Archive for the ‘science’ Category

Conditions like those inside Neptune cause diamond formation

August 27th, 2017

Enlarge / That lovely blue exterior could be hiding a heart of diamond. (credit: NASA)

Carbon, oxygen, and nitrogen are some of the easiest heavier elements to form through fusion. As a result, they’re common in our Solar System, typically found combined with hydrogen to make ammonia, water, and methane. In the gas and ice giants of the outer Solar System, however, these chemicals are placed under extreme pressures, where chemistry starts to get a bit weird. Do these chemicals survive the crushing interiors of these planets?

One intriguing idea is that methane doesn’t survive. As pressure and temperature increase, methane should start condensing into more complex hydrocarbons. Then, as pressures increase further, calculations indicate the hydrogen and carbon should separate out, leaving pure carbon to sink to the depths of these planets. As a result, it’s been hypothesized that, close to their core, planets like Neptune and Uranus have a layer of pure diamond.

While some evidence supporting this theory has surfaced over the years, it’s been hard to precisely replicate the temperatures and pressures found inside the planets. Now, new work done at the SLAC X-ray laser facility supports the idea that these planets are full of diamonds. But the work indicates the diamonds only form at greater depths than we’d previously thought.

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Posted in astronomy, chemistry, diamonds, laser, materials science, planetary science, science | Comments (0)

Hearing voices? You might just be primed for it

August 27th, 2017

Enlarge (credit: flickr user: David Wood)

Hallucinations tend to be associated with psychosis, but the reality is more complicated than that. Some people who hear voices don’t suffer from other mental health problems, and the voices they hear aren’t distressing. These “non-clinical voice-hearers” provide an important opportunity to understand hallucinations without the complications of mental illness or medication.

A preliminary study published this week in the journal Brain reports that non-clinical voice-hearers were more likely to detect language in a recording of distorted speech. Voice-hearers also showed some different patterns in brain activation as they listened. The results could help to explain why some people are more likely to hear voices, as well as help to direct future research on the topic.

Hearing meaning in noise

Ben Alderson-Day, the lead author on the paper, is a psychologist at Durham University whose research focuses on auditory hallucinations. To investigate differences of perception in voice-hearers, Alderson-Day and his colleagues used sine-wave speech, which strips out some of the most vital acoustic properties of speech and leaves something that sounds kind of like a series of clicks and whistles. It’s possible to understand it—once you already know what it says, or once you’ve listened to quite a bit of sine-wave speech. (Listen to some examples here.)

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Posted in Behavioral science, Biology, Neuroscience, science | Comments (0)

The Babylonians discovered a strange form of trigonometry

August 25th, 2017

Enlarge / The 3,700-year-old Babylonian tablet known as Plympton 322 turned out to be a trig table, expressed in ratios of the lengths of the sides of the triangles, rather than angles. (credit: UNSW/Andrew Kelly)

The Babylonian civilization was at its peak roughly 4,000 years ago, with architecturally advanced cities throughout the region known today as Iraq. Babylonians were especially brilliant with math, and they invented the idea of zero as well as the base 60 number system we still use today to describe time (where there are 60 minutes in an hour). Now it appears that the Babylonians invented trigonometry, almost 1,000 years before Pythagoras was born.

University of New South Wales mathematicians Daniel Mansfield and Norman Wildberger discovered this after a breakthrough analysis of an ancient cuneiform tablet, written between 1822-1762 BCE in the Babylonian city of Larsa. Long a mystery, the tablet shows three columns of numbers. Describing their work in Historica Mathematica, the researchers call the tablet “a trigonometric table of a completely unfamiliar kind and… ahead of its time by thousands of years.”

Mathematician Daniel Mansfield explains the Babylonian system for doing trigonometry.

What made it hard for scholars to figure this out before was the complete unfamiliarity of the Babylonians’ trigonometric system. Today we use the Greek system, which describes triangles using angles that are derived from putting the triangle inside a circle. The Babylonians, however, used ratios of the line lengths of the triangle to figure out its shape. They did it by putting the triangle inside a rectangle and completely circumvented the ideas of sin, cos, and tan, which are key to trigonometry today.

