Headlines of the day
Snake eats family dog as kids watch (CNN)
Eskimo village sues over global warming (CNN)
William F. Buckley, Crypto-Fascist, Is Correcting Usage In Heaven (Gawker)
It’s right next to the porch light region and just above the “wait ‘till your father gets home” lobe.
Why Do We Love Babies? Parental Instinct Region Found In The Brain
ScienceDaily (Feb. 27, 2008) — Why do we almost instinctively treat babies as special, protecting them and enabling them to survive? Darwin originally pointed out that there is something about infants which prompts adults to respond to and care for them which allows our species to survive. Nobel-Prize-winning zoologist Konrad Lorenz proposed that it is the specific structure of the infant face, including a relatively large head and forehead, large and low lying eyes and bulging cheek region, that serves to elicit these parental responses. But the biological basis for this has remained elusive.
Now, a possible brain basis for this parental instinct has been reported. This research was led by Morten Kringelbach and Alan Stein from the University of Oxford and was funded by the Wellcome Trust and TrygFonden Charitable Foundation. The authors showed that a region of the human brain called the medial orbitofrontal cortex is highly specifically active within a seventh of a second in response to (unfamiliar) infant faces but not to adult faces.
This finding has potentially important clinical application in relation to postnatal depression, which is common, occurring in approximately 13% of mothers after birth and often within six weeks. The present findings could eventually provide opportunities for early identification of families at risk.
The research team used a neuroimaging method called magnetoencephalography (MEG) at Aston University, UK. This is an advanced neuroscientific tool which offers both excellent temporal (in milliseconds) and spatial (in millimetres) resolution of whole brain activity. Because the researchers were primarily interested in the highly automatized processing of faces, they used an implicit task that required participants to monitor the colour of a small red cross and to press a button as soon as the colour changed. This was interspersed by adult and infant faces that were shown for 300 ms, but which were not important to solve the task.
The authors found a key difference in the early brain activity of normal adults when they viewed infant faces compared to adult faces. In addition to the well documented brain activity in the visual areas of the brain in response to faces, early activity was found in the medial orbitofrontal cortex to infant faces but not adult faces. This wave of activity starts around a seventh of a second after presentation of an infant face. These responses are almost certainly too fast to be consciously controlled and are therefore perhaps instinctive.
The medial orbitofrontal cortex is located in the front of the brain, just over the eyeballs. It is a key region of the emotional brain and appears to be related to the ongoing monitoring of salient reward-related stimuli in the environment. In the context of the experiment, the medial orbitofrontal cortex may provide the necessary emotional tagging of infant faces that predisposes us to treat infant faces as special and plays a key role in establishing a parental bond.
Wednesday, February 27, 2008
Tuesday, February 26, 2008
Making Science More Better For You on 02/26/08
Headline of the day
Falling icicles kill six in Russia...(Drudge)
Hard water…
Once again, British researchers demonstrate they have a tough time distinguishing between fact and opinion
Materialistic society is 'damaging' children: poll
(Breitbart) Children feel under pressure to own the latest designer clothes and computer games and most adults believe the "commercialisation of childhood" is damaging young people's well-being, a poll said Tuesday.
A survey by GfK NOP for the Children's Society showed that out of the 1,225 adults questioned, 89 percent felt that children are more materialistic now than in previous generations.
Evidence submitted to the inquiry from children themselves suggests that they do feel under pressure to keep up with the latest trends, the society added.
The poll is part of a larger inquiry into childhood and includes evidence by professionals and members of the public on issues such as lifestyle, learning, friends and family.
Professor of child psychology Philip Graham -- who is leading the inquirys lifestyle theme -- believes that commercial pressures may have "worrying psychological effects" on children.
"One factor that may be leading to rising mental health problems is the increasing degree to which children and young people are preoccupied with possessions; the latest in fashionable clothes and electronic equipment.
"Evidence both from the United States and from the UK suggests that those most influenced by commercial pressures also show higher rates of mental health problems," he said.
Commenting on the results of the poll, chief executive of the Childrens Society Bob Reitemeier said: "As adults we have to take responsibility for the current level of marketing to children. To accuse children of being materialistic in such a culture is a cop out.
"Unless we question our own behaviour as a society we risk creating a generation who are left unfulfilled through chasing unattainable lifestyles."
Rowan Williams, the Archbishop of Canterbury and patron of the inquiry, added: "Children should be encouraged to value themselves for who they are as people rather than what they own.
"The selling of lifestyles to children creates a culture of material competitiveness and promotes acquisitive individualism at the expense of the principles of community and cooperation."
Other results in the poll showed that just over 60 percent wants the government to ban junk food adverts and nearly 7 in ten agreed that violent video games make children more aggressive.
The final report and recommendations of the Good Childhood Inquiry will be published in early 2009
Breaking news: Cool kids often ridicule those who are less attractive. Years later, geeks use this to justify their trip to the bell tower with an AK. Film at 11.
Acne May Prevent People From Participating In Sport And Exercise, Says Research
ScienceDaily (Feb. 26, 2008) — Acne patients who are highly anxious about their skin condition say they are less likely to participate in sport or exercise, according to new research at the
The study, published in the Journal of Health Psychology, involved 50 young to middle-aged adults recruited from a national acne support group.
As well as saying that they were less likely to participate in sport or exercise, acne sufferers who perceived their skin to be negatively evaluated by others also experienced lower self-esteem and a poorer quality of life. This pattern was similar in both men and women.
The researchers say that ‘dermatological social anxiety’ is often overlooked in studies on motivation for sport and exercise in favour of physical inhibitions.
“The skin is the most visible organ in the human body and, as such, is an important part of personal image,” said Dr Martyn Standage, a lecturer in the School for Health at the University of Bath.
“Fear of having one’s skin evaluated by others has implications for physical and social wellbeing.
“Sport and exercise activities provide many opportunities for the skin to be exposed to evaluation. Due to this, acne sufferers may become so anxious about their appearance that it prevents them from participating in physical activity.”
Want cookie, must have cookie, will have cookie, give cookie
Children Show Goal-oriented Behavior By Age Three
ScienceDaily (Feb. 22, 2008) — Hang on, parents. After the terrible twos come the goal-oriented threes. Kids seem to grow into the ability to act in pursuit of goals outside of what they can immediately sense sometime around that age, according to a new study. Researchers found that by around age 3, children appear to shape their behavior in response to the outcomes they've come to expect. Anticipated outcomes that they value move them to act more than do outcomes that they don't -- a hallmark of emerging autonomy.
At the University of Cambridge, a trio of psychologists trained 72 children between 18 months and 4 years old, divided into three 10-month age bands (averaging 1.3 to 2.2 years, 2.3 to 3.075 years, and 3.08 to 4 years) to touch a red or green butterfly icon on a touch-screen display to see different cartoon video clips. The children came to associate one butterfly with one cartoon sequence and the other butterfly with another.
After that, the experimenters devalued one of the outcomes by showing that sequence repeatedly, until the children became bored with it. Thus, the less-viewed cartoon clips became, by contrast, more interesting and valuable. The researchers then re-tested the children, who should now have associated one butterfly with a valued cartoon and the other butterfly with a less-valued cartoon.
