Identical photons generated 150 million kilometers apart

Science - Posted On:2019-08-22 11:45:00 Source: arstechnica

Up until the mid-20th century, light was pretty ordinary. Yes, it was both a particle and a wave, but it didn’t do anything very weird. Then scientists, under-employed after the end of World War II, started paying more attention to the properties of light. This was, in part, driven by the availability of surplus searchlights, which could be turned into cheap arrays of light detectors to measure the properties of stars.

That began the photon gold rush, with scientists identifying all sorts of interesting potential behaviors. But actually observing them would require having rather special light sources, which didn’t exist. Now, scientists have shown that our own Sun can be turned into one of these light sources.

When two photons are indistinguishable, they can be made to play some unexpected tricks. The diagram below shows an example: two identical photons hit a partially reflective mirror at the same time. We cannot predict where they will go, but wherever it is, they go together. If the world was classical, we would expect that each behaves independently, and half the time, they would choose different directions. But we're in a quantum world, so this doesn't happen.

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Vaping-linked lung disease cases jump from 94 to 153 in 5 days, CDC says

Science - Posted On:2019-08-22 11:45:00 Source: arstechnica

Cases of severe lung disease linked to vaping rose from 94 to 153—a jump of over 60%—in just five days, according to an update by the Centers for Disease Control and Prevention.

On Saturday, August 17, the CDC announced its investigation into the cases, which have puzzled health officials. The cases tend to involve gradual breathing difficulties, coughing, fatigue, chest pain, and weight loss, which leads to hospitalization (no one had died from the condition). Health officials say there’s no evidence pointing to an infectious agent behind the illnesses. The only commonality appears to be recent use of e-cigarettes, aka vaping.

As of the August 17, the agency had counted 94 probable cases from 14 states between June 28 and August 15. In an update released late Wednesday, August 21, the CDC said the figures are up to 153 probable cases between June 28 and August 20, spanning 16 states.

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Physicists discover hidden text in what was thought to be blank Egyptian papyri

Science - Posted On:2019-08-22 08:14:57 Source: arstechnica

A team of German scientists has used a combination of cutting-edge physics techniques to virtually "unfold" an ancient Egyptian papyrus, part of an extensive collection housed in the Berlin Egyptian Museum. Their analysis revealed that a seemingly blank patch on the papyrus actually contained characters written in what had become "invisible ink" after centuries of exposure to light.

Most of the papyri in the collection were excavated around 1906 by an archaeologist named Otto Rubensohn, on Elephantine Island, near the city of Aswan. They've been gathering dust in storage for much of the ensuing decades, and because they are so fragile, more than 80% of the text within remains undeciphered. “Today, much of this papyrus has aged considerably, so the valuable texts can easily crumble if we try to unfold or unroll them,” said co-author Heinz-Eberhard Mahnke of Helmholtz-Zentrum Berlin and Freie Universität Berlin. That makes noninvasive imaging methods essential to the project.

In 2016, an international team of scientists developed a method for "virtually unrolling" a badly damaged ancient scroll found on the western shore of the Dead Sea, revealing the first few verses from the book of Leviticus. The so-called En Gedi scroll was recovered from the ark of an ancient synagogue destroyed by fire around 600 CE. To the naked eye, it resembled a small lump of charcoal, so fragile that there was no safe way to analyze the contents. The team's approach combined digital scanning with micro-computed tomography—a noninvasive technique often used for cancer imaging—with segmentation to digitally create pages, augmented with texturing and flattening techniques. Then they developed software (Volume Cartography) to virtually unroll the scroll.

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Researchers Are Creepily Close To Predicting When You're Going To Die

science - Posted On:2019-08-21 23:44:58 Source: slashdot

An anonymous reader quotes a report from Ars Technica: If death is in the cards, it may also be in your blood. Measurements of 14 metabolic substances in blood were pretty good at predicting whether people were likely to die in the next five to 10 years. The data was published this week in Nature Communications. A team of researchers led by data scientists in the Netherlands came up with the fateful 14 based on data from 44,168 people, aged 18 to 109. The data included death records and measurements of 226 different substances in blood. Of the 44,168 people, 5,512 died during follow-up periods of nearly 17 years. The researchers then put their death panel to the test. They used the 14 blood measurements to try to predict deaths in a cohort of 7,603 Finnish people who were surveyed in 1997. Of those Finns, 1,213 died during follow-up. Together, the 14 blood measurements were about 83% accurate at predicting the deaths that occurred within both five years and 10 years. The accuracy dropped to about 72% when predicting deaths for people over 60 years old, though. Read more of this story at Slashdot.

