Shared by mike
I want a pair of glasses that does this.

Magnetic field lines on the Sun, on August 20, 2010. Credit: NASA SDO/Lockheed Martin Space Systems Compan

The Sun's corona is threaded with a complex network of magnetic fields, and this amazing new image from the Solar Dynamics Observatory shows the magnetic field lines associated with a coronal hole that is now turning to face Earth. This map is from data taken on August 20, 2010 by the Helioseismic and Magnetic Imager instrument (HMI). The magnetic field lines are color coded: white lines show fields that are closed, not releasing solar wind, and gold lines show open fields, letting solar wind escape. Understanding these magnetic fields is important because it is thought that solar storms and flares, which can affect us here on Earth, result from changes in the structure and connections of these fields.
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Read the rest of Amazing Image: Map of Magnetic Field Lines of the Sun (214 words)

nancy for Universe Today, 2010. | Permalink | 7 comments | Add to del.icio.us
Post tags: Helioseismic and Magnetic Imager, Solar Dynamics Observatory

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Some birds can sense the Earth's magnetic field and orientate themselves with the ease of a compass needle. This ability is a massive boon for migrating birds, keeping frequent flyers on the straight and narrow. But this incredible sense is closely tied to a more mundane sense vision. Thanks to special molecules in their retinas, birds like the European robins can literally see magnetic fields. The fields appear as patterns of light and shade, or even colour, superimposed onto what they normally see.

Katrin Stapput from Goethe University has shown that this magnetoreception' ability depends on a clear image from the right eye. If it's covered by translucent frosted goggle, the birds become disorientated; if the left eye is covered, they can navigate just fine. So the robin's vision acts as a gate for its magnetic sense. Darkness (or even murkiness) keeps the gate shut, but light opens it, allowing the internal compass to work.

The magnetic sense of birds was first discovered in robins in 1968, and its details have been teased out ever since. Years of careful research have told us that the ability depends on light and particularly on the right eye and the left half of the brain. The details still aren't quite clear but, for now, the most likely explanation involves a molecule called cryptochrome. Cryptochrome is found in the light-sensitive cells of a bird's retina and scientists think that it affects just how sensitive those cells are.

When cryptochrome is struck by blue light, it shifts into an active state where it has an unpaired electron these particles normally waltz in pairs but here, they dance solo. The same thing happens in a companion molecule called FAD and together, the two are known as a radical pair. Magnetic fields act upon the unpaired electrons and govern how long it takes for the radical pair to revert back to their normal, inactive state. And because cryptochrome affects the sensitivity of a bird's retina, so do magnetic fields.

The upshot is that in magnetic fields put up a filter of light or dark patches over what a bird normally sees. These patches change as the bird turns and tilts its head, providing it with a visual compass made out of contrasting shades.

To test the bounds of this ability, Stapput wanted to see what would happen if she blurred a robin's vision. She outfitted her robins with somewhat unflattering goggles, with clear foil on one side and frosted foil on the other. Both allowed 70% of light to get through, but the frosted foil disrupted the clarity of the image.

The robins were kept in cages until they were ready to migrate and let loose in funnel-shaped cages lined with correction fluid. As they orientated themselves and changed course, they created scratches on the cage walls which told Stapput which direction they were heading in. These scratches revealed that with both eyes open, the robins flew straight north as they would normally do in the wild. If their left field of vision was frosted, they went the same way. But if their right eye was covered, they became disorientated, heading in completely random directions.

This experiment shows that the internal compass doesn't just depend on light birds also need to see a clear image with their right eye in order to find they way. After all, their magnetic sense only provides them with information that lies on top of the images they normally see. If that image is blurry, the magnetic sense is useless. To put it another way, driving with an excellent Satnav won't do you much good if your windscreen is covered in frost.

But Stapput thinks that birds also need a sharp, focused image to separate the information from their visual and magnetic senses. Since both lie on top of each other, and both involve differences in light and shade, the potential for confusion is high. But thanks to lines and edges, the images that birds see tend to have sharp transitions between light and shade; by contrast, changes in magnetic fields are smooth and more gradual. So sharp changes in contrast are probably due to the boundaries of objects, but smoother changes are probably due to magnetic effects.

