'Utterly bizarre' chimera crab fossil discovered: 'Makes you wonder 'what else is out there' - Fox News

Even Dr. Frankenstein and his monster would be jealous of this creature.

Paleontologists have unearthed the fossil of an ancient crab that lived between 90 and 95 million years ago and is so "utterly bizarre" it literally perplexed the researchers.

Known as Callichimaera perplexa, which means "perplexing beautiful chimera," the crab had an assortment of body parts that would make Mr. Potato Head green with envy.

'GIANT LION' FOSSILS DISCOVERED IN MUSEUM DRAWER

“We started looking at these fossils and we found they had what looked like the eyes of a larva, the mouth of a shrimp, claws of a frog crab, and the carapace of a lobster,“ said Javier Luque, lead author and postdoctoral paleontologist in the Department of Biological Sciences at the University of Alberta and at Yale University, in a statement.

Luque continued: “We have an idea of what a typical crab looks like—and these new fossils break all those rules."

An artistic reconstruction of Callichimaera perplexa: the "strangest crab that has ever lived." (Credit: Oksana Vernygora, UAlberta)

In Greek mythology, a chimera had the head of a lion, the body of a goat and the tail of a snake.

The researchers wrote that the discovery and C. perplexa's body type challenges the conventional view of what earlier crabs looked like. "Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical 'crab-like' body plan since the Early Cretaceous," the study's abstract reads.

The study was published in the journal Science Advances.

The crab's giant eyes likely helped it to hunt smaller crustaceans while swimming in the ancient Cretaceous period oceans. "We don't think they were filter feeders," Luque told Live Science. "We think they were actually active predators."

C. perplexa was first discovered in 2005 in the Andes Mountains, along with other ancient crustaceans such as lobsters and shrimp. Since then, Luque and a team of researchers have analyzed the fossil (no bigger than a quarter) in great detail and suggested that it spent its life swimming, in stark contrast to modern-day crabs, who spend their lives crawling.

FOSSILIZED REMAINS OF 430 MILLION-YEAR-OLD SEA MONSTER FOUND

“We found dozens of animals, from tiny baby specimens to mature individuals in which we found reproductive organs—a smoking gun that proves these were adult organisms and not larvae. We can even see individual facets on the large compound eyes of these creatures,” Luque added in the statement. “It’s an incredible amount of detail, and we’ve been able to reconstruct them like they were living yesterday."

Callichimaera perplexa: the oldest swimming crab from the dinosaur era. (Credit: Daniel Ocampo R., Vencejo Films)

Luque said that it's not unusual to find different body types in older rocks, as life was still expanding into new forms.

“This discovery, from the mid-Cretaceous, illustrates that there are still surprising discoveries of more recent, weird organisms waiting to be found, especially in the tropics," he concluded. "It makes you wonder ‘what else is out there for us to discover?’“

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2019-04-25 14:16:49Z
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One of Stephen Hawking's Most Famous Theories About Black Holes Just Suffered a Huge Blow - Live Science

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One of Stephen Hawking's Most Famous Theories About Black Holes Just Suffered a Huge Blow  Live Science

A search through the Andromeda galaxy for tiny, ancient black holes finds none, striking a stinging blow to Stephen Hawking's theory of dark matter.

https://www.livescience.com/65300-hawking-black-hole-theory-unlikely.html

2019-04-25 11:15:00Z
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Holy Pleistocene Batman, the answer's in the cave - Phys.org

Bats flying out of an Indonesian cave for their nightly meal. Credit: Chris Wurster

Let's say you wanted to solve a 20,000-year-old mystery, where would you start? Perhaps archaeology and geology come to mind. Or, you could sift through a 3-metre pile of bat faeces.

Researchers from James Cook University in Cairns, Australia, chose the bat poo in their quest to answer to a long-standing question: why is there some much biodiversity on the islands of Sumatra, Borneo and Java, when not so long ago (geologically speaking) they were all part of one vast continent?