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Researchers are creepily close to predicting when you’re going to die

Science - Posted On:2019-08-21 17:45:00 Source: arstechnica

If death is in the cards, it may also be in your blood.

Measurements of 14 metabolic substances in blood were pretty good at predicting whether people were likely to die in the next five to 10 years. The data was published this week in Nature Communications.

A team of researchers led by data scientists in the Netherlands came up with the fateful 14 based on data from 44,168 people, aged 18 to 109. The data included death records and measurements of 226 different substances in blood. Of the 44,168 people, 5,512 died during follow-up periods of nearly 17 years.

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One could fly to Mars in this spacious habitat and not go crazy

Science - Posted On:2019-08-21 15:30:00 Source: arstechnica

On Wednesday, Sierra Nevada Corporation—the company that makes aerospace equipment, not beer—showed off its proposed in-space habitat for the first time. The inflatable habitat is, first and foremost, large. It measures more than 8 meters long, and with a diameter of 8 meters has an internal volume of 300 meters, which is about one-third the size of the International Space Station.

Sierra Nevada developed this full-scale prototype under a NASA program that funded several companies to develop habitats that could be used for a space station in orbit around the Moon, as well as potentially serving as living quarters for a long-duration transit to and from Mars. As part of the program, NASA astronauts have, or will, spend three days living in and evaluating the prototypes built by Sierra Nevada, Boeing, Lockheed Martin, Northrop Grumman, and Bigelow Aerospace.

The selling point for Sierra Nevada's habitat is its size, which is possible because the multi-layered fabric material can be compressed for launch, then expanded and outfitted as a habitat once in space. It can fit within a standard payload fairing used for launch vehicles such as SpaceX's Falcon Heavy rocket, United Launch Alliance's Vulcan booster, or NASA's Space Launch System. It is light enough for any of those rockets to launch to the Moon.

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Color-changing metal may provide early sign of illness

Science - Posted On:2019-08-21 12:30:00 Source: arstechnica

Many of you will know that I mostly write about physics. My knowledge of human biology is limited to being reasonably certain that I have a body. At one point, some of my research could have had a medical application, but it involved diseases, which was knowledge I didn’t have. A recent paper on using quantum effects to improve medical diagnosis has given me flashbacks to those halcyon days, even though I still don't understand diseases.

One thing I am aware of is that it is usually preferable to be diagnosed for a disease early. It might be the difference between taking a pill and having your liver decorate a surgeon’s instruments. That means your doctor needs a cheap and effective way to see whether you have the disease. This is where, hopefully, physicists—and maybe even some physics—can come into play.

Most diseases release proteins or other molecules that signal the problem. If you have sensitive enough detectors, then you can pick up these signals and identify potential problems early. The challenge is that almost all tests of this sort are concentration sensitive: that is, if there aren’t many molecules, the signal will be weak and the test will return a false negative.

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Your heatwave could be worse because of a drought somewhere else

Science - Posted On:2019-08-21 09:59:56 Source: arstechnica

Long-lived heatwaves in the mid-latitudes are typically the result of an atmospheric pattern known as a “blocking high.” In a blocking high, the jet stream bends in a north-pointing ridge (in the Northern Hemisphere, anyway), creating an area of high atmospheric pressure as long as it stays bent. High pressure means air tends to sink towards the surface rather than rise, making it hard for any clouds to break up the blue sky. The blocking high also distorts the average wind directions as it brings warmer air from the south up to the north.

That’s the pattern that produced Russia’s incredibly deadly 2010 summer heatwave. Instead of westerly winds, warm air coming from Kazakhstan moved in on Moscow. One reason Russia got so hot during this time is that it was already in a drought. Similar to how the human body cools itself by producing sweat that evaporates off your skin, soil moisture limits how quickly the land surface can heat up. With the soil already dry, Russia lacked this cooling buffer.

A group of researchers led by Dominik Schumacher at Ghent University have now extended this idea upwind, showing that the heatwave was linked to drought in Kazakhstan’s neck of the woods, as well.

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Record-breaking 20 qubits entangle to make “Schrödinger’s cat” in the lab

Science - Posted On:2019-08-21 08:14:56 Source: arstechnica

Schrödinger's cat is quite possibly the most famous paradox in physics, and rudimentary real-world versions have even been built in the laboratory. Now a team of German physicists has set a new record by building a quantum "cat" out of 20 entangled qubits, as described in a recent paper in Science. A second group of Chinese researchers has successfully done the same with 18 qubits. The prior record, set in 2011, was 14 qubits.