Stapput's study certainly provides good support for the radical pair explanation, but it doesn't rule out an alternative hypothesis. Some birds, such as pigeons, have small crystals of magnetite in their beaks. This iron-rich magnetic mineral could provide further clues about the surrounding magnetic fields, especially in darkness.

Reference: Current Biology http://dx.doi.org/10.1016/j.cub.2010.05.070

Image from Ernst Vikne and Theoretical and Computational Physics Group

More on magnetic senses:

• Google Earth shows that cow and deer herds align like compass needles
• Bats: compasses, tongues and memories
• Power lines disrupt the magnetic alignment of cows and deer

Focusing magnetic fields on the visual cortex of the brain caused the subjects to see luminous discs and lines. When the focus was moved around within the visual cortex, the subjects reported seeing the lights move...

The researchers make a convincing argument that some ball lightning reports are spurred by hallucinations, said John Abrahamson, a chemist and ball lightning expert at the University of Canterbury in New Zealand who was not involved in the study.

But "I cannot believe that most of the images reported as ball lightning are due to this brain influence," Abrahamson said in an email.

For one thing, the colors of light seen by the subjects in the experiment were "white, gray, or in unsaturated colors." But ball lightning has been reported in a variety of colors, including orange, green, and blue, Abrahamson said.

Evidence for the existence of Earth's magnetic field has been pushed back about 250 million years, new research suggests. The field may therefore be old enough to have shielded some of the planet's earliest life from the sun's most harmful cosmic radiation.

Earth's magnetic field was born by 3.45 billion years ago, a team including researchers from the University of Rochester in New York and the University of KwaZulu-Natal in South Africa report in the March 5 issue of Science.

That date fallsduring life's earliest stages of development, between the period when the Earth was pummeled by interplanetary debris and when the atmosphere filled with oxygen. Several earlier studies had suggested that a magnetic field is a necessary shield against deadly solar radiation that can strip away a planet's atmosphere, evaporate water and snuff out life on its surface.

I think it's a magnificent piece of work, a real landmark, says geophysicist David Dunlop of the University of Toronto, who was not involved in the research. It pushes the boundary back about as far back as you could reasonably expect to measure on Earth.

The researchers measured the magnetic strength of certain rocks found in the Kaapvaal craton of South Africa, a geologic region known to date back more than 3 billion years.

Just finding old rocks wasn't enough, though. It's a Goldilocks theory of finding rocks, says John Tarduno of the University of Rochester, a coauthor of the new study. Iron minerals record the strength and direction of the magnetic field that was present during their formation. But when rocks are heated in subsequent geological processes, they can lose or overwrite that record.

We had to find a rock that had just enough iron to record a magnetic signature, but not so much that it would be affected by later chemical changes, Tarduno says.

The Greenstone Belt in South Africa had rocks that were just right: crystals of quartz less than two millimeters long with nanometer-sized bits of iron-containing magnetite embedded in them.

Quartz is the perfect capsule, Tarduno says. It's not affected by later events, but it has these [iron] inclusions in it.

Tarduno and his colleagues had studied similar rocks in 2007 and found that a magnetic field half as strong as today's was present 3.2 billion years ago. Using a specially designed magnetometer and improved lab techniques, the team detected a magnetic signal in 3.45-billion-year-old rocks that was between 50 and 70 percent the strength of the present-day field, Tarduno says.

When we think about the origin of life, there are two threads to follow, Tarduno says. One obviously is water. But you also have to have a magnetic field, because that protects the atmosphere from erosion and the complete removal of water. Mars may be dry today because it lost its magnetic field early on, he adds.

To determine if the early magnetic field was enough to hold back the rain of radiation, the team needed to know what the sun was doing. Tarduno and Eric Mamajek, an astronomer at the University of Rochester, used observations of young sunlike stars to infer how strong a solar wind the Earth was up against.

The young sun probably rotated more quickly than it does today, Tarduno says. This quick rotation powered a strong magnetic field, which heated the sun's atmosphere and carried away mass and angular momentum in a strong solar wind of charged particles. The team calculated that the point where the Earth's magnetic field cancels out the solar wind would be only about five Earth radii above the planet's center, less than half of the 10.7 radii it is today.

