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What is Theory of Relativity !!

What is Theory of Relativity !! | Science Communication from mdashf | Scoop.it
Just from a simpler form of Gravity I have proved in an article written couple days ago thats to be completed with these derivations but the ideas have been described: that gravitational time dilat...
mdashf's insight:

Whats Relativity theory and how some of its most talked about ideas are quantitatively Relativistic but conceptually even classical ideas (such as Galilean/Newtonian theory) gives rise to such. Some mentions here but some other Relativity articles in the same period gives more details.

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The latest trends in physics. Speed of Light.

Much of this article is reviewed and updated today, the: (07 January 2014). It has become more interesting, less confusing and more clarifying. Its totally worth reading this article, I would say. ...
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A reviewed and edited article from mdashf that clarifies issues regarding speed of light and in what way the author saw the neutrino could have broken the speed barrier of Einstein's photons, which they could not nevertheless fo rother reasons. 

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A few thoughts on religion and science

A few thoughts on religion and science | Science Communication from mdashf | Scoop.it
Secularism is not an idea of looking at religions equally as we have often been told. All religions are different from each other and so are their Gods. The "Gods" reflect the mindset of their beli...
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Some casual thoughts on science and religion from a  write-up of 2009, January by me.  

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characteristics of photon

characteristics of photon | Science Communication from mdashf | Scoop.it
SO mass-energy equivalence is a special theory of realtivity effect and gravitational tensor-coupling has got nothing to do with it. A photon gets it's energy-momentum (( energy/momentum)) from QED...
mdashf's insight:

When it comes to mass and energy, particles with and without mass then exactly what you should be careful about. The Uncertainty relations will produce additional "not so talked about relations of uncertainty" !! A very fundamental, known but not all sides known aspect of Physics which I have discovered after many different problems were related and caused me to think about the problem for more than half a year and gradually shed qualitative as well as quantitative light into the matter, plus the mathematical form helped me "solve" the OPERA anomaly from fundamental Physics POV. This article answers some of these " care to be taken " in Photon-matters at a good detail. {1. will be well read only if conncted with some more articles which are nonetheless to be found on the same website but not the same sequence 2. Only one line needs to be corrected: perhaps the talking about rest-mass or rest-frame of photon, this I have corrected and devoted one full article recently within last 1 week, but you are encouraged to find that article then matters will be far more clear, plus I am thinking to write a few more articles in this context pretty soon}

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Optical Path

Optical Path | Science Communication from mdashf | Scoop.it
In the last few weeks I am trying to understand why light traverses straight lines and why it refracts. The other day I saw a little mug floating inside a bucket full of water. Inside water any obj...
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Well written although slightly technical !!

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Why Sun is circular but star twinkles?

Why Sun is circular but star twinkles? | Science Communication from mdashf | Scoop.it
The frequency of light is small because the energy or intensity is low. So you see twinkles. But light is still moving at the same speed towards us. It takes 4.5 years from some stars while taking ...
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CERN Physicists Attempt to Measure Gravitational Mass of Antihydrogen

CERN Physicists Attempt to Measure Gravitational Mass of Antihydrogen | Science Communication from mdashf | Scoop.it

A team of researchers working with CERN’s Antihydrogen Laser Physics Apparatus (ALPHA) has reported the first direct measurement of gravity’s effect on antimatter, specifically antihydrogen in free fall.

 

“The atoms that make up ordinary matter fall down, so do antimatter atoms fall up? Do they experience gravity the same way as ordinary atoms, or is there such a thing as antigravity?”

 

“These questions have long intrigued physicists,” said Dr Joel Fajans of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, co-author of apaper reporting the results in Nature Communications.

 

“Because in the unlikely event that antimatter falls upwards, we’d have to fundamentally revise our view of physics and rethink how the Universe works.”

 

So far, all the evidence that gravity is the same for matter and antimatter is indirect, so the team decided to use their ongoing antihydrogen research to tackle the question directly.

 

The ALPHA experiment captures antiprotons and combines them with antielectons (positrons) to make antihydrogen atoms, which are stored and studied for a few seconds in a magnetic trap. Afterward, however, the trap is turned off and the atoms fall out. The researchers realized that by analyzing how antihydrogen fell out of the trap, they could determine if gravity pulled on antihydrogen differently than on hydrogen – the anomaly would be noticeable in ALPHA’s existing data on 434 anti-atoms.