Erwin Schrödinger originally proposed his thought experiment to illustrate the innate absurdity of quantum mechanics. He envisioned putting a hypothetical cat in a box containing a radioactive substance, a detector to sense any emitted radiation, and a lethal vial of poison. If the radioactive substance decays, the detector will trigger the release of the poison and the cat dies. If it doesn't, the cat remains alive. But a strict interpretation of quantum mechanics holds that until someone opens the box to see what happened, the cat exists in a superposition of states, both alive and dead.

It really is possible to build a version of Schrödinger's cat in the laboratory. It's more of a quantum "cat state," whereby two or more particles manage to be in two different states at the same time. In 2005, for instance, National Institute of Standards and Technology researchers created a quantum cat state out of six atoms in simultaneous "spin up" and "spin down" states—rather like spinning clockwise and counterclockwise at the same time. Other groups have done the same with photons.

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Pig To Human Heart Transplants 'Possible Within Three Years'

science - Posted On:2019-08-20 23:44:58 Source: slashdot

An anonymous reader quotes a report from The Guardian: Adapted pig hearts could be transplanted into patients within three years, according to a report citing the surgeon who pioneered heart transplantation in the UK. On the 40th anniversary of the first successful heart transplant, Sir Terence English told The Sunday Telegraph that his protege from that operation would try to replace a human kidney with a pig's this year. "If the result of xenotransplantation is satisfactory with porcine kidneys to humans, then it is likely that hearts would be used with good effects in humans within a few years," the 87-year-old said. "If it works with a kidney, it will work with a heart. That will transform the issue." The anatomy and physiology of a pig's heart is similar to that of a human's, so they are used as models for developing new treatments. Read more of this story at Slashdot.

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With Artemis, NASA at risk of repeating Apollo mistakes, scientist warns

Science - Posted On:2019-08-20 17:29:59 Source: arstechnica

In the nearly five months that have passed since Vice President Mike Pence directed NASA to return humans to the Moon by 2024, the space agency has made significant progress toward that goal.

During this time and under the leadership of administrator Jim Bridenstine, the agency has let contracts for both the elements of the Lunar Gateway, the small space station that will follow a distant orbit around the Moon. NASA has also begun to solicit ideas from industry about their designs for a three-stage lunar lander, upon which construction could begin sometime in 2020. The agency is also soliciting cargo deliveries to the Moon.

These are big steps, and getting a large agency like NASA moving quickly is difficult. For all of this, however, there are storm clouds on the horizon. Most obviously, there is the matter of paying for the Artemis Program to put humans on the Moon—the US House did not including funding for this effort in its preliminary fiscal year 2020 budget, and the Senate has yet to draft a budget. If there is not additional funding, NASA cannot give industry funds to go and do the work.

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NASA Mission To Jupiter Moon Europa Moves Step Closer To Launch

science - Posted On:2019-08-20 16:14:59 Source: slashdot

A NASA mission to explore the most tantalizing of Jupiter's 79 moons has been given the green light to proceed to the final stages of development. From a report: Europa -- which is slightly smaller than our own moon -- has long been considered a possible candidate in the hunt for alien life. Evidence suggests there is an ocean below the moon's thick, icy crust that might be tens of miles deep. Scientists believe this body of water could contain the right chemical cocktail for life and could even be home to some form of living organisms. Europa appears to have the hat-trick of conditions needed to kick off life: water, possibly chemistry, and energy in the form of tidal heating, a phenomenon arising from gravitational tugs acting on the moon. This could not only drive chemical reactions but also aid movement of chemical substances between rock, surface and ocean, possibly through hydrothermal vents. It is proposed that the NASA mission, named Europa Clipper, will make a number of close flybys -- it cannot orbit the moon as Jupiter's radiation belt would fry its electronics -- carrying cameras and intruments to measure the moon's magnetic field. The mission will look for subsurface lakes and provide data on the thickness of the moon's icy crust. The team also hope to confirm the presence of plumes of water, previously detected by NASA's Galileo spacecraft and the Hubble space telescope. If confirmed, it would mean scientists would not need to find a way of hacking through the moon's icy crust to explore the makeup of the ocean. Read more of this story at Slashdot.