The amount of radiation regularly reaching Earth from the sun 3.45 billion years ago would be comparable to what rains down on the planet during the most powerful solar storms today, Tarduno says. The aurora borealis, caused by solar wind particles accelerating along Earth's magnetic field, would have been visible as far south as present-day New York City.

The study can be used to guide our searches for other life-bearing planets as well, says astronomer Moira Jardine of the University of St. Andrews in Scotland. Astronomers might want to focus more on older, less active stars or search for planets with their own magnetic fields, she says.

Despite the fact that no extrasolar planets with magnetic fields have ever been detected, Jardine and Tarduno remain optimistic. It's just another parameter we need to think about, Tarduno says.

Images: 1) J. Tarduno, R. Cottrell. 2) NASA.

See Also:

• Telegraphs Ran on Electric Air in Crazy 1859 Magnetic Storm
• Moon Rock Reveals Hot Molten Core
• Cockroaches Use Earth's Magnetic Field to Steer
• Jupiter's Magnetic Moon Generates Spectacular Light Show

Shared by Garci
Rubn gracias por la recomendacin... si vienen a Madrid habr que verlos.

Un sueco mudado a Londres llamado Simon Balthazar propone desde all a Fanfarlo. Tiene un remoto parecido vocal con David Byrne que, jugando con canciones ms pop, se escora tal que Clap Your Hands Say Yeah a una rama menos arisca. Es pop florido transocenico que bebe de las estructuras de The Magnetic Fields una vez reposado en las marmitas britnicas un ejemplo contemporneo ms de cantautor sera Tim Ten Yen- con proliferacin de arreglos de viento y cuerda.

La produccin de Peter Katis The National, Interpol- pone un contrapunto regio el sonido que consigue de un instrumento como el piano, ms seco y viril, siempre ha aportado solemnidad- que compensa lo difano de algunas melodas, propiciando una bienvenida tensin. La entrada de Drowning Men es muy Clap Your Hands Say Yeah cuando solo una cancin antes The Walls Are Coming Down- los arreglos recordaban a un Dent May de vacaciones en Puerto Vallarta. Resumiendo, domina la variedad de arreglos en un marco pop definitivamente decidido a sonar elegante, sobrio y exquisito. Solo al abasto de quienes tienen el buen gusto de hacer versiones de Neutral Milk Hotel genial la de In The Aeroplane Over The Sea colgada en Youtube-, Will Oldham yejemSmashing Pumpkins.

Tonight we took a 2600 year journey with Penny and Sheldon from the ancient Greeks through Isaac Newton to Niels Bohr to Erwin Schrdinger to the Dutch researchers that Leonard is currently ripping off.

From the Ancient Greeks: Ancient societies, including the Greeks, watched the skies carefully. Since they didn't have Google Calendar, it was only by watching the positions of the stars each night could they mark the passing of the days and seasons and know the best time to plant crops. (It must have been a nice time to be an astronomer. If you didn't treat your astrophysicist nicely, you might not have enough food next year.) Most of the points of light in the sky, the stars, appeared to stay in the same place with respect to each other, year after year for as long as anyone could remember. But a precious few, just five, moved relative to these fixed stars. We know them as Mercury, Venus, Mars, Jupiter and Saturn. As Sheldon explains, our Greeks forbears called them wanderers, or as we have derived from their language planets.

Your science consultant stands up to a UCLA astronomy professor who voted out Pluto.

When you look out the side window of your car, you can see objects fixed to the ground, bushes, trees, poles etc. Those near the side of the road zip by. Objects in the distance seem to barely move at all. Although you have the same speed relative to all the fixed objects outside your car, close objects have a high angular speed and you have to turn your head fast to watch them. The far objects have a low angular speed which don't require much tracking of your eyes. This allows us to understand the motions in the sky of stars versus the planets. The change in position in the sky is determined by their angular speed. Even though stars are moving extremely fast relative to the solar system, most faster than even the outer planets, they are so far away that changes in their position on the sky (their angular position) can only be detected with careful observation, if at all. For example, compare the farthest planet, Neptune (thanks, Pluto-haters) to the closest known star Proxima-Centauri, a little red dwarf star. Neptune is about 4,500,000,000 kilometers from Earth and moving a modest 5 kilometers per second relative to the Sun. If you watch Neptune over the course of a lifetime it will move halfway around the sky relative to the stars since it completes an orbit around the Sun every 164 years. By comparison, Proxima Centauri moves even faster than Neptune relative to the Sun but its position relative to other stars barely moves; its angular speed is tiny. The key difference is that Proxima Centauri is 40,000,000,000,000 kilometers away. Only precise astronomical measurements can see its motions, only hundredths of a degree over a lifetime.