One theory has been that the former continent (Sundaland) was dissected by a savanna corridor. "That might explain why Sumatra and Borneo each have their own species of orang-utan, even though they were linked by land for millions of years," Dr. Chris Wurster said. "The corridor would have divided the two separate rainforest refuges, as the sea does now."

The corridor theory has been boosted by millions of insect-eating bats, which have gathered evidence about the landscape over millennia and deposited it in layers in their caves.

"Bat poo is highly informative, and especially so in the tropics, where the climate can make some of the more traditional modes of investigation less available," Dr. Wurster said.

A three-metre pile of bat faeces at Salah Cave in Borneo gave the researchers a 40,000-year-old record composed of insect skeletons.

"We can't tell what insects the bats were eating throughout that time, because they're in tiny fragments, but we can read the chemistry," Dr. Wurster said.

Bats clustering together on the wall of an Indonesian cave. Credit: Chris Wurster

"Eating insects that have been feeding on tropical grasses results in faeces with a characteristic chemical imprint. It's quite different from the result you'd get from eating insects that fed on tropical trees."

According to the bat record the landscape around Saleh Cave (now featuring lush rainforest) was once dominated by tropical grasses.

"Combined with other cave studies in the region, this leads us to support the corridor theory, and also gives us some confidence as to the extent of the corridor," Dr. Wurster said.

The corridor could also shed light on human pre-history.

"A savanna corridor, which would be much more easily traversed than rainforest, might help to explain how people moved relatively quickly through this region and on to Australia and New Guinea."

'Savanna in equatorial Borneo during the late Pleistocene' is published in the latest edition of Scientific Reports.

Dr. Chris Wurster is a Senior Research Associate at James Cook University, specialising in stable isotope geochemistry.

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Citation: Holy Pleistocene Batman, the answer's in the cave (2019, April 25) retrieved 25 April 2019 from https://phys.org/news/2019-04-holy-pleistocene-batman-cave.html

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2019-04-25 09:00:01Z
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Observation of two-neutrino double electron capture in 124Xe with XENON1T - Nature.com

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Coello Pérez, E. A., Menéndez, J. & Schwenk, A. Two-neutrino double electron capture on 124Xe based on an effective theory and the nuclear shell model. Preprint at https://arxiv.org/abs/1809.04443 (2018).

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2019-04-24 17:03:45Z
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Dark matter detector observes rarest event ever recorded - Phys.org

The XENON1T dark matter collaboration has observed the radioactive decay of xenon-124, which has a half-life of 1.8 X 1022 years Credit: XENON1T

How do you observe a process that takes more than one trillion times longer than the age of the universe? The XENON Collaboration research team did it with an instrument built to find the most elusive particle in the universe—dark matter. In a paper to be published tomorrow in the journal Nature, researchers announce that they have observed the radioactive decay of xenon-124, which has a half-life of 1.8 X 10²² years.

"We actually saw this decay happen. It's the longest, slowest process that has ever been directly observed, and our dark matter detector was sensitive enough to measure it," said Ethan Brown, an assistant professor of physics at Rensselaer, and co-author of the study. "It's an amazing to have witnessed this process, and it says that our detector can measure the rarest thing ever recorded."

The XENON Collaboration runs XENON1T, a 1,300-kilogram vat of super-pure liquid xenon shielded from cosmic rays in a cryostat submerged in water deep 1,500 meters beneath the Gran Sasso mountains of Italy. The researchers search for dark matter (which is five times more abundant than ordinary matter, but seldom interacts with ordinary matter) by recording tiny flashes of light created when particles interact with xenon inside the detector. And while XENON1T was built to capture the interaction between a dark matter particle and the nucleus of a xenon atom, the detector actually picks up signals from any interactions with the xenon.

The evidence for xenon decay was produced as a proton inside the nucleus of a xenon atom converted into a neutron. In most elements subject to decay, that happens when one electron is pulled into the nucleus. But a proton in a xenon atom must absorb two electrons to convert into a neutron, an event called "double-electron capture."

Double-electron capture only happens when two of the electrons are right next to the nucleus at just the right time, Brown said, which is "a rare thing multiplied by another rare thing, making it ultra-rare."

