Friday, May 28, 2010
Constructing The World's Largest Observatory
ESOcast 17: Constructing ALMA — The World's Largest Observatory.
High in the Chilean Andes, the first antennas of the Atacama Large Millimeter/ submillimeter Array, or ALMA for short, move in unison.
Work progresses at a frantic pace in this ambitious project, which, in a few years from now, will consist of 66 antennas, working together at an altitude of 5000 metres. Once completed, ALMA will enable astronomers to study the cold Universe in unprecedented detail.
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In this episode we are going to visit the ALMA observatory in the Atacama Desert in Chile. Here, ESO, together with its international partners, is building what will become the world´s largest astronomical facility. ALMA will observe the Universe in millimetre and submillimetre wavelengths. This will allow astronomers to study both very cold objects as well as very distant objects in the early Universe.
And because such observations are disturbed by water vapour in the atmosphere, ALMA's being built on one of the driest places on Earth, the Chajnantor plateau at an altitude of 5000 metres, which also makes it one of the highest astronomy sites in the world. ALMA will be operated at two distinct sites: First, there's the Array Operations Site up on the plateau where the antenna are actually located and then further down there's the Operations Support Facility.
Constructing the ALMA observatory in the arid Atacama desert and at such high altitude is no easy undertaking. Before the antennas are brought to the high site they must be assembled at the Operations Support Facility or OSF.
Located at 2900 metres altitude, the OSF also serves as the control centre for the antenna array, which is located at the high site.
With majestic volcanoes looming in the distance, engineers are busy integrating and verifying the various parts of the antennas and by now, many antennas at various assembly stages can be found at the OSF. Each new antenna must meet very strict requirements. The surface of each dish is accurate to much less than the thickness of a sheet of paper, and the antennas can be pointed precisely enough to pick out a golf ball at a distance of 15 km.
In many ways the OSF has become the heart of the ALMA project. This is where the staff lives during their shifts and where much of the daily routine is going on. There are lots of meetings between various groups of scientists and engineers and there are even scientific conferences that are being held at this remote location. The OSF also houses the two transporters that are used to move the antennas. So with the scientists and engineers assembling and testing the antennas and conducting the operations at the high site, the OSF has become a rather busy and vibrant place.
Scientists and engineers test the ultimate performance of the complex system. Pointing and holography tests are performed round the clock and the experts make sure that only antennas fulfilling the tough ALMA specifications get the green light.
After an antenna has successfully passed all tests at the OSF, the time has come to move it up to the Array Operations Site, which lies at an altitude of 5000 metres. This was successfully done for the first time in September 2009. A giant custom-designed transporter is used to bring up the antenna. As each antenna weighs about 100 tons this is a delicate task that requires the utmost attention. Two transporters are available and they are also used to move the antennas to different positions to reconfigure the ALMA array.
The Array Operations Site is a place of extremes. Strong winds, low temperatures and a thin atmosphere. However, because of its extreme dryness and altitude, the site offers excellent conditions for observing the submillimetre radio waves for which ALMA was designed. In addition, Chajnantor offers plenty of space. And that's needed because, in its most extended configuration, the array of antennas measures 16 kilometres across. Despite the harsh conditions, work is ongoing to prepare the plateau for the antennas.
There is also the technical building, which will eventually be used to receive the data from the antennas to further process and then to transmit them to the OSF. Now as the number of antennas at the high site is constantly increasing, the project is moving into a new and important phase: that of Commissioning and Science Verification.
ALMA is rapidly moving forward and it holds a bright future for many areas of astronomy. For example, it will provide us with some unique insight into how stars and planets form, and it will be one of the premier tools to study the first stars and galaxies in the early and distant Universe. And so, many of us astronomers simply can't wait to get their hands on to this fantastic science machine!
• http://www.eso.org/
Thursday, May 27, 2010
Life On Mars
ESA Podcast: Why go to Mars?
Millions of years ago, the primitive environments of Mars and Earth were probably similar, so since life exists on Earth, then we can legitimately consider the hypothesis that it could also have developed on Mars.
Signatures of life
Where there's water, there could be life. "Meteorites from Mars that have landed on Earth show clear evidence that conditions appropriate to life did exist on the planet, including in the recent past," said Colin Pillinger, Consortium Leader for the Beagle 2 lander at the Open University, Milton Keynes, UK. "However, features in the meteorites which have been described as nanofossils are highly controversial. Unfortunately, we cannot be sure that organic matter found in the meteorites is the remnant of organisms that lived on Mars and not due to contamination on Earth. We need to repeat the experiments on rocks that never left the Red Planet."
The Beagle 2 lander would have looked for signatures of life on Mars, whether long-dead or still-living, by measuring the ratio of two different types of carbon in the rock. Biological processes on Earth favour the lighter isotope of carbon, carbon-12, over the heavier carbon-13. Hence, a high carbon-12 to carbon-13 ratio is taken as evidence of life and has been found in rocks up to 4000 million years old, even where geological processing has occurred.
On Earth, some life that is still active produces another signature - methane. The simplest biological sources, such as those associated with peat bogs, rice fields and ruminant animals, continuously supply fresh gas to replace that destroyed by oxidation.
Methane also has a very short lifetime on Mars because of the oxidising nature of the atmosphere, so its presence would indicate a replenishing source, which may be life, even if it is buried beneath the surface. If this methane exists, the Mars Express orbiter's PFS intrument will be able to detect this gas in the atmosphere.
The only previous landers to look directly for evidence of life on Mars were NASA's Vikings in 1976. However, Mars's harsh, oxidising atmosphere would almost certainly have destroyed any such evidence on the surface.
http://www.esa.int/
Wednesday, May 26, 2010
Science Bytes - Episode 18
In this episode, we explore in-depth the various logical fallacies in the first of a three-part arc. Music by Kevin MacLeod of incompetech.com.
Send any and all pictures/submissions to sciencebytes@hotmail.com! Be in the videos! Thanks for watching and best wishes to you all!
Next Time: Logical Fallacies, Part II
Hidden Universe: Trilogy Of Terror
The Hidden Universe of the Spitzer Space Telescope (Episode 3): The Trilogy of Terror.
A trilogy of spooky star-forming regions tell a haunting tale of the lives and deaths of stars.
This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.
The Hidden Universe' video series showcases some of the most exciting discoveries in infrared astronomy from NASA's Spitzer Space Telescope. Looking beyond the visible spectrum of light, Spitzer can see a whole new universe of dust and stars hidden from our Earth-bound eyes.
• http://www.spitzer.caltech.edu/
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Tuesday, May 25, 2010
'The Evolution of Confusion' by Dan Dennett, AAI 2009
Dan Dennett talks about purposely-confusing theology and how it's used. He also describes his new project interviewing clergyman who secretly don't believe anymore, and introduces a new term: "Deepity."
Dan Dennett is the author of many excellent books, including "Breaking the Spell: Religion as a Natural Phenomenon" and "Darwin's Dangerous Idea". He is also featured in the video "The Four Horsemen" along with Richard Dawkins, Sam Harris and Christopher Hitchens.
Download Quicktime Version
Small: http://c0116791.cdn.cloudfiles.racksp...
720p HD: http://c0116791.cdn.cloudfiles.racksp...
Watch "The Four Horsemen" in HD on YouTube:
http://www.youtube.com/watch?v=9DKhc1...
Filmed by
JOSH TIMONEN
Edited by
JOEL PASHBY
Marijuana: Myths and Facts
Myth: Marijuana's Harms Have Been Proved Scientifically. In the 1960s and 1970s, many people believed that marijuana was harmless. Today we know that marijuana is much more dangerous than previously believed.
Fact: In 1972, after reviewing the scientific evidence, the National Commission on Marihuana and Drug Abuse concluded that while marijuana was not entirely safe, its dangers had been grossly overstated. Since then, researchers have conducted thousands of studies of humans, animals, and cell cultures. None reveal any findings dramatically different from those described by the National Commission in 1972. In 1995, based on thirty years of scientific research editors of the British medical journal Lancet concluded that "the smoking of cannabis, even long term, is not harmful to health."
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Myth: Marijuana Has No Medicinal Value. Safer, more effective drugs are available. They include a synthetic version of THC, marijuana's primary active ingredient, which is marketed in the United States under the name Marinol.
Fact: Marijuana has been shown to be effective in reducing the nausea induced by cancer chemotherapy, stimulating appetite in AIDS patients, and reducing intraocular pressure in people with glaucoma. There is also appreciable evidence that marijuana reduces muscle spasticity in patients with neurological disorders. A synthetic capsule is available by prescription, but it is not as effective as smoked marijuana for many patients. Pure THC may also produce more unpleasant psychoactive side effects than smoked marijuana. Many people use marijuana as a medicine today, despite its illegality. In doing so, they risk arrest and imprisonment.
