An international team led by Princeton University scientists has discovered an elusive massless particle theorized 85 years ago. The particle could give rise to faster and more efficient electronics because of its unusual ability to behave as matter and antimatter inside a crystal, according to new research
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NASA Headquarters, Washington
December 05, 2011
PASADENA, Calif. -- NASA's Voyager 1 spacecraft has entered a new region between our solar system and interstellar space. Data obtained from Voyager over the last year reveal this new region to be a kind of cosmic purgatory. In it, the wind of charged particles streaming out from our sun has calmed, our solar system's magnetic field is piled up, and higher-energy particles from inside our solar system appear to be leaking out into interstellar space.
"Voyager tells us now that we're in a stagnation region in the outermost layer of the bubble around our solar system," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. "Voyager is showing that what is outside is pushing back. We shouldn't have long to wait to find out what the space between stars is really like."
Although Voyager 1 is about 11 billion miles (18 billion kilometers) from the sun, it is not yet in interstellar space. In the latest data, the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere, the bubble of charged particles the sun blows around itself. The data do not reveal exactly when Voyager 1 will make it past the edge of the solar atmosphere into interstellar space, but suggest it will be in a few months to a few years.
The latest findings, described today at the American Geophysical Union's fall meeting in San Francisco, come from Voyager's Low Energy Charged Particle instrument, Cosmic Ray Subsystem and Magnetometer.
Scientists previously reported the outward speed of the solar wind had diminished to zero in April 2010, marking the start of the new region. Mission managers rolled the spacecraft several times this spring and summer to help scientists discern whether the solar wind was blowing strongly in another direction. It was not. Voyager 1 is plying the celestial seas in a region similar to Earth's doldrums, where there is very little wind.
During this past year, Voyager's magnetometer also detected a doubling in the intensity of the magnetic field in the stagnation region. Like cars piling up at a clogged freeway off-ramp, the increased intensity of the magnetic field shows that inward pressure from interstellar space is compacting it.
Voyager has been measuring energetic particles that originate from inside and outside our solar system. Until mid-2010, the intensity of particles originating from inside our solar system had been holding steady. But during the past year, the intensity of these energetic particles has been declining, as though they are leaking out into interstellar space. The particles are now half as abundant as they were during the previous five years.
At the same time, Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside, which is another indication of the approaching boundary.
"We've been using the flow of energetic charged particles at Voyager 1 as a kind of wind sock to estimate the solar wind velocity," said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We've found that the wind speeds are low in this region and gust erratically. For the first time, the wind even blows back at us. We are evidently traveling in completely new territory. Scientists had suggested previously that there might be a stagnation layer, but we weren't sure it existed until now."
Launched in 1977, Voyager 1 and 2 are in good health. Voyager 2 is 9 billion miles (15 billion kilometers) away from the sun.
The Voyager spacecraft were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both. JPL is a division of the California Institute of Technology. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate in Washington. For more information about the Voyager spacecraft, visit:http://www.nasa.gov/voyager.
For more information about NASA media events at the American Geophysical Union meeting, visit:http://www.nasa.gov/agu.
A brief introduction to the brain
Neuroscience is a vast subject, so we have tried to present the basic information you may need in order to understand the neuroscience behind mindfulness. Much of the content of this page has been extracted or adapted from Dr Shanida Nataraja's book "The Blissful Brain: Neuroscience and proof of the power of meditation", which is available in the Mindfulnet Amazon shop located on the resources page. All extracts and illustrations have been reproduced with the permission of the publisher & author
The human brain is organised in a hierarchical manner: the oldest parts controlling the more primitive, instinctual behavioural reflexes; the newest parts controlling the more sophisticated cognitive, sensory and motor functions. The human brain is made up of three main blocks: the forebrain, the midbrain and the hindbrain.
The oldest part of the human brain, the hindbrain, evolved more than 500 million years ago. It closely resembles the brain of a modern reptile, so is sometimes called "the mammalian brain". It is responsible for automatic physiological reflexes that control breathing, heart rate and digestion, and coordinate movement and sense perception.
The midbrain contains neurones responsible for temperature control and the fine tuning of movement. It relays sensory information from the bodies sensory organs to the forebrain. It also plays an important part of the limbic system, a group of brain structures associated with the expression of emotion.