When the ultra-rare happened, and a double-electron capture occurred inside the detector, instruments picked up the signal of electrons in the atom re-arranging to fill in for the two that were absorbed into the nucleus.

"Electrons in double-capture are removed from the innermost shell around the nucleus, and that creates room in that shell," said Brown. "The remaining electrons collapse to the ground state, and we saw this collapse process in our detector."

The achievement is the first time scientists have measured the half-life of this xenon isotope based on a direct observation of its radioactive decay.

"This is a fascinating finding that advances the frontiers of knowledge about the most fundamental characteristics of matter," said Curt Breneman, dean of the School of Science. "Dr. Brown's work in calibrating the detector and ensuring that the xenon is scrubbed to the highest possible standard of purity was critical to making this important observation."

The XENON Collaboration includes more than 160 scientists from Europe, the United States, and the Middle East, and, since 2002, has operated three successively more sensitive liquid xenon detectors in the Gran Sasso National Laboratory in Italy. XENON1T, the largest detector of its type ever built, acquired data from 2016 until December 2018, when it was switched off. Scientists are currently upgrading the experiment for the new XENONnT phase, which will feature an active detector mass three times larger than XENON1T. Together with a reduced background level, this will boost the detector's sensitivity by an order of magnitude.

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More information: Observation of two-neutrino double electron capture in 124Xe with XENON1T, Nature (2019). DOI: 10.1038/s41586-019-1124-4 , https://www.nature.com/articles/s41586-019-1124-4

Provided by Rensselaer Polytechnic Institute

Citation: Dark matter detector observes rarest event ever recorded (2019, April 24) retrieved 24 April 2019 from https://phys.org/news/2019-04-dark-detector-rarest-event.html

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2019-04-24 17:00:12Z
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Dark Matter Detector Makes Incredible Neutrino Observation - Gizmodo

Part of the XENON experiment.

Photo: The XENON collaboration

A detector designed to hunt for dark matter has made a particle physics observation that will hopefully help physicists establish important truths about our Universe. No, it didn’t spot dark matter, but the new result proves that these ultra-sensitive detectors are valuable to scientists for multiple reasons.

Gravity-wise, the Universe behaves as if it contains way more matter than astronomers have actually identified, so physicists have built experiments to hunt for candidates for this so-called dark matter. The hunt for the most popular dark matter candidate has so far turned up empty. But one of these dark matter experiments, called XENON1T, has now observed a process that has avoided multiple detection attempts, one that will hopefully help scientists better understand the shadowy particle called the neutrino.

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“It proves that this XENON detector technology we use for dark matter is much more versatile,” graduate student Christian Wittweg, Ph.D student at the University of Münster in Germany, told Gizmodo. “We get all these cool analyses... for free after having built an experiment sensitive enough to hunt for dark matter.”

Scientists are pretty sure that the second most abundant particle in the Universe (after photons, particles of light) is the neutrino. But neutrinos are very hard to detect and measure. We know they have mass, but don’t know how much. We know that they have an antiparticle, a sort of evil twin that causes both particles to annihilate if they meet, but don’t know the nature of that antiparticle. There are a ton of neutrino mysteries to solve. The new measurement, called “two-neutrino double electron capture,” is an important stepping stone to providing those answers.

Two-neutrino double electron capture is an exceedingly rare particle interaction that was first theorized in 1955 and “has escaped detection for decades,” according to the paper published in Nature. In the process, two protons in the atomic nucleus spontaneously and simultaneously absorb a pair of electrons orbiting the nucleus, releasing a pair of neutrinos. The experimental signature of the event is a barrage of x-rays and electrons resulting from other electrons orbiting the atom replacing the two absorbed by the nucleus. And when I say rare, I mean rare. The average amount of time it would take half of the xenon atoms in a sample to undergo this reaction is 1.8 × 10²² years, according to the paper. That’s roughly a trillion times the age of the Universe.

