'Star in a Jar' Fusion Reactor Works and Promises Infinite Energy
For several decades now, scientists from around the world have been pursuing a ridiculously ambitious goal: They hope to develop a nuclear fusion reactor that would generate energy in the same manner as the sun and other stars, but down here on Earth.
Incorporated into terrestrial power plants, this "star in a jar" technology would essentially provide Earth with limitless clean energy, forever. And according to new reports out of Europe this week, we just took another big step toward making it happen.
In a study published in the latest edition of the journal Nature Communications, researchers confirmed that Germany's Wendelstein 7-X (W7-X) fusion energy device is on track and working as planned. The space-age system, known as a stellerator, generated its first batch of hydrogen plasma when it was first fired up earlier this year. The new tests basically give scientists the green light to proceed to the next stage of the process.
It works like this: Unlike a traditional fission reactor, which splits atoms of heavy elements to generate energy, a fusion reactor works by fusing the nuclei of lighter atoms into heavier atoms. The process releases massive amounts of energy and produces no radioactive waste. The "fuel" used in a fusion reactor is simple hydrogen, which can be extracted from water.
However, to achieve fusion, scientists must generate enormously high temperatures to heat the hydrogen into a plasma state. The plasma is so hot, in fact, that it would instantly burn material used to contain it. That's where the stellerator design comes in. The W7-X device confines the plasma within magnetic fields generated by superconducting coils cooled down to near absolute zero. The plasma — at temperatures upwards of 80 million degrees Celsius — never comes into contact with the walls of the containment chamber. Neat trick, that.
The W7-X is the world's largest and most sophisticated stellerator and is currently operated by Max Planck Institute for Plasma Physics in Germany. But development of the W7-X has been an ongoing, international effort. The latest tests were conducted in collaboration with scientists from the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL).
David Gates, principal research physicist for the advanced projects division of PPPL, leads the agency's collaborative efforts in regard to the W7-X project. In an email exchange from his offices at Princeton, Gates said the latest tests verify that the W7-X magnetic "cage" is working as planned.
"This lays the groundwork for the exciting high-performance plasma operations expected in the near future," Gates said.
In terms of the big-picture goal, Gates said that nuclear fusion reactors, if properly developed and deployed, would provide the planet with safe, clean and virtually inexhaustible energy.
"The fuel source is found in seawater in quantities sufficient to last tens of thousands of years," he said. "The waste product is helium, an inert gas. A viable fusion reactor would provide a secure, plentiful and environmentally benign energy resource to all nations."
That last part is critical. Gates said he's encouraged by fact that the W7-X project, and nuclear fusion research in general, is the result of close collaboration among scientists from around the world.
'Fusion is a problem best solved by the peoples of all nations working together, since the entire world will benefit from it."
How Humans Lost Their Tail, Twice
Humans can't seem to keep a tail, suggests new research that finds our early ancestors lost tails not just once, but twice.
The findings, published in the journal Current Biology, not only help explain why people don't wag dog-like tails, but they also shed light on why we all have a tailbone and begin life with an actual tail that gradually disappears.
"Fleshy tails go all the way back to the earliest vertebrate ancestors and are found in very young embryos, so it would be very difficult to get rid of them entirely without causing other problems," author Lauren Sallan told Seeker. "As a result, both fishes and humans have had to stunt growth instead, leaving a buried, vestigial tail much like the legs of whales."
The origins of this mysterious vestigial tail go back to fish. For the study, Sallan, an assistant professor in the University of Pennsylvania's Department of Earth and Environmental Science, analyzed 350-million-year-old hatchlings of the fossil fish Aetheretmon. This jawed fish distant ancestor of terrestrial animals today had both a scaly, fleshy tail and a flexible tail fin, sitting one atop the other.
Sallan found these structures were entirely separate. By comparing the Aetheretmon hatchlings with those of living fish, she found that the two "tails" started out one atop the other and then grew on their own. This discovery overturns at least two centuries of scientific belief that the modern adult fish tail fin was simply added to the end of an ancestral tail shared with land animals.
The disconnect means that the two tails went on their own evolutionary paths. Fish lost the fleshy tail and kept the flexible one to improve their swimming. Having just the back fin, she explained, "allows for more refined movements, which a muscular tail (originally present for power swimming) would disrupt."
Fish that evolved to become semi-aquatic and then land-dwelling animals lost the flexible back fin, but kept the fleshier one that over time became the familiar appendage we now see on dogs, cats, cows and many other animals. As dogs show, tails are useful for visual communication, slapping away flying insects and other functions.