The most evolved part is the forebrain which is composed of cerebral hemispheres, and is what we most commonly think of as the brain, and the hypothalamus and thalamus. In the last 100,000 years, the weight of the human brain has tripled, and most of this growth has been in the cerebral hemispheres. The neurones of the forebrain control cognitive, sensory and motor function, as well as regulating reproductive functions, eating, sleeping and the display of emotion
Although you may often hear people referring to "left brain thinking" or "right brain thinking" there are extensive connections between the two brain hemispheres and information is processed by using both hemispheres of the brain. Imaging studies have shown that most cognitive tasks such as problem solving or strategic planning or strategic planning activates neurones in more than one brain region simultaneously, or at least in close succession.
For example is you are inspecting a new, never seen before object, the left hemisphere examines the object logically to see how it has been made, what it is made from, any distinguishing marks, and attempts based on the information gathered to guess what the object might be, and may try to logically catagorise it. This gives a partial description. The right hemisphere looks at the object more holistically, notes any functions in its design, or clues about what it may have been used for, how it feels, or any emotions it may evoke. The right hemisphere puts this into the context of what it already 'knows' about the world and then offers creative suggestions for its function. By working together as a team, sharing logical and creative information, the two hemispheres can generate a more complete description.
In the western world, most individuals navigate through their everyday life in a fashion dominated by left brain thinking. Missing out on right brain activity results in too much thinking going on: too much frantic doing, not enough time being.
According to neuroscientist, Dr Shanida Nataraja, westerners use the left hemisphere of their brain too much.
For simplicity of explanation, the left hemisphere is associated with analytical, rational and logical processing, where as the right hemisphere is associated with abstract thought, non verbal awareness, visual & spatial perception and the expression and modulation of emotions. In the western world, most individuals navigate through their everyday life in a fashion dominated by left brain thinking. Missing out on right brain activity results in too much thinking going on: too much frantic doing, not enough time being.
Practicing mindfulness can bring about calmness, stilling the brain chatter, and help us shift towards right brain mode.
By engaging our right brain we activate the parasympathetic nervous system (as opposed to the adrenaline releasing sympathetic system). More parasympathetic activity means less stress and therefore better health.
According to Neuroscientist Dr Shanida Nataraja's studies, those new to meditation practices such as mindfulness often put pressure on themselves to be successful and "get there" quickly - a left brain "are we there yet?" approach - and consequently take longer to benefit. Shinda suggests that the key is to be kind to yourself, acknowledging thought and letting go. This activates certain pathways in the brain which reduce left brain activity
Mindfulness is classed as a passive form of meditation. The following illustrations and description of the overall chain of brain processes during mindfulness meditation is an extract from Dr Shanida Nataraja's book "The Blissful Brain: Neuroscience and proof of the power of meditation", which is available in the Mindfulnet Amazon shop located on the resources page. The extracts and illustrations have been reproduced with the permission of the publisher & author.
At the same time, the meditator also becomes less aware of sensory information stemming from his external environment, and therefore less aware of his orientation in space and time. This dissolving of the self / non-self boundary is reflected in a decrease of activity in the right parietal lobe. Not only does it have an impact on activity in the right orientation association area (leading to a loss of sense of space and/or time), but it also has an impact on activity in the right verbal-conceptual area, leading to an inability to convey the experience efficiently through language. (see step 1 in illustration above)
This chain of events is thought to result in the activation of two important structures in the limbic system. There are extensive connections between the parietal lobe's orientation association area and the hippocampus (see step 2 on illustration above), which in turn stimulates the amygdala. These two structures are responsible for assigning emotional significance to our experiences. The activation of the hippocampus conveys emotional significance of the experience and imprints the emotionally charged experience and imprints in our long term memory.
When practicing mindfulness the activation of the amygdala confers emotional significance to the lack of sensory information. Through these actions on the hypothalamus, the amygdala modifies the activity of the autonomic nervous system (see step 3 in illustration above).
First a blissful, peaceful state arises from the maximal activation of the parasympathetic (relaxation) nervous system, and then, as the different neural, hormonal and other triggers swing in, there is a maximal activation of the sympathetic (arousal) nervous system, producing a mentally clear and alert state. Physiological effects, such as changes to breathing rate, heart rate or blood pressure are the result of the amygdala's effect on midbrain structures that control these functions (see step 4 in illustration above).
Both of the left and right orientation and verbal-conceptual association areas are therefore switched off. A lack of activity in the right orientation association area gives rise to a sense of unity and wholeness, where as lack of activity in the left orientation association area results in the dissolving of the self/non-self boundary
Some of us need regular amounts of coffee or other chemical enhancers to make us cognitively sharper. A newly published study suggests that mindfulness would prepare us just as well.