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XENON1T is an experiment perfectly equipped to measure this rare event. Firstly, it contains a crapload of xenon atoms—3.2 tons worth of liquid xenon (though, as a note, the xenon isotope used for this measurement makes up only a small fraction of the total xenon atoms). Secondly, the whole setup is buried deep within an Italian mountain, shielding it from pretty much any particle that could cause a false signal. And finally, scientists understand pretty much every bit of noise that could produce a signal in the experiment, increasing their confidence that they’ve actually found something important when an anomalous signal appears.

After 214 days of observing (177 days of usable data), the researchers’ analysis revealed approximately 126 two-neutrino double electron capture events.

This is an incredible scientific accomplishment. “It’s the longest half-life ever measured directly,” Ph.D student Chiara Capelli from the University of Zurich who works on XENON told Gizmodo

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Researchers aren’t calling their results a “discovery,” because their statistics didn’t hit the five-standard deviation threshold particle physicists require in order to use that word. Instead, they’re calling it an “observation,” as the result carried a significance of 4.4 sigma. That means there’s only a one in a few hundred thousand chance that they’d see this result had the reaction not existed—but it will take a bit more observing to get to the one-in-3.5 million odds required by physicists to announce a discovery.

Next, scientists will hunt for a no-neutrino, or neutrinoless double electron capture, an even rarer event in which, after the double neutrino electron capture event, the two neutrinos collide and emit a gamma ray. This would demonstrate that neutrinos are their own antiparticles, and would allow scientists to put a number to the neutrinos’s mass. It’s also a complimentary search to a reaction called neutrinoless double beta decay—sort of like the opposite of neutrinoless double electron capture, where two neutrons spontaneously and simultaneously turn into protons, emitting electrons and a pair of neutrinos that annihilate one another.

We don’t know if these “neutrinoless” reactions would really happen, but it’s an important question to particle physicists. If neutrinos really are their own antiparticle, it would help explain why neutrinos are so low-mass and maybe why there’s so much more matter than antimatter in the Universe.

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Ultimately, scientists need more observing time. XENON will soon upgrade to XENONnT with even more liquid xenon, which will allow scientists to observe these events more frequently, and to observe neutrinoless events that have even longer half-lives, explained Laura Baudis, professor of physics at the University of Zurich.

But most importantly, it’s proof that these experiments are sensitive enough that they can perform other important measurements beyond just hunting for dark matter.

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2019-04-24 17:00:00Z
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Why a 'Faint Rumble' on Mars Is 'So Exciting' - Newser

(Newser) – It was a "faint rumble" but it meant something big—the first seismic signal detected on the surface of a planetary body other than our home planet and moon. We have NASA's Martian InSight lander to thank. The lander has been listening for quakes that could shed light on Mars' guts since its robotic arm deposited a shielded seismometer on the western side of Elysium Planitia last December, a few weeks after the lander touched down. The key moment—hear it here—came April 6, 128 days into the mission. "This particular Marsquake—the first one we've seen—is a very, very small one," says the mission's chief scientist, Bruce Banerdt. "You wouldn't even notice this one in your day-to-life." Adds researcher Tom Pike, per the BBC: "There are a lot of uncertainties" but "it's probably only a Magnitude 1 to 2 event, perhaps within [62 miles] or so."

The tremor—which lasted 10 minutes, per National Geographic—could indicate movement inside the planet or a meteorite impact. "Interestingly, InSight's scientists say the character of the rumble reminds them very much of the type of data the Apollo sensors gathered on the lunar surface," per the BBC. The team is also investigating lesser signals detected March 14, April 10, and April 11 but can't yet confirm they were seismic events. "When you've got one, you don't know whether you were just lucky, but when we see two or three we will have a better idea" about the activity within the planet, Pike tells the BBC. Yet one confirmed "Marsquake" seems enough for InSight's seismometer boss Philippe Lognonné. "It's so exciting to finally have proof that Mars is still seismically active," he says, per Space.com. "We've been waiting [for] months." (Read more Mars stories.)

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2019-04-24 14:08:00Z
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