Xenophilia (True Strange Stuff)

Blog of the real Xenophilius Lovegood, a slightly mad scientist

Archive for October 17th, 2011

Dark matter gets even more mysterious

Posted by Anonymous on October 17, 2011

http://www.cfa.harvard.edu/image_archive/2011/98/lores.jpgLike all galaxies, our Milky Way is home to a strange substance called dark matter. Dark matter is invisible, betraying its presence only through its gravitational pull. Without dark matter holding them together, our galaxy’s speedy stars would fly off in all directions. The nature of dark matter is a mystery — a mystery that a new study has only deepened.”After completing this study, we know less about dark matter than we did before,” said lead author Matt Walker, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics.

The standard cosmological model describes a universe dominated by dark energy and dark matter. Most astronomers assume that dark matter consists of “cold” i.e. slow-moving exotic particles that clump together gravitationally. Over time these dark matter clumps grow and attract normal matter, forming the galaxies we see today.

Cosmologists use powerful computers to simulate this process. Their simulations show that dark matter should be densely packed in the centers of galaxies. Instead, new measurements of two dwarf galaxies show that they contain a smooth distribution of dark matter. This suggests that the standard cosmological model may be wrong.”Our measurements contradict a basic prediction about the structure of cold dark matter in dwarf galaxies. Unless or until theorists can modify that prediction, cold dark matter is inconsistent with our observational data,” Walker stated.Dwarf galaxies are composed of up to 99 percent dark matter and only one percent normal matter like stars. This disparity makes dwarf galaxies ideal targets for astronomers seeking to understand dark matter.Walker and his co-author Jorge Peñarrubia University of Cambridge, UK analyzed the dark matter distribution in two Milky Way neighbors: the Fornax and Sculptor dwarf galaxies.

These galaxies hold one million to 10 million stars, compared to about 400 billion in our galaxy. The team measured the locations, speeds and basic chemical compositions of 1500 to 2500 stars.”Stars in a dwarf galaxy swarm like bees in a beehive instead of moving in nice, circular orbits like a spiral galaxy,” explained Peñarrubia. “That makes it much more challenging to determine the distribution of dark matter.”

Their data showed that in both cases, the dark matter is distributed uniformly over a relatively large region, several hundred light-years across. This contradicts the prediction that the density of dark matter should increase sharply toward the centers of these galaxies.”If a dwarf galaxy were a peach, the standard cosmological model says we should find a dark matter ‘pit’ at the center. Instead, the first two dwarf galaxies we studied are like pitless peaches,” said Peñarrubia.

Some have suggested that interactions between normal and dark matter could spread out the dark matter, but current simulations don’t indicate that this happens in dwarf galaxies. The new measurements imply that either normal matter affects dark matter more than expected, or dark matter isn’t “cold.” The team hopes to determine which is true by studying more dwarf galaxies, particularly galaxies with an even higher percentage of dark matter.

via CfA Press Room.

Posted in Physics, Space | Leave a Comment »

When will the 7 billionth human be born?

Posted by Anonymous on October 17, 2011

<img class="alignleft" title="Room for a small one, but for how much longer?(Image: Keystone/ZUMA/Rex Features)” src=”http://www.newscientist.com/data/images/ns/cms/mg21228344.500/mg21228344.500-1_300.jpg&#8221; alt=”Room for a small one, but for how much longer?(Image: Keystone/ZUMA/Rex Features)” />ON 31 October, a newborn baby somewhere in the world will become the 7 billionth member of the human race. Or so says the UN – alternatively, this date could be at least a year too early.

Behind the UN’s patina of certainty may lie outdated and unreliable census data. The suspicion is that millions of births and deaths have not been counted and there is huge uncertainty about the rate at which women are giving birth.

The precise “day of 7 billion” may not matter much. But the inaccuracies make it harder to answer a more important question: is human population set to peak within the next few decades or will it carry on growing beyond that?

Wolfgang Lutz of the Vienna Institute of Demography says the UN is “under political pressure to disregard uncertainty and name a date” for 7 billion. But he and colleague Sergei Scherbov estimate that the world probably won’t reach 7 billion until early in 2013, though it could be as late as 2020. …

via When will the 7 billionth human be born? – environment – 14 October 2011 – New Scientist.

Posted in Earth, Survival | Leave a Comment »

Was ‘first photographed UFO’ a comet that nearly hit the earth in 1883?

Posted by Anonymous on October 17, 2011

Killer comet? Mexican scientists believe this photograph taken in 1883 shows a comet that came close to hitting the earthMexican astronomer José Banilla took the image, which appears to show something passing in front of the sun, on August 12 1883.