Adult apes, including human ancestors, took the tail loss process a step further, Sallan said, "losing the remaining bony tail for better upright movement. Like fish, the remnants of an embryonic bony tail are buried in our lower backs—the coccyx or tailbone—stunted by a loss of molecular signals that would otherwise cause it to grow out like an arm or leg. Thus, humans and fish embryos share mechanisms for controlling tail form."
The fossil record for early apes is not great, but since apes lack tails, she thinks our primate ancestors lost them when they first started to walk on two legs. Monkeys that often walk this way have stunted tails, further proving that tails can get in the way of moving around while upright.
'Mythical' Sea Blob Finally Spotted a Century After Its Discovery
A mysterious sea blob that looks like a psychedelic Slinky has finally been spotted, more than a century after it was first described.
The translucent, sea-dwelling invertebrate, called Bathochordaeus charon, was identified recently off the coast of Monterey, California, by scientists using a remotely operated vehicle (ROV). Though B. charon was first discovered a century ago, no one had managed to confirm its existence in all those years, Rob Sherlock, a scientist at the Monterey Bay Aquarium Research Institute who found the creature, told Live Science in an email. [See Photos of the Translucent Sea Blob]
Mysterious sea creature
B. charon belongs to a group of sea creatures known as larvaceans — normally teensy, millimeter-size creatures whose bodies resemble a tadpole's, with a large "head" (actually a trunk) and a tail, Sherlock said.
Though the sea is teeming with tiny larvaceans, the larger versions, which can have bodies extending up to 3.9 inches (10 centimeters), are much less common. To eat, the sea blob filters food through its shimmering, parachute-like mucus "house" almost 3.3 feet (1 m) in length. By waving its tail, it stirs the water and pulls particles directly into its house. Large particles get trapped and form a fine dusting of marine "snow" on the house, while the smaller particles pass through, concentrating and then funneling into a feeding tube that goes into the mouth, Sherlock said. (The tiny larvaceans also don mucus homes, but they're smaller.)
If a passing squid or fish crashes through the house, or big particles clog the feeding tube, larvaceans simply move on and build another house. Without their houses, they cannot eat, Sherlock said.
First sightings
The first report of B. charon's existence came in 1899, when professor Carl Chun of Leipzig University came across one in the south Atlantic Ocean while leading the Valdivia Expedition, a German mission aimed at exploring the deep sea. Chun believed the creature welled up from the deepest depths of the ocean, so he named the larvacean after Charon, who in Greek mythology ferries the souls of the dead across the river Styx, the researchers reported Aug. 16 in the journal Marine Biodiversity Records.
In the decades that followed, several other naturalists reported spotting giant larvaceans, though only a few were captured alive and described thoroughly. In 1936, for instance, British marine biologist Walter Garstang collected a set of giant larvaceans that differed from Chun's, and they were classified as a new species, Bathochordaeus stygius. [Marine Marvels: Spectacular Photos of Sea Creatures]
Because the two sets of specimens were similar and Chun's originals were lost to history, scientists eventually began to wonder whether Chun's originally described B. charon was actually the same species as B. stygius. One famous larvacean expert even suggested combining the two species names, Sherlock said. Part of the difficulty in capturing these creatures is that they don't fare well in the trawling nets typically used to collect specimens, Sherlock said.
Hiding in plain sight
Sherlock and his colleagues happened upon the new species when the team's ROV, called Doc Ricketts, was exploring the waters of Monterey Bay. As soon as they saw it, the crew carefully collected it in a sealed, thermally insulated container.
"Since the vehicle was recovered some tens of minutes later, the animal was alive, in fantastic shape, and we preserved it right away in order to send it to the Smithsonian," Sherlock said. "We had no idea, until we looked more closely at the specimen, that we had actually found B. charon, the species first described over a hundred years ago."
Genetics and analysis of physical features confirmed the find, Sherlock said. It was official: There really were two distinct species of giant larvacean — B. stygius and B. charon.
"It felt like Chun had finally been vindicated after years of doubt," Sherlock said.
When the team went back over videos from Monterey Bay from the past 25 years, they realized the creature had been spotted many times in the bay. Whether they dwell in places between Monterey Bay and the South Atlantic, however, remains to be seen.
Still, this mythical sea blob is fairly rare; over the course of the past few decades, biologists have seen hundreds of B. stygius, but captured footage of only a dozen B. charon individuals, Sherlock said.
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