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Video: How removing tattoos with lasers works


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 Video: How removing tattoos with lasers works

10/30/14 9:01pm

Smarter Every Day takes an in-depth look at something super cool: removing tattoos with the help of lasers. The science behind it is fascinating, all the zapping lasers do is basically break down the bigger ink blobs inside your skin and let your body’s white blood cells and liver take care of the rest of the removal process.

But just because you can remove a tattoo with laers doesn’t mean you should start thinking tattoos aren’t permanent. It’s a helluva process.

 


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Seeing the Explosion Inside a See Through Engine Shows You How Engines Work


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Seeing the Explosion Inside a See Through Engine Shows You How Engines Work

1/31/17 9:34pm

This particular engine we’re looking at has four strokes: the intake, the compression, the combustion (or power), and the exhaust. Smarter Every Dayvisited the guys of 805 Road King and their see through engine to show us exactly what’s going on in an engine when we fire it up and it’s pretty fascinating stuff.

It’s much easier to understand what’s happening in an engine by, well, looking at a see through engine because you can see how the strokes are all connected but the basic actions go like this: the intake stroke is when the air-fuel mixture gets drawn into the cylinder. The compression happens when the intake valve closes and the piston in the cylinder pumps up to compress the gas. The combustion happens when a spark plug fires up and ignites the air-fuel mixture, pushing the piston back down in the cylinder. In the exhaust stroke, the gas pumps out the exhaust valve.

It’s obviously slightly more complicated than that (but not by much!), so you can watch the video by Smarter Every Day in the video below. He does a fantastic job illustrating everything.

There Are Way Worse Ways Carbon Monoxide Can Kill


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There Are Way Worse Ways Carbon Monoxide Can Kill You

Wednesday 2:55pm

Image: Senior Airman Christopher Hubenthal/Wikimedia Commons

Us Earthlings are quite lucky to be living at around standard temperature and pressure. Life has evolved to comfortably handle the shapes in which most molecules have arranged themselves under temperatures of about 32 degrees Fahrenheit and atmospheric pressures of an average day at sea level. But on other planets, at other temperatures and pressures, lots of things we take for granted would probably just kill us. Even the usual killers might be worse.

Take your friendly, colorless, odorless murder machine, carbon monoxide. It’s a gas here on Earth. But an international team of physicists ran a simulation of the possible ways carbon monoxide molecules could arrange themselves, and found that when formed at the right pressure, it’s a polymer that could be a powerful explosive. They published their research this month in Physical Review B.

Carbon monoxide is an especially prevalent molecule in interstellar space, pointed out Dennis Klug, Principal Research Scientist at the National Research Council of Canada in Ottawa. “If that’s the case, it’s going to occur in many different environments and have lots of time to evolve, including into this structure we predict,” a structure that seems to be stable even at low energies, he told Gizmodo.

Carbon monoxide’s ability to form polymers—molecules made from a base piece that repeats, including plastics—isn’t a new insight, but the researchers applied a fairly new method called “Ab initio random structure searching” to scan through the ways the molecules might arrange themselves at different pressures, using the laws of chemistry and quantum mechanics. The method approaches near god-mode chemistry predicting abilities, where researchers plug in some molecules and other parameters and receive what the structure of the molecule would look like, which could lead to information on its properties.

Contrary to what you might expect, the team’s search found that the most stable cabon monoxide structure at ambient pressure and temperature would be a polymer, a repeating molecule with a backbone of carbon and oxygen rings called Pna21. But this stuff couldn’t form spontaneously—it needs to be made at high pressures, maybe around ten thousand times higher than sea level pressure. And unlike other carbon monoxide polymers discovered previously, Pna21 would be absolutely explosive, five to ten times more so than the same amount of TNT, thanks to the huge amount of energy it stores.

We don’t see carbon monoxide form this way on Earth, but the polymer could exist elsewhere in the galaxy, maybe inside planets or gas clouds.

It’s important to note that these computer algorithm searches for new chemical structures are carried out at a temperature of absolute zero, something unachievable in our natural universe. Adding temperature and entropy, the relative disorder of the system, into the mix would be important, Nicholas Harrison, physicist at Imperial College, London, told Gizmodo. Additionally, he said, at room temperatures these polymers might rapidly oxidize into carbon dioxide. Harrison had no idea how this thing would behave at an ambient pressure at room temperature in the presence of other molecules.

But Harrison was excited about the computational algorithm, given the importance of a crystal’s structure to its properties.

As for applications, who knows? Scientists have only theorized that this Pna21 polymer exists, they haven’t made it. Maybe we can suck carbon dioxide from the atmosphere and store or transport energy in these carbon monoxide crystals. There are probably way better molecules for doing that job, but it’s nice to think about what sorts of problems strange chemistry might help us solve.

Anyway, literally everything can kill you if you try hard enough and believe in yourself. Chaos reigns.