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Myth: Marijuana is Highly Addictive. Long term marijuana users experience physical dependence and withdrawal, and often need professional drug treatment to break their marijuana habits.
Fact: Most people who smoke marijuana smoke it only occasionally. A small minority of Americans - less than 1 percent - smoke marijuana on a daily basis. An even smaller minority develop a dependence on marijuana. Some people who smoke marijuana heavily and frequently stop without difficulty. Others seek help from drug treatment professionals. Marijuana does not cause physical dependence. If people experience withdrawal symptoms at all, they are remarkably mild.
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Myth: Marijuana is a Gateway Drug. Even if marijuana itself causes minimal harm, it is a dangerous substance because it leads to the use of "harder drugs" like heroin, LSD, and cocaine.
Fact: Marijuana does not cause people to use hard drugs. What the gateway theory presents as a causal explanation is a statistic association between common and uncommon drugs, an association that changes over time as different drugs increase and decrease in prevalence. Marijuana is the most popular illegal drug in the United States today. Therefore, people who have used less popular drugs such as heroin, cocaine, and LSD, are likely to have also used marijuana. Most marijuana users never use any other illegal drug. Indeed, for the large majority of people, marijuana is a terminus rather than a gateway drug.
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Myth: Marijuana Offenses Are Not Severely Punished. Few marijuana law violators are arrested and hardly anyone goes to prison. This lenient treatment is responsible for marijuana continued availability and use.
Fact: Marijuana arrests in the United States doubled between 1991 and 1995. In 1995, more than one-half-million people were arrested for marijuana offenses. Eighty-six percent of them were arrested for marijuana possession. Tens of thousands of people are now in prison or marijuana offenses. An even greater number are punished with probation, fines, and civil sanctions, including having their property seized, their driver's license revoked, and their employment terminated. Despite these civil and criminal sanctions, marijuana continues to be readily available and widely used.
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Myth: Marijuana Policy in the Netherlands is a Failure. Dutch law, which allows marijuana to be bought, sold, and used openly, has resulted in increasing rates of marijuana use, particularly in youth.
Fact: The Netherlands' drug policy is the most nonpunitive in Europe. For more than twenty years, Dutch citizens over age eighteen have been permitted to buy and use cannabis (marijuana and hashish) in government-regulated coffee shops. This policy has not resulted in dramatically escalating cannabis use. For most age groups, rates of marijuana use in the Netherlands are similar to those in the United States. However, for young adolescents, rates of marijuana use are lower in the Netherlands than in the United States. The Dutch people overwhelmingly approve of current cannabis policy which seeks to normalize rather than dramatize cannabis use. The Dutch government occasionally revises existing policy, but it remains committed to decriminalization.
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Myth: Marijuana Kills Brain Cells. Used over time, marijuana permanently alters brain structure and function, causing memory loss, cognitive impairment, personality deterioration, and reduced productivity.
Fact: None of the medical tests currently used to detect brain damage in humans have found harm from marijuana, even from long term high-dose use. An early study reported brain damage in rhesus monkeys after six months exposure to high concentrations of marijuana smoke. In a recent, more carefully conducted study, researchers found no evidence of brain abnormality in monkeys that were forced to inhale the equivalent of four to five marijuana cigarettes every day for a year. The claim that marijuana kills brain cells is based on a speculative report dating back a quarter of a century that has never been supported by any scientific study.
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Myth: Marijuana Causes an Amotivational Syndrome. Marijuana makes users passive, apathetic, and uninterested in the future. Students who use marijuana become underachievers and workers who use marijuana become unproductive.
Fact: For twenty-five years, researchers have searched for a marijuana-induced amotivational syndrome and have failed to find it. People who are intoxicated constantly, regardless of the drug, are unlikely to be productive members of society. There is nothing about marijuana specifically that causes people to lose their drive and ambition. In laboratory studies, subjects given high doses of marijuana for several days or even several weeks exhibit no decrease in work motivation or productivity. Among working adults, marijuana users tend to earn higher wages than non-users. College students who use marijuana have the same grades as nonusers. Among high school students, heavy use is associated with school failure, but school failure usually comes first.
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Myth: Marijuana Impairs Memory and Cognition. Under the influence of marijuana, people are unable to think rationally and intelligently. Chronic marijuana use causes permanent mental impairment.
Fact: Marijuana produces immediate, temporary changes in thoughts, perceptions, and information processing. The cognitive process most clearly affected by marijuana is short-term memory. In laboratory studies, subjects under the influence of marijuana have no trouble remembering things they learned previously. However, they display diminished capacity to learn and recall new information. This diminishment only lasts for the duration of the intoxication. There is no convincing evidence that heavy long-term marijuana use permanently impairs memory or other cognitive functions.
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Myth: Marijuana Can Cause Permanent Mental Illness. Among adolescents, even occasional marijuana use may cause psychological damage. During intoxication, marijuana users become irrational and often behave erratically.
Fact: There is no convincing scientific evidence that marijuana causes psychological damage or mental illness in either teenagers or adults. Some marijuana users experience psychological distress following marijuana ingestion, which may include feelings of panic, anxiety, and paranoia. Such experiences can be frightening, but the effects are temporary. With very large doses, marijuana can cause temporary toxic psychosis. This occurs rarely, and almost always when marijuana is eaten rather than smoked. Marijuana does not cause profound changes in people's behavior.
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Myth: Marijuana Causes Crime. Marijuana users commit more property offenses than nonusers. Under the influence of marijuana, people become irrational, aggressive, and violent.
Fact: Every serious scholar and government commission examining the relationship between marijuana use and crime has reached the same conclusion: marijuana does not cause crime. The vast majority of marijuana users do not commit crimes other than the crime of possessing marijuana. Among marijuana users who do commit crimes, marijuana plays no causal role. Almost all human and animal studies show that marijuana decreases rather than increases aggression.
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Myth: Marijuana Interferes With Male and Female Sex Hormones. In both men and women, marijuana can cause infertility. Marijuana retards sexual development in adolescents. It produces feminine characteristics in males and masculine characteristics in females.
Fact: There is no evidence that marijuana causes infertility in men or women. In animal studies, high doses of THC diminish the production of some sex hormones and can impair reproduction. However, most studies of humans have found that marijuana has no impact of sex hormones. In those studies showing an impact, it is modest, temporary, and of no apparent consequence for reproduction. There is no scientific evidence that marijuana delays adolescent sexual development, has feminizing effect on males, or a masculinizing effect on females.
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Myth: Marijuana Use During Pregnancy Damages the Fetus. Prenatal marijuana exposure causes birth defects in babies, and, as they grow older, developmental problems. The health and well being of the next generation is threatened by marijuana use by pregnant women.
Fact: Studies of newborns, infants, and children show no consistent physical, developmental, or cognitive deficits related to prenatal marijuana exposure. Marijuana had no reliable impact on birth size, length of gestation, neurological development, or the occurrence of physical abnormalities. The administration of hundreds of tests to older children has revealed only minor differences between offspring of marijuana users and nonusers, and some are positive rather than negative. Two unconfirmed case-control studies identified prenatal marijuana exposure as one of many factors statistically associated with childhood cancer. Given other available evidence, it is highly unlikely that marijuana causes cancer in children.
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Myth: Marijuana Use Impairs the Immune System. Marijuana users are at increased risk of infection, including HIV. AIDS patients are particularly vulnerable to marijuana's immunopathic effects because their immune systems are already suppressed.
Fact: There is no evidence that marijuana users are more susceptible to infections than nonusers. Nor is there evidence that marijuana lowers users' resistance to sexually transmitted diseases. Early studies which showed decreased immune function in cells taken from marijuana users have since been disproved. Animals given extremely large doses of THC and exposed to a virus have higher rates of infection. Such studies have little relevance to humans. Even among people with existing immune disorders, such as AIDS, marijuana use appears to be relatively safe. However, the recent finding of an association between tobacco smoking and lung infection in AIDS patients warrants further research into possible harm from marijuana smoking in immune suppressed persons.
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Myth: Marijuana is More Damaging to the Lungs Than Tobacco. Marijuana smokers are at a high risk of developing lung cancer, bronchitis, and emphysema.
Fact: Moderate smoking of marijuana appears to pose minimal danger to the lungs. Like tobacco smoke, marijuana smoke contains a number of irritants and carcinogens. But marijuana users typically smoke much less often than tobacco smokers, and over time, inhale much less smoke. As a result, the risk of serious lung damage should be lower in marijuana smokers. There have been no reports of lung cancer related solely to marijuana, and in a large study presented to the American Thoracic Society in 2006, even heavy users of smoked marijuana were found not to have any increased risk of lung cancer. Unlike heavy tobacco smokers, heavy marijuana smokers exhibit no obstruction of the lung's small airway. That indicates that people will not develop emphysema from smoking marijuana.