Via Dr. Stefan Gruenwald
mdashf's insight:

Do antiparticles get duped by gravity or they get equal shares in a swing of gravity. Do they get an opposite swing? 

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Birds' UV Vision has arisen independently more than 14 times during evolution

Birds' UV Vision has arisen independently more than 14 times during evolution | Science Communication from mdashf | Scoop.it

Birds depend on their color vision for selecting mates, hunting or foraging for food, and spotting predators. Until recently, ultraviolet vision was thought to have arisen as a one-time development in birds. But a new DNA analysis of 40 bird species shows the shift between violet (shorter wavelengths on the electromagnetic spectrum) and ultraviolet vision has occurred at least 14 times.

 

"Birds see color in a different way from humans," study co-author Anders Ödeen, an animal ecologist at Uppsala University in Sweden, told LiveScience. Human eyes have three different color receptors, or cones, that are sensitive to light of different wavelengths and mix together to reveal all the colors we see. Birds, by contrast, have four cones, so "they see potentially more colors than humans do," Ödeen said.

 

Birds themselves are split into two groups based on the color of light (wavelength) that their cones detect most acutely. Scientists define them as violet-sensitive or ultraviolet-sensitive, and the two groups don't overlap, according to Ödeen. Birds of each group would see the same objects as different hues.

 

The study researchers sequenced the DNA from the 40 species of birds, from the cockatiel to the whitebearded manakin. They extracted DNA from the bases of feather quills, blood, muscle or other tissue. From that DNA, the scientists reconstructed the proteins that make up the light-sensitive pigments in the birds' eyes. Differences in the DNA revealed which birds were sensitive to violet light versus ultraviolet.

 

"That change is very simple, apparently," Ödeen said. "It just takes a single mutation" in the DNA sequence. While that change may seem insignificant, it can be compared to the difference humans see between red and green. Why the bird lineages switched their color sensitivity — essentially species of a certain branch on the family tree evolved to have the reverse type of vision — is still something of a mystery. The ability to attract mates while still evading predators could be one reason. Ultraviolet light might also provide higher contrast that makes finding food easier. Other factors are environmental — open spaces have more UV light than do forests, for example. Ultimately, the color sensitivity may be a result of other changes that affect the amount of ultraviolet light the birds' eyes receive.


Via Dr. Stefan Gruenwald
mdashf's insight:

the suckers are real dreamers and visionaries 

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Giuliano Cipollari's curator insight, February 16, 2013 9:37 AM

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Subatomic calculations from the Higgs boson indicate finite lifespan for our universe

Subatomic calculations from the Higgs boson indicate finite lifespan for our universe | Science Communication from mdashf | Scoop.it

Scientists are still sorting out the details of last year's discovery of the Higgs boson particle, but add up the numbers and it's not looking good for the future of the universe, scientists said.

 

"If you use all the physics that we know now and you do what you think is a straightforward calculation, it's bad news," Joseph Lykken, a theoretical physicist with the Fermi National Accelerator Laboratory in Batavia, Illinois. 

Lykeen spoke before presenting his research at the American Association for the Advancement of Science meeting in Boston.

 

"It may be that the universe we live in is inherently unstable and at some point billions of years from now it's all going to get wiped out," said Lykken, who is also on the science team at Europe's Large Hadron Collider, or LHC, the world's largest and highest-energy particle accelerator.

 

Physicists last year announced they had discovered what appears to be a long-sought subatomic particle called the Higgs boson, which is believed to give matter its mass.

 

Work to study the Higgs' related particles, necessary for confirmation, is ongoing. If confirmed, the discovery would help resolve a key puzzle about how the universe came into existence some 13.7 billion years ago - and perhaps how it will end.

 

"This calculation tells you that many tens of billions of years from now, there'll be a catastrophe," Lykken said. "A little bubble of what you might think of as an ‘alternative' universe will appear somewhere and then it will expand out and destroy us," Lykken said, adding that the event will unfold at the speed of light.

 

Scientists had grappled with the idea of the universe's long-term stability before the Higgs discovery, but stepped up calculations once its mass began settling in at around 126 billion electron volts - a critical number it turns out for figuring out the fate of the universe.