Relative to the younger children, those who were 32 months (nearly 3 years) and older touched the butterfly for the less-valued cartoon significantly less often than they touched the butterfly for the more novel cartoon. During that test, the cartoons were not actually presented; the children had to rely on their memories of which butterfly icon produced which cartoon. This test thus showed that the actions of the older children behavior depended on the current values of the
Falling icicles kill six in Russia...(Drudge)
Hard water…
Once again, British researchers demonstrate they have a tough time distinguishing between fact and opinion
Materialistic society is 'damaging' children: poll
(Breitbart) Children feel under pressure to own the latest designer clothes and computer games and most adults believe the "commercialisation of childhood" is damaging young people's well-being, a poll said Tuesday.
A survey by GfK NOP for the Children's Society showed that out of the 1,225 adults questioned, 89 percent felt that children are more materialistic now than in previous generations.
Evidence submitted to the inquiry from children themselves suggests that they do feel under pressure to keep up with the latest trends, the society added.
The poll is part of a larger inquiry into childhood and includes evidence by professionals and members of the public on issues such as lifestyle, learning, friends and family.
Professor of child psychology Philip Graham -- who is leading the inquirys lifestyle theme -- believes that commercial pressures may have "worrying psychological effects" on children.
"One factor that may be leading to rising mental health problems is the increasing degree to which children and young people are preoccupied with possessions; the latest in fashionable clothes and electronic equipment.
"Evidence both from the United States and from the UK suggests that those most influenced by commercial pressures also show higher rates of mental health problems," he said.
Commenting on the results of the poll, chief executive of the Childrens Society Bob Reitemeier said: "As adults we have to take responsibility for the current level of marketing to children. To accuse children of being materialistic in such a culture is a cop out.
"Unless we question our own behaviour as a society we risk creating a generation who are left unfulfilled through chasing unattainable lifestyles."
Rowan Williams, the Archbishop of Canterbury and patron of the inquiry, added: "Children should be encouraged to value themselves for who they are as people rather than what they own.
"The selling of lifestyles to children creates a culture of material competitiveness and promotes acquisitive individualism at the expense of the principles of community and cooperation."
Other results in the poll showed that just over 60 percent wants the government to ban junk food adverts and nearly 7 in ten agreed that violent video games make children more aggressive.
The final report and recommendations of the Good Childhood Inquiry will be published in early 2009
Breaking news: Cool kids often ridicule those who are less attractive. Years later, geeks use this to justify their trip to the bell tower with an AK. Film at 11.
Acne May Prevent People From Participating In Sport And Exercise, Says Research
ScienceDaily (Feb. 26, 2008) — Acne patients who are highly anxious about their skin condition say they are less likely to participate in sport or exercise, according to new research at the
The study, published in the Journal of Health Psychology, involved 50 young to middle-aged adults recruited from a national acne support group.
As well as saying that they were less likely to participate in sport or exercise, acne sufferers who perceived their skin to be negatively evaluated by others also experienced lower self-esteem and a poorer quality of life. This pattern was similar in both men and women.
The researchers say that ‘dermatological social anxiety’ is often overlooked in studies on motivation for sport and exercise in favour of physical inhibitions.
“The skin is the most visible organ in the human body and, as such, is an important part of personal image,” said Dr Martyn Standage, a lecturer in the School for Health at the University of Bath.
“Fear of having one’s skin evaluated by others has implications for physical and social wellbeing.
“Sport and exercise activities provide many opportunities for the skin to be exposed to evaluation. Due to this, acne sufferers may become so anxious about their appearance that it prevents them from participating in physical activity.”
Want cookie, must have cookie, will have cookie, give cookie
Children Show Goal-oriented Behavior By Age Three
ScienceDaily (Feb. 22, 2008) — Hang on, parents. After the terrible twos come the goal-oriented threes. Kids seem to grow into the ability to act in pursuit of goals outside of what they can immediately sense sometime around that age, according to a new study. Researchers found that by around age 3, children appear to shape their behavior in response to the outcomes they've come to expect. Anticipated outcomes that they value move them to act more than do outcomes that they don't -- a hallmark of emerging autonomy.
At the University of Cambridge, a trio of psychologists trained 72 children between 18 months and 4 years old, divided into three 10-month age bands (averaging 1.3 to 2.2 years, 2.3 to 3.075 years, and 3.08 to 4 years) to touch a red or green butterfly icon on a touch-screen display to see different cartoon video clips. The children came to associate one butterfly with one cartoon sequence and the other butterfly with another.
After that, the experimenters devalued one of the outcomes by showing that sequence repeatedly, until the children became bored with it. Thus, the less-viewed cartoon clips became, by contrast, more interesting and valuable. The researchers then re-tested the children, who should now have associated one butterfly with a valued cartoon and the other butterfly with a less-valued cartoon.
Relative to the younger children, those who were 32 months (nearly 3 years) and older touched the butterfly for the less-valued cartoon significantly less often than they touched the butterfly for the more novel cartoon. During that test, the cartoons were not actually presented; the children had to rely on their memories of which butterfly icon produced which cartoon. This test thus showed that the actions of the older children behavior depended on the current values of the
Monday, February 25, 2008
Making Science More Better For You on 02/25/08
Headlines of the day
Cannibalistic iguana chokes on toy lizard (CNN)
Suicidal pets get anti-depressants (News.com.au)
So how come there are no notes?
40-year-old son accused of Tasering mom at late night party (Sun-Sentinal.com)
Lawyers gird for inevitable conflict
Python Snakes, An Invasive Species In Florida, Could Spread To One Third Of US
ScienceDaily (Feb. 24, 2008) — Burmese pythons—an invasive species in south Florida—could find comfortable climatic conditions in roughly a third of the United States according to new "climate maps" developed by the U.S. Geological Survey (USGS). Although other factors such as type of food available and suitable shelter also play a role, Burmese pythons and other giant constrictor snakes have shown themselves to be highly adaptable to new environments.
The just-released USGS maps can help natural resource agencies manage and possibly control the spread of non-native giant constrictor snakes, such as the Burmese python, now spreading from Everglades National Park in Florida. These "climate match" maps show where climate in the U.S. is similar to places in which Burmese pythons live naturally (from Pakistan to Indonesia).
A look at the map shows why biologists are concerned.
The maps show where climate alone would not limit these snakes. One map shows areas in the U.S. with current climatic conditions similar to those of the snakes' native ranges. A second map projects these "climate matches" at the end of this century based on global warming models, which significantly expands the potential habitat for these snakes.
Biologists with Everglades National Park confirmed a breeding population of Burmese python in the Florida Everglades in 2003, presumably the result of released pets. Python populations have since been discovered in Big Cypress National Preserve to the north, Miami's water management areas to the northeast, Key Largo to the southeast, and many state parks, municipalities, and public and private lands in the region.
Hopefully, someone is developing the "tissues of death"
Bacteria Use 'Invisibility Cloak' To Hide From Human Immune System
ScienceDaily (Feb. 24, 2008) — Scientists at the University of York have characterised an important new step in the mechanism used by bacteria to evade our immune system.
It is an ‘invisibility cloak’ which means that bacteria like Haemophilus influenzae, a common cause of ear infections in children, can move about the body without the risk of being attacked by the immune system.
A multidisciplinary research team from the Departments of Biology and Chemistry at York have been studying how bacteria capture the molecule used to make the ‘cloak’, called sialic acid.
The researchers have now discovered an enzymatic activity that helps in the more efficient capture of sialic acids released from our cell surfaces. As well as using the sialic acid to make the ‘invisibility cloak’ other bacteria use similar methods to capture sialic acid as a simple food source, so are literally eating us from the inside!
Ok, so what aren’t they telling us—and do they have brussels sprouts?