While past research using neuroimaging technology has shown that meditation techniques can promote significant changes in brain areas associated with concentration, it has always been assumed that extensive training was required to achieve this effect.
Surprisingly, the benefits may be achievable even without all the work. Psychologists studying the effects of a meditation technique known as "mindfulness " found that mindfulness-trained participants showed a significant improvement in their critical cognitive skills (and performed significantly higher in cognitive tests than a control group) after only four days of training for only 20 minutes each day.
Molecular diffusion in a boundary-free medium depends only on the molecular size, the temperature, and medium viscosity. However, the critical determinant of the molecular diffusion property in inhomogeneous biological tissues has not been identified. Here, using an in vitro system and a high-resolution MR imaging technique, we show that the length of the intact plasma membrane is a major determinant of water diffusion in a controlled cellular environment and that the cell perimeter length (CPL) is sufficient to estimate the apparent diffusion coefficient (ADC) of water in any cellular environment in our experimental system (ADC = −0.21 × CPL + 1.10). We used this finding to further explain the different diffusion kinetics of cells that are dying via apoptotic or non-apoptotic cell death pathways exhibiting characteristic changes in size, nuclear and cytoplasmic architectures, and membrane integrity. These results suggest that the ADC value can be used as a potential biomarker for cell death
شما را به تقواى الهى و پارسایى در دینتان و تلاش براى خدا و راستگویى و امانتدارى درباره کسى که شما را امین دانسته ـ نیکوکار باشد یا بدکار ـ و طول سجود و حُسنِ همسایگى سفارش مىکنم.
امام حسن عسکری علیهالسلام فرمودند: شما را به تقواى الهى و پارسایى در دینتان و تلاش براى خدا و راستگویى و امانتدارى درباره کسى که شما را امین دانسته ـ نیکوکار باشد یا بدکار ـ و طول سجود و حُسنِ همسایگى سفارش مىکنم.
محمّد(صلى الله علیه وآله وسلم)براى همین آمده است.
در میان جماعت هاى آنان نماز بخوانید و بر سر جنازه آنها حاضر شوید و مریضانشان را عیادت کنید. و حقوقشان را ادا نمایید، زیرا هر یک از شما چون در دینش پارسا و در سخنش راستگو و امانتدار و خوش اخلاق با مردم باشد، گفته مىشود: این یک شیعه است، و این کارهاست که مرا خوشحال مىسازد.
تقواى الهى داشته باشید، مایه زینت باشید نه زشتى، تمام دوستى خود را به سوى ما بکشانید و همه زشتى را از ما بگردانید.
زیرا هر خوبى که درباره ما گفته شود ما اهل آنیم و هر بدى درباره ما گفته شود ما از آن به دوریم.
در کتاب خدا براى ما حقّى و قرابتى از پیامبر خداست و خداوند ما را پاک شمرده، احدى جز ما مدّعى این مقام نیست، مگر آن که دروغ مىگوید.
زیاد به یاد خدا باشید و زیاد یاد مرگ کنید و زیاد قرآن را تلاوت نمایید و زیاد بر پیغمبر(صلى الله علیه وآله وسلم) سلام و تحیّت بفرستید. زیرا صلوات بر پیامبر خدا(صلى الله علیه وآله وسلم) ده حسنه دارد.
آنچه را به شما گفتم حفظ کنید و شما را به خدا مىسپارم، و سلام بر شما.
متن حدیث:
أُوصیکُمْ بِتَقْوَى اللّهِ وَ الْوَرَعِ فى دینِکُمْ وَالاِْجْتَهادِ لِلّهِ وَ صِدْقِ الْحَدیثِ وَ أَداءِ الأَمانَةِ إِلى مَنِ ائْتَمَنَکُمْ مِنْ بَرٍّ أَوْ فاجِر وَ طُولُ السُّجُودِ وَ حُسْنِ الْجَوارِ. فَبِهذا جاءَ مُحَمَّدٌ(صلى الله علیه وآله وسلم) صَلُّوا فى عَشائِرِهِمْ وَ اشْهَدُوا جَنائِزَهُمْ وَ عُودُوا مَرْضاهُمْ وَ أَدُّوا حُقُوقَهُمْ، فَإِنَّ الرَّجُلَ مِنْکُمْ إِذا وَرَعَ فى دینِهِ وَ صَدَقَ فى حَدیثِهِ وَ أَدَّى الاَْمانَةَ وَ حَسَّنَ خُلْقَهُ مَعَ النّاسِ قیلَ: هذا شیعِىٌ فَیَسُرُّنى ذلِکَ. إِتَّقُوا اللّهَ وَ کُونُوا زَیْنًا وَ لا تَکُونُوا شَیْنًا، جُرُّوا إِلَیْنا کُلَّ مَوَدَّة وَ ادْفَعُوا عَنّا کُلَّ قَبیح، فَإِنَّهُ ما قیلَ فینا مِنْ حَسَن فَنَحْنُ أَهْلُهُ وَ ما قیلَ فینا مِنْ سُوء فَما نَحْنُ کَذلِکَ.