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Myth: Marijuana's Active Ingredient, THC, Gets Trapped in Body Fat. Because THC is released from fat cells slowly, psychoactive effects may last for days or weeks following use. THC's long persistence in the body damages organs that are high in fat content, the brain in particular.
Fact: Many active drugs enter the body's fat cells. What is different (but not unique) about THC is that it exits fat cells slowly. As a result, traces of marijuana can be found in the body for days or weeks following ingestion. However, within a few hours of smoking marijuana, the amount of THC in the brain falls below the concentration required for detectable psychoactivity. The fat cells in which THC lingers are not harmed by the drug's presence, nor is the brain or other organs. The most important consequence of marijuana's slow excretion is that it can be detected in blood, urine, and tissue long after it is used, and long after its psychoactivity has ended.
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Myth: Marijuana Use is a Major Cause Of Highway Accidents. Like alcohol, marijuana impairs psychomotor function and decreases driving ability. If marijuana use increases, an increase in of traffic fatalities is inevitable.
Fact: There is no compelling evidence that marijuana contributes substantially to traffic accidents and fatalities. At some doses, marijuana affects perception and psychomotor performances- changes which could impair driving ability. However, in driving studies, marijuana produces little or no car-handling impairment- consistently less than produced by low moderate doses of alcohol and many legal medications. In contrast to alcohol, which tends to increase risky driving practices, marijuana tends to make subjects more cautious. Surveys of fatally injured drivers show that when THC is detected in the blood, alcohol is almost always detected as well. For some individuals, marijuana may play a role in bad driving. The overall rate of highway accidents appears not to be significantly affected by marijuana's widespread use in society.
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Myth: Marijuana Related Hospital Emergencies Are Increasing, Particularly Among Youth. This is evidence that marijuana is much more harmful than most people previously believed.
Fact: Marijuana does not cause overdose deaths. The number of people in hospital emergency rooms who say they have used marijuana has increased. On this basis, the visit may be recorded as marijuana-related even if marijuana had nothing to do with the medical condition preceding the hospital visit. Many more teenagers use marijuana than use drugs such as heroin and cocaine. As a result, when teenagers visit hospital emergency rooms, they report marijuana much more frequently than they report heroin and cocaine. In the large majority of cases when marijuana is mentioned, other drugs are mentioned as well. In 1994, fewer than 2% of drug related emergency room visits involved the use of marijuana.
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Myth: Marijuana Is More Potent Today Than In The Past. Adults who used marijuana in the 1960s and 1970s fail to realize that when today's youth use marijuana they are using a much more dangerous drug.
Fact: When today's youth use marijuana, they are using the same drug used by youth in the 1960s and 1970s. A small number of low-THC sample sized by the Drug Enforcement Administration are used to calculate a dramatic increase in potency. However, these samples were not representative of the marijuana generally available to users during this era. Potency data from the early 1980s to the present are more reliable, and they show no increase in the average THC content of marijuana. Even if marijuana potency were to increase, it would not necessarily make the drug more dangerous. Marijuana that varies quite substantially in potency produces similar psychoactive effects.
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Myth: Marijuana Use Can Be Prevented. Drug education and prevention programs reduced marijuana use during the 1980s. Since then, our commitment has slackened, and marijuana use has been rising. By expanding and intensifying current anti-marijuana messages, we can stop youthful experimentation.
Fact: There is no evidence that anti-drug messages diminish young people's interest in drugs. Anti-drug campaigns in the schools and the media may even make drugs more attractive. Marijuana use among youth declined throughout the 1980s, and began increasing in the 1990s. This increase occurred despite young people's exposure to the most massive anti-marijuana campaign in American history. In a number of other countries, drug education programs are based on a "harm reduction" model, which seeks to reduce the drug-related harm among those young people who do experiment with drugs.
Original author: http://www.facebook.com/notes/united-atheist-front/marijuana-myths-and-facts/125243560837056
Fact: In 1972, after reviewing the scientific evidence, the National Commission on Marihuana and Drug Abuse concluded that while marijuana was not entirely safe, its dangers had been grossly overstated. Since then, researchers have conducted thousands of studies of humans, animals, and cell cultures. None reveal any findings dramatically different from those described by the National Commission in 1972. In 1995, based on thirty years of scientific research editors of the British medical journal Lancet concluded that "the smoking of cannabis, even long term, is not harmful to health."
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Myth: Marijuana Has No Medicinal Value. Safer, more effective drugs are available. They include a synthetic version of THC, marijuana's primary active ingredient, which is marketed in the United States under the name Marinol.
Fact: Marijuana has been shown to be effective in reducing the nausea induced by cancer chemotherapy, stimulating appetite in AIDS patients, and reducing intraocular pressure in people with glaucoma. There is also appreciable evidence that marijuana reduces muscle spasticity in patients with neurological disorders. A synthetic capsule is available by prescription, but it is not as effective as smoked marijuana for many patients. Pure THC may also produce more unpleasant psychoactive side effects than smoked marijuana. Many people use marijuana as a medicine today, despite its illegality. In doing so, they risk arrest and imprisonment.
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Myth: Marijuana is Highly Addictive. Long term marijuana users experience physical dependence and withdrawal, and often need professional drug treatment to break their marijuana habits.
Fact: Most people who smoke marijuana smoke it only occasionally. A small minority of Americans - less than 1 percent - smoke marijuana on a daily basis. An even smaller minority develop a dependence on marijuana. Some people who smoke marijuana heavily and frequently stop without difficulty. Others seek help from drug treatment professionals. Marijuana does not cause physical dependence. If people experience withdrawal symptoms at all, they are remarkably mild.
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Myth: Marijuana is a Gateway Drug. Even if marijuana itself causes minimal harm, it is a dangerous substance because it leads to the use of "harder drugs" like heroin, LSD, and cocaine.
Fact: Marijuana does not cause people to use hard drugs. What the gateway theory presents as a causal explanation is a statistic association between common and uncommon drugs, an association that changes over time as different drugs increase and decrease in prevalence. Marijuana is the most popular illegal drug in the United States today. Therefore, people who have used less popular drugs such as heroin, cocaine, and LSD, are likely to have also used marijuana. Most marijuana users never use any other illegal drug. Indeed, for the large majority of people, marijuana is a terminus rather than a gateway drug.
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Myth: Marijuana Offenses Are Not Severely Punished. Few marijuana law violators are arrested and hardly anyone goes to prison. This lenient treatment is responsible for marijuana continued availability and use.
Fact: Marijuana arrests in the United States doubled between 1991 and 1995. In 1995, more than one-half-million people were arrested for marijuana offenses. Eighty-six percent of them were arrested for marijuana possession. Tens of thousands of people are now in prison or marijuana offenses. An even greater number are punished with probation, fines, and civil sanctions, including having their property seized, their driver's license revoked, and their employment terminated. Despite these civil and criminal sanctions, marijuana continues to be readily available and widely used.
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Myth: Marijuana Policy in the Netherlands is a Failure. Dutch law, which allows marijuana to be bought, sold, and used openly, has resulted in increasing rates of marijuana use, particularly in youth.
Fact: The Netherlands' drug policy is the most nonpunitive in Europe. For more than twenty years, Dutch citizens over age eighteen have been permitted to buy and use cannabis (marijuana and hashish) in government-regulated coffee shops. This policy has not resulted in dramatically escalating cannabis use. For most age groups, rates of marijuana use in the Netherlands are similar to those in the United States. However, for young adolescents, rates of marijuana use are lower in the Netherlands than in the United States. The Dutch people overwhelmingly approve of current cannabis policy which seeks to normalize rather than dramatize cannabis use. The Dutch government occasionally revises existing policy, but it remains committed to decriminalization.
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Myth: Marijuana Kills Brain Cells. Used over time, marijuana permanently alters brain structure and function, causing memory loss, cognitive impairment, personality deterioration, and reduced productivity.
Fact: None of the medical tests currently used to detect brain damage in humans have found harm from marijuana, even from long term high-dose use. An early study reported brain damage in rhesus monkeys after six months exposure to high concentrations of marijuana smoke. In a recent, more carefully conducted study, researchers found no evidence of brain abnormality in monkeys that were forced to inhale the equivalent of four to five marijuana cigarettes every day for a year. The claim that marijuana kills brain cells is based on a speculative report dating back a quarter of a century that has never been supported by any scientific study.
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Myth: Marijuana Causes an Amotivational Syndrome. Marijuana makes users passive, apathetic, and uninterested in the future. Students who use marijuana become underachievers and workers who use marijuana become unproductive.