Doomsday' seed vault to open in Norway
LONGYEARBYEN, Norway (CNN) -- A vast underground vault storing millions of seeds from around the world is scheduled to open this week in a mountain on a remote island near the Arctic Ocean.
art.seeds.norway.ap.jpg
The inside of one of the vaults at the Svalbard Global Seed Vault, which will hold 4.5m different seed types.
Dubbed the "Doomsday Vault," the seed bank is considered the ultimate safety net for the world's seed collections, protecting them from a wide range of threats including war, natural disasters, lack of funding or simply poor agricultural management.
The Norwegian government paid to build the vault in a mountainside near Longyearbyen, in the remote Svalbard islands between Norway and the North Pole. Building began last year, and the vault is scheduled to open officially Tuesday.
The Svalbard Global Seed Vault, as it is officially known, can hold as many as 4.5 million seed samples and will eventually house almost every variety of most important food crops in the world, according to the Global Crop Diversity Trust, which is paying to collect and maintain the seeds.
The United Nations founded the trust in 2004 to support the long-term conservation of crop diversity, and countries and foundations provide the funding.
"The seed vault is the perfect place for keeping seeds safe for centuries," said Cary Fowler, executive director of the trust. "At these temperatures, seeds for important crops like wheat, barley and peas can last for up to 10,000 years."
The vault's location deep inside a mountain in the frozen north ensures the seeds can be stored safely no matter what happens outside.
"We believe the design of the facility will ensure that the seeds will stay well-preserved even if such forces as global warming raise temperatures outside the facility," said Magnus Bredeli Tveiten, project manager for the Norwegian government.
Don't Miss
The vault sits at the end of a 120-meter (131-yard) tunnel blasted inside the mountain. Workers used a refrigeration system to bring the vault to -18 degrees Celsius (just below 0 degrees Fahrenheit), and a smaller refrigeration system plus the area's natural permafrost and the mountain's thick rock will keep the vault at least -4 C (25 F).
The vault at Svalbard is similar to an existing seed bank in Sussex, England, about an hour outside London. The British vault, called the Millennium Seed Bank, is part of an scientific project that works with wild plants, as opposed to the seeds of crops.
Paul Smith, the leader of the Millennium Seed Bank project, said preserving the seeds of wild plants is just as important as preserving the seeds of vital crops.
"We must give ourselves every option in the future to use the whole array of plant diversity that is available to us," Smith told CNN.
The idea for the Arctic seed bank dates to the 1980s but only became a possibility after the International Treaty on Plant Genetic Resources came into force in 2004, the Norwegian government said. The treaty provided an international framework for conserving and accessing crop diversity.
advertisement
Svalbard is designed to store duplicates of seeds from seed collections around the world.
The Norwegian government says it has paid 50 million Norwegian Kroner ($9.4 million) to build the seed vault.
Cannibalistic iguana chokes on toy lizard (CNN)
Suicidal pets get anti-depressants (News.com.au)
So how come there are no notes?
40-year-old son accused of Tasering mom at late night party (Sun-Sentinal.com)
Lawyers gird for inevitable conflict
Python Snakes, An Invasive Species In Florida, Could Spread To One Third Of US
ScienceDaily (Feb. 24, 2008) — Burmese pythons—an invasive species in south Florida—could find comfortable climatic conditions in roughly a third of the United States according to new "climate maps" developed by the U.S. Geological Survey (USGS). Although other factors such as type of food available and suitable shelter also play a role, Burmese pythons and other giant constrictor snakes have shown themselves to be highly adaptable to new environments.
The just-released USGS maps can help natural resource agencies manage and possibly control the spread of non-native giant constrictor snakes, such as the Burmese python, now spreading from Everglades National Park in Florida. These "climate match" maps show where climate in the U.S. is similar to places in which Burmese pythons live naturally (from Pakistan to Indonesia).
A look at the map shows why biologists are concerned.
The maps show where climate alone would not limit these snakes. One map shows areas in the U.S. with current climatic conditions similar to those of the snakes' native ranges. A second map projects these "climate matches" at the end of this century based on global warming models, which significantly expands the potential habitat for these snakes.
Biologists with Everglades National Park confirmed a breeding population of Burmese python in the Florida Everglades in 2003, presumably the result of released pets. Python populations have since been discovered in Big Cypress National Preserve to the north, Miami's water management areas to the northeast, Key Largo to the southeast, and many state parks, municipalities, and public and private lands in the region.
Hopefully, someone is developing the "tissues of death"
Bacteria Use 'Invisibility Cloak' To Hide From Human Immune System
ScienceDaily (Feb. 24, 2008) — Scientists at the University of York have characterised an important new step in the mechanism used by bacteria to evade our immune system.
It is an ‘invisibility cloak’ which means that bacteria like Haemophilus influenzae, a common cause of ear infections in children, can move about the body without the risk of being attacked by the immune system.
A multidisciplinary research team from the Departments of Biology and Chemistry at York have been studying how bacteria capture the molecule used to make the ‘cloak’, called sialic acid.
The researchers have now discovered an enzymatic activity that helps in the more efficient capture of sialic acids released from our cell surfaces. As well as using the sialic acid to make the ‘invisibility cloak’ other bacteria use similar methods to capture sialic acid as a simple food source, so are literally eating us from the inside!
Ok, so what aren’t they telling us—and do they have brussels sprouts?
Doomsday' seed vault to open in Norway
LONGYEARBYEN, Norway (CNN) -- A vast underground vault storing millions of seeds from around the world is scheduled to open this week in a mountain on a remote island near the Arctic Ocean.
art.seeds.norway.ap.jpg
The inside of one of the vaults at the Svalbard Global Seed Vault, which will hold 4.5m different seed types.
Dubbed the "Doomsday Vault," the seed bank is considered the ultimate safety net for the world's seed collections, protecting them from a wide range of threats including war, natural disasters, lack of funding or simply poor agricultural management.
The Norwegian government paid to build the vault in a mountainside near Longyearbyen, in the remote Svalbard islands between Norway and the North Pole. Building began last year, and the vault is scheduled to open officially Tuesday.
The Svalbard Global Seed Vault, as it is officially known, can hold as many as 4.5 million seed samples and will eventually house almost every variety of most important food crops in the world, according to the Global Crop Diversity Trust, which is paying to collect and maintain the seeds.
The United Nations founded the trust in 2004 to support the long-term conservation of crop diversity, and countries and foundations provide the funding.
"The seed vault is the perfect place for keeping seeds safe for centuries," said Cary Fowler, executive director of the trust. "At these temperatures, seeds for important crops like wheat, barley and peas can last for up to 10,000 years."
The vault's location deep inside a mountain in the frozen north ensures the seeds can be stored safely no matter what happens outside.
"We believe the design of the facility will ensure that the seeds will stay well-preserved even if such forces as global warming raise temperatures outside the facility," said Magnus Bredeli Tveiten, project manager for the Norwegian government.
Don't Miss
The vault sits at the end of a 120-meter (131-yard) tunnel blasted inside the mountain. Workers used a refrigeration system to bring the vault to -18 degrees Celsius (just below 0 degrees Fahrenheit), and a smaller refrigeration system plus the area's natural permafrost and the mountain's thick rock will keep the vault at least -4 C (25 F).
The vault at Svalbard is similar to an existing seed bank in Sussex, England, about an hour outside London. The British vault, called the Millennium Seed Bank, is part of an scientific project that works with wild plants, as opposed to the seeds of crops.