لَناحَقٌّ فى کِتابِ اللّهِ وَ قَرابَةٌ مِنْ رَسُولِ اللّهِ وَ تَطْهیرٌ مِنَ اللّهِ لا یَدَّعیهِ أَحَدٌ غَیْرُنا إِلاّ کَذّابٌ. أَکْثِرُوا ذِکْرَ اللّهِ وَ ذِکْرَ الْمَوْتِ وَ تِلاوَةَ الْقُرانِ وَ الصَّلاةَ عَلَى النَّبِىِّ(صلى الله علیه وآله وسلم)فَإِنَّ الصَّلاةَ عَلى رَسُولِ اللّهِ عَشْرُ حَسَنات، إِحْفَظُواما وَصَّیْتُکُمْ بِهِ وَ أَسْتَوْدِعُکُمُ اللّهَ وَ أَقْرَأُ عَلَیْکُمْ السَّلامَ.
شواهد جدید دانشمندان نشان میدهد اختروش پنهانی که آن را به عنوان درخشانترین کهکشان جهان میشناسیم، شدیدا دچار آشفتگی شده و به احتمال زیاد سرانجام کل موجودی گازهای ستارهای شکل خود را بیرون میریزد.
گروهی از محققان با استفاده از آرایه بزرگ میلیمتری/ زیرمیلیمتری آتاکاما حرکات واقعی محیط میان ستارهای این کهکشان، یعنی حرکات گازها و گرد و خاک بین ستارههای آن را ردیابی کردهاند.
این کهکشان 12.4 میلیارد سال نوری از ما فاصله دارد.
به گفته تیانو دیازسنتوز از دانشگاه دیگو پورتالز، محققان از این مشاهدات نتیجه گرفتند که کهکشان ذکر شده در اثر آشوبهایی دچار خود فروپاشی شده است.
بر اساس نتایج مطالعات قبلی که توسط فضاپیمای اکتشافی میدان گسترده مادون قرمز انجام شد، این کهکشان با لقب W2246-0526 نورهای مادون قرمزی از خود ساطع میکند که 350 تریلیون برابر نور خورشید است.
طبق شواهدی محکم، این کهکشان یک اختروش پنهان است که در مرکزش یک سیاهچاله غولپیکر خوشاشتها قرار دارد و در فاصلهای بسیار دور در پشت یک لایه ضخیم از گرد و خاک پنهان شده است.
روبروتو آسف، ستارهشناس دانشگاه دیگو پورتالز و سرپرست تیم مشاهدهای ALMA، گفت: ویژگیهای ذکر شده، این جرم آسمانی را به یک هیولای مادون قرمز تبدیل کرده است.
آسف در ادامه افزود: انرژی پرتوهای مادون قرمز ساطع شده از میان این گرد و خاک تاثیر شدید و مستقیمی بر روی کل این کهکشان میگذارد و آشفتگی زیادی در محیط میان ستارهای سراسر آن به وجود میآورد.
مشاهدات این گروه تحقیقاتی در Astrophysical Journal Letters منتشر شده است.
ISNA
ایستگاه فضایی بینالمللی نزدیک به زمین است و در فاصله حدود ۴۰۰ کیلومتری از زمین قرار دارد. سیاره زحل اما یک میلیارد و ۶۰۰ میلیون کیلومتر با زمین در حال حاضر فاصله دارد. عکاس این تصویر را ۱۵ ژانویه در آلمان گرفته است که ثبت آن با محاسباتی بسیار دقیق میسر شده است. عکاس دوربین را به تلسکوپ متصل کرده و با سرعت ۴۲ فریم بر ثانیه شروع به فیلمبرداری کرده است. گذر ایستگاه فضایی از مقابل زحل فقط ۰٫۰۲ ثانیه طول کشیده است.
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