2251
This is what happens if you burn calcium gluconate on a stove [note: sped up video]
[source, read more: buff.ly/3yV3LOq]
twitter.com/chemicalsreact…
2252
This mesmerizing aerial view of hundreds of sheep being herded shows the beauty of a chaotic motion and how it approximates the behavior of a fluid
[source and full video, Tim Whittaker: buff.ly/2UTPiwQ]
2253
264 years ago #Today, the predicted return of comet 1P/Halley was first sighted by Johann Georg Palitzsch. Edmond Halley had predicted in 1705 the return of the comet every 75.5 years. For the first time the scientific prediction had been proven bit.ly/2C52msG
2254
Megathura crenulata is a northeastern Pacific Ocean species of limpet. Its blood contains a hemocyanin that appears blue due to its copper content
[read more: buff.ly/3DDWzXg]
[video by Aron Sanchez-Baranda, sped up 3x: buff.ly/3kWkzh7]
2255
Why is speed at sea measured in knots? From the 15th century, sailors tossed a log attached to a rope with knots tied in it at equal intervals. They would count the number of knots that were pulled off the reel in a given amount of time [read more: buff.ly/3mMc8WZ]
2256
The Uffington White Horse is a highly stylised prehistoric hill figure, 110 m (360 ft) long, formed from deep trenches filled with crushed white chalk, located in the Oxfordshire county, UK. It is presumed to date to the late Bronze Age (1380-550 BCE) ow.ly/LWyB30oa8kX
2257
Leonardo is a bipedal robot that combines walking with flying to create a new type of locomotion. It can walk a slackline, hop, and even ride a skateboard
[📹 Laurie Leshin]
[learn more: buff.ly/3DBGv81]
2258
Splitfin flashlightfish have two bean shaped torch-like organs under its eyes containing bioluminescent symbiotic bacteria that grow in tubular structures & produce a constant bluish light
[read more: buff.ly/3GYyOxC]
[📹 buff.ly/3XNiRjS]
2259
The numbat (Myrmecobius fasciatus) is an insectivorous marsupial once widespread across southern Australia, now restricted to several small colonies in Western Australia and considered an endangered species
[read more: buff.ly/3It8ZV0]
2260
This picture by Sue Dougherty shows strings of tiny water droplets forming lines across a common loon’s face, visualizing the natural hydrophobic coating properties of its feathers
[source: buff.ly/3r5BdN8]
[read more: buff.ly/3yppOeU]
2261
The balls behind the horizontal lines are all the same color.
This one and many other color illusion by
@NovickProf
are available here: bit.ly/2O74l2I
Explanation of the Munker illusion: engineering.utep.edu/novick/colors/
2262
The first ever synthetically produced color pigment, Egyptian blue, was created around 2,200 BCE. In 2006 scientists discovered it glows under fluorescent lights, allowing us to detect it on artifacts where it is no longer visible to the naked eye ow.ly/Y7ub30ocpOu
2263
Watch a giant pacific octopus kill a shark. Even though it is a spiny dogfish shark (never larger than 1.5 m in length) and the scene takes place in an aquarium tank, it's always an impressive event
[source and full video, National Geographic: ow.ly/K6Es50kK3Fh]
2264
Puya Raimondii, also known as queen of the Andes, is the largest species of bromeliad, reaching up to 15 m (50 ft) in height. It is native to the high Andes of Bolivia and Peru
[read more: buff.ly/3es488l]
2265
A hand warmer generally contains a supersaturated solution of sodium acetate which releases heat upon crystallization when a nucleation center is formed by pressing on the metal disc [read more: buff.ly/3CUHm3R] [source: buff.ly/3BP1UJN]
2266
Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded
This clip by TikTok's mooneyfinemineral shows how you open an enhydro one: buff.ly/3AkxJfP
twitter.com/crazyfunnystuf…
2267
Gyroscopes form an important in keeping the International Space Station and satellites pointing the right way as they orbit our planet. ESA astronaut Tim Peake shows how gyroscopes can be used to keep spacecraft stable
[read more: buff.ly/3HDaPBL]
2268
Prodim Proliner measuring head works with a wire that can be stretched out for several meters. The measuring pen at the end of the wire marks the relevant points that are directly translated into a digital DXF CAD file: buff.ly/3KqxzH0 [video: vimeo.com/569734987]
2269
Great black-backed gulls are opportunistic feeders and apex predators: they will readily eat almost anything that they can swallow. This video by @irenemendezcruz shows one swallowing an entire rabbit [read more: buff.ly/3ps1oNA]
2270
The great potoo, or Ghost Bird.
[source, read more: buff.ly/3VOS8SP]
2271
Summer in Japan means colorful explosions in the sky, where some 200 firework festivals called “hanabi taikai” are held across the country. Photographers compete to capture the most eye-opening moments of these nighttime events [source, credits: buff.ly/2xIszeI]
2272
The real master of disguise
[how octopuses change color: buff.ly/3yBHE0p]
[📹 Nick Ruberg: buff.ly/3ENHSTB]
2273
Born 203 years ago #Today, Léon Foucault was a physicist and he's best known for proving the Earth's rotation with his pendulum, making the discovery at 2 am in the cellar he shared with his mother buff.ly/2MEJlUM
2274
This impressive photo by Keri Lee Nelson shows us a mushroom-shaped iceberg. Part of a larger iceberg that's slowly shedding weight via calving, as it loses weight the smooth part (which has been submerged for some time) is rising out the water [source: buff.ly/2QLLvRd]
2275
Lascaux is a complex of caves in southwestern France. Over 600 Upper Paleolithic parietal wall paintings (19,000 year old) cover the interior walls and ceilings of the cave. This website allows you to take a virtual tour of the cave: buff.ly/386DL2C
Astronomy, astronautics, meteorology, physics. Engineer, trying to build the big picture of #science via selected & curated pics, videos & links