Astronomy
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The Outer Solar System Keeps Getting Weirder
Several newly discovered objects on the outskirts of the solar system suggest that something strange is afoot. While some scientists point to the odd behavior of the newfound residents as further proof for the existence of the hypothetical Planet Nine (a yet-unseen superEarth proposed to inhabit the outskirts) not everyone is convinced.
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The newest of these objects is L91, an icy world that can travel as far from the sun as 1430 astronomical units (AU), or 1,430 times the Earth-sun distance, one of the longest known orbital periods. L91 never draws closer to the sun than 50 AUs, farther away than even Pluto. And L91’s distant path is shifting.
“It’s orbit is changing in quite a remarkable way,” astrophysicist Michele Bannister told scientists last week at the American Astronomical Society’s Division for Planetary Sciences in Pasadena, California. Bannister, an astrophysicist at Queen’s University Belfast, identified minute changes in the object’s orbit that could come from the passing gravity of other stars or interactions with the hypothetical Planet Nine. Simulations by the team suggest that the tiny tugs are more likely to come from beyond the solar system, whether distant stars or galactic winds.
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‘Something is happening’
L91 isn’t the only new object in the sky. Another team of astronomers reported a handful of smaller icy bodies traveling beyond Neptune. Similarities in the orbits of objects like these led to the proposal of Planet Nine.
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One of these objects, 2014 FE72, is the first known to come from the Oort Cloud, the icy shell around the solar system where comets are born. With an orbit that takes it out more than 3,000 AUs, it may also suffer from the influence of passing stars or the gravity of Planet Nine
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How Many Planets Are There In The Galaxy?
On a clear night, and when light pollution isn’t a serious factor, looking up at the sky is a breathtaking experience. On occasions like these, it is easy to be blown away by the sheer number of stars out there. But of course, what we can see on any given night is merely a fraction of the number of stars that actually exist within our Galaxy.
What is even more astounding is the notion that the majority of these stars have their own system of planets. For some time, astronomers have believed this to be the case, and ongoing research appears to confirm it. And this naturally raises the question, just how many planets are out there? In our galaxy alone, surely, there must be billions!
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Number of Stars:
To be clear, the actual number of stars in the Milky Way is subject to some dispute. Essentially, astronomers are forced to make estimates due to the fact that we cannot view the Milky Way from the outside. And given that the Milky Way is in the shape of a barred, spiral disc, it is difficult for us to see from one side to the other – thanks to light interference from its many stars.
As a result, estimates of how many stars there are come down to calculations of our galaxy’s mass, and estimates of how much of that mass is made up of stars. Based on these calculations, scientists estimate that the Milky Way contains between 100 and 400 billion stars (though some think there could be as many as a trillion).
Doing the math, we can then say that the Milky Way galaxy has – on average – between 800 billion and 3.2 trillion planets, with some estimates placing that number as high a 8 trillion! However, in order to determine just how many of them are habitable, we need to consider the number of exoplanets discovered so far for the sake of a sample analysis.
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Biology
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The Buzz About Edible Bugs: Can They Replace Beef?
Edible bugs might sound unappetizing to many Westerners, but they've long been included in traditional diets in other regions of the world, which are now home to more than 2 billion people, according a report by the U.N. Food and Agriculture Organization. The report also notes that about 1,900 insect species have been documented as a food source globally. That they're a source of protein is well established, but if the world is to turn to bugs to replace meat, the critters will need to offer more than protein. Iron is a particularly important nutrient that is often missing in non-meat diets, causing iron-deficiency anemia, which can lead to lower cognition, immunity, poor pregnancy outcomes and other problems. In light of these concerns, Yemisi Latunde-Dada and colleagues wanted to find out whether commonly eaten insects could contribute to a well-rounded meal.
The researchers analyzed grasshoppers, crickets, mealworms and buffalo worms for their mineral contents and estimated how much of each nutrient would likely get absorbed if eaten, using a lab model of human digestion. The insects had varying levels of iron, calcium, copper, magnesium, manganese and zinc. Crickets, for example, had higher levels of iron than the other insects did. And minerals including calcium, copper and zinc from grasshoppers, crickets and mealworms are more readily available for absorption than the same minerals from beef. The results therefore support the idea that eating bugs could potentially help meet the nutritional needs of the world's growing population, the researchers say.