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A Diet Based on Caloric Restriction Might Make You Live Longer. It'll Certainly Feel Like Longer.

science - Posted On:2019-08-20 15:00:00 Source: slashdot

A diet based on caloric restriction might make you live longer. It'll certainly feel like longer. Called Prolon, it's a five-day, $250 meal kit which arrives in a white cardboard container a little bigger than a shoebox. It involves eating about 800 calories each day. The idea is that temporarily shifts your body into a starvation state, prompting your cells to consume years of accumulated cellular garbage before unleashing a surge of restorative regeneration. The idea that starving yourself while still taking in crucial nutrients will let you live longer is not new. The practice, called caloric restriction, is the only proven way to extend life in a wide variety of creatures. There are currently trials underway to see if the diet might help protect human patients from the ravages of chemotherapy, too. However, experiments have found that doing it for extended periods is a problem, and probably not practical for most people. Research on the "fast-mimicking diet" is still limited, but the Prolon diet has been sold in 15 countries and tried by more than 150,000 people. Read how Adam Piore got on when he tried it out. Read more of this story at Slashdot.

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Super-Earth at a nearby star is a Mercury-like hunk of rock

Science - Posted On:2019-08-20 14:15:00 Source: arstechnica

The most common star in our galaxy is a red dwarf, smaller and dimmer than Earth. Because these small stars put out much less radiation, the region where planets could have liquid water on their surfaces is much closer to the star. In these exosolar systems, the habitable zone is typically closer to the star than Mercury is to our Sun.

That's a good match to our current technology, which is best at identifying planets close to their host stars. But it has raised questions about whether these close-in planets could actually be habitable, given that red dwarf stars are prone to violent outbursts. Now, researchers have taken a close look at a planet orbiting close to a red dwarf and have found that it looks like a bare rock, suggesting that its star may have stripped off any atmosphere that once existed.

Studying the atmosphere of an exoplanet typically involves observations of it creating a partial eclipse of its host star. In these cases, some of the starlight passes through the planet's atmosphere, allowing us to get a sense of its composition. If there's no sign of this sort of change, then we typically infer that the planet doesn't have an atmosphere.

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The ambitious Europa Clipper has cleared an important step toward flight

Science - Posted On:2019-08-20 09:44:56 Source: arstechnica

NASA has given its ambitious Europa Clipper mission a green light to proceed into final design and then into construction of the spacecraft. The multibillion-dollar mission remains on target for a launch in 2023 or 2025, the agency said.

Each of NASA's major programs must follow a complicated "lifecycle," in which different phases of development—from formulation of the project idea through launch—are gated by required approvals. This is part of NASA's effort to ensure that programs are developed to certain standards. In this case, the Europa mission has passed what is known as "Key Decision Point-C," the stage at which programs undergo a rigorous review, move from preliminary into final design, and then the construction of spacecraft components begins.

NASA has never sent a dedicated mission to a moon in the Solar System other than Earth's own Moon. But Jupiter's Europa satellite is special, with what scientists believe to be a vast ocean beneath its icy shell capable of harboring life. The large, capable Europa Clipper spacecraft is due to make more than 40 flybys of the moon to better characterize the ice, its thickness, and the ocean below.

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How SpaceX Plans To Move Starship From Cocoa Site To Kennedy Space Center

science - Posted On:2019-08-20 03:14:58 Source: slashdot

New submitter RhettLivingston writes: Real plans for the move of Starship Mk 2 from its current construction site in Cocoa to the Kennedy Space Center have finally emerged. A News 6 Orlando report identifies permit applications and observed preparations for the move,which will take a land and sea route. Barring some remarkably hasty road compaction and paving, the prototype will start its journey off-road, crossing a recently cleared path through vacant land to reach Grissom Parkway. It will then travel east in the westbound lanes of SR 528 for a short distance before loading to a barge in the Indian river via a makeshift dock. The rest of the route is relatively conventional, including offloading at KSC at the site previously used for delivery of the Space Shuttle's external fuel tanks. Given the recent construction of new facilities at the current construction site, it is likely that this will not be the last time this route is utilized. SpaceX declined to say how the company will transport the spacecraft or when the relocation will occur. SpaceX's "Mk2" orbital Starship prototype is designed to test out the technologies and basic design of the final Starship vehicle -- a giant passenger spacecraft that SpaceX is making to take people to the Moon and Mars. Read more of this story at Slashdot.