 

The calculation requires knowing the mass of the Higgs to within one percent, as well as the precise mass of other related subatomic particles. "You change any of these parameters to the Standard Model (of particle physics) by a tiny bit and you get a different end of the universe," Lyyken said.

 

Earth will likely be long gone before any Higgs boson particles set off an apocalyptic assault on the universe. Physicists expect the sun to burn out in 4.5 billion years or so, and expand, likely engulfing Earth in the process.


Via Dr. Stefan Gruenwald
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Stanford scientists fit a light-emitting bioprobe in a single living cell without damage to the cell

Stanford scientists fit a light-emitting bioprobe in a single living cell without damage to the cell | Science Communication from mdashf | Scoop.it

If engineers at Stanford have their way, biological research may soon be transformed by a new class of light-emitting probes small enough to be injected into individual cells without harm to the host.

 

Welcome to biophotonics, a discipline at the confluence of engineering, biology and medicine in which light-based devices – lasers and light-emitting diodes (LEDs) – are opening up new avenues in the study and influence of living cells.

 

The team described their probe in a paper published online Feb. 13, 2013 by the journal Nano Letters. It is the first study to demonstrate that tiny, sophisticated devices known as light resonators can be inserted inside cells without damaging the cell. Even with a resonator embedded inside, a cell is able to function, migrate and reproduce as normal.

 

The researchers call their device a "nanobeam," because it resembles a steel I-beam with a series of round holes etched through the center. This beam, however, is not massive, but measure only a few microns in length and just a few hundred nanometers in width and thickness. It looks a bit like a piece from an erector set of old. The holes through the beam act like a nanoscale hall of mirrors, focusing and amplifying light at the center of the beam in what are known as photonic cavities.

 

Structurally, the new device is a sandwich of extremely thin layers of the semiconductor gallium arsenide alternated with similarly thin layers of light-emitting crystal, a sort of photonic fuel known as quantum dots. The structure is carved out of chips or wafers, much like sculptures are chiseled out of rock. Once sculpted, the devices remain tethered to the thick substrate.

 

For biological applications, the thick, heavy substrate presents a serious hurdle for interfacing with single cells. The underlying and all-important nanocavities are locked in position on the rigid material and unable to penetrate cell walls.

 

Shambat's breakthrough came when he was able to peel away the photonic nanobeams. He then glued the ultrathin photonic device to a fiberoptic cable with which he steers the needle-like probe toward and into the cell.

 

Once inserted in the cell, the probe emits light, which can be observed from outside. For engineers, it means that almost any application of these powerful photonic devices can be translated into the previously off-limits environment of the cell interior. In one finding that the authors describe as stunning, they loaded their nanobeams into cells and watched as the cells grew, migrated around the research environment and reproduced. Each time a cell divided, one of the daughter cells inherited the nanobeam from the parent and the beam continued to function as expected.

 

This inheritability frees researchers to study living cells over long periods of time, a research advantage not possible with existing detection techniques, which require cells be either dead or fixed in place.

 

"Our nanoscale probes can reside in cells for long periods of time, potentially providing sensor feedback or giving control signals to the cells down the road," said Shambat. "We tracked one cell for eight days. That's a long time for a single-cell study."

 


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Next Generation Solar Cells Made From Graphene -- One Photon Can Be Converted Into Multiple Electrons

Next Generation Solar Cells Made From Graphene -- One Photon Can Be Converted Into Multiple Electrons | Science Communication from mdashf | Scoop.it

A new discovery by researchers at the ICFO has revealed that graphene is even more efficient at converting light into electricity than previously known. Graphene is capable of converting a single photon of light into multiple electrons able to drive electric current. The discovery is an important one for next-generation solar cells, as well as other light-detecting and light-harvesting technologies.

 

A paradigm shift in the materials industry is likely within the near-future as a variety of unique materials replaces those that we commonly use today, such as plastics. Among these new materials, graphene stands out. The single-atom-thick sheet of pure carbon has an enormous number of potential applications across a variety of fields. Its potential use in high-efficiency, flexible, and transparent solar cells is among the potential applications. Some of the other most discussed applications include: foldable batteries/cellphones/computers, extremely thin computers/displays, desalination and water purificationtechnology, fuel distillation, integrated circuits, single-molecule gas sensors, etc.