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Climate Change Shifts How Long Ants Hang On To Coveted Real Estate
Heating small patches of forest shows how climate warming might change the winner-loser dynamics as species struggle for control of prize territories. And such shifts in control could have wide-ranging effects on ecosystems.
The species are cavity-nesting ants in eastern North America. Normally, communities of these ant species go through frequent turnovers in control of nest sites. But as researchers heated enclosures to mimic increasingly severe climate warming, the control started shifting toward a few persistent winners. Several heat-loving species tended to stay in nests unusually long, instead of being replaced in faster ant upheavals, says Sarah Diamond of Case Western Reserve University in Cleveland.
That’s worrisome not only for the new perpetual losers among ants but for the ecosystem as a whole, she and her colleagues argue October 26 in Science Advances. Ants have an outsized effect on ecosystems. They churn up soil, shape the flow of nutrients and disperse seeds to new homes. Ant species that can’t compete in a warmer climate may blink out of the community array, with consequences for other species they affect.
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Warmth gave an edge to a few heat-tolerant species such as Temnothorax longispinosus in the forest in Massachusetts. This tiny ant can build colonies inside an acorn and is a known target for attacks by slavemaker ants that invade nests instead of establishing their own. With increased warming, however, it and a few other heat-loving ants tended to hold their nests longer.
Those longer stints destabilize the ant community with its usual faster pace of turnovers of nests, which typically gives more species a chance at decent shelter and better luck in surviving in the community. What’s more, the analysis showed that the more a plot was heated, the more time the ants would need after some disturbance to return to the equilibrium of their usual affairs.
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Chemistry
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Lead Isotopes Track Roman Empire’s Water Supplies
Measuring the isotopic composition of lead in layers of sediment in Naples has allowed researchers to track how Roman settlements and the network of pipes that supplied them with water changed throughout history.
It is known that the Romans used lead pipes to transport water – back in 2014 a team led by Hugo Delile at the University of Lyon in France used isotopic analysis of lead in the sediment of the river Tiber to investigate whether they could have been poisoned by lead leaching into drinking water. This time the team measured lead isotopes in excavated sediments from the ancient harbour in Naples. By analysing sediment from different points in history, the team were able to explore the effect of the eruption of Vesuvius in AD79 had on the area’s water supplies.
They found a dramatic shift in lead isotope composition of a sediment layer that postdates the eruption, compared with samples from older sediments, marking a switch to different pipes. This suggests the eruption damaged the existing network, and that rebuilding it took about 15 years. They were also able to track subsequent ‘upgrades’ to the pipe system, which continued to expand until the empire began to decline in the fifth century. The team suggest lead isotope analysis could be a useful tool for studying changing settlement patterns in the region during the fifth and sixth centuries.
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Fragranced Products: Risks For People And Profits?
A University of Melbourne researcher has found that over one-third of Americans report health problems -- from asthma attacks to migraine headaches -- when exposed to common fragranced consumer products such as air fresheners, cleaning supplies, laundry products, scented candles, cologne, and personal care products.
The study also found that fragranced products may affect profits, with more than 20% of respondents entering a business, but leaving as quickly as possible if they smell air fresheners or some fragranced product. More than twice as many customers would choose hotels and airplanes without fragranced air than with fragranced air.
In the workplace, over 15% of the population lost workdays or a job due to fragranced product exposure. Over 50% of Americans surveyed would prefer fragrance-free workplaces. And over 50% would prefer that health care facilities and professionals were fragrance-free.
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[The research was conducted by Professor Anne Steinemann, from the University of Melbourne School of Engineering] found that fragranced products -- even those called green, natural, and organic -- emitted hazardous air pollutants. However, fragranced consumer products sold in the US (and other countries) are not required to list all ingredients on their labels or material safety data sheets. Nearly two-thirds of the population surveyed were not aware of this lack of disclosure, and would not continue to use a fragranced product if they knew it emitted hazardous air pollutants.
