Voyager: The Spacecraft

In slow motion, vortex rings can be truly stunning. This video shows two bubble rings underwater as they interact with one another. Upon approach, the two low-pressure vortex cores link up in what’s known as vortex reconnection. Note how the vortex rings split and reconnect in two places – not one. According to Helmholtz’s second theorem a vortex cannot end in a fluid–it must form a closed path (or end at a boundary); that’s why both sides come apart and together this way. After reconnection, waves ripple back and forth along the distorted vortex ring; these are known as Kelvin waves. Some of those perturbations bring two sides of the enlarged vortex ring too close to one another, causing a second vortex reconnection, which pinches off a smaller vortex ring. (Image source: A. Lawrence; submitted by Kam-Yung Soh)

Note: As with many viral images, locating a true source for this video is difficult. So far the closest to an original source I’ve found is the Instagram post linked above. If you know the original source, please let me know so that I can update the credit accordingly. Thanks!

The U.S. Women’s Team win gold at the 2014 Nanning World Championships

Cathedrals Beach, Galicia

The Myth of Prometheus

Before the creation of humanity, the Greek gods won a great battle against a race of giants called the Titans. Most Titans were destroyed or driven to the eternal hell of Tartarus. But the Titan Prometheus, whose name means foresight, persuaded his brother Epimetheus to fight with him on the side of the gods. 

As thanks, Zeus entrusted the brothers with the task of creating all living things. Epimetheus was to distribute the gifts of the gods among the creatures. To some, he gave flight; to others, the ability to move through water or race through grass. He gave the beasts glittering scales, soft fur, and sharp claws.

Meanwhile, Prometheus shaped the first humans out of mud. He formed them in the image of the gods, but Zeus decreed they were too remain mortal and worship the inhabitants of Mount Olympus from below. Zeus deemed humans subservient creatures vulnerable to the elements and dependent on the gods for protection. However, Prometheus envisioned his crude creations with a greater purpose. So when Zeus asked him to decide how sacrifices would be made, the wily Prometheus planned a trick that would give humans some advantage. He killed a bull and divided it into two parts to present to Zeus. On one side, he concealed the succulent flesh and skin under the unappealing belly of the animal. On the other, he hid the bones under a thick layer of fat. When Zeus chose the seemingly best portion for himself, he was outraged at Prometheus’s deception. 

Fuming, Zeus forbade the use of fire on Earth, whether to cook meat or for any other purpose. But Prometheus refused to see his creations denied this resource. And so, he scaled Mount Olympus to steal fire from the workshop of Hephaestus and Athena. He hid the flames in a hollow fennel stalk and brought it safely down to the people. This gave them the power to harness nature for their own benefit and ultimately dominate the natural order. 

With fire, humans could care for themselves with food and warmth. But they could also forge weapons and wage war. Prometheus’s flames acted as a catalyst for the rapid progression of civilization. When Zeus looked down at this scene, he realized what had happened. Prometheus had once again wounded his pride and subverted his authority. 

Furious, Zeus imposed a brutal punishment. Prometheus was to be chained to a cliff for eternity. Each day, he would be visited by a vulture who would tear out his liver and each night his liver would grow back to be attacked again in the morning. Although Prometheus remained in perpetual agony, he never expressed regret at his act of rebellion. His resilience in the face of oppression made him a beloved figure in mythology. He was also celebrated for his mischievous and inquisitive spirit, and for the knowledge, progress, and power he brought to human hands. 

He’s also a recurring figure in art and literature. In Percy Bysshe Shelley’s lyrical drama “Prometheus Unbound,” the author imagines Prometheus as a romantic hero who escapes and continues to spread empathy and knowledge. Of his protagonist, Shelley wrote, “Prometheus is the type of the highest perfection of moral and intellectual nature, impelled by the purest and the truest motives to the best and noblest ends.” His wife Mary envisaged Prometheus as a more cautionary figure and subtitled her novel “Frankenstein: The Modern Prometheus.” This suggests the damage of corrupting the natural order and remains relevant to the ethical questions surrounding science and technology today. As hero, rebel, or trickster, Prometheus remains a symbol of our capacity to capture the powers of nature, and ultimately, he reminds us of the potential of individual acts to ignite the world.

From the TED-Ed Lesson The myth of Prometheus - Iseult Gillespie

Animation by Léa Krawczyk ( @lea–krawczyk )

Which new battery will take electric vehicles across the finish line?

For the past seven years or so, electric vehicles have been on the rise. Tesla is practically a household name, and it’s not uncommon to see EVs from companies like Nissan, Chevy, and BMW on the road now. That wouldn’t have happened without the lithium ion battery. Right now, lithium ion is the most popular battery type for electric vehicles. It can last up to 200 miles on a single charge, and it’s not too expensive to make, which means EVs are also relatively affordable.

But experts say that lithium ion batteries can only take electric cars so far—both on the road and in the marketplace. Before they can beat more popular combustion engine cars, electric vehicles will need a battery makeover, which is why countless engineers and scientists are searching for the next EV battery.

So what’s it going to look like? There are dozens of battery chemistries to play with. But how many of them can even approach the success of lithium ion? Electric vehicle advocate and blogger Chelsea Sexton joins George Crabtree, the director of the Joint Center for Energy Storage Research at Argonne National Laboratory, to discuss potential successors to the popular lithium ion battery.

Sunday’s are for relaxing with a good book.

Chemists discover structure of bacterial enzyme that generates useful polymers

MIT chemists have determined the structure of a bacterial enzyme that can produce biodegradable plastics, an advance that could help chemical engineers tweak the enzyme to make it even more industrially useful.

The enzyme generates long polymer chains that can form either hard or soft plastics, depending on the starting materials that go into them. Learning more about the enzyme’s structure could help engineers control the polymers’ composition and size, a possible step toward commercial production of these plastics, which, unlike conventional plastic formed from petroleum products, should be biodegradable.

“I’m hoping that this structure will help people in thinking about a way that we can use this knowledge from nature to do something better for our planet,” says Catherine Drennan, an MIT professor of chemistry and biology and Howard Hughes Medical Institute Investigator. “I believe you want to have a good fundamental understanding of enzymes like this before you start engineering them.”

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Self-assembling particles brighten future of LED lighting

Just when lighting aficionados were in a dark place, LEDs came to the rescue. Over the past decade, LED technologies – short for light-emitting diode – have swept the lighting industry by offering features such as durability, efficiency and long life.

Now, Princeton engineering researchers have illuminated another path forward for LED technologies by refining the manufacturing of light sources made with crystalline substances known as perovskites, a more efficient and potentially lower-cost alternative to materials used in LEDs found on store shelves.

The researchers developed a technique in which nanoscale perovskite particles self-assemble to produce more efficient, stable and durable perovskite-based LEDs. The advance, reported January 16 in Nature Photonics, could speed the use of perovskite technologies in commercial applications such as lighting, lasers and television and computer screens.

“The performance of perovskites in solar cells has really taken off in recent years, and they have properties that give them a lot of promise for LEDs, but the inability to create uniform and bright nanoparticle perovskite films has limited their potential,” said Barry Rand an assistant professor of electrical engineering and the Andlinger Center for Energy and the Environment at Princeton.

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