Fact: For twenty-five years, researchers have searched for a marijuana-induced amotivational syndrome and have failed to find it. People who are intoxicated constantly, regardless of the drug, are unlikely to be productive members of society. There is nothing about marijuana specifically that causes people to lose their drive and ambition. In laboratory studies, subjects given high doses of marijuana for several days or even several weeks exhibit no decrease in work motivation or productivity. Among working adults, marijuana users tend to earn higher wages than non-users. College students who use marijuana have the same grades as nonusers. Among high school students, heavy use is associated with school failure, but school failure usually comes first.
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Myth: Marijuana Impairs Memory and Cognition. Under the influence of marijuana, people are unable to think rationally and intelligently. Chronic marijuana use causes permanent mental impairment.
Fact: Marijuana produces immediate, temporary changes in thoughts, perceptions, and information processing. The cognitive process most clearly affected by marijuana is short-term memory. In laboratory studies, subjects under the influence of marijuana have no trouble remembering things they learned previously. However, they display diminished capacity to learn and recall new information. This diminishment only lasts for the duration of the intoxication. There is no convincing evidence that heavy long-term marijuana use permanently impairs memory or other cognitive functions.
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Myth: Marijuana Can Cause Permanent Mental Illness. Among adolescents, even occasional marijuana use may cause psychological damage. During intoxication, marijuana users become irrational and often behave erratically.
Fact: There is no convincing scientific evidence that marijuana causes psychological damage or mental illness in either teenagers or adults. Some marijuana users experience psychological distress following marijuana ingestion, which may include feelings of panic, anxiety, and paranoia. Such experiences can be frightening, but the effects are temporary. With very large doses, marijuana can cause temporary toxic psychosis. This occurs rarely, and almost always when marijuana is eaten rather than smoked. Marijuana does not cause profound changes in people's behavior.
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Myth: Marijuana Causes Crime. Marijuana users commit more property offenses than nonusers. Under the influence of marijuana, people become irrational, aggressive, and violent.
Fact: Every serious scholar and government commission examining the relationship between marijuana use and crime has reached the same conclusion: marijuana does not cause crime. The vast majority of marijuana users do not commit crimes other than the crime of possessing marijuana. Among marijuana users who do commit crimes, marijuana plays no causal role. Almost all human and animal studies show that marijuana decreases rather than increases aggression.
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Myth: Marijuana Interferes With Male and Female Sex Hormones. In both men and women, marijuana can cause infertility. Marijuana retards sexual development in adolescents. It produces feminine characteristics in males and masculine characteristics in females.
Fact: There is no evidence that marijuana causes infertility in men or women. In animal studies, high doses of THC diminish the production of some sex hormones and can impair reproduction. However, most studies of humans have found that marijuana has no impact of sex hormones. In those studies showing an impact, it is modest, temporary, and of no apparent consequence for reproduction. There is no scientific evidence that marijuana delays adolescent sexual development, has feminizing effect on males, or a masculinizing effect on females.
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Myth: Marijuana Use During Pregnancy Damages the Fetus. Prenatal marijuana exposure causes birth defects in babies, and, as they grow older, developmental problems. The health and well being of the next generation is threatened by marijuana use by pregnant women.
Fact: Studies of newborns, infants, and children show no consistent physical, developmental, or cognitive deficits related to prenatal marijuana exposure. Marijuana had no reliable impact on birth size, length of gestation, neurological development, or the occurrence of physical abnormalities. The administration of hundreds of tests to older children has revealed only minor differences between offspring of marijuana users and nonusers, and some are positive rather than negative. Two unconfirmed case-control studies identified prenatal marijuana exposure as one of many factors statistically associated with childhood cancer. Given other available evidence, it is highly unlikely that marijuana causes cancer in children.
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Myth: Marijuana Use Impairs the Immune System. Marijuana users are at increased risk of infection, including HIV. AIDS patients are particularly vulnerable to marijuana's immunopathic effects because their immune systems are already suppressed.
Fact: There is no evidence that marijuana users are more susceptible to infections than nonusers. Nor is there evidence that marijuana lowers users' resistance to sexually transmitted diseases. Early studies which showed decreased immune function in cells taken from marijuana users have since been disproved. Animals given extremely large doses of THC and exposed to a virus have higher rates of infection. Such studies have little relevance to humans. Even among people with existing immune disorders, such as AIDS, marijuana use appears to be relatively safe. However, the recent finding of an association between tobacco smoking and lung infection in AIDS patients warrants further research into possible harm from marijuana smoking in immune suppressed persons.
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Myth: Marijuana is More Damaging to the Lungs Than Tobacco. Marijuana smokers are at a high risk of developing lung cancer, bronchitis, and emphysema.
Fact: Moderate smoking of marijuana appears to pose minimal danger to the lungs. Like tobacco smoke, marijuana smoke contains a number of irritants and carcinogens. But marijuana users typically smoke much less often than tobacco smokers, and over time, inhale much less smoke. As a result, the risk of serious lung damage should be lower in marijuana smokers. There have been no reports of lung cancer related solely to marijuana, and in a large study presented to the American Thoracic Society in 2006, even heavy users of smoked marijuana were found not to have any increased risk of lung cancer. Unlike heavy tobacco smokers, heavy marijuana smokers exhibit no obstruction of the lung's small airway. That indicates that people will not develop emphysema from smoking marijuana.
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Myth: Marijuana's Active Ingredient, THC, Gets Trapped in Body Fat. Because THC is released from fat cells slowly, psychoactive effects may last for days or weeks following use. THC's long persistence in the body damages organs that are high in fat content, the brain in particular.
Fact: Many active drugs enter the body's fat cells. What is different (but not unique) about THC is that it exits fat cells slowly. As a result, traces of marijuana can be found in the body for days or weeks following ingestion. However, within a few hours of smoking marijuana, the amount of THC in the brain falls below the concentration required for detectable psychoactivity. The fat cells in which THC lingers are not harmed by the drug's presence, nor is the brain or other organs. The most important consequence of marijuana's slow excretion is that it can be detected in blood, urine, and tissue long after it is used, and long after its psychoactivity has ended.
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Myth: Marijuana Use is a Major Cause Of Highway Accidents. Like alcohol, marijuana impairs psychomotor function and decreases driving ability. If marijuana use increases, an increase in of traffic fatalities is inevitable.
Fact: There is no compelling evidence that marijuana contributes substantially to traffic accidents and fatalities. At some doses, marijuana affects perception and psychomotor performances- changes which could impair driving ability. However, in driving studies, marijuana produces little or no car-handling impairment- consistently less than produced by low moderate doses of alcohol and many legal medications. In contrast to alcohol, which tends to increase risky driving practices, marijuana tends to make subjects more cautious. Surveys of fatally injured drivers show that when THC is detected in the blood, alcohol is almost always detected as well. For some individuals, marijuana may play a role in bad driving. The overall rate of highway accidents appears not to be significantly affected by marijuana's widespread use in society.
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Myth: Marijuana Related Hospital Emergencies Are Increasing, Particularly Among Youth. This is evidence that marijuana is much more harmful than most people previously believed.
Fact: Marijuana does not cause overdose deaths. The number of people in hospital emergency rooms who say they have used marijuana has increased. On this basis, the visit may be recorded as marijuana-related even if marijuana had nothing to do with the medical condition preceding the hospital visit. Many more teenagers use marijuana than use drugs such as heroin and cocaine. As a result, when teenagers visit hospital emergency rooms, they report marijuana much more frequently than they report heroin and cocaine. In the large majority of cases when marijuana is mentioned, other drugs are mentioned as well. In 1994, fewer than 2% of drug related emergency room visits involved the use of marijuana.
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Myth: Marijuana Is More Potent Today Than In The Past. Adults who used marijuana in the 1960s and 1970s fail to realize that when today's youth use marijuana they are using a much more dangerous drug.
Fact: When today's youth use marijuana, they are using the same drug used by youth in the 1960s and 1970s. A small number of low-THC sample sized by the Drug Enforcement Administration are used to calculate a dramatic increase in potency. However, these samples were not representative of the marijuana generally available to users during this era. Potency data from the early 1980s to the present are more reliable, and they show no increase in the average THC content of marijuana. Even if marijuana potency were to increase, it would not necessarily make the drug more dangerous. Marijuana that varies quite substantially in potency produces similar psychoactive effects.
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Myth: Marijuana Use Can Be Prevented. Drug education and prevention programs reduced marijuana use during the 1980s. Since then, our commitment has slackened, and marijuana use has been rising. By expanding and intensifying current anti-marijuana messages, we can stop youthful experimentation.