Paul Smith, the leader of the Millennium Seed Bank project, said preserving the seeds of wild plants is just as important as preserving the seeds of vital crops.
"We must give ourselves every option in the future to use the whole array of plant diversity that is available to us," Smith told CNN.
The idea for the Arctic seed bank dates to the 1980s but only became a possibility after the International Treaty on Plant Genetic Resources came into force in 2004, the Norwegian government said. The treaty provided an international framework for conserving and accessing crop diversity.
advertisement
Svalbard is designed to store duplicates of seeds from seed collections around the world.
The Norwegian government says it has paid 50 million Norwegian Kroner ($9.4 million) to build the seed vault.
Friday, February 15, 2008
Making Science More Better For You on 02/15/08
Headline of the day
Police: Man calls 911 27,000 times (CNN)
Well, it seemed like an emergency to him.
Police: Man calls 911 27,000 times (CNN)
Well, it seemed like an emergency to him.
Thursday, February 14, 2008
Making Science More Better For You on 02/14/08
Headlines of the day
DUI hearing postponed; defendant was drunk (Seattle Times)
Finding love getting easier in rural areas (CNN)
Don’t feel sheepish.
DUI hearing postponed; defendant was drunk (Seattle Times)
Finding love getting easier in rural areas (CNN)
Don’t feel sheepish.
What gave it away? Was it the golden arches? Astronomers See Signs of Other Solar Systems Like Ours (KYW Newsradio) |
| Scientists have discovered smaller versions of Jupiter and Saturn in a distant solar system. This suggests that there may be a lot of solar systems out there similar to ours. And this brings us one step closer to answering the question, "Is there another planet like Earth in our galaxy?" A team of astronomers has discovered two planets about 80 percent of the size of our Jupiter and Saturn in a solar system 5,000 light years away. Astronomer Scott Gaudi at Ohio State University, using a new technique called gravitational microlensing, says the fact that two planets were discovered right off the bat indicates that our galaxy may host many planetary systems like ours: "It was still this completely open question: how common are solar systems like our own? Our results show that indeed there are other solar systems out there like our own -- and they might well be common."
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Wednesday, February 13, 2008
Making Science More Better For You on 02/13/08
Headlines of the day
Woman, 89, uses ax to smash door glass after being locked out (The Obscure Store)
"Marketers salivate over lickable ads" (WSJ)
We have a great deal of respect for all the great metaphysical traditions, economics in particular. The Nobel people think these guys are doing dynamite work.
Why Youth Hostel Showers Are Like The Stock Market: Variety Provides Stabililty
ScienceDaily (Feb. 12, 2008) — Diversity keeps you warm. At least that is true while you're having a shower in youth hostels. If you like, this sums up the research project just published by scientists from the Universities of Fribourg and Bonn. Their result is not as trivial as it sounds. Ultimately it shows that heterogeneity provides stability, whether this is in a shower, in power grids or even on the stock market.
Having a shower in a youth hostel can be risky when there is not enough hot water for everybody. If only one visitor turns up the hot tap during the early morning shower, everyone else is threatened by an icy gush of water. This unwanted form of hydrotherapy is particularly likely to happen when all the shower taps have the same possible settings, in other words if cold and hot water can be adjusted to exactly the same amount in all showers. But if the water taps in each shower have their individual quirks, the risk of extreme fluctuations is less.
At least that is what the Bonn economist Christina Matzke and her colleague Damien Challet, a physicist at the University of Fribourg, say. They modelled the temperature profile of showers in a youth hostel on the computer. 'All in all, heterogeneous taps offer advantages -- they prevent the average shower temperature of all guests from suddenly dropping or rising,' Christina Matzke explains. 'From the perspective of the individual they also have disadvantages, as it's more difficult for each person to set the right temperature.'
The problem sounds comical, but in principle it can be applied to all situations where people compete for a scarce resource, whether this is hot water, electricity or equities. One thing is always true, the more individualistic the behaviour of those involved in the market is, the more stable the whole system becomes. Put simply, the only reason why our electricity grid does not break down is that not all the inhabitants of Germany switch on the tumble drier at the same time. And if all shareholders made strictly rational decisions on their investments, there would probably be a lot more turbulence on the stock market.
The result is also significant from a theoretical point of view. 'We show what different results economic models can produce, depending on whether they are based on homogeneous or heterogeneous behaviour,' Christina Matzke emphasises. Accordingly, it is important to account for differences in individual behaviour when making forecasts. Although it sounds obvious, economists long ignored this insight. For decades their models were dominated by 'homo economicus', an imaginary standardised market investor who always made rational decisions rather than deciding according to individual criteria.
From this thing that look like a rummage sale ashtray we can deduce that this creature was 25 feet long. At least it was in the afternoon.
A Baby Dinosaur, 72 Million Years Old
By NED POTTER/ABC News
The Mexican state of Coahuila, due west of the southern tip of Texas, is arid country today. But 72 million years ago it was a tropical paradise, warm and moist, close to a vast sea that divided what eventually became North America.
Now, scientists report they have found a new dinosaur species there -- one of the very few ever discovered in Mexico.
It was apparently a duck-billed plant eater, probably about 25 feet long. Scientists hesitate to guess too much about it, but they say they can tell from its bone structure that it was probably not fully grown. An adult of the species could have been 10 feet longer.
"Close your eyes," said Terry Gates, a paleontologist at the Utah Museum of Natural History at the University of Utah. "I want you to imagine yourself on a beach in Puerto Vallarta. Nice day, with the sun and the ocean -- and then, when you open your eyes, you're suddenly looking at this thing."
Gates was on the team, from Mexico, Canada and the United States, that dug up the fossil and reconstructed it. The work took more than 10 years, partly because the skull was shattered -- and buried under 12 feet of rock and dirt. They called the new species Velafrons coahuilensis.
It is different from almost any other duck-billed dinosaur ever found. The reassembled skull has a large hollow bulge on top, through which it probably breathed.
"The really cool thing about these duck-billed dinosaurs is that their nasal passages probably allowed them to make some kind of music," said Gates. "We don't know exactly what kinds of sounds they would make, but it is likely to be somewhat like what trumpeters make."
Gates said it is likely that such an ornate crest on top of the head might have been useful in attracting a mate. Beauty, even in the late cretaceous period, was in the eye of the beholder.
The desert terrain of northern Mexico has made dinosaur hunting difficult there. For lack of rain, there is little erosion, so buried fossils are rarely exposed over time.
Velafrons coahuilensis was found, like many fossils, by accident. Parts of it protruded from the earth on the outskirts of the small Mexican town of Rincon, Colo.
Volunteers from the area tried for a decade to dig it up. Not until 2002 did scientists from Utah mount an expedition. They saw how difficult the dig would be, and came back with a jackhammer.
It took two years, back at the lab, for the skull to be reconstructed. They also found fossils of turtles, fish and lizards buried in the area around the dinosaur skeleton.
What killed the great animal? That question is as mysterious as the many about how it lived.
Scientists wonder about the geography of the area. Central America would not have formed yet 72 million years ago, so Mexico would have been the southern end of the continent. It is quite possible, say the researchers, that the young dinosaur was caught in a prehistoric hurricane.
"This discovery is part of a new window that's being opened up," said paleontologist Scott Sampson of the Utah Museum. "It won't be the only Mexican dinosaur for long."
"The really cool thing about these duck-billed dinosaurs is that their nasal passages probably allowed them to make some kind of music," said Gates. "We don't know exactly what kinds of sounds they would make, but it is likely to be somewhat like what trumpeters make." Were they more like Miles or Dizzy?”