When it was released publicly in 1886 in the magazine L’Astronomie it was dubbed the first photo of a UFO – a series of 447 objects that looked ‘misty’ and ‘left behind a similar misty trace.’

A new study by the Univeridad Nacional Autónoma de México now suggests that it was a comet in the process of breaking up.

‘Our working hypothesis is that what Bonilla observed in 1883 was a highly fragmented comet, in an approach almost flush to the Earth’s surface,’ writes Hector Javier Durand Manterola, the lead author of the report.

‘Using the results reported by Bonilla, we can estimate the distance at which the objects approach to the Earth’s surface.

‘According to our calculations, the distance at which the objects passed over was between 538 km and 8,062 km, – and the width of the objects was between 46 m and 795m’

The mass of the original comet could have been up to eight times the mass of Halley’s comet.

If the photograph did show a comet in such close proximity to the Earth, it should have resulted in a meteor shower. Bonilla’s photograph was taken just before the annual Perseid meteor shower (pictured) – but 1883’s shower was no brighter than usual …

Using the time that it took the object to cross the sun combined with the location of Bonilla’s observatory, the report calculated that the object would be at most 8,000km away, and possibly much less.

‘The only bodies in the Solar System which are surrounded by a bright mistiness are the comets, so it is appropriate to suppose that the objects seen by Bonilla were small comets,’ said the scientists.

And as well as being shockingly close to earth, the scientists believe that the comet could have had the same mass as the object that wiped out the dinosaurs – eight times the mass of Halley’s comet. …

via Was ‘first photographed UFO’ a comet that nearly hit the earth in 1883? | Mail Online.

Posted in Space, UFOs | Leave a Comment »

Sleights of hand, sleights of mind

Posted by Anonymous on October 17, 2011

… “In principle, neuroscience and magic have little in common,” says Susana Martinez-Conde, director of the Visual Neuroscience Laboratory at the Barrow Neurological Institute in Phoenix, Arizona. “In fact, they are hugely complementary and magicians have a lot to offer us. They can manipulate the attention and consciousness of spectators so much better than we do in the lab.” A few years ago, Martinez-Conde and her husband Stephen Macknik decided to investigate exactly how magicians fool the brain so adeptly. In doing so, they founded the exciting new discipline they refer to as ‘neuromagic,’ which aims to “pop the hood on your brain as you are suckered in by sleights of hand.” …

Magicians have a repertoire of perhaps several dozen techniques which they use to deceive spectators and enhance perception of their tricks. One of these is ‘misdirection,’ which exploits inattentional blindness and change blindness, two phenomena that psychologists have studied intensively in recent years.

Studies of inattentional blindness show that focused attention can make us oblivious to sights that would otherwise be glaringly obvious, while studies of change blindness show that dramatic changes in a scene can go unnoticed if they occur during a brief interruption, even when we look directly at the scene.

Magicians take advantage of this to manipulate their spectators’ attentional spotlight. They know, for example, that the eyes give off important social cues, and that people have a natural impulse to pay attention to the objects that others are attending to. They exploit this ‘joint attention’ by using their eye movements to divert the audience’s attention away from the ‘method’ – the secret action behind the trick – and towards the magical effect.

They also know that the sudden appearance of a new and unusual object will immediately draw the audience’s attention. Hence, producing a flying dove gives them an opportunity to perform other hidden manoeuvres.

These cognitive illusions are used together with optical illusions that exploit the properties of light; visual illusions that exploit how the brain interprets images; memory illusions that exploit the reconstructive nature of our recollections; special effects such as explosions; and various gimmicks, including secret devices and mechanical artifacts. …

“Instead of isolating the specific variables and using one effect, magicians lump everything together, putting illusions on top of illusions,” says Martinez-Conde. The magic show is a form of ‘mental jujitsu’ that bombards the senses, overloading the brain with multiple tasks that cannot be processed simultaneously. “It’s a super-stimulus and we really are defenceless. It’s virtually impossible for spectators to penetrate these layers and get at the method of the trick.” …

Read the rest here: Sleights of hand, sleights of mind | Mo Costandi | Neurophilosophy blog | Science | guardian.co.uk.

