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Gifs Explained: Exploding Coffee

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A few months ago, Buzzfeed posted a list called “21 Reasons Why You Should Have Paid Attention In Science Class,” composed of a bunch of cool, weird sciencey gifs. My initial reaction was, “Okay, pretty neat, but what am I actually seeing here?” Plenty of comments on the post echoed that thought, but Buzzfeed still hasn’t answered the cries of the writhing, curious masses.

I figure it's about time to take matters into my own hands and start explaining these things, starting with the ones from the original list that I can figure out or trace back to their source. Best case scenario, that gives us 21 cool gifs. Obviously, that’s not all the cool science gifs out there, so if you find any sciencey gifs or images that make you say, “Huh? What the heck is going on there?” send them my way!

Anyway, here’s our first gif, featuring what appears to be a cup of coffee exploding into a miniature Leaning Tower of Pisa.


So, what the heck is going on here?

Well, to start, that’s not coffee in there. It’s actually p-nitroaniline and sulfuric acid, which I cannot recommend drinking for a morning pick-me-up. When brought together and heated, the two go through what chemistry textbooks dryly refer to as a “vigorous reaction,” where they decompose and form a solid black-brown foam.

NASA studied the reaction in the 1970s because the foams which are formed have a low density and are flame-retardant, and had potential as a fire-control measure in the tight confines of spaceships. Here’s what they had to say about the reaction:

“The first, or pre-expansion, stage is the interval up to about 230°C. Water is the major gaseous constituent, with some nitroaniline subliming at higher mole ratios; sulfur dioxide is absent. Dehydration and sulfonation are the main chemical processes; some deamination also takes place.

“The second, or aphrogenic (intumescent), stage begins at about 230°C for 4- nitroaniline…and is over within a 50° interval when the heating rate is 6°/min. Sulfur dioxide and water are major gaseous products. [This is when the foamy tentacle bursts forth - Matt].

“The third stage, in air, represents oxidative decomposition of the residue (the primary product of the exothermal reaction) and dissociation of variable amounts of ammonium salts present in the residue.”

In layman’s terms, as the nitroaniline and acid climb in temperature, they experience some different chemical processes—losing water and amines and gaining sulfur compounds—and then explode into foam, which then breaks down.

You can see the buildup to the explosion in this video, which the gif was taken from.

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science
Why a Howling Wind Sounds So Spooky, According to Science
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Halloween is swiftly approaching, meaning you'll likely soon hear creepy soundtracks—replete with screams, clanking chains, and howling winds—blaring from haunted houses and home displays. While the sound of human suffering is frightful for obvious reasons, what is it, exactly, about a brisk fall gust that sends shivers up our spines? In horror movie scenes and ghost stories, these spooky gales are always presented as blowing through dead trees. Do bare branches actually make the natural wailing noises louder, or is this detail added simply for atmospheric purposes?

As the SciShow's Hank Green explains in the video below, wind howls because it curves around obstacles like trees or buildings. When fast-moving air goes around, say, a tree, it splits up as it whips past, before coming back together on the other side. Due to factors such as natural randomness, air speed, and the tree's surface, one side's wind is going to be slightly stronger when the two currents rejoin, pushing the other side's gust out of the way. The two continue to interact back-and-forth in what could be likened to an invisible wrestling match, as high-pressure airwaves and whirlpools mix together and vibrate the air. If the wind is fast enough, this phenomenon will produce the eerie noise we've all come to recognize in horror films.

Leafy trees "will absorb some of the vibrations in the air and dull the sound, but without leaves—like if it's the middle of the winter or the entire forest is dead—the howling will travel a lot farther," Green explains. That's why a dead forest on a windy night sounds so much like the undead.

Learn more by watching SciShow's video below.

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Space
SpaceX's Landing Blooper Reel Shows That Even Rocket Scientists Make Mistakes
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SpaceX's Falcon 9 rocket launches.
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On March 30, 2017, SpaceX did something no space program had done before: They relaunched an orbital class rocket from Earth that had successfully achieved lift-off just a year earlier. It wasn't the first time Elon Musk's company broke new ground: In December 2015, it nailed the landing on a reusable rocket—the first time that had been done—and five months later landed a rocket on a droneship in the middle of the ocean, which was also unprecedented. These feats marked significant moments in the history of space travel, but they were just a few of the steps in the long, messy journey to achieve them. In SpaceX's new blooper reel, spotted by Ars Technica, you can see just some of the many failures the company has had along the way.

The video demonstrates that failure is an important part of the scientific process. Of course when the science you're working in deals with launching and landing rockets, failure can be a lot more dramatic than it is in a lab. SpaceX has filmed their rockets blowing up in the air, disintegrating in the ocean, and smashing against landing pads, often because of something small like a radar glitch or lack of propellant.

While explosions—or "rapid unscheduled disassemblies," as the video calls them—are never ideal, some are preferable to others. The Falcon 9 explosion that shook buildings for miles last year, for instance, ended up destroying the $200 million Facebook satellite onboard. But even costly hiccups such as that one are important to future successes. As Musk once said, "If things are not failing, you are not innovating enough."

You can watch the fiery compilation below.

[h/t Ars Technica]

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