At the other extreme, one of the fastest lights you will see move across the night sky is likely an airplane. They are moving at only 0.2 kilometers per second. But since they are close, say 100 kilometers away, they move faster on the sky than planets or stars. Galileo and Newton realized this, except for the part about airplanes. They knew that if the Earth orbited the Sun, the lack of apparent motion of the fixed stars meant they were extremely distant. The Universe was much larger than imagined. That story of the learning the Universe is larger than we thought is repeated many times throughout the history of astronomy. First by realizing the nearby stars are really so far away. Then by measuring the extent of the galaxy. When other galaxies were discovered our idea of the size of the Universe grew larger still. Today we do not know how large the Universe is, we only know that the speed of light is not fast enough to let us see all of it.

Through Isaac Newton: Newton explained why the planets orbit the Sun much like how a child might swing a cat by its tail over his head. If the child lets go, the cat flies off in whatever direction it was heading. In the absence of the Sun, the planets would fly off in straight lines at constant speed in one direction. Instead, the Sun pulls on the planets using gravity. The inward pull causes the planets to move in orbits around the Sun rather than straight lines. The same force of gravity that pulls objects to the ground on the surface of the Earth is what causes the planets to orbit the Sun, the Moon to orbit the Earth and what causes the Earth and Moon together to orbit the Sun together, just like the planets.

But what Sheldon was trying to get Penny to say?

Notice that the Moon and Earth go around the Sun together, even though they have wildly different masses. Objects of different masses fall at the same rate in a vacuum. Their masses don't matter. The Sun causes objects at the same distance to move the same way. So the Earth and the Moon move around the Sun at the same rate. The Moon's extra motion around the Earth is just a small variation in its journey around the Sun. Even the tiny International Space Station orbiting the Earth, really has its path dominated by the Sun. Its motion around the Earth is just a tiny little wiggle in its path around the Sun.

To Niels Bohr: Theorists had tried many models to explain the architecture of the atom. But it was only once the experimentalist Ernest Rutherford scattered charged particles from gold foils that it became clear that a central positive charge, an atomic nucleus, was surrounded by distant electrons with negative charge. The motion of the planets around the massive central Sun served as a convenient model. First the Japanese physicist Hantaro Nagoka (1904) proposed the electrons formed rings much like the dust surrounding Saturn. Rutherford himself proposed a planetary model (1911), just as planets orbit the Sun under the force of gravity, Rutherford proposed electrical forces kept the electrons in orbit around an atomic nucleus. Yet even at the time, physicists knew this could not work, since electrons moving in a circle mut radiate light, lose energy, and fall inward, crashing into the nucleus. The Danish physicist Niels Bohr (1913) took the planetary model, but proposed that only certain distances from the nucleus were allowed, i.e. that the energy levels were quantized. Such quantization had previously served Planck and Einstein to describe the behavior of light. Now, Bohr gave birth to a quantum mechanical view of matter, the branch of physics necessary to explain atomic and molecular structure and upon which much of modern technology is based.

The planetary model for the atom, with which Niels Bohr started quantum mechanics, is a view of the atom still held by much of the public.

To Erwin Schrdinger: Bohr's model was inspirational, but still didn't work so well. For example, all electrons in this planetary picture would carry angular momentum around the nucleus, but many do not. The predicted intensity of radiation from atoms did not match the data. In 1926, Erwin Schrdinger developed a more rigorous description of quantum mechanics and the atom. Rather than thinking of electrons like planets, it is because of Schrdinger we think of the electrons being distributed in regions around the atom. Electrons are more or less likely to be found in any one place given by a mathematical function resembling a wave. Schrdinger therefore called it the wave-function and in quantum mechanics every particle has one.