Via Dr. Stefan Gruenwald
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Edward Miller's curator insight, March 20, 2013 10:00 PM

With this discovery of Graphene able to conduct electricity and convert light at an exorbitant rate, the future of Solar Energy seems bright.

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Where are WE heading ??

Where are WE heading ?? | Science Communication from mdashf | Scoop.it
This is an "instantaneous" essay I wrote as I see our standing in the world, or as I can think. Disclaimer: I can be completely wrong-witted and you may be completely dumb-witted.Where are we headi...
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134 Lectures about the Foundations of Modern Physics (Stanford Courses - Prof. Leonard Susskind)

134 Lectures about the Foundations of Modern Physics (Stanford Courses - Prof. Leonard Susskind) | Science Communication from mdashf | Scoop.it
Free video course on Foundations of Modern Physics by Leonard Susskind of Stanford. This Stanford Continuing Studies course is a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics.

 

This Stanford Continuing Studies course is a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on classical mechanics, quantum mechanics, the general and special theories of relativity, electromagnatism, cosmology, black holes and statistical mechanics. While these courses build upon one another, each section of the course also stands on its own, and both individually and collectively they will allow the students to attain the "theoretical minnimum" for thinking intelligently about physics. Quantum theory governs the universe at its most basic level. In the first half of the 20th century physics was turned on its head by the radical discoveriies of Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, and Erwin Schroedinger. An entire new logical and mathematical foundation - quantum mechanics - eventually replaced classical physics. This course explores the quantum world, including the particle theory of light, the Heisenberg Uncertainty Principle, and the Schroedinger Equation. The course is taught by Leonard Susskind, the Felix Bloch Professor of Physics at Stanford University.

 

Here is a comprehensive listing of all lectures from Dr. Susskind:

 

http://www.youtube.com/view_play_list?p=189C0DCE90CB6D81
http://www.youtube.com/playlist?list=PLA27CEA1B8B27EB67
http://www.youtube.com/playlist?list=PL5F9D6DB4231291BE
http://www.youtube.com/view_play_list?p=84C10A9CB1D13841
http://www.youtube.com/view_play_list?p=CCD6C043FEC59772
http://www.youtube.com/view_play_list?p=6C8BDEEBA6BDC78D
http://www.youtube.com/view_play_list?p=F363FFF951EC0673
http://www.youtube.com/view_play_list?p=B72416C707D85AB0
http://www.youtube.com/view_play_list?p=888811AA667C942F
http://www.youtube.com/playlist?list=PL8BCB4981DD1A0108
http://www.youtube.com/playlist?list=PLA2FDCCBC7956448F
http://www.youtube.com/playlist?list=PL3E633552E58EB230
http://www.youtube.com/playlist?list=PL47F408D36D4CF129
http://www.youtube.com/playlist?list=PL701CD168D02FF56F

 

http://glenmartin.wordpress.com/home/leonard-susskinds-online-lectures/


Via Dr. Stefan Gruenwald
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Carlos Garcia Pando's comment, April 20, 2013 2:37 PM
Thanks for sharing. and Prof. Susskind too.
Tania Gammage's curator insight, May 12, 2013 11:47 PM

Awesome for HSC physics, six week sequence of classes.

Aviva Lev-Ari, PhD, RN's comment, May 13, 2013 6:57 AM
Any thanks, this is the way to go, sharing, sharing, sharing, curls to You
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Demystifying the Higgs Boson – an attempt | Cosmology at AIMS

Demystifying the Higgs Boson – an attempt | Cosmology at AIMS | Science Communication from mdashf | Scoop.it
I wrote this little piece as an attempt to communicate the key ideas behind the Higgs in new ways, a notoriously difficult thing to do without the underlying mathematics, as emphasised here and, controversially, here – BB The ...

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Interference of two plane harmonic waves.

Interference of two plane harmonic waves. | Science Communication from mdashf | Scoop.it
Optics Series Lecture, Lecture – VII.

“Conditions of interference, Interference of two plane harmonic waves.”

This lecture was delivered on 7th February in a lecture session of 1 and 1/2 hours. This lecture was delivered to Physics elective students but intended as a lecture towards Honors students at a later date.