Woman, 89, uses ax to smash door glass after being locked out (The Obscure Store)
"Marketers salivate over lickable ads" (WSJ)
We have a great deal of respect for all the great metaphysical traditions, economics in particular. The Nobel people think these guys are doing dynamite work.
Why Youth Hostel Showers Are Like The Stock Market: Variety Provides Stabililty
ScienceDaily (Feb. 12, 2008) — Diversity keeps you warm. At least that is true while you're having a shower in youth hostels. If you like, this sums up the research project just published by scientists from the Universities of Fribourg and Bonn. Their result is not as trivial as it sounds. Ultimately it shows that heterogeneity provides stability, whether this is in a shower, in power grids or even on the stock market.
Having a shower in a youth hostel can be risky when there is not enough hot water for everybody. If only one visitor turns up the hot tap during the early morning shower, everyone else is threatened by an icy gush of water. This unwanted form of hydrotherapy is particularly likely to happen when all the shower taps have the same possible settings, in other words if cold and hot water can be adjusted to exactly the same amount in all showers. But if the water taps in each shower have their individual quirks, the risk of extreme fluctuations is less.
At least that is what the Bonn economist Christina Matzke and her colleague Damien Challet, a physicist at the University of Fribourg, say. They modelled the temperature profile of showers in a youth hostel on the computer. 'All in all, heterogeneous taps offer advantages -- they prevent the average shower temperature of all guests from suddenly dropping or rising,' Christina Matzke explains. 'From the perspective of the individual they also have disadvantages, as it's more difficult for each person to set the right temperature.'
The problem sounds comical, but in principle it can be applied to all situations where people compete for a scarce resource, whether this is hot water, electricity or equities. One thing is always true, the more individualistic the behaviour of those involved in the market is, the more stable the whole system becomes. Put simply, the only reason why our electricity grid does not break down is that not all the inhabitants of Germany switch on the tumble drier at the same time. And if all shareholders made strictly rational decisions on their investments, there would probably be a lot more turbulence on the stock market.
The result is also significant from a theoretical point of view. 'We show what different results economic models can produce, depending on whether they are based on homogeneous or heterogeneous behaviour,' Christina Matzke emphasises. Accordingly, it is important to account for differences in individual behaviour when making forecasts. Although it sounds obvious, economists long ignored this insight. For decades their models were dominated by 'homo economicus', an imaginary standardised market investor who always made rational decisions rather than deciding according to individual criteria.
From this thing that look like a rummage sale ashtray we can deduce that this creature was 25 feet long. At least it was in the afternoon.
A Baby Dinosaur, 72 Million Years Old
By NED POTTER/ABC News
The Mexican state of Coahuila, due west of the southern tip of Texas, is arid country today. But 72 million years ago it was a tropical paradise, warm and moist, close to a vast sea that divided what eventually became North America.
Now, scientists report they have found a new dinosaur species there -- one of the very few ever discovered in Mexico.
It was apparently a duck-billed plant eater, probably about 25 feet long. Scientists hesitate to guess too much about it, but they say they can tell from its bone structure that it was probably not fully grown. An adult of the species could have been 10 feet longer.
"Close your eyes," said Terry Gates, a paleontologist at the Utah Museum of Natural History at the University of Utah. "I want you to imagine yourself on a beach in Puerto Vallarta. Nice day, with the sun and the ocean -- and then, when you open your eyes, you're suddenly looking at this thing."
Gates was on the team, from Mexico, Canada and the United States, that dug up the fossil and reconstructed it. The work took more than 10 years, partly because the skull was shattered -- and buried under 12 feet of rock and dirt. They called the new species Velafrons coahuilensis.
It is different from almost any other duck-billed dinosaur ever found. The reassembled skull has a large hollow bulge on top, through which it probably breathed.
"The really cool thing about these duck-billed dinosaurs is that their nasal passages probably allowed them to make some kind of music," said Gates. "We don't know exactly what kinds of sounds they would make, but it is likely to be somewhat like what trumpeters make."
Gates said it is likely that such an ornate crest on top of the head might have been useful in attracting a mate. Beauty, even in the late cretaceous period, was in the eye of the beholder.
The desert terrain of northern Mexico has made dinosaur hunting difficult there. For lack of rain, there is little erosion, so buried fossils are rarely exposed over time.
Velafrons coahuilensis was found, like many fossils, by accident. Parts of it protruded from the earth on the outskirts of the small Mexican town of Rincon, Colo.
Volunteers from the area tried for a decade to dig it up. Not until 2002 did scientists from Utah mount an expedition. They saw how difficult the dig would be, and came back with a jackhammer.
It took two years, back at the lab, for the skull to be reconstructed. They also found fossils of turtles, fish and lizards buried in the area around the dinosaur skeleton.
What killed the great animal? That question is as mysterious as the many about how it lived.
Scientists wonder about the geography of the area. Central America would not have formed yet 72 million years ago, so Mexico would have been the southern end of the continent. It is quite possible, say the researchers, that the young dinosaur was caught in a prehistoric hurricane.
"This discovery is part of a new window that's being opened up," said paleontologist Scott Sampson of the Utah Museum. "It won't be the only Mexican dinosaur for long."
"The really cool thing about these duck-billed dinosaurs is that their nasal passages probably allowed them to make some kind of music," said Gates. "We don't know exactly what kinds of sounds they would make, but it is likely to be somewhat like what trumpeters make." Were they more like Miles or Dizzy?”
Tuesday, February 12, 2008
Making Science More Better For You on 02/12/08
Headlines of the day
Ex-Florida prison boss: Drunken orgies tainted system (CNN)
What gave it away?
Falling moose nearly takes out trooper ( Anchorage Daily News)
And where is squirrel?
UPDATE: Hardwired for love: Are robots the sex partners of the future? (Drudge)
A future where even the lawyers get some.
Meth Deposited in ATM, Woman Jailed...(AP)
Talk about a speedy transaction...
Mummified Corpse Found in Bathtub of Arizona Renter (Breitbart.com)
“Oh yeah? Check the lease.
Newsweek: We may still be (unconscious) racists
Really?
Today’s episode of Gil Scott-Heron’s “And Whitey’s on the Moon.”
Scientists prove Napoleon not poisoned
Researchers measured arsenic levels using nuclear reactor to irradiate hair
ROME - Italian scientists say they have proved Napoleon was not poisoned, scotching the legend the French emperor was murdered by his British jailors.
Napoleon's post-mortem said he died of stomach cancer aged 51, but the theory he was assassinated to prevent any return to power has gained credence in recent decades as some studies indicated his body contained a high level of the poison arsenic.
"It was not arsenic poisoning that killed Napoleon at Saint Helena," said researchers at the University of Pavia who tested the theory the British killed him while he was in exile on the South Atlantic island in 1821.
The Italian research — which studied hair samples from various moments in his life which are kept in museums in Italy and France — showed Napoleon's body did have a high level of arsenic, but that he was already heavily contaminated as a boy.
The scientists used a nuclear reactor to irradiate the hairs to get an accurate measure of the levels of arsenic.
Looking at hairs from several of Napoleon's contemporaries, including his wife and son, they found arsenic levels were generally much higher than is common today.
"The result? There was no poisoning in our opinion because Napoleon's hairs contain the same amount of arsenic as his contemporaries," the researchers said in a statement published on the university's website.
The study found the samples taken from people living in the early 1800s contained 100 times as much arsenic than the current average. Glues and dyes commonly used at the time are blamed for high environmental levels of the toxic element.