Fact: There is no evidence that anti-drug messages diminish young people's interest in drugs. Anti-drug campaigns in the schools and the media may even make drugs more attractive. Marijuana use among youth declined throughout the 1980s, and began increasing in the 1990s. This increase occurred despite young people's exposure to the most massive anti-marijuana campaign in American history. In a number of other countries, drug education programs are based on a "harm reduction" model, which seeks to reduce the drug-related harm among those young people who do experiment with drugs.
Original author: http://www.facebook.com/notes/united-atheist-front/marijuana-myths-and-facts/125243560837056
Evolution of Sex
We need sex to survive. What would happen if we didn't have sex? Sex is one of the fundamental drivers of descent with modification. Sex is the driving force of evolution. In fact, sex turbo charges it. This video series shows why sex is so important to us and why we would do almost anything to get it. Every home should have the History Channel.
Part One:
Part Two:
Part Three:
Part Four:
Part One:
Part Two:
Part Three:
Part Four:
The Evolution of Jaws
Jawed vertebrates evolved from jawless ancestors over 400 million years ago, and the evolution of a biting lower jaw was a critical step in vertebrate evolution. This series, courtesy of the History Channel, takes us on a journey which explores the diversity of jaw evolution.
Part One:
Part Two:
Part Three:
Part Four:
Part Five:
Part One:
Part Two:
Part Three:
Part Four:
Part Five:
Climate Change - Meet the Scientists
In response to several requests, I'll put references in the video description rather than the body of the video:
John Coleman listed as media graduate in 1957
University of Illinois Alumni Association
http://www.uiaa.org/illinois/honors/c...
Coleman claiming to be a meteorologist in Weather Channel founder suing Gore? Glenn Beck interview with John Coleman, March 5, 2008
Transcript at:
http://www.glennbeck.com/content/arti...
Certified Broadcast Meteorologist Program
http://www.ametsoc.org/amscert/index....
list of Certified Broadcast Meteorologist (CBM)
http://www.ametsoc.org/memdir/seallis...
Christopher Moncktons resume:
Whos Who 2010
Oregon Petition found at:
http://www.oism.org/pproject/
Steven C. Zylkowski credentials found at:
http://www.forestprod.org/durability0...
http://www.forestprod.org/durability0...
Earl Aaagard web page:
http://www.theseventhday.tv/Experts/a...
John Stossel clip from Global Warming? Really Bad? on YouTube
http://www.youtube.com/watch?v=XUlGoa...
Bob Carter listed as palaeoclimatologist in US Senate Minority Report,
http://epw.senate.gov/public/index.cf...
Sorry to ruin the fun, but an ice age cometh
Phil Chapman
The Australian, April 23, 2008
Chapman bio on NASA website:
http://www.jsc.nasa.gov/Bios/htmlbios...
Tim Ball 28 Years Professor of Climatology at the University of Winnipeg
Letter to Paul Martin
http://www.john-daly.com/guests/marti...
Tim Ball: for 32 years I was a Professor of Climatology at the University of Winnipeg.
Deniers vs Alarmists in the Eco-Argument
Orato website, May 28th, 2006
http://www.orato.com/health-science/g...
Tim Ball lettrt to Royal Society, listed as professor of climatology
http://www.pbs.org/moyers/moyersoname...
and
http://sciencepolicy.colorado.edu/pro...
University of Winnipeg website:
http://www.uwinnipeg.ca/
Geography course units at the University of Winnipeg
http://www.uwinnipeg.ca/index/cms-fil...
Tim Ball described as professor of geography
Fraser Institute Website
http://www.fraserinstitute.org/author...
Tim Ball letter to Royal Society, listed as retired professor of geography:
http://www.nhinsider.com/nhigb/2006/9...
Global Warming, Two Points of View
Bio of Tim Ball showing time spent at University of Winnipeg
http://www.stam.mb.ca/Global_Warming_...
Life-Saving Satellites
NASA GOES: Life-Saving Satellites - Search And Rescue: Saved By A Weather Satellite
When weather struck ... His only chance for survival, was a signal sent to space just before he was dragged under water. Denniss emergency beacon activated and transmitted a distress signal triggering a chain reaction into an intricate Search And Rescue Satellite-Aided Tracking System that has been saving lives since 1982. NASA, NOAA, the U.S. Air Force, and the U.S. Coast Guard are working together to eliminate this search, out of search and rescue to reduce the amount of time to reach victims in distress.
There have been over twenty seven thousand people saved by this system, many of which were been done by the GOES satellites. The GOES (Geostationary Operational Environmental Satellites) weather satellites have the ability to constantly oversee a large area of the Earth, and send real time data to users. Every country that can see the GOES satellite is able to pick up the distress down link.
The beacon goes of and sends a message out to whoever can hear it. A GOES satellite if its in view of the beacon will see it and then itll take that message and just relay it, repeat it back down to the ground. If the distress is from an old beacon, which does not transmit its own location, then the GOES satellites provide an immediate alert. Then you wait until the POES satellite flies over and gives you the location.
These beacons can be encoded with GPS location and thats been an advancement over the last fifteen years. This allows us to not only speed up the rescue coordination effort but the chances of survival for someone in a distressed environment is pretty significant. That information thats coming from, directly from the distress beacon to the satellites is the one key link that we have to actually find out where something is happening and hopefully again if the beacon is registered, tells us who that beacon belongs to.
Technology developed by NASA and operated by NOAA led to a quick coast guard response and a challenging navy rescue. People take for granted the risks the rescue personnel, so anything we can do to minimize the area that they have to cover, the amount of hours they have to fly, is better for them.
A new system called the Distress Alerting Satellite System or DASS is currently being tested successfully at the NASA Goddard Space Flight Center in Maryland. The Distress Alerting System will carry a search and rescue repeater on a complete constellation of satellites. In the case that the GPS systems that means twenty-four satellites will be lessening for victims all over the surface of the Earth.
With the new system the information that we get will be quicker, it will be more accurate from the instant that there is a distress happening out there. Once the system is fully operational the ultimate goal of eliminating the search out of search and rescue will be accomplished.
• http://www.nasa.gov/goes-p
• http://goes.gsfc.nasa.gov/text/goesfa...
Sunday, May 23, 2010
Galactic Center - Das galaktische Zentrum
NASA's Hidden Universe Gallery Explorer (Episode 9): The Galactic Center - Das galaktische Zentrum.
Als galaktisches Zentrum wird das Massenzentrum unserer Milchstraße bezeichnet. Es liegt im Sternbild Schütze, wo auch das sichtbare Band der Milchstraße am dichtesten erscheint. Das galaktische Zentrum enthält das nächste uns bekannte supermassereiche Schwarze Loch und zeigt andere ungewöhnliche astrophysikalische Phänomene.
The fantastic structures at the center of our Milky Way Galaxy, hidden from us in visible light, are revealed through infrared imagery. This video series showcases some of the most exciting discoveries in infrared astronomy from NASA's Spitzer Space Telescope. Looking beyond the visible spectrum of light, Spitzer can see a whole new universe of dust and stars hidden from our Earth-bound eyes.
Das Sternbild Schütze (lat. Sagittarius) enthält zwar besonders viele Sterne und Nebel, doch das galaktische Zentrum selbst ist hinter dunklen Staubwolken der interstellaren Materie verborgen. Im sichtbaren Licht kann es daher nicht beobachtet werden.
Mit langwelligerer Strahlung (Infrarot und Radiowellen) sowie im harten Röntgenbereich sind jedoch Beobachtungen möglich, da diese Bereiche des elektromagnetischen Spektrums Staub wesentlich besser durchdringen. Außerdem stellt das galaktische Zentrum den Mittelpunkt der galaktischen Rotation aller im Milchstraßensystem vorhandenen Körper dar und kann als solches indirekt erschlossen werden.
Die Entfernung der Erde zum Zentrum der Milchstraße (ca. 8 kpc) ist 100 bis 1000fach kleiner als die zu den Kernen der nächsten vergleichbaren Galaxien. Es kann deshalb sehr viel genauer untersucht werden. Zum Beispiel können die Eigenschaften und Bewegungen einzelner Sterne bestimmt werden.
• http://de.wikipedia.org/wiki/Galaktis...
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The Galactic Center is the rotational center of the Milky Way galaxy. It is located at a distance of 8.33 kpc (~27,000 light years) from the Earth in the direction of the constellations Sagittarius, Ophiuchus, and Scorpius where the Milky Way appears brightest. It is believed that there is a supermassive black hole at the Galactic Center of the Milky Way.
Because of interstellar dust along the line of sight, the Galactic Center cannot be studied at visible, ultraviolet or soft X-ray wavelengths. The available information about the Galactic Center comes from observations at gamma ray, hard X-ray, infrared, sub-millimetre and radio wavelengths.