To the Dutch researchers that Leonard is currently ripping off: Wave-functions behave counter-intuitively. Perhaps because our intuition was developed more while running across the African Savannah than while orbiting an atomic nucleus. One particularly counter-intuitive behavior of the wave-function is the Aharohnov-Bohm effect featured so prominently in this episode. The effect describes what happens to the wave-function near a magnetic field. It isn't surprising, perhaps, that if your particle, described by its wave-function, crosses a region with a magnetic field that something about it might change. What Yakir Aharonov and David Bohm predicted using Schrdinger's wave-function description is that you could have an effect by just going around, but never sampling directly, a magnetic field. Specifically, if electrons follow two different paths around a region of magnetic field and come together, they will have changed in different ways: While one wave-function might be at the crest of its wave, another might be at its trough. Putting the electrons together after their separate journeys, makes the interference pattern that Bernadette so rightly admired because they can be beautiful. The effect was predicted and subsequently observed with magnetic fields decades ago.

The Dutch researchers Leonard was ripping off have seen the effect now with electric, not just magnetic fields. The Dutch researchers accomplished it using electrons naturally moving around their sample, through a process called diffusion. Leonard was trying it even more directly by passing a beam of electrons through a sample. You may have noticed they added a vacuum pipe carrying an electron beam into Leonard's lab. (The end of the pipe is covered in aluminum foil, to keep the flange clean while being built.) The small nan0-fabricated rings would keep all their electric field inside and he would steer his electrons around either side and create an beautiful interference pattern.

An electron interference pattern. Electrons can behave like waves on the ocean, forming crests and troughs in their intensity.

I leared something new hearing Penny describe the whole thing to Leonard. Before she said it to the live audience, I never realized the Aharonov-Bohm effect was so funny. I bet we could have had them rolling in the aisles if we mentioned the Stern-Gerlach effect.

P.S. Easter Egg alert. You can see your science consultant in tonight's episode sitting across from an actual UCLA graduate student in theoretical physics, our very own Sheldon. (He is even working on one of the same problems: N=8 Supergravity.) A gold star to the first person who identifies which scene it is. Scenes are rehearsed several times and then run through several times in front of the camera to get it right. Luckily the props department gave us an interesting little book on quadrupole moments of nuclei from the 1960s to read. Most of the books you see around the apartment and on the sets are real physics books, some very interesting, so there is always something good for us to read between takes.

Since Sunday is Valentine's Day I thought it was appropriate to create a Mixcast dedicated to love. I'm lucky enough to find myself with someone special this year, so it definitely has a positive slant to it. If I was single this would be probably be an eff' love mix, but maybe I'll do that next year no matter what circumstance I find myself in, just to balance things out.

These are some of my favorite lovey songs and I think they work pretty well together. I opted for another mini-mix because you shouldn't have to listen to my voice when you're trying to makeout with your potential spouse/date/lover/desperate friend. I hope you enjoy it and remember that love is all you need.

Here's this week's tracklist:
More Adventurous by Rilo Kiley
First Day of My Life by Bright Eyes
Postcards From Italy by Beirut
God Only Knows by The Beach Boys
The Luckiest by Ben Folds
Center Of Gravity by Yo La Tengo
In My Life by The Beatles
Reservations by WIlco
I Must Be In a Good Place Now by Vetiver
Lullabye by Ben Folds Five
Asleep And Dreaming by The Magnetic Fields

Bobby

69 Love Songs was released September 7, 1999 by Merge. I was in school in Buffalo at the time and taking a break from music writing, so I was able to approach the collection entirely as a fan, which has affected how I listen to these three volumes. I'd been into the Magnetic Fields since Distant Plastic Trees/The Wayward Bus -- when Susan Anway was on lead vocals -- and remember being taken aback when Stephin Merritt started voicing his own songs on The House Of Tomorrow EP. A friend and I had a debate about whether or not his delivery was varied or emotional enough. Truth. We were in a record store in New Jersey. I mention this because it's weird to think about that now: Who would question the warm baritone that's vocalized so many classic (and whether he likes it or not) touching songs? I'm a fan of Holiday through Get Lost, but as far as performance go, everything feels a bit outmatched by the sheer volume (and quality) of voices and points of view Merritt takes on via his 69 Love Songs. You get the female vocals of Claudia Gonson and various guests, yes, but Merritt impressively chews the scenery without departing from that nonchalant, somehow endlessly appealing voice.

