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aamukherjee Entropie -
alchymista Alchymista -
crownedrose Hymn To The Sea -
epistemophobiarunsdeep Falling Over Myself. -
expose-the-light Quarks to Quasars -