"The environment in which people lived in the early 1800s evidently caused the intake of quantities of arsenic that today we would consider dangerous," the scientists said.
One theory was that Napoleon was poisoned accidentally by arsenic vapor from dyes in his wallpaper at Saint Helena, but the study showed there was no massive increase in arsenic levels in his latter years.
"It is clear that one cannot talk about a case of poisoning, but of a constant absorption of arsenic," the researchers said.
Napoleon had been exiled once before — on the Italian island of Elba after his failed invasion of Russia. But he returned to France and was finally defeated at Waterloo in 1815 after which he was sent to the much more remote Saint Helena.
Golly, we’re glad they cleared that up.
Lord Vader Has No Comment
New Cosmic Theory Unites Dark Forces
Michael Schirber
Special to SPACE.com
SPACE.com Mon Feb 11, 6:46 AM ET
The two biggest mysteries in cosmology may be one. A new theory says that dark matter and dark energy could arise from a single dark fluid that permeates the whole universe. And this could mean Earth-based dark matter searches will come up empty.
Dark matter, as originally hypothesized, is extra hidden mass that astrophysicists calculate is necessary for holding together fast-turning galaxies. The most popular notion is that this matter is made of some yet-to-be-identified particle that has almost no interactions with light or ordinary matter. Yet it seems to be everywhere, acting as a scaffolding for galaxy clusters and the whole structure of the universe.
On the other hand, dark energy is needed to explain the more recently-discovered acceleration of the universe's expansion. It supposedly exists all throughout space, delivering a pressure that counteracts gravity.
It's counterintuitive that one substance could be both a gravitational anchor for galaxies and anti-gravity force for the universe. However, HongSheng Zhao of the University of St Andrews in Scotland claims that a fluid-like dark energy can act like dark matter when its density becomes high enough.
"Dark energy is a property of the vacuum — of fields that we do not easily see," Zhao told Space.com. "From it, we can derive the dark matter effect."
Zhao compares this dark fluid to Earth's atmosphere. Atmospheric pressure causes air to expand, but part of the air can collapse to form clouds. In the same way, the dark fluid might generally expand, but it also could collect around galaxies to help hold them together.
Unification
Zhao is not the first theorist to try to bring dark energy and dark matter under the same framework.
The type of dark fluid that Zhao is looking at is similar to one that Pedro Ferreira of the University of Oxford and his colleagues devised a few years ago.
"[Our theory] involves positing a preferred time direction, in some sense a special time frame," Ferreira said. "It has the interesting effect of modifying Einstein's theory of general relativity."
The idea is similar to the "ether," an invisible medium that physicists once thought light waves travelled through. Einstein's relativity did away with the need for such a medium, but cosmologists have recently found that an ether-like substance can mimic dark matter.
The presence of such a substance changes the way gravity works. This is most noticeable in the distant outskirts of a galaxy, where the galaxy's gravitational pull would be expected to be small, but the ether makes it much stronger.
The ether "effectively softens space-time in regions of low [gravitational] acceleration making it more sensitive to the presence of mass than usual," Ferreira explained.
Zhao has refined this approach and found that it can match a lot of astronomical data, as reported in a recent article in Astrophysical Journal Letters.
"I like [Zhao's model] because it shows that these theories are predictive and, if worked out in detail, can be tested properly against experiment," Ferreira said.
For one, Zhao's fluid divides itself into a dark energy part and a dark matter part with the same ratio that is seen from observations (dark energy is about 75 percent of the universe's mass-energy content, while dark matter is about 21 percent and normal matter makes up the last 4 percent).
Although the fluid is all around us, Zhao found that it does not affect the motion of Earth or the other planets, which is "reassuring," he said, because data shows that our solar system obeys traditional gravity to very high accuracy.
But the fluid does affect the speed at which galaxies can rotate. Some 75 years ago, astronomers noticed that galaxies were turning faster than would be expected from the amount of normal light-emitting matter they contained. The answer seemed to require some form of unseen dark matter.
However, Zhao has shown that his fluid can keep galaxies from flying apart just as well as dark matter can.
Zhao has also tested his model against the bullet cluster of galaxies, where a massive collision appears to have stripped hot gas from its dark matter envelope. This "naked" dark matter was seen as iron-clad proof for traditional dark matter theories, but Zhao claims that his fluid can reproduce the same effect.
Christian Boehmer from University College London thinks it "compelling" that Zhao's model can reproduce so much galaxy data.
If the dark fluid is mimicking dark matter, then scientists are searching in vain for the elusive dark matter particle, often called a WIMP (for weakly interacting massive particle).
Currently, several experiments are trying to detect a rare collision of a WIMP on Earth or observe gamma rays from distant WIMP self-annihilations.
"Direct detections will be more difficult," Zhao said. WIMPs may still exist, but there won't be as many of them as predicted.
Without WIMPs to worry about, the dark fluid could make scientists' jobs easier.
But not many cosmologists are ready to abandon dark matter just yet. The dark fluid idea is still fairly new, so some issues have yet to be worked out, whereas dark matter is a fairly mature theory.
"The current [dark matter] model provides the best fit to the data and is therefore the best model at hand," Boehmer said.
However, Boehmer agrees that having two unknowns — dark matter and dark energy — make up 95 percent of the universe is a bit embarrassing for cosmology.
"Frankly speaking, these are just fancy words we use to name something we do not understand," he said.
If a simpler model (with a single word) can explain all the data, then cosmologists will gladly accept it, Boehmer said.
"The type of dark fluid that Zhao is looking at is similar to one that Pedro Ferreira of the University of Oxford and his colleagues devised a few years ago". Let’s see, that called for shoe polish and eye of newt, if we remember correctly.
Is this a pitch for a prehistoric yogurt ad?
How Did Huge Dinosaurs Find Enough Food? Did Bacteria Aid Their Digestion?
ScienceDaily (Feb. 12, 2008) — Scientists from the University of Bonn are researching which plants giant dinosaurs could have lived off more than 100 million years ago. They want to find out how the dinosaurs were able to become as large as they did. In fact such gigantic animals should not have existed according to general rules of ecology.
Dinosaur digestion
Take 200 milligrammes of dried and ground equisetum, ten millilitres of digestive juice from sheep's rumen, a few minerals, carbonate and water. Fill a big glass syringe with the mix, clamp this into a revolving drum and put the whole thing into an incubator, where the brew can rotate slowly. In this way you obtain the artificial 'dinosaur rumen'. With this apparatus (also used as a 'Menke gas production technique' in assessing food for cows) Dr. Jürgen Hummel from the Bonn Institute of Animal Sciences (Bonner Institut für Tierwissenschaften) is investigating which plants giant dinosaurs could have lived off more than 100 million years ago, since this is one of the pieces which are still missing in the puzzle involving the largest land animals that ever walked the earth. The largest of these 'sauropod dinosaurs' with their 70 to 100 tonnes had a mass of ten full grown elephants or more than 1000 average people.
Larger than permitted
How the dinosaurs could ever attain this size is something which scientists from Germany and Switzerland are investigating. The Bonn palaeontologist, Professor Martin Sander, the coordinator of the research group 'Biology of the Sauropod Dinosaurs: The Evolution of Gigantism', says, 'There is a law to which most animals living today conform. The larger an animal, the smaller the density of the population, i.e. the fewer animals of the same species there are per square kilometre.' The larger an animal is, the larger the amount of food it has to have in order to survive. Therefore a specific area can only feed a certain maximum number of animals.