Posted in Mind | Leave a Comment »

Oldest artist’s workshop in the world discovered

Posted by Anonymous on October 17, 2011

<img class="alignleft" title="Prehistoric paint pot (Image: Science/AAAS)” src=”http://www.newscientist.com/data/images/ns/cms/dn21046/dn21046-2_300.jpg&#8221; alt=”Prehistoric paint pot (Image: Science/AAAS)” />Prehistoric paint pot (Image: Science/AAAS)

Grind up some ochre, melt some bone-marrow fat, mix the lot with a splash of urine – and paint your body with it. It sounds like an avant-garde performance but it may have happened some 100,000 years ago, in the oldest known artist’s workshop – a cave in South Africa. The complex pigments that humans mixed there, and the tools they used to do it, are revealing just how cunning some of our earliest ancestors were.

The purpose of the paint is unknown, but the researchers who discovered the workshop at the Blombos cave on South Africa’s southern coast (see photo) think it was most likely applied to skin for decoration or ritual, or perhaps even as an insect repellent.

Inside the cave, Christopher Henshilwood of the University of the Witwatersrand in Johannesburg, South Africa, and his team found tools and two abalone shells (see photos) that were used for mixing and storing the paint. Alongside one of them were quartzite stones used to hammer and grind ochre to a powder, and animal bones used to stir the powder with other materials, which included bone, charcoal, quartz fragments and other stones.

They also discovered evidence that some of the bones had been heated, probably to melt fat from the marrow that would have then bound the minerals. “There were also quartzite fragments to cement it, mixed with a liquid, probably urine,” says Henshilwood.

The whole lot survived together in one place because after the cave was abandoned it filled with wind-blown sand, sealing the cache as a “time capsule”, says Henshilwood. …

via Oldest artist’s workshop in the world discovered – life – 13 October 2011 – New Scientist.

Posted in Archaeology, Art | Leave a Comment »

America’s child death shame: Child dies every 5 hrs

Posted by Anonymous on October 17, 2011

Every five hours a child dies from abuse or neglect in the US.

The latest government figures show an estimated 1,770 children were killed as a result of maltreatment in 2009.

A recent congressional report concludes the real number could be nearer 2,500.

In fact, America has the worst child abuse record in the industrialised world. Why?

… In Texas, one of the states with the worst child abuse records, the Dallas Children’s Medical Center is dealing with a rising number of abused children and increasing levels of violence. Meanwhile, the Houston Center is expanding its services to deal with the rising problem of child sex abuse.Just like Emma Thompson, hundreds more children fall through the cracks of the child protection system. h the cracks of the child protection system.

Some blame overworked investigators and inefficient management, while others say it’s the federal government’s drive to keep families together that is the problem.

But child protection officials in Texas, a state with one of the highest total number of child deaths from abuse and neglect in the US, say such cases are complicated and difficult to assess – especially when a child’s guardians are hiding what is really going on.In Washington, politicians are beginning to recognise what some now describe as a “national crisis”.

A congressional hearing in July heard from experts in the field about what can be done to prevent deaths from child abuse. A national commission is being set up to coordinate a country-wide response.

Many believe home visits to new parents by qualified health professionals, preparing them for the difficulties of family life, are key to that strategy. …

via BBC News – America’s child death shame.

I’ve wondered in the past if G.W. Bush’s empathy lacking mind of  resulted from his being abused as a child. What is it about Texas? Most executions, most child abuse deaths, most ex’s living there…

Posted in Crime | 4 Comments »

‘Criminal’ penguin caught on film

Posted by Anonymous on October 17, 2011

http://news.bbcimg.co.uk/media/images/56052000/jpg/_56052095_penguinthief.jpgA “criminal” stone-stealing Adelie penguin has been captured on camera by a BBC film crew.

The team, filming for the documentary Frozen Planet, spent four months with the penguin colony on Ross Island, Antarctica.

The footage they captured shows a male penguin stealing stones from its neighbour’s nest.

The birds build their stone nests to elevate and protect their eggs from run-off when the Antarctic ice melts.

Males with the best nests are more likely to attract a mate, so, in a colony of half a million penguins, the best stones are highly prized.

Jeff Wilson, director of the shoot, explained that he and the cameraman, Mark Smith, knew that the birds occasionally stole stones from one another. But he said it was a challenge to capture the moment in the chaos of a busy penguin colony.

“The’re only a foot and a half tall, so you have to get down to penguin level,” he told BBC Nature.

“So poor old Mark, was crawling around and there were adelies constantly looking right down the barrel of his lens.

“It’s appealing at first, but when it happens for the hundredth time as you’re trying to get the shots you need, you start to lose patience.”

He added that the colony was “the most aurally exhausting place”.

“You’re bombarded with sound,” he recalled.

“There are 250,000 males building nests and on top of all the breeding penguins, you have groups of adolescent non-breeding penguins. They’re just in the way causing trouble.”