• http://en.wikipedia.org/wiki/Galactic...
• http://www.spitzer.caltech.edu/Media/...
Global Warming Facts
NASA Global Warming Facts: 2009 - Second Warmest Year on Record; End of Warmest Decade
Global climate change ... NASA's eyes on the Earth: A warming world - global temperature update ... piecing together the temperature puzzle.
Each year, scientists at NASA'S Goddard Institute for Space Studies analyze global temperature data. The past year, 2009, tied as the second warmest year since global instrumental temperature records began 130 years ago. Worldwide, the mean temperature was 0.57°C (1.03°F) warmer than the 1951-1980 base period. And January 2000 to December 2009 came out as the warmest decade on record.
• http://climate.nasa.gov/warmingworld
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2009 was tied for the second warmest year in the modern record, a new NASA analysis of global surface temperature shows. The analysis, conducted by the Goddard Institute for Space Studies (GISS) in New York City, also shows that in the Southern Hemisphere, 2009 was the warmest year since modern records began in 1880.
Although 2008 was the coolest year of the decade, due to strong cooling of the tropical Pacific Ocean, 2009 saw a return to near-record global temperatures. The past year was only a fraction of a degree cooler than 2005, the warmest year on record, and tied with a cluster of other years — 1998, 2002, 2003, 2006 and 2007 1998 and 2007 — as the second warmest year since recordkeeping began.
"There's always an interest in the annual temperature numbers and on a given year's ranking, but usually that misses the point," said James Hansen, the director of GISS. "There's substantial year-to-year variability of global temperature caused by the tropical El Niño-La Niña cycle. But when we average temperature over five or ten years to minimize that variability, we find that global warming is continuing unabated."
January 2000 to December 2009 was the warmest decade on record. Throughout the last three decades, the GISS surface temperature record shows an upward trend of about 0.2°C (0.36°F) per decade. Since 1880, the year that modern scientific instrumentation became available to monitor temperatures precisely, a clear warming trend is present, though there was a leveling off between the 1940s and 1970s.
The near-record temperatures of 2009 occurred despite an unseasonably cool December in much of North America. High air pressures in the Arctic decreased the east-west flow of the jet stream, while also increasing its tendency to blow from north to south and draw cold air southward from the Arctic. This resulted in an unusual effect that caused frigid air from the Arctic to rush into North America and warmer mid-latitude air to shift toward the north.
"Of course, the contiguous 48 states cover only 1.5 percent of the world area, so the U.S. temperature does not affect the global temperature much,' said Hansen. In total, average global temperatures have increased by about 0.8°C (1.5°F) since 1880.
"That's the important number to keep in mind," said Gavin Schmidt, another GISS climatologist. "In contrast, the difference between, say, the second and sixth warmest years is trivial since the known uncertainty — or noise — in the temperature measurement is larger than some of the differences between the warmest years."
Decoding the Temperature Record: Climate scientists agree that rising levels of carbon dioxide and other greenhouse gases trap incoming heat near the surface of the Earth and are the key factors causing the rise in temperatures since 1880, but these gases are not the only factors that can impact global temperatures.
• http://www.giss.nasa.gov/research/new...
Friday, May 21, 2010
A Real Shooting Star
The Hidden Universe (Episode 13): Mira - A real shooting star!
The star Mira (Omicron Ceti) has kept a stunning secret that scientists have only just discovered in the glow of ultraviolet light.
This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.
When people say they see a shooting star after noticing a momentary streak of light in the night sky, what they really see are meteors burning up as they enter the Earths atmosphere—nothing to do with stars at all.
However, Mira, the star in this video, really is a shooting star—traveling at supersonic speed and trailing a glowing tail. Go ahead make a wish. You have some time to come up with a good one. The length of the tail and the speed of the star means it has been doing this for at least 30,000 years.
Mira (pronounced my-rah) is also known as Omicron Ceti. Mira is the only normal star known to have a tail. You cant even see Mira very well in the image because it is tiny compared to the tail. Mira is 350 lightyears from Earth. If you could see the star and its tail with your naked eyes, it would be as long as the width of four full Moons! The tail stretches an astonishing 13 light-years. If our Sun had a tail like this, it would reach far beyond the edge of the solar system and extend nearly three times further than Proxima Centauri, the closest star to the Sun. In fact, the 20 nearest stars to the Sun are closer than the length of Miras tail.
• http://spitzer.caltech.edu/
• http://spaceplace.nasa.gov/en/educato...
Scientist Claims To Make First Man-Made Cell Dr Craig Venter Creates Synthetic Life In Laboratory.
Science, it works, bitches!
Thursday, May 20, 2010
Science Breakthrough! Synthetic Cell
Molecular biologists have created the first bacterium controlled by synthesized DNA.
LA Times Article:
http://www.latimes.com/news/science/l...
Nature News Article:
http://www.nature.com/news/2010/10052...
Newsnight Interview:
http://www.youtube.com/watch?v=_WbNu_...
BBC Interview:
http://www.youtube.com/watch?v=eoqBSN...
Skype Interview:
http://www.youtube.com/watch?v=G2fifu...
http://www.youtube.com/watch?v=S-qd05...
LA Times Article:
http://www.latimes.com/news/science/l...
Nature News Article:
http://www.nature.com/news/2010/10052...
Newsnight Interview:
http://www.youtube.com/watch?v=_WbNu_...
BBC Interview:
http://www.youtube.com/watch?v=eoqBSN...
Skype Interview:
http://www.youtube.com/watch?v=G2fifu...
http://www.youtube.com/watch?v=S-qd05...
Wednesday, May 19, 2010
Theory of Mind - Robert Seyfarth, RDF TV
Robert Seyfarth talks about how children develop a 'theory of mind'.
Presented by
THE RICHARD DAWKINS FOUNATION
Directed by
JOSH TIMONEN
Tuesday, May 18, 2010
Into the Night Volcano
The historic eruption of Hawaii's Kilauea volcano in 1959. Here's Nature red in tooth and claw, at its most beautiful and violent at the same time. Music by Kevin MacLeod of Incompetech.com.
Can Monkeys Talk? - Robert Seyfarth, RDF TV
Robert Seyfarth describes how monkey calls used by Vervet Monkeys might be precursors to language.
To read more about language in monkeys (and chimps), see the NY Times article: "Deciphering the chatter of monkeys and chimps"
http://richarddawkins.net/articles/49...
Download Quicktime Version (720p HD):
http://c0116791.cdn.cloudfiles.racksp...
See more at:
http://richarddawkins.net
If you enjoy content like this, please consider donating to RDFRS here:
http://richarddawkins.net/pages/donate
Presented by
THE RICHARD DAWKINS FOUNDATION
Directed by
JOSH TIMONEN Category:
CERN: HIT - A New Dimension In Cancer Therapy
Spotlight on CERN - LHC News: A short tour of HIT - The Heidelberg Ion Beam Therapy Center.
HIT: A new dimension in radiotherapy
HIT is the world's first heavy ion therapy facility with a movable radiation source (gantry). The beam head can be rotated by 360° around the patient. Numerous angles of irradiation can be selected.
HIT is the world's first ion therapy facility using the Intensity-controlled Rasterscan technique which offers the highest level precision in the three-dimensional radiation of tumors ever reached in the world.
HIT is the first hospital-based treatment facility at a clinic in Europe where patients can be treated with protons as well as with various heavy ions (helium, carbon and oxygen ions). Ions offer the highest precision in tumor irradiation. Heavy ions also have a greater destructive power than the conventional radiation therapy.
HIT ist the first therapy facility in the world that is equipped with robot-controlled treatment tables. This guaratees the highest level of precision in positioning the patient under the radiation source.
• http://www.klinikum.uni-heidelberg.de...
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Heidelberg Ion Therapy Centre (HIT)
A new cancer therapy facility developed at the GSI Centre for Heavy Ion Research has begun routine operations. Ion beam therapy is precise, effective and gentle. It offers better chances of a cure, shorter treatment cycles and fewer side effects. The ion beams penetrate the body and exert their full impact deep in the tissue, where they can precisely hit pinhead-sized tumour clusters. To reach the tumour, the ions are accelerated to about three quarters the speed of light, or almost one billion km/h. The ion beams are steered with millimetre accuracy.
The surrounding healthy tissue remains mostly unaffected, which makes the method ideal for treating deep-seated tumours close to vital organs. Before treating the first patient, GSI scientists spent decades doing basic research on the radiobiological effects of ions and on developing a technique to target the tumour precisely and safely. "Initially, it was thought impossible. We succeeded thanks to the collaboration between various disciplines," says Gerhard Kraft, initiator and pioneer of ion beam therapy. Approximately 1,300 patients can be treated at HIT each year. Since 1997, 440 patients have been treated with carbon ion beams at the GSI. Clinical studies record a cure rate of up to 90%.