At the same time there is a lower limit to the density of population. If this is undercut, the species dies out: 'In this case diseases can rapidly wipe out the whole stock. Moreover, finding a mate becomes difficult,' Martin Sander explains. An animal like the 100-tonne argentinosaurus should have normally not had this 'minimum population density', actually it should not have been able to exist. But there are hypotheses for this apparent paradox: for example the giant dinosaurs presumably had a metabolism that was lower than that of mammals. In this context it is unclear how nutritious the plants were that formed their diet.
This question is being investigated by Dr. Jürgen Hummel in conjunction with Dr. Marcus Clauss from the University of Zurich. 'We assume that the herbivorous dinosaurs must have had a kind of fermenter, similar to the rumen in cows today.' Almost all existing herbivores digest their food by using bacteria in this way. The panda is the exception. Because the panda is not like this its digestion is inefficient. It stuffs bamboo leaves into its mouth all day long, in order to meet its energy needs, despite the fact that it does not move about much, thereby saving energy.
Jürgen Hummel transforms glass syringes into simple fermenters, which he fills with bacteria from the sheep's rumen. 'These micro-organisms are very old from an evolutionary point of view; we can therefore assume that they also existed in the past,' he explains. To the mix of bacteria he adds dried and ground food plants: grass, foliage or herbs which still form part of animals' diet, and for comparison equisetum, Norfolk Island pine or ginkgo leaves, i.e. parts of plants which have been growing for more than 200 million years on earth. The gas formed during the fermentation process presses the plunger out of the syringes. Jürgen Hummel can therefore read the success of the fermentation process directly off their scales. This is measured according to a simple rule: the more gas is produced, the 'higher the quality' of the food.
Equisetum is bad for the teeth
These 'old' plants stand their ground surprisingly well compared to today's flora. 'The difference is not as great as might be expected,' Jürgen Hummel emphasises. The bacteria digest ginkgo even better than foliage, but they seem to prefer equisetum most. With it gas production is even higher than with some grasses. Nevertheless, equisetum figures in the diet of comparatively few animals. The reason is that in addition to the toxins present in many modern species it wears down animals' teeth too much. 'Equisetum contains a lot of silicates,' Jürgen Hummel says. 'It acts like sand paper.'
However, many dinosaurs did not have any molars at all. They just pulled up their food and gulped it down. The mechanical break-up may have been carried out by a 'gastric mill'. Similar to today's birds, dinosaurs may have swallowed stones with which they ground the food to a paste with their muscular stomach. However, there are no clear indications of this. Only recently the Bonn palaeontologist Dr. Oliver Wings doubted that dinosaurs had bezoar stones, at least this assumption could not be verified from fossil findings.
The results of the research have now been published in the journal 'Proceedings of the Royal Society B'.
Ex-Florida prison boss: Drunken orgies tainted system (CNN)
What gave it away?
Falling moose nearly takes out trooper ( Anchorage Daily News)
And where is squirrel?
UPDATE: Hardwired for love: Are robots the sex partners of the future? (Drudge)
A future where even the lawyers get some.
Meth Deposited in ATM, Woman Jailed...(AP)
Talk about a speedy transaction...
Mummified Corpse Found in Bathtub of Arizona Renter (Breitbart.com)
“Oh yeah? Check the lease.
Newsweek: We may still be (unconscious) racists
Really?
Today’s episode of Gil Scott-Heron’s “And Whitey’s on the Moon.”
Scientists prove Napoleon not poisoned
Researchers measured arsenic levels using nuclear reactor to irradiate hair
ROME - Italian scientists say they have proved Napoleon was not poisoned, scotching the legend the French emperor was murdered by his British jailors.
Napoleon's post-mortem said he died of stomach cancer aged 51, but the theory he was assassinated to prevent any return to power has gained credence in recent decades as some studies indicated his body contained a high level of the poison arsenic.
"It was not arsenic poisoning that killed Napoleon at Saint Helena," said researchers at the University of Pavia who tested the theory the British killed him while he was in exile on the South Atlantic island in 1821.
The Italian research — which studied hair samples from various moments in his life which are kept in museums in Italy and France — showed Napoleon's body did have a high level of arsenic, but that he was already heavily contaminated as a boy.
The scientists used a nuclear reactor to irradiate the hairs to get an accurate measure of the levels of arsenic.
Looking at hairs from several of Napoleon's contemporaries, including his wife and son, they found arsenic levels were generally much higher than is common today.
"The result? There was no poisoning in our opinion because Napoleon's hairs contain the same amount of arsenic as his contemporaries," the researchers said in a statement published on the university's website.
The study found the samples taken from people living in the early 1800s contained 100 times as much arsenic than the current average. Glues and dyes commonly used at the time are blamed for high environmental levels of the toxic element.
"The environment in which people lived in the early 1800s evidently caused the intake of quantities of arsenic that today we would consider dangerous," the scientists said.
One theory was that Napoleon was poisoned accidentally by arsenic vapor from dyes in his wallpaper at Saint Helena, but the study showed there was no massive increase in arsenic levels in his latter years.
"It is clear that one cannot talk about a case of poisoning, but of a constant absorption of arsenic," the researchers said.
Napoleon had been exiled once before — on the Italian island of Elba after his failed invasion of Russia. But he returned to France and was finally defeated at Waterloo in 1815 after which he was sent to the much more remote Saint Helena.
Golly, we’re glad they cleared that up.
Lord Vader Has No Comment
New Cosmic Theory Unites Dark Forces
Michael Schirber
Special to SPACE.com
SPACE.com Mon Feb 11, 6:46 AM ET
The two biggest mysteries in cosmology may be one. A new theory says that dark matter and dark energy could arise from a single dark fluid that permeates the whole universe. And this could mean Earth-based dark matter searches will come up empty.
Dark matter, as originally hypothesized, is extra hidden mass that astrophysicists calculate is necessary for holding together fast-turning galaxies. The most popular notion is that this matter is made of some yet-to-be-identified particle that has almost no interactions with light or ordinary matter. Yet it seems to be everywhere, acting as a scaffolding for galaxy clusters and the whole structure of the universe.
On the other hand, dark energy is needed to explain the more recently-discovered acceleration of the universe's expansion. It supposedly exists all throughout space, delivering a pressure that counteracts gravity.
It's counterintuitive that one substance could be both a gravitational anchor for galaxies and anti-gravity force for the universe. However, HongSheng Zhao of the University of St Andrews in Scotland claims that a fluid-like dark energy can act like dark matter when its density becomes high enough.
"Dark energy is a property of the vacuum — of fields that we do not easily see," Zhao told Space.com. "From it, we can derive the dark matter effect."
Zhao compares this dark fluid to Earth's atmosphere. Atmospheric pressure causes air to expand, but part of the air can collapse to form clouds. In the same way, the dark fluid might generally expand, but it also could collect around galaxies to help hold them together.
Unification
Zhao is not the first theorist to try to bring dark energy and dark matter under the same framework.
The type of dark fluid that Zhao is looking at is similar to one that Pedro Ferreira of the University of Oxford and his colleagues devised a few years ago.
"[Our theory] involves positing a preferred time direction, in some sense a special time frame," Ferreira said. "It has the interesting effect of modifying Einstein's theory of general relativity."
The idea is similar to the "ether," an invisible medium that physicists once thought light waves travelled through. Einstein's relativity did away with the need for such a medium, but cosmologists have recently found that an ether-like substance can mimic dark matter.