Written by Carey

Have you heard, cellphones are deadly. Science told us so this week when Dr. Ronald B. Herberman of the esteemed University of Pittsburgh Cancer Institute realized that cellphones emit death rays that fry your brain and turn you into a baby-eating Communist, or give you cancer or whatever. Dr. Despair isn't a downer though! Inside, 10 practical ways to keep your precious little brain safe from those ubiquitous chirping cancer slabs

1. Do not allow children to use a cell phone, except for emergencies. The developing organs of a fetus or child are the most likely to be sensitive to any possible effects of exposure to electromagnetic fields.

2. While communicating using your cell phone, try to keep the cell phone away from the body as much as possible. The amplitude of the electromagnetic field is one fourth the strength at a distance of two inches and fifty times lower at three feet. Whenever possible, use the speaker-phone mode or a wireless Bluetooth headset, which has less than 1/100th of the electromagnetic emission of a normal cell phone. Use of a hands-free ear piece attachment may also reduce exposures.

3. Avoid using your cell phone in places, like a bus, where you can passively expose others to your phone's electromagnetic fields.

4. Avoid carrying your cell phone on your body at all times. Do not keep it near your body at night such as under the pillow or on a bedside table, particularly if pregnant. You can also put it on flight or off-line mode, which stops electromagnetic emissions.

5. If you must carry your cell phone on you, make sure that the keypad is positioned toward your body and the back is positioned toward the outside so that the transmitted electromagnetic fields move away from your rather than through you.

6. Only use your cell phone to establish contact or for conversations lasting a few minutes, as the biological effects are directly related to the duration of exposure. For longer conversations, use a land line with a corded phone, not a cordless phone, which uses electromagnetic emitting technology similar to that of cell phones.

7. Switch sides regularly while communicating on your cell phone to spread out your exposure. Before putting your cell phone to the ear, wait until your correspondent has picked up. This limits the power of the electromagnetic field emitted near your ear and the duration of your exposure.

8. Avoid using your cell phone when the signal is weak or when moving at high speed, such as in a car or train, as this automatically increases power to a maximum as the phone repeatedly attempts to connect to a new relay antenna.

9. When possible, communicate via text messaging rather than making a call, limiting the duration of exposure and the proximity to the body.

10. Choose a device with the lowest SAR possible (SAR = Specific Absorption Rate, which is a measure of the strength of the magnetic field absorbed by the body). SAR ratings of contemporary phones by different manufacturers are available by searching for sar ratings cell phones on the internet.

Of course, science doesn't actually know for certain whether cellphones are safe or whether they cause debilitating brain tumors. Further research is needed is a common refrain, though this is the sort of thing that will work itself out over the next decade as more, um, tumors data become available.

Important Precautionary Advice Regarding Cell Phone Use [University of Pittsburgh Cancer Institute via firedoglake] (Thanks to Shaula!)
(Photo: Getty)

It had been rumored for months that Yahoo! was going to get out of the subscription music business. Yesterday, they announced that they were shutting down Yahoo! Unlimited and turning over the subscriber base to Rhapsody. Yahoo! also announced that they are buying the Firefox plugin called FoxyTunes. The coolest thing about FoxyTunes is their web service called FoxyTunes Planet which is like a netvibes for music. Here's the FoxyTunes Planet page on the Magnetic Fields.

I see this as a recognition by Yahoo! Music that the subscription business is tough and that's its easier to build a business on top of the music and other music related services that are already out there on the web.

The most interesting thing to me is Yahoo!'s new blog music player which is an acknowledgement that mp3 blogging is a big deal. Imagine if that were the first step in building a music service on top of the blogs? Like Hype Machine? Of course, the best thing for them to do is buy the Hype Machine.

But all of this assumes that Yahoo! is going to continue as a stand alone entity which doesn't seem that likely right now.