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Ecology
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2016 Antarctic Ozone Hole Attains Moderate Size, Consistent With Scientific Expectations
The hole in Earth’s ozone layer that forms over Antarctica each September grew to about 8.9 million square miles in 2016 before starting to recover, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) who monitor the annual phenomenon.
“This year we saw an ozone hole that was just below average size,” said Paul A. Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center in Greenbelt, Maryland. “What we’re seeing is consistent with our expectation and our understanding of ozone depletion chemistry and stratospheric weather.”
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In addition to the area of the ozone hole, scientists also measure the concentration of ozone that would be found in a column of atmosphere extending from the surface to the edge of space. The most common unit for measuring ozone concentration is the Dobson Unit, which is the number of ozone molecules that would be required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 32 degrees Fahrenheit at an atmospheric pressure equivalent to Earth’s surface.
This year, the ozone layer reached a minimum concentration of 114 Dobson Units on Oct. 1, 2016. In 2015, the ozone layer reached a minimum of 101 Dobson units on October 4. During the 1960s, before the Antarctic ozone hole occurred, average ozone concentrations above the South Pole ranged from 260 to 320 Dobson units.
This year’s Antarctic ozone hole is similar to the 2013 hole which reached 9.3 million square miles. Although warmer than average stratospheric weather conditions reduce ozone depletion, the current ozone hole area is large compared to the 1980s, when the depletion of the ozone layer above Antarctica was first detected. This is because levels of ozone-depleting substances remain high enough to produce significant ozone loss.
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See How Arctic Sea Ice Is Losing Its Bulwark Against Warming Summers
Arctic sea ice, the vast sheath of frozen seawater floating on the Arctic Ocean and its neighboring seas, has been hit with a double whammy over the past decades: as its extent shrunk, the oldest and thickest ice has either thinned or melted away, leaving the sea ice cap more vulnerable to the warming ocean and atmosphere.
“What we’ve seen over the years is that the older ice is disappearing,” said Walt Meier, a sea ice researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This older, thicker ice is like the bulwark of sea ice: a warm summer will melt all the young, thin ice away but it can’t completely get rid of the older ice. But this older ice is becoming weaker because there’s less of it and the remaining old ice is more broken up and thinner, so that bulwark is not as good as it used to be.”
Direct measurements of sea ice thickness are sporadic and incomplete across the Arctic, so scientists have developed estimates of sea ice age and tracked their evolution from 1984 to the present. Now, a new NASA visualization of the age of Arctic sea ice shows how sea ice has been growing and shrinking, spinning, melting in place and drifting out of the Arctic for the past three decades.
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Physics
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Electrical Currents Can Be Now Be Switched On And Off At The Smallest Conceivable Scale
Robert Wolkow is no stranger to mastering the ultra-small and the ultra-fast. A pioneer in atomic-scale science with a Guinness World Record to boot (for a needle with a single atom at the point), Wolkow's team, together with collaborators at the Max Plank Institute in Hamburg, have just released findings that detail how to create atomic switches for electricity, many times smaller than what is currently used.
What does it all mean? With applications for practical systems like silicon semi-conductor electronics, it means smaller, more efficient, more energy-conserving computers, as just one example of the technology revolution that is unfolding right before our very eyes (if you can squint that hard).
"This is the first time anyone's seen a switching of a single-atom channel," explains Wolkow, a physics professor at the University of Alberta and the Principal Research Officer at Canada's National Institute for Nanotechnology. "You've heard of a transistor—a switch for electricity—well, our switches are almost a hundred times smaller than the smallest on the market today."
Today's tiniest transistors operate at the 14 nanometer level, which still represents thousands of atoms. Wolkow's and his team at the University of Alberta, NINT, and his spinoff QSi, have worked the technology down to just a few atoms. Since computers are simply a composition of many on/off switches, the findings point the way not only to ultra-efficient general purpose computing but also to a new path to quantum computing.
"We're using this technology to make ultra-green, energy-conserving general purpose computers but also to further the development of quantum computers. We are building the most energy conserving electronics ever, consuming about a thousand times less power than today's electronics."
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