Electromagnetic Waves.
Light is an electromagnetic wave. In-fact its a transverse electromagnetic wave which means the oscillation of E and B fields produces light which propagates in a direction that is perpendicular to the plane that contains the E and B fields. In other words E, B and k the vector that denotes the direction of light propagation, are mutually perpendicular vectors.

We will study these details in a later intended lecture. EM waves are not only transverse waves but also vector waves, that is; E and B are vector fields whose undulation is summarized as light.

Light is a general name for all EM waves but visible light is that particular part of EM waves which has frequency of wave such that the wavelength varies from approximately 400 - 700 nm. In vacuum -- only in vacuum, light always moves at a fixed speed: namely c = 3×108 m/s. Therefore light whose wavelength lies between 400 - 700 nm is called as visible light: we can write in vacuum c = νλ.

Light as a transverse wave phenomenon of vector fields is comprehensively described by four equations known as Maxwell's Equations. The Maxwell's Equations are a summary of important and fundamental laws of electricity and magnetism -- together called as electromagnetism, such as Gauss Law and Ampere's Law. These equations produce the wave equation of motion, a linear, homogeneous, 2nd order differential equation that we will study a few lectures afterwards.

If you are quite serious and technically well equipped though, you can have a glimpse of it all -- and may be work out to your satisfaction, by following the link to my slide-share presentations. There are many other important Physics concepts that are worked out in great detail, in those slide-share presentations by me. eg check: Electromagnetic Waves.

Let us therefore write the wave equation of motion, where the 3 components of E field -- such as Ex, Ey or Ez or the 3 components of B field such as Bx, By, Bz, are denoted as ψ chosen anyone at one time. eg we can chose Ex = ψ. In general we have: 
mdashf's insight:
The very basics of interference, described for plane polarized harmonic waves. 
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Milkyway supernova to be visible from Earth within 50 years - Indian Express

Milkyway supernova to be visible from Earth within 50 years - Indian Express | Science Communication from mdashf | Scoop.it
In some good news for space enthusiasts, a Milky Way supernova could be visible from Earth sometime in the next 50 years.
mdashf's insight:

1. Supernovae will be visible from earth (naked eye has lower chance but infrared telescope 100 % chance) 

 

2. Within next 50 years time. and this supernovae is from our own galaxy Milky-way.

 

3. A supernovae is the phenomena of a star exploding violently into its constituents and throwing that debris into its surrounding in terms of matter and radiation that glows in visible, infrared and other forms of radiation. Matter includes neutrinos, the tiny little constituents of Universe that are almost mass-less and charge-less like the photons and far more mysterious. The stars are nuclear fire-houses. When all the nuclear  fuel is exhausted the star has no more and its shells are thrown off much like an exploding bomb. The inner core continues to collapse gravitationally forming so called black-holes if critical condition of the star-mass being 1.4 times higher than Sun's mass is satisfied. 

 

4. The scientists are hopeful to study the release of neutrino which is produced often days or hours before the other forms of radiation is produced hence this can shed more understanding into the phenomena.

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What's Your Writing Fee? - ProfHacker - The Chronicle of Higher Education

What's Your Writing Fee? - ProfHacker - The Chronicle of Higher Education | Science Communication from mdashf | Scoop.it
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100 $ per piece is not on the lower bottom of a compensation although if someone pays you 500 $ per piece that would be awesome, and its only you who has proved what to earn. If one devotes full time writing and gets 5 articles a day written one can in 20 working days a month gets 10000 $ which is an excellent compensation for any one writing and earning simply from writing. I do not disagree how many hours go into writing and how difficult certain research can become. I simply think of how sustainably one can write. The more one is writing the more one owuld be at wit's end. 

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Could Einstein have thought Equivalence from simple notions of Geometry ? Yes.

Could Einstein have thought Equivalence from simple notions of Geometry ? Yes. | Science Communication from mdashf | Scoop.it
Now it may also be related that light bends in a denser media compared to a rarer media because an additional rotational force is working. In other words the definition of straight line has to chan...
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Writing a motivational letter for PhD ..

Writing a motivational letter for PhD .. | Science Communication from mdashf | Scoop.it
6. Why do you want to work for our organization? Where do you see yourself in 8-10 years from now?