[Phys Rev B]

Another One of Saturn’s Moons May Have a Global Ocean


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Another One of Saturn’s Moons May Have a Global Ocean

9/30/16 1:10pm

A parting view of Saturn’s moon Dione from Cassini’s final flyby on April 17th, 2015. Image: NASA/JPL-Caltech/Space Science Institute

The evidence is mounting that our solar system is rife with oceans. Last week, scientists reported that Pluto could have an insanely deep liquid water swimming pool beneath its surface, and on Monday, NASA revealed new evidence for geyser activity on icy Europa. Now, another frozen moon is poised to join the club of outer space scuba retreats: Dione.

The fourth largest moon of Saturn, Dione was first imaged by the Voyager space probes in the 1980s, and has been viewed more recently by the Cassini spacecraft, during a series of five close flybys. It’s a beautiful, cratered ball of ice and rock, home to deep canyons and towering cliffs. While early flybys offered hints of geologic activity, there’s never been a smoking gun to prove Dione is alive inside—particularly when compared with its next-door neighbor (and orbital resonance partner) Enceladus, which is spewing seawater out of enormous geysers.

Dione against a backdrop of Saturn’s rings. Image: NASA/JPL-Caltech/Space Science Institute

But a new study, which has been accepted for publication in Geophysical Research Letters, suggests we may have underestimated Dione. The moon could have a liquid water ocean beneath its surface, just like Enceladus. Using a geophysical model that depicts a crust ‘floating’ atop a mantle, Mikael Beuthe of the Royal Observatory of Belgium shows that gravity data collected by Cassini can be explained by a ~100 kilometer (62 mile)-thick shell of ice enveloping a 65 kilometer (40 mile)-deep ocean. Dione’s ocean, in turn, would smother a rocky core.

The first evidence for a subsurface ocean on Enceladus also came from gravity anomalies detected by Cassini, in a series of flybys between 2010 and 2012. As the spacecraft zipped past the moon, its velocity was slightly altered due to variations in Enceladus’ gravitational field. That change in velocity was measured from Earth via the Doppler effect—a shift in the radio frequency of Cassini’s transmissions.

In 2014, researchers at the Jet Propulsion Laboratory concluded that Cassini’s radio transmissions were hinting at a south polar sea beneath Enceladus’ icy shell. But a year later, independent measurements of Enceladus’ “libration”—a slight wobble as it orbits Saturn—revealed that the ocean is probably global.

“For Dione, we did a similar gravity-topography analysis as was done for Enceladus in 2014, but with improved techniques,” Beuthe told Gizmodo. “Thus that’s the best evidence we have now for a present-day ocean on Dione.”

Color map of Dione’s surface, showing ice cliffs and patches of smooth terrain that indicate recent geologic resurfacing. Image: Wikimedia

According to Beuthe, we won’t be able to confirm Dione’s ocean with libration measurements the way we did for Enceladus, both because Dione is more spherical and because its crust is thicker. But there are other reasons to suspect this moon’s ocean is the real deal.

For one, gravity data also tells us Dione has a rocky core, spanning approximately 70 percent of its total radius. As radioactive elements decay within the core, they produce heat, melting the overlying ice. This almost certainly caused a subsurface ocean to form in Dione’s early history—which, by the way, might not have been too long ago.

“We don’t yet know whether the ocean froze or not afterwards,” Beuthe said. “But freezing would cause global expansion which should be seen in a certain type of cracks [which have] not been observed on the surface.”

Icy cliffs and smooth terrains also hint at recent geologic activity, which again, is difficult to explain if Dione is simply a ball of ice frozen to rock. Detection of geysers, similar to those seen on Enceladus and Europa, would really seal the deal for an ocean on Dione. But we haven’t seen geysers yet, and given the estimated thickness of Dione’s crust, Beuthe isn’t so sure we will.

To confirm the ocean, he says, “we need a new mission, which won’t happen for a long time.”

If Beuthe’s hunch about Dione is correct, the astrobiology implications are thrilling. It’s likely the ocean would have been around for the moon’s entire existence, long enough for microbial life to emerge under the right conditions. Another mind boggling thought: perhaps Dione and Enceladus have been exchanging alien microbes for hundreds of millions of years.

If one thing is becoming clear, it’s that oceans are not so unusual or special in our cosmic backyard. Does that mean life isn’t, either? We’ll need to keep exploring to find out.

Saturn’s Moon Enceladus Has the Basic Ingredients For Life


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Saturn’s Moon Enceladus Has the Basic Ingredients For Life

Enceladus. (Image: NASA)

Saturn’s moon Enceladus features a warm subterranean ocean covered in ice. In an extraordinary new finding, scientists have confirmed the existence of a chemical energy source within this moon’s water that’s capable of sustaining living organisms here on Earth. Enceladus is now officially the best place beyond Earth to look for life.

Molecular hydrogen is being produced in the ocean of Enceladus, according to a new study published today in Science. The most plausible source of this hydrogen is hydrothermal reactions between hot rocks and water in the ocean beneath the moon’s icy surface. So in addition to warm water, organic molecules, and certain minerals, this moon is also producing an accessible source of energy that could conceivably support alien microbes.