The presence of such a substance changes the way gravity works. This is most noticeable in the distant outskirts of a galaxy, where the galaxy's gravitational pull would be expected to be small, but the ether makes it much stronger.
The ether "effectively softens space-time in regions of low [gravitational] acceleration making it more sensitive to the presence of mass than usual," Ferreira explained.
Zhao has refined this approach and found that it can match a lot of astronomical data, as reported in a recent article in Astrophysical Journal Letters.
"I like [Zhao's model] because it shows that these theories are predictive and, if worked out in detail, can be tested properly against experiment," Ferreira said.
For one, Zhao's fluid divides itself into a dark energy part and a dark matter part with the same ratio that is seen from observations (dark energy is about 75 percent of the universe's mass-energy content, while dark matter is about 21 percent and normal matter makes up the last 4 percent).
Although the fluid is all around us, Zhao found that it does not affect the motion of Earth or the other planets, which is "reassuring," he said, because data shows that our solar system obeys traditional gravity to very high accuracy.
But the fluid does affect the speed at which galaxies can rotate. Some 75 years ago, astronomers noticed that galaxies were turning faster than would be expected from the amount of normal light-emitting matter they contained. The answer seemed to require some form of unseen dark matter.
However, Zhao has shown that his fluid can keep galaxies from flying apart just as well as dark matter can.
Zhao has also tested his model against the bullet cluster of galaxies, where a massive collision appears to have stripped hot gas from its dark matter envelope. This "naked" dark matter was seen as iron-clad proof for traditional dark matter theories, but Zhao claims that his fluid can reproduce the same effect.
Christian Boehmer from University College London thinks it "compelling" that Zhao's model can reproduce so much galaxy data.
If the dark fluid is mimicking dark matter, then scientists are searching in vain for the elusive dark matter particle, often called a WIMP (for weakly interacting massive particle).
Currently, several experiments are trying to detect a rare collision of a WIMP on Earth or observe gamma rays from distant WIMP self-annihilations.
"Direct detections will be more difficult," Zhao said. WIMPs may still exist, but there won't be as many of them as predicted.
Without WIMPs to worry about, the dark fluid could make scientists' jobs easier.
But not many cosmologists are ready to abandon dark matter just yet. The dark fluid idea is still fairly new, so some issues have yet to be worked out, whereas dark matter is a fairly mature theory.
"The current [dark matter] model provides the best fit to the data and is therefore the best model at hand," Boehmer said.
However, Boehmer agrees that having two unknowns — dark matter and dark energy — make up 95 percent of the universe is a bit embarrassing for cosmology.
"Frankly speaking, these are just fancy words we use to name something we do not understand," he said.
If a simpler model (with a single word) can explain all the data, then cosmologists will gladly accept it, Boehmer said.
"The type of dark fluid that Zhao is looking at is similar to one that Pedro Ferreira of the University of Oxford and his colleagues devised a few years ago". Let’s see, that called for shoe polish and eye of newt, if we remember correctly.
Is this a pitch for a prehistoric yogurt ad?
How Did Huge Dinosaurs Find Enough Food? Did Bacteria Aid Their Digestion?
ScienceDaily (Feb. 12, 2008) — Scientists from the University of Bonn are researching which plants giant dinosaurs could have lived off more than 100 million years ago. They want to find out how the dinosaurs were able to become as large as they did. In fact such gigantic animals should not have existed according to general rules of ecology.
Dinosaur digestion
Take 200 milligrammes of dried and ground equisetum, ten millilitres of digestive juice from sheep's rumen, a few minerals, carbonate and water. Fill a big glass syringe with the mix, clamp this into a revolving drum and put the whole thing into an incubator, where the brew can rotate slowly. In this way you obtain the artificial 'dinosaur rumen'. With this apparatus (also used as a 'Menke gas production technique' in assessing food for cows) Dr. Jürgen Hummel from the Bonn Institute of Animal Sciences (Bonner Institut für Tierwissenschaften) is investigating which plants giant dinosaurs could have lived off more than 100 million years ago, since this is one of the pieces which are still missing in the puzzle involving the largest land animals that ever walked the earth. The largest of these 'sauropod dinosaurs' with their 70 to 100 tonnes had a mass of ten full grown elephants or more than 1000 average people.
Larger than permitted
How the dinosaurs could ever attain this size is something which scientists from Germany and Switzerland are investigating. The Bonn palaeontologist, Professor Martin Sander, the coordinator of the research group 'Biology of the Sauropod Dinosaurs: The Evolution of Gigantism', says, 'There is a law to which most animals living today conform. The larger an animal, the smaller the density of the population, i.e. the fewer animals of the same species there are per square kilometre.' The larger an animal is, the larger the amount of food it has to have in order to survive. Therefore a specific area can only feed a certain maximum number of animals.
At the same time there is a lower limit to the density of population. If this is undercut, the species dies out: 'In this case diseases can rapidly wipe out the whole stock. Moreover, finding a mate becomes difficult,' Martin Sander explains. An animal like the 100-tonne argentinosaurus should have normally not had this 'minimum population density', actually it should not have been able to exist. But there are hypotheses for this apparent paradox: for example the giant dinosaurs presumably had a metabolism that was lower than that of mammals. In this context it is unclear how nutritious the plants were that formed their diet.
This question is being investigated by Dr. Jürgen Hummel in conjunction with Dr. Marcus Clauss from the University of Zurich. 'We assume that the herbivorous dinosaurs must have had a kind of fermenter, similar to the rumen in cows today.' Almost all existing herbivores digest their food by using bacteria in this way. The panda is the exception. Because the panda is not like this its digestion is inefficient. It stuffs bamboo leaves into its mouth all day long, in order to meet its energy needs, despite the fact that it does not move about much, thereby saving energy.
Jürgen Hummel transforms glass syringes into simple fermenters, which he fills with bacteria from the sheep's rumen. 'These micro-organisms are very old from an evolutionary point of view; we can therefore assume that they also existed in the past,' he explains. To the mix of bacteria he adds dried and ground food plants: grass, foliage or herbs which still form part of animals' diet, and for comparison equisetum, Norfolk Island pine or ginkgo leaves, i.e. parts of plants which have been growing for more than 200 million years on earth. The gas formed during the fermentation process presses the plunger out of the syringes. Jürgen Hummel can therefore read the success of the fermentation process directly off their scales. This is measured according to a simple rule: the more gas is produced, the 'higher the quality' of the food.
Equisetum is bad for the teeth
These 'old' plants stand their ground surprisingly well compared to today's flora. 'The difference is not as great as might be expected,' Jürgen Hummel emphasises. The bacteria digest ginkgo even better than foliage, but they seem to prefer equisetum most. With it gas production is even higher than with some grasses. Nevertheless, equisetum figures in the diet of comparatively few animals. The reason is that in addition to the toxins present in many modern species it wears down animals' teeth too much. 'Equisetum contains a lot of silicates,' Jürgen Hummel says. 'It acts like sand paper.'
However, many dinosaurs did not have any molars at all. They just pulled up their food and gulped it down. The mechanical break-up may have been carried out by a 'gastric mill'. Similar to today's birds, dinosaurs may have swallowed stones with which they ground the food to a paste with their muscular stomach. However, there are no clear indications of this. Only recently the Bonn palaeontologist Dr. Oliver Wings doubted that dinosaurs had bezoar stones, at least this assumption could not be verified from fossil findings.
The results of the research have now been published in the journal 'Proceedings of the Royal Society B'.
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