At the heart of HIT lies an accelerator built for therapeutic use and adapted to medical routine operation. The three treatment areas at HIT are located next to the accelerators, two of which advance the GSI technology. The third area features a rotating ion beam guidance system with which the beam can be fired at the patient's tumour from any angle, thus vastly enhancing the treatment options. HIT is operated by the University Hospital Heidelberg, where a special building is home to the new facility. With the exception of Japan, Germany is the only country to offer such a unique cancer treatment. Under a licence agreement between the GSI and Siemens AG, two more facilities modelled on HIT are under construction in Marburg and Kiel.
• http://www.research-in-germany.de/med...
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Heidelberg Ion Therapy Centre opens
The Heidelberg Ion Therapy Centre (HIT) celebrated its opening at the Heidelberg University Hospital on 2 November. Developed with scientists and engineers at GSI in Darmstadt, the novel ion-beam cancer therapy facility is now ready to treat large numbers of patients, some 1300 a year.
HIT uses beams of ions, i.e. positively charged carbon or hydrogen atoms, which penetrate the body and exert their full impact deep within the tissue (CERN Courier December 2006 p17). To reach the tumour tissue, the ion beams are accelerated and then steered with such precision that they can irradiate a tumour the size of a tennis ball with millimetre accuracy, point by point. The surrounding healthy tissue remains mostly unaffected, so the method is particularly suited for treating deep-seated tumours that are close to vital or important organs such as the brain stem or the optic nerve.
The new facility has grown out of pioneering work at GSI, which has conducted fundamental research in radiobiology, nuclear physics and accelerator technology for therapeutic uses since 1980. The construction of a pilot ion-therapy project at GSI began in 1993 in a collaboration between GSI, the Heidelberg University Hospital, the Deutsches Krebsforschungszentrum in Heidelberg and the Forschungszentrum Dresden-Rossendorf.
• http://cerncourier.com/cws/article/ce...
Sunday, May 16, 2010
Cosmic Visions: New Space Science Missions
Cosmic Visions: New ESA Space Science Missions Move Forward.
Under its Cosmic Vision initiative, the European Space Agency has selected three medium-sized science missions to enter the definition phase. Spacecraft to study dark energy, Earth-like exoplanets and our own Sun now have to prove that they can be built within the allocated budgets. 2011, just two of them will be retained to go forward for launches no earlier than 2017. This movie describes the three missions Euclid, Plato and Solar Orbiter.
Since the early '60s, ESA has excelled in pushing back the frontiers in space science: exploring the nearest planets and the most distant celestial bodies of our solar system; lifting the veil with powerful telescopes on galaxy and star formation and probing the most violent processes in the Universe; and better understanding its evolution since the Big Bang.
The three selected missions are the finalists from some 50 proposals which were whittled down to just six in late 2007 and submitted for industrial assessment. In February, the Agency's Science Programme Committee pared down the choice once more.
The project called Euclid will investigate key issues in physics, cosmology and general relativity. Until about 30 years ago astronomers thought the Universe was composed of ordinary matter -- protons, neutrons, electrons and atoms.
But the picture has changed dramatically: it is today assumed that ordinary matter only accounts for 4 % of the Universe, 20 % being dark matter and the remainder a mysterious dark energy.
The Euclid spacecraft will house a wide-field, high-precision telescope. For three years it will scan the entire sky, accurately measuring the effects of dark energy, believed to be the main driver of an accelerated expansion of the Universe. Euclid will also map in three dimensions the distribution of dark matter.
Following in the footsteps of the COROT and Kepler telescopes, the PLATO mission will address the 'holy grail' question of the existence of other Earth-like worlds.
Scanning the sky with an increased field of view, and by detecting the decrease in light as planets transit in front of their host star, the missaims to discover many more exoplanets, including those with orbital periods like our own. Observing brighter stars than previous missions, PLATO will be able to characterise planetary systems, the host stars and their planets at the same time.
Several missions -- such as Ulysses, SOHO, the Clusters, or Stereo -- have already studied our own Sun. The big difference with the third mission to be selected is, in a word: distance. Solar Orbiter will place itself as close to the Sun as Mercury itself, braving the intense heat and light, ten times more intense than that felt on Earth.
From an orbit allowing views of all sides of the Sun including its poles, the spacecraft is expected to deliver images of the Suns surface and data of the powerful magnetic fields, and high-resolution views of the powerful eruptions of solar particles that are spewed into space.
Given the extreme environment, Solar Orbiter is a considerable chanllenge, and will rely on much of the technology already developed for the Bepi-Colombo mission, ESA's probe to orbit Mercury.
Each mission has now entered the definition phase to validate the the configuration choices of their spacecraft and science instruments, the technologies to be used, their launch and operations scenarios.
But perhaps their greatest challenge probably will be to stay within their allotted 470 Million euro budgets knowing full well that ESA's selection process ist not over: in 2011 only two of the three missions -- and however merit-worthy -- can be retained to go-ahead.
• http://www.esa.int/
Saturday, May 15, 2010
Mapping One Billion Stars In The Milky Way And Beyond
Science@ESA Vodcast (Episode 6, Part 2): Charting the Galaxy ... from Hipparcos to Gaia - Mapping one billion stars in the Milky Way and beyond.
In this sixth episode of the Science@ESA vodcast series Rebecca Barnes discovers the motions of the stars, learns how astronomers measure their distances and looks at the new European mission that will really get to grips with our place in the Universe.
Gaia is a global space astrometry mission. Its goal is to create the largest and most precise 3-D chart of our Milky Way galaxy by providing unprecedented positional and radial velocity measurements for about one billion stars in our galaxy and throughout the Local Group.
ESA GAIA MISSION
Gaia is an ambitious mission to chart a three-dimensional map of our galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about one percent of the Galactic stellar population.
Combined with astrophysical information for each star, provided by on-board multi-colour photometry, these data will have the precision necessary to quantify the early formation, and subsequent dynamical, chemical and star formation evolution of the Milky Way Galaxy.
Additional scientific products include detection and orbital classification of tens of thousands of extra-solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our Solar System, through galaxies in the nearby Universe, to some 500.000 distant quasars. It will also provide a number of stringent new tests of general relativity and cosmology.
• http://sci.esa.int/science-e/www/area...
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Gaia will conduct a census of a thousand million stars in our Galaxy, monitoring each of its target stars about 70 times over a five-year period. It will precisely chart their positions, distances, movements, and changes in brightness. It is expected to discover hundreds of thousands of new celestial objects, such as extra-solar planets and failed stars called brown dwarfs. Within our own Solar System, Gaia should also observe hundreds of thousands of asteroids.
Additional scientific benefits include the detection and characterisation of tens of thousands of extra-solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our Solar System, through galaxies in the nearby Universe, to about 500 000 distant quasars. It will also provide stringent new tests of Albert Einsteins general relativity theory.
Gaia will rely on the proven principles of ESAs Hipparcos mission to create an extraordinarily precise three-dimensional map of more than a thousand million stars throughout our Galaxy and beyond. Gaia will also map the motions of stars, which encode their origins and evolution. Gaia will provide the detailed physical properties of each star observed, revealing luminosity, temperature, gravity and composition. This huge stellar census will provide the basic observational data to tackle an enormous range of important problems related to the origin, structure and evolutionary history of our Galaxy.
At its heart, Gaia contains two optical telescopes that can precisely determine the location of stars and split their light into a spectrum for analysis. The spacecraft itself can be divided into two sections: the payload module and the service module. The payload consists of the telescopes and three instruments. The service module contains the propulsion system, the communications units and other essential components that allow the spacecraft to function and return data to Earth. Beneath the service module and the payload module is the sunshield and solar array assembly.
• http://www.esa.int/export/esaSC/12037...
Thursday, May 13, 2010
Portrait of a Solar System 20 Light Years Away
This ESOCast briefly describes the planetary mother lode detected around the red dwarf star Gliese 581. This star may be tiny, but it could harbor something big. From ESO with the famous Dr. J.
Spiky Sight - Sea Urchins Use Whole Body As Eye
Sea urchins don't seem to have any problems avoiding predators or finding comfortable dark corners to hide in, but they appear to do all this without eyes. So how do they see? It appears that sea urchins may use the whole surface of their bodies as a compound eye, and the animals' spines may shield their bodies from light coming from wide angles to enable them to pick out relatively fine visual detail. Divya Yerramilli and Sönke Johnsen from Duke University explain that if this is the case, sea urchins with densely packed spines will have better vision than sea urchins with sparsely packed spines, so they decided to test the vision of Strongylocentrotus purpuratus sea urchins, with tightly packed spines, to find out how well they see.