Mention the strong point of your varsity's choice: eg if Nethrlands CooCoo University is ...
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why scientists think photon is massless ?

why scientists think photon is massless ? | Science Communication from mdashf | Scoop.it
GHz makes the time window really small. For such a senstive time measurement one must make a correspondingly larger error on energy therefore mass. That is uncertainty principle of energy-time. SO ...
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Experimental and theoretical reason why photons, the carriers that bring us light, are ones without any mass.

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Virtual quantum particles can have real physical effects: A vacuum can yield flashes of light

Virtual quantum particles can have real physical effects: A vacuum can yield flashes of light | Science Communication from mdashf | Scoop.it

A vacuum might seem like empty space, but scientists have discovered a new way to seemingly get something from that nothingness, such as light. And the finding could ultimately help scientists build incredibly powerful quantum computers or shed light on the earliest moments in the universe's history.

 

Quantum physics explains that there are limits to how precisely one can know the properties of the most basic units of matter—for instance, one can never absolutely know a particle's position and momentum at the same time. One bizarre consequence of this uncertainty is that a vacuum is never completely empty, but instead buzzes with so-called “virtual particles” that constantly wink into and out of existence.

 

These virtual particles often appear in pairs that near-instantaneously cancel themselves out. Still, before they vanish, they can have very real effects on their surroundings. For instance, photons—packets of light—can pop in and out of a vacuum. When two mirrors are placed facing each other in a vacuum, more virtual photons can exist around the outside of the mirrors than between them, generating a seemingly mysterious force that pushes the mirrors together.

 

This phenomenon, predicted in 1948 by the Dutch physicist Hendrick Casimir and known as the Casimir effect, was first seen with mirrors held still . Researchers also predicted a dynamical Casimir effect that can result when mirrors are moved, or objects otherwise undergo change. Now quantum physicist Pasi Lähteenmäki at Aalto University in Finland and his colleagues reveal that by varying the speed at which light can travel, they can make light appear from nothing.

 

The speed of light in a vacuum is constant, according to Einstein's theory of relativity, but its speed passing through any given material depends on a property of that substance known as its index of refraction. By varying a material's index of refraction, researchers can influence the speed at which both real and virtual photons travel within it. Lähteenmäki says one can think of this system as being much like a mirror, and if its thickness changes fast enough, virtual photons reflecting off it can receive enough energy from the bounce to turn into real photons. "Imagine you stay in a very dark room and suddenly the index of refraction of light [of the room] changes," Lähteenmäki says. "The room will start to glow."

 

The researchers began with an array of 250 superconducting quantum-interference devices, or SQUIDs—circuits that are extraordinarily sensitive to magnetic fields. They inserted the array inside a refrigerator. By carefully exerting magnetic fields on this array, they could vary the speed at which microwave photons traveled through it by a few percent. The researchers then cooled this array to 50 thousandths of a degree Celsius above absolute zero. Because this environment is supercold, it should not emit any radiation, essentially behaving as a vacuum. "We were simply studying these circuits for the purpose of developing an amplifier, which we did," says researcher Sorin Paraoanu, a theoretical physicist at Aalto University. "But then we asked ourselves—what if there is no signal to amplify? What happens if the vacuum is the signal?"

 

The investigators caution that such experiments do not constitute a magical way to get more energy out of a system than what is input. For instance, it takes energy to change a material's index of refraction.

Instead, such research could help scientists learn more about the mysteries of quantum entanglement, which lies at the heart of quantum computers—advanced machines that could in principle run more calculations in an instant than there are atoms in the universe. The entangled microwave photons the experimental array generated "can be used for a form of quantum computation known as 'continuous variable' quantum information processing,” Girvin says. “This is a direction which is just beginning to open up.” Wilson adds that these systems “might be used to simulate some interesting scenarios. For instance, there are predictions that during cosmic inflation in the early universe, the boundaries of the universe were expanding nearly at light-speed or faster than the speed of light. We might predict there'd be some dynamical Casimir radiation produced then, and we can try and do tabletop simulations of this."

So the static Casimir effect involves mirrors held still; the dynamical Casimir effect can for instance involve mirrors that move.