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The Babylonians discovered a strange form of trigonometry

August 25th, 2017

Enlarge / The 3,700-year-old Babylonian tablet known as Plympton 322 turned out to be a trig table, expressed in ratios of the lengths of the sides of the triangles, rather than angles. (credit: UNSW/Andrew Kelly)

The Babylonian civilization was at its peak roughly 4,000 years ago, with architecturally advanced cities throughout the region known today as Iraq. Babylonians were especially brilliant with math, and they invented the idea of zero as well as the base 60 number system we still use today to describe time (where there are 60 minutes in an hour). Now it appears that the Babylonians invented trigonometry, almost 1,000 years before Pythagoras was born.

University of New South Wales mathematicians Daniel Mansfield and Norman Wildberger discovered this after a breakthrough analysis of an ancient cuneiform tablet, written between 1822-1762 BCE in the Babylonian city of Larsa. Long a mystery, the tablet shows three columns of numbers. Describing their work in Historica Mathematica, the researchers call the tablet “a trigonometric table of a completely unfamiliar kind and… ahead of its time by thousands of years.”

Mathematician Daniel Mansfield explains the Babylonian system for doing trigonometry.

What made it hard for scholars to figure this out before was the complete unfamiliarity of the Babylonians’ trigonometric system. Today we use the Greek system, which describes triangles using angles that are derived from putting the triangle inside a circle. The Babylonians, however, used ratios of the line lengths of the triangle to figure out its shape. They did it by putting the triangle inside a rectangle and completely circumvented the ideas of sin, cos, and tan, which are key to trigonometry today.

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The end-Cretaceous mass extinction was rather unpleasant

August 25th, 2017

(credit: Don Davis/NASA)

There are a few hellish episodes in Earth’s unfathomably long history that make even Hollywood’s most bombastic disaster movie look like a sunny picnic. The end-Cretaceous extinction is the most well-known, since it wiped out the dinosaurs (minus the birds, of course) and opened the door for the mammalian revolution—which most human beings regard as generally a good thing.

Though the story is probably familiar, there are still significant questions about exactly what happened during that cataclysm. Many species were seemingly in trouble before that colossal meteoroid crashed into the coastal Yucatan, perhaps partly because of a long-lived series of massive volcanic eruptions in what is now India. This has led some to question whether the impact was as deadly as it’s made out to be. But we’ve also filled in some details of just how the meteoroid impact would mess up the Earth, and these include mind-blowing tsunamis, rampant wildfires, and see-sawing climate effects. So how lethal was the impact?

A team led by Charles Bardeen at the National Center for Atmospheric Research employed a climate model to investigate one major aspect of this story. In many places around the world, there is a thin geologic layer that marks the time of the impact event. It contains soot that apparently blanketed the planet after wildfires kicked it up into the air. (These wildfires would be triggered globally by the heat of debris reentering the atmosphere.) Was there enough soot to black out the Sun?

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Posted in climate model, k-pg mass extinction, k-t mass extinction, mass extinctions, science | Comments (0)

Carbon nanotube “yarn” generates electricity when stretched

August 24th, 2017

Enlarge / When the yarn is stretched, the LED lights up. (credit: AAAS/Science)

Spare energy is all around us, from the pressure exerted by every footfall to the heat given off by heavy machinery. In some cases, like regenerative braking in cars, it’s easy to harvest, and the equipment needed to do so is simple and economic. In many others, however, we’re not there yet.

It’s not that we don’t have the materials to do so. Piezoelectric generators can harvest stresses and strains, while triboelectric generators can harvest friction, to give two examples. The problem is that their efficiency is low and the cost of the materials is currently high, making them bad fits for any applications.

But a study in today’s issue of Science describes a “yarn” made of carbon nanotubes that can produce electricity when stretched. Its developers go on to demonstrate its use in everything from wearable fabrics to ocean-based wave power generators. Given that the raw material for carbon nanotubes is cheap and there are lots of people trying to bring their price down, this seems to have the potential to find some economic applications.

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Posted in carbon nanotubes, Energy, materials science, science | Comments (0)

Confederate sub’s weapon killed its own crew, researchers find

August 24th, 2017

The Confederate submarine CSS H. L. Hunley bears the distinction of being the first submarine to ever sink an enemy ship. But the Hunley, a work of state-of-the-art engineering for its time, never returned from that mission on February 17, 1864. Instead, after exploding a “torpedo” below the waterline of the Union sloop-of-war USS Housatonic in Charleston Harbor, the sub was lost at sea. 