Placing individual urchins in a brightly lit arena with a 6 cm or 9 cm diameter dark disk on the arena's wall, the team viewed the shadows of the moving animals from beneath the arena's white floor. Would the sea urchins see the disk and respond to it, or would they be oblivious to the disk's presence? Recording 39 urchins' responses to the disk at different positions around the arena's perimeter, the duo saw that the urchins wandered randomly around the arena when the 6 cm diameter disk was in place; they didn't respond to it. But it was a different matter with the 9 cm diameter disk; the urchins either raced toward it or fled in the opposite direction.
Calculating the visual angle of the 9 cm diameter disk from a sea urchin's perspective, Yerramilli and Johnsen suggest that the sea urchin's visual resolution is at least 10 deg. And when the pair calculated the sea urchin's visual resolution based on the animal's spine density, they found that it could be as good as 8 deg., but not good enough to see the smaller 6 cm diameter disk.
But why did some of the sea urchins career toward the disk while others turned away? Yerramilli and Johnsen suspect that it depends on the sea urchin's interpretation of the dark object. Some of the animals may interpret the object as a predator and flee, while others identify it as shelter and head towards it. What is more surprising is that the urchins' vision is as good as Nautilus and horseshoe crab vision, which is quite impressive for an echinoid that has turned its whole body into an eye.
• http://jeb.biologists.org/cgi/content...
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Wednesday, May 12, 2010
Monday, May 10, 2010
Molecular Evolution: Genes And Proteins
Molecular evolution is the process of evolution at the scale of DNA, RNA, and proteins. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology and population genetics sought to understand recent discoveries on the structure and function of nucleic acids and protein. Some of the key topics that spurred development of the field have been the evolution of enzyme function, the use of nucleic acid divergence as a "molecular clock" to study species divergence, and the origin of non-functional or junk DNA. Recent advances in genomics, including whole-genome sequencing, high-throughput protein characterization, and bioinformatics have led to a dramatic increase in studies on the topic. In the 2000s, some of the active topics have been the role of gene duplication in the emergence of novel gene function, the extent of adaptive molecular evolution versus neutral drift, and the identification of molecular changes responsible for various human characteristics especially those pertaining to infection, disease, and cognition.
http://en.wikipedia.org/wiki/Gene_evo...
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Principles of molecular evolution
Mutations are permanent, transmissible changes to the genetic material (usually DNA or RNA) of a cell. Mutations can be caused by copying errors in the genetic material during cell division and by exposure to radiation, chemicals, or viruses, or can occur deliberately under cellular control during the processes such as meiosis or hypermutation. Mutations are considered the driving force of evolution, where less favorable (or deleterious) mutations are removed from the gene pool by natural selection, while more favorable (or beneficial) ones tend to accumulate. Neutral mutations do not affect the organism's chances of survival in its natural environment and can accumulate over time, which might result in what is known as punctuated equilibrium; the modern interpretation of classic evolutionary theory.
http://en.wikipedia.org/wiki/Gene_evo...
The Erie Sounds Of Saturn
The Cassini spacecraft began detecting intense radio emissions from the planet Saturn. They come from the planets aurorae, where magnetic field lines threat the polar regions. These signals have been shifted into the range of human hearing and compressed in time.
Eagle Nebula - Pillars Of Creation And Destruction
The Hidden Universe of the Spitzer Space Telescope (Episode 6): The Eagle Nebula - Pillars of creation and destruction.
This video series showcases some of the most exciting discoveries in infrared astronomy from NASA's Spitzer Space Telescope. Looking beyond the visible spectrum of light, Spitzer can see a whole new universe of dust and stars hidden from our Earth-bound eyes.
Theyre known as the Pillars of Creation, but according to recent Spitzer observations these ghostly apparitions have already met their own destruction!
This nursery for baby stars is known as M16 or the Eagle Nebula. But whether or not youve heard the name, youve likely seen it before. In 1995 the Hubble Space Telescope gave us the "Pillars of Creation", which has become a truly iconic image for astronomy.
Now the Spitzer Space Telescope has exposed this Eagles infrared plumage. The pillars, opaque in visible light, become ghostly, transparent columns of glowing dust. The dark spots seen in their tips shed light, or more appropriately shadow, on their formation.
In regions like this, dust particles are easily destroyed by ultraviolet light from hot, young stars. The densest dust clumps, opaque even in the infrared, will erode more slowly and shield the areas behind them. Columns emerge, impressive but hardly more substantial than shadows.
Spitzer has let astronomers view the Eagle Nebula in many different shades and combinations of infrared light. But one of these observations has hinted at a grim fate for the Pillars. Nicholas Flagey, a graduate student at the Institute dAstrophysique Spatiale in Orsay, France, explains.
When we use the seven infrared color images that Spitzer obtained for the Eagle Nebula, we see that six of them look almost exactly the same. But one of them, the 24 micron image, is completely different from the other ones. The oddball warm dust at 24 microns is here seen as red, while the cooler dust at shorter wavelengths is blue-green.
We see that there is dust that is much more hot inside the nebula and to explain this we guess there is a shock wave that heats the dust and the gas that didnt heat the pillars of creation. And to make this shockwave, what we think is that there was a massive star that goes on into a supernova.
Flagey and his team estimate the light from this Eagle-born supernova explosion would have reached Earth one to two thousand years ago. We should see its slow-moving shockwave smash into the fragile pillars within the next thousand years.
"So at the end the pillars are going to be destroyed by the shockwave. They are going to crumble because some parts of them are not dense enough to resist the shockwave. So at the end the pillars of creation are going to be the pillars of destruction." In fact this show is a cosmic delayed broadcast of events that happened long ago. The Eagle Nebula is 7000 light years away, indicating how long its light takes to reach us. The Pillars of Creation had crumbled to dust, so to speak, well before the great pyramids were built!
But creation and destruction can be two sides of the same coin. An infrared view reveals baby stars nestled within the doomed pillars, stars that will be exposed when the shockwave brushes the dust away.
The same shockwave will continue to expand through the Eagle, colliding with and compressing other dust clouds. Astronomers think this process can trigger a new generation of star formation. More pillars will arise, just as weve seen throughout our studies of the Milky Way, as a natural stage in the ongoing life cycle of stars.
• http://www.spitzer.caltech.edu/
Friday, May 7, 2010
Cassiopeia A - 3D Fly-through
The Beautiful Universe: Chandra in HD (3): Cassiopeia A - 3-D Fly-through.
Since its launch on July 23, 1999, the Chandra X-ray Observatory has been NASA's flagship mission for X-ray astronomy, taking its place in the fleet of "Great Observatories."
The many faces of Cassiopeia A
Cassiopeia A (Cas A), the youngest known supernova remnant in the Milky Way galaxy, has been observed with unprecedented precision over the five year lifetime of the Chandra Observatory. From one of the first observations in 1999 to a million second long observation in 2004, Chandra images have been instrumental in unlocking the mysteries of this recent stellar explosion.
• http://chandra.harvard.edu/fifth/casa/
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NASA's Chandra X-ray Observatory is a telescope specially designed to detect X-ray emission from very hot regions of the Universe such as exploded stars, clusters of galaxies, and matter around black holes. Because X-rays are absorbed by Earth's atmosphere, Chandra must orbit above it, up to an altitude of 139,000 km (86,500 mi) in space.
The Smithsonian's Astrophysical Observatory in Cambridge, MA, hosts the Chandra X-ray Center which operates the satellite, processes the data, and distributes it to scientists around the world for analysis. The Center maintains an extensive public web site about the science results and an education program.
Chandra carries four very sensitive mirrors nested inside each other. The energetic X-rays strike the insides of the hollow shells and are focussed onto electronic detectors at the end of the 9.2- m (30-ft.) optical bench. Depending on which detector is used, very detailed images or spectra of the cosmic source can be made and analyzed.
Chandra has imaged the spectacular, glowing remains of exploded stars, and taken spectra showing the dispersal of elements. Chandra has observed the region around the supermassive black hole in the center of our Milky Way, and found black holes across the Universe.
Chandra has traced the separation of dark matter from normal matter in the collision of galaxies in a cluster and is contributing to both dark matter and dark energy studies. As its mission continues, Chandra will continue to discover startling new science about our high-energy Universe.
• http://chandra.harvard.edu/
Thursday, May 6, 2010
Wednesday, May 5, 2010
Pluto Red Outpost of the Final Frontier
Pluto was kicked off the list of major planets. It seems to have responded by turning a mysterious red color, according to scientists working with the Hubble Space Telescope. They're now trying to find out what makes its surface so dynamic. From the Space Telescope Science Institute.
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