recycled air bubble that clings to the anole's head
[read more: buff.ly/3CWg2la]
2171
Unlike most birds, kiwis have heavy bones filled with marrow. Their powerful legs make up a third of their body weight and allow them to even outrun a person
[read more: buff.ly/30SrReC]
[clip by YT's Peter: buff.ly/3cJO8xP-]
2172
Cownose rays typically swim in groups, which allows them to use their synchronized wing flaps to stir up sediment and expose buried clams and oysters, sometimes even surfing a wave
[read more: buff.ly/3CFV0XP-]
[video: buff.ly/3l2cd7L-]
2173
Dry-ice blasting uses dry ice, the solid form of carbon dioxide, accelerated in a pressurized air stream. Here it's used used to deburr and deflash in preparation prior to painting
[read more: buff.ly/3l38mr5-]
[source: buff.ly/3xkCmnj]
2174
After working as a kite maker for over 30 years, Feng Tsan Huang of Taiwan has created his masterpiece: the bike kite. It's 2 meters tall and weighs just 0.8 kg, thanks to carbon fiber beam and polyester panels [source: buff.ly/2JUFvkx]
2175
Unexpected cleaners: black vultures remove debris, ticks, and peck at sores of capybaras, with an overview of tick-removing birds in Brazil
[full paper: buff.ly/3l6PnvL-]
[video by Fernando Perez Piedrabuena: buff.ly/3cMYq0j-]
Astronomy, astronautics, meteorology, physics. Engineer, trying to build the big picture of #science via selected & curated pics, videos & links