Just how the sub was lost had been a mystery for over a century. The Hunley would not be found again until it was discovered on the floor of Charleston Bay in 1995. The sub was recovered five years later—largely intact, with the remains of its crew all at their stations. Based on the findings of Clemson University archaeologists who examined and restored the sub, it did not appear any attempt was made by the crew to escape.

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Posted in civil war, CSS Hunley, science, Submarines, Tech | Comments (0)

SpaceX goes for a dozen today, and to surpass Russia in launches

August 24th, 2017

Enlarge / The static fire test of the Falcon 9 rocket launch of Formosat-5 is completed last week. (credit: SpaceX)

SpaceX is not a country, but if it were the company would be tied with Russia for the most orbital launches of 2017. Both SpaceX and Russia have launched 11 successful orbital missions this year, followed by China with eight and European firms at six. SpaceX’s US-based rival, United Launch Alliance, has flown five rockets.

Today, SpaceX goes for a dozen launches this year, with the launch attempt of the Formosat-5 from Space Launch Complex 4 East at Vandenberg Air Force Base in California. The 42-minute launch window opens at 2:51pm ET. After the first stage sends the satellite on its way to low Earth orbit, the booster will attempt a landing on a drone ship in the Pacific Ocean. The webcast below should begin 15 to 20 minutes before the window opens.

From 2013 through 2016, the company averaged only six successful launches per calendar year. SpaceX also had a couple of high-profile accidents, including a second-stage failure during a launch in 2015, and a launch pad accident in 2016. With Thursday’s launch attempt, SpaceX will try to continue the momentum it has built throughout 2017.

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Rick Perry’s “baseload” study released, offers a lifeline to coal, nuclear

August 24th, 2017

Enlarge / DUNKIRK, NEW YORK, UNITED STATES – 2016/10/09: A NRG owned coal fired energy facility that plans to convert to a natural gas facility. (Photo by John Greim/LightRocket via Getty Images) (credit: Getty Images)

The US Department of Energy (DOE) released a report late Wednesday night recommending that power markets revise how they value coal and nuclear power. The report also admits that low natural gas prices are a primary cause of recent coal plant closures.

The report has been controversial since its inception. In mid-April, Energy Secretary Rick Perry directed his team to study grid reliability and security for 60 days. Although the memo never mentioned renewables, it implicated “certain policies” that apparently unfairly threatened coal-burning plants.

That led critics to wonder whether renewable energy—critical for the mitigation of climate change—would get a fair shake in Perry’s study. Grid operators have been able to put a fair amount of renewable energy on the grid without reliability suffering, but the tone of Perry’s memo suggested that a conclusion contradicting that fact had been predetermined.

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Posted in baseload study, coal, Department of Energy, grid, renewable, Rick Perry, science | Comments (0)

Analysis of 187 documents concludes Exxon “misled the public” on climate change

August 24th, 2017

Enlarge / Oil processing towers and gas processing infrastructure stand at the Exxon Mobil Corp. (credit: Dimas Ardian/Bloomberg via Getty Images)

A review of 187 ExxonMobil documents, published by two Harvard researchers on Wednesday, has found that the company ”misled the public” on climate change.

The documents included internal papers published by journalists at InsideClimate News as well as 50 “peer-reviewed articles on climate research and related policy analysis” written by ExxonMobil researchers. The oil and gas company made the internal papers public and challenged anyone to “read all of these documents and make up your own mind,” accusing journalists of cherry-picking data.

Geoffrey Supran and Naomi Oreskes, from Harvard’s Department of the History of Science, took up that challenge, comparing the information in the documents cited by ExxonMobil against the information conveyed in the publicly-available advertorial columns published by the company on anthropogenic (or human-caused) climate change in the New York Times. They found that “83 percent of peer-reviewed papers and 80 percent of internal documents acknowledge that climate change is real and human-caused, yet only 12 percent of advertorials do so, with 81 percent instead expressing doubt.”

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Posted in Biz & IT, climate change, exxon, science | Comments (0)