 


Via Dr. Stefan Gruenwald
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Any Two Pages on the Web Are Connected By 19 Clicks or Less

Any Two Pages on the Web Are Connected By 19 Clicks or Less | Science Communication from mdashf | Scoop.it

No one knows for sure how many individual pages are on the web, but right now, it’s estimated that there are more than 14 billion. Recently, though, Hungarian physicist Albert-László Barabási discovered something surprising about this massive number: Like actors in Hollywood connected by Kevin Bacon, from every single one of these pages you can navigate to any other in 19 clicks or less.

 

Barabási’s findings involved a simulated model of the web that he created to better understand its structure. He discovered that of the roughly 1 trillion web documents in existence—the aforementioned 14 billion-plus pages, along with every image, video or other file hosted on every single one of them—the vast majority are poorly connected, linked to perhaps just a few other pages or documents.

 

Distributed across the entire web, though, are a minority of pages—search engines, indexes and aggregators—that are very highly connected and can be used to move from area of the web to another. These nodes serve as the “Kevin Bacons” of the web, allowing users to navigate from most areas to most others in less than 19 clicks.

 

Barabási credits this “small world” of the web to human nature—the fact that we tend to group into communities, whether in real life or the virtual world. The pages of the web aren’t linked randomly, he says: They’re organized in an interconnected hierarchy of organizational themes, including region, country and subject area.

 

Interestingly, this means that no matter how large the web grows, the same interconnectedness will rule. Barabási analyzed the network looking at a variety of levels—examining anywhere from a tiny slice to the full 1 trillion documents—and found that regardless of scale, the same 19-click-or-less rule applied.


Via Dr. Stefan Gruenwald
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New way to probe Earth's deep interior using particle physics proposed

New way to probe Earth's deep interior using particle physics proposed | Science Communication from mdashf | Scoop.it

Researchers from Amherst College and The University of Texas at Austin have described a new technique that might one day reveal in higher detail than ever before the composition and characteristics of the deep Earth.

There's just one catch: The technique relies on a fifth force of nature (in addition to gravity, the weak and strong nuclear forces and electromagnetism) that has not yet been detected, but which some particle physicists think might exist. Physicists call this type of force a long-range spin-spin interaction. If it does exist, this exotic new force would connect matter at Earth's surface with matter hundreds or even thousands of kilometers below, deep in Earth's mantle. In other words, the building blocks of atoms—electrons, protons, and neutrons—separated over vast distances would "feel" each other's presence. The way these particles interact could provide new information about the composition and characteristics of the mantle, which is poorly understood because of its inaccessibility.

 

"The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth," says Jung-Fu "Afu" Lin, associate professor at The University of Texas at Austin's Jackson School of Geosciences and co-author of the study appearing this week in the journal Science.

 

This new force could help settle a scientific quandary. When earth scientists have tried to model how factors such as iron concentration and physical and chemical properties of matter vary with depth—for example, using the way earthquake rumbles travel through the Earth or through laboratory experiments designed to mimic the intense temperatures and pressures of the deep Earth—they get different answers. The fifth force, assuming it exists, might help reconcile these conflicting lines of evidence.

 

Earth's mantle is a thick geological layer sandwiched between the thin outer crust and central core, made up mostly of iron-bearing minerals. The atoms in these minerals and the subatomic particles making up the atoms have a property called spin. Spin can be thought of as an arrow that points in a particular direction. It is thought that Earth's magnetic field causes some of the electrons in these mantle minerals to become slightly spin-polarized, meaning the directions in which they spin are no longer completely random, but have some preferred orientation. These electrons have been dubbed geoelectrons.


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Photo-Electric Effect, Quantum Mechanics, Quantization, Wave Particle Duality !!

Photo-Electric Effect, Quantum Mechanics, Quantization, Wave Particle Duality !! | Science Communication from mdashf | Scoop.it
The fact that zero mass particles exist simply might be a coincidence of nature, that a very small energy was produced randomly. Again since it transmitted a longer distance or infinite distance mi...
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Four Steps To Deal With Dishonest People | Science Communication from mdashf | Scoop.it
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Higgs boson breakthrough a triumph of human curiosity - Vancouver Sun

Higgs boson breakthrough a triumph of human curiosity - Vancouver Sun | Science Communication from mdashf | Scoop.it

The announcement last week of the first definitive evidence of a new particle, likely the long-awaited Higgs boson ...


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