Each male adelie penguin build its nest just out of “pecking distance” of its neighbours. Mr Wilson likened the density of nests and the constant activity of the animals to a field of tents at a festival.

“Adelies are like festival-goers that have had too much caffeine,” he said. “They’re aggressive and hyperactive.”

Despite this, Mr Smith managed to capture a remarkable sequence, with one penguin repeatedly returning to its nest to add stones, apparently unaware of the fact that his neighbour would steal a stone every time his nest was unattended. …

via BBC Nature – ‘Criminal’ penguin caught on film.

Posted in Biology, Crime | Leave a Comment »

FBI’s DNA database upgrade plans come under fire

Posted by Anonymous on October 17, 2011

Forensic scientistA major upgrade of the Federal Bureau of Investigation’s (FBI) DNA database system has come under fire from members of the forensic science community.

The Codis system is used to generate the genetic profiles stored in the US national DNA database.

The FBI wants to expand the number of genetic markers used by Codis to classify individual DNA profiles.

But a former science chief at the bureau says the plan is not being driven by scientists’ needs.

Dr Bruce Budowle, along with colleagues Arthur Eisenberg and Jianye Ge, outlined the objections at the Promega 22nd International Symposium on Human Identification (ISHI) in Maryland, US.

Another scientist told BBC News the changes were vitally important because they would set down how DNA profiles were recorded in the United States for perhaps “the next 20 years”.

While working at the FBI in the 1990s, Dr Budowle helped choose the genetic markers currently used by Codis.

He says the review is a good idea, but that choosing the right markers for forensic casework is crucial.

He told BBC News the FBI did not sufficiently consult with the forensic science community before making its recommendations.

“The first time around we took a community-wide approach – 21 laboratories rolling up their sleeves and generating data we could analyse and [use to] make decisions,” explained Dr Budowle, from the University of North Texas Health Science Center in Fort Worth.

“This time around, they formed a working group of around five [scientists] and an FBI person to decide what the core set should be.

“Should the needs of Codis – our national database system – drive the casework processes, or should the needs of casework drive the Codis processes?

“I would hope the latter is obviously what should be done.”

The US national database – the largest in the world – currently contains about 10 million offender profiles and has assisted in more than 141,000 investigations.

Codis (which stands for COmbined DNA Index System ) uses a set of 13 genetic markers – known as the “core loci” – to generate individual DNA profiles. ….

The importance of these markers was demonstrated in the case of a British man arrested in 1999. His DNA profile matched that collected in a burglary when compared at six genetic loci.

The suspect spent several months in jail before his lawyer demanded a 10-marker re-test. The suspect differed from the burglary suspect at one of the four additional markers and was set free.

While the probabilities of such chance matches between unrelated individuals are relatively small, they increase as DNA databases grow in size.

… We have seen some forensic practices adopted too quickly, and those result in tragic wastes of precious investigation time, wrongful prosecutions, and more victims,” he said.

A similar challenge to that faced by the FBI looms for custodians of the UK’s National DNA database (NDAD), which holds about four million profiles.

The NDAD currently uses 10 core loci to generate profiles; but Professor Sir Alec Jeffreys, who helped pioneer DNA profiling, has recommended the number be increased to 15 or 16. …

via BBC News – FBI’s DNA database upgrade plans come under fire.

Posted in Biology, Crime, Politics | Leave a Comment »

Van Gogh did not kill himself, authors claim

Posted by Anonymous on October 17, 2011

http://news.bbcimg.co.uk/media/images/56103000/jpg/_56103765_jex_1202395_de27-1.jpgVincent van Gogh did not kill himself, the authors of new biography Van Gogh: The Life have claimed.

Steven Naifeh and Gregory White Smith say that, contrary to popular belief, it was more likely he was shot accidentally by two boys he knew who had “a malfunctioning gun”.

The authors came to their conclusion after 10 years of study with more than 20 translators and researchers.

The Van Gogh Museum in Amsterdam called the claim “dramatic” and “intriguing”.

In a statement, however, curator Leo Jansen said “plenty of questions remain unanswered” and that it would be “premature to rule out suicide”.

He added that the new claims would “generate a great deal of discussion”.

Van Gogh died in Auvers-sur-Oise, France, in 1890 aged 37.

The Dutch master had been staying at the Auberge Ravoux inn from where he would walk to local wheat fields to paint.

It has long been thought that he shot himself in a wheat field before returning to the inn where he later died. …

Thousands of previously untranslated letters written by the artist were among documents studied by the authors to create a research database containing 28,000 notes.

via BBC News – Van Gogh did not kill himself, authors claim.

Posted in Art, History | Leave a Comment »

 
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