Indeed, hydrothermal processes near volcanic vents are known to sustain complex ecosystems here on Earth. The new study marks an important development in our ability to assess the habitability of distant celestial objects, while setting the stage for future missions.

Underrated compared with Jupiter’s icy moon Europa, Enceladus is one of the most fascinating objects in the Solar System. A mid-sized Saturnian moon that measures about 313 miles (504 km) in diameter, it features a geologically young, dynamic surface. Because it’s in an eccentric (i.e. non-circular) orbit around its gas giant host, scientists think gravitational forces are causing Enceladus to twist and contort—and that those contortions are generating heat in the moon’s rocky core. The warmth generated by these tidal forces is probably what allows the moon to sustain water in a liquid state—lots of it. Enceladus may be covered in an icy shell, but beneath the surface lies a globe-spanning liquid ocean about 37 miles (60 km) deep.

This hidden ocean—which may be as warm as 90 degrees Celsius (194 degrees Fahrenheit) at the bottom—is one of many reasons that Enceladus is considered a prime candidate for extraterrestrial life.

Geysers erupting thorough Enceladus’ icy surface. (Image: NASA)

In 2005, NASA’s Cassini probe spotted plumes erupting from the Enceladus’ south polar terrain, sending water vapor and solid particles from that subterranean ocean off into space. Back in 2015, NASA directed Cassini to perform a deep dive through this vapor, collecting valuable information with its instruments, most notably the Ion and Neutral Mass Spectrometer (INMS). Chemical analysis of the plume indicated the presence of organic and nitrogen-bearing molecules, as well as salts and silicates, which strongly suggest ocean water is in contact with a rocky core.

In a subsequent trip through the plume, Cassini’s INMS was put into a mode that minimized analytical artifacts that had compromised the measurements of the energy source molecular hydrogen, or H2, during previous flybys. An analysis of this improved data by scientists J. Hunter Waite, Christopher Glein, Jonathan Lunine, and others, confirmed that the molecular hydrogen being detected by Cassini is in fact produced within Enceladus. As scientific discoveries go, that’s huge.

Molecular hydrogen is light and chemically reactive, so it’s not the kind of thing that would just normally stick around on this moon without a source to replenish it. The confirmation essentially means that some kind of chemical process is actively making the molecule within the moon itself.

Image: NASA/Cassini

“In our paper we looked at several ways Enceladus might make molecular hydrogen,” Lunine, an astronomer at the Cornell Center for Astrophysics and Planetary Science, told Gizmodo. “The one that seems to explain the large amount of molecular hydrogen observed is the reaction at the seafloor of certain kinds of minerals with hot water, which makes molecular hydrogen.” In other words, a hydrothermal reaction.

“Cassini found a lot of hydrogen—so much that it must be actively produced,” Lunine continued. “If the hydrothermal activity that makes the molecular hydrogen were to shut down, the molecular hydrogen would be consumed by reactions until there was very little left—much less than what is observed by INMS.”

If hydrothermal chemical reactions are indeed responsible for the molecular hydrogen, that means the methane previously detected by Cassini might be generated from carbon dioxide (also detected by Cassini) through a reaction with hydrogen. When Cassini flew through the plume in 2015, it measured upwards of 1.4 percent hydrogen per volume of sample, and up to 0.8 percent per volume carbon dioxide. Together, these are signatures of a process known as methanogenesis—a metabolic reaction that sustains microbes in deep, dark undersea environments on Earth.

“These mineral-water reactions are the restaurant at the bottom of the ocean of Enceladus, making goodies [i.e. molecular hydrogen (H2) and methane (CH4)] that primitive microbes could eat,” said Lunine. “This doesn’t tell us whether life is there or not—it just makes the case for the ocean being able to support life that much stronger.”

A hydrothermal event on Earth. (Image: NOAA)

Deep sea hydrothermal vent environments are also speculated to exist on Jupiter’s moon, Europa. These vents are of critical importance to astrobiologists, as they’re known to sustain entire marine ecosystems on Earth. Moreover, the recent discovery of what may be the world’s oldest fossil in Quebec suggests that life on Earth may have originated around hydrothermal vents.

“The H2 discovery completes the case for going back to Enceladus to look for life,” said Lunine. “The discovery of native molecular hydrogen (H2) completes the set of what I would call the ‘basic’ requirements for life as we know it: Liquid water, organic molecules, minerals, and an accessible source of “free” energy. The H2 gives us the last of these.”

Excitingly, it may be easier to detect traces of life on this moon than we realize. We could potentially do so by flying a spacecraft through a plume equipped with more modern instruments than those aboard Cassini (remember, Cassini was launched 20 years ago). Scientists could look at the plume’s chemistry in more detail, searching for the molecular signatures of life in the subsurface ocean; in other words, we would let the ocean come to us. This basically describes the Enceladus Life Finder (ELF) mission, which would involve no landing, drilling or melting—just ten or so deep dives into that tantalizing south polar plume.

“So Enceladus is, in my view, the best place beyond Earth to go look for life—a demonstrably habitable ocean that is being spewed into space for us to sample,” Lunine told Gizmodo. “What are we waiting for?”

[Science]