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Scientists Are 99 Percent Sure They Just Detected a Black Hole Eating a Neutron Star

science - Posted On:2019-08-19 23:44:58 Source: slashdot

An anonymous reader quotes a report from Motherboard: On Wednesday, a gravitational wave called S190814bv was detected by the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) and its Italian counterpart Virgo. Based on its known properties, scientists think there is a 99% probability that the source of the wave is a black hole that ate a neutron star. In contrast to black hole mergers, neutron star collisions do produce a lot of light. When a gravitational wave from a neutron star crash was detected in 2017, scientists were able to pinpoint bright emissions from the event -- called an optical counterpart -- in the days that followed the wave detection. This marked the dawn of a technique called "multi-messenger astronomy," in which scientists use multiple types of signals from space to examine astronomical objects. Ryan Foley, an astronomer at UC Santa Cruz, was part of the team that tracked down that first optical counterpart, a feat that has not yet been repeated. He and his colleagues are currently scanning the skies with telescopes, searching for any light that might have been radiated by the new suspected merger of a black hole and neutron star. If the team were to pick up light from the event within the coming weeks, they would be witnessing the fallout of a black hole spilling a neutron star's guts while devouring it. This would provide a rare glimpse of the exotic properties of these extreme astronomical objects and could shed light on everything from subatomic physics to the expansion rate of the universe. "We've never detected a neutron star and a black hole together," said Foley. "If it turns out to be right, then we've confirmed a new type of star system. It's that fundamental." He added: "If you learn about how neutron stars are built, that can tell you about how atoms are built. This is something that is fundamental to everything in our daily life works." Read more of this story at Slashdot.

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Neanderthals suffered from a veritable epidemic of swimmer’s ear

Science - Posted On:2019-08-19 18:14:59 Source: arstechnica

Swimmer's ear happens when constant exposure to cold water irritates tissues in the ear canal, causing bony growths to form. As its name implies, it commonly shows up in people who spend a lot of time in the water. But it also shows up in almost half of Neanderthal skulls from Eurasia, according to a recent study.

Washington University paleoanthropologist Erik Trinkaus and his colleagues studied fossils, digital scans, photographs, and other archaeologists' reports from 77 Neanderthals and Homo sapiens who lived in Europe and Asia during the Pleistocene. Based on this sampling of remains with preserved inner ear bones, a surprising number of Neanderthals were running around Pleistocene Eurasia with swimmer's ear.

You won't get swimmer's ear from a single cold-water surfing trip. It takes long-term exposure to cold water or cold, damp air for the irritation to actually reshape the bone. If you're looking at a skeleton, swimmer's ear is the kind of trait that can tell you something about a person's habits in life. Anthropologists still aren't exactly sure what swimmer's ear tells us about Neanderthals' lifestyle, but it may have something to do with genetics, hygiene, and a taste for shellfish.

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Why did so many Neanderthals end up with swimmer’s ear?

Science - Posted On:2019-08-19 17:15:00 Source: arstechnica

Swimmer's ear happens when constant exposure to cold water irritates tissues in the ear canal, causing bony growths to form. As its name implies, it commonly shows up in people who spend a lot of time in the water. But it also shows up in almost half of Neanderthal skulls from Eurasia, according to a recent study.

Washington University paleoanthropologist Erik Trinkaus and his colleagues studied fossils, digital scans, photographs, and other archaeologists' reports from 77 Neanderthals and Homo sapiens who lived in Europe and Asia during the Pleistocene. Based on this sampling of remains with preserved inner ear bones, a surprising number of Neanderthals were running around Pleistocene Eurasia with swimmer's ear.

You won't get swimmer's ear from a single cold-water surfing trip. It takes long-term exposure to cold water or cold, damp air for the irritation to actually reshape the bone. If you're looking at a skeleton, swimmer's ear is the kind of trait that can tell you something about a person's habits in life. Anthropologists still aren't exactly sure what swimmer's ear tells us about Neanderthals' lifestyle, but it may have something to do with genetics, hygiene, and a taste for shellfish.

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Newt Gingrich Trying To Sell Trump on a Cheap Moon Plan

science - Posted On:2019-08-19 16:59:59 Source: slashdot

WindBourne writes: Newt Gingrich and an eclectic band of NASA skeptics are trying to sell President Donald Trump on a reality show-style plan to jump-start the return of humans to the moon -- at a fraction of the space agency's estimated price tag. The proposal, whose other proponents range from an Air Force lieutenant general to the former publicist for pop stars Michael Jackson and Prince, includes a $2 billion sweepstakes pitting billionaires Elon Musk, Jeff Bezos and other space pioneers against each other to see who can establish and run the first lunar base, according to a summary of the plan shared with POLITICO. That's far less taxpayer money than NASA's anticipated lunar plan, which relies on traditional space contractors, such as Boeing and Lockheed Martin, and is projected to cost $50 billion or more. Backers of the novel approach have briefed administration officials serving on the National Space Council, several members of the group confirmed, though they declined to provide specifics of the internal conversations. Read more of this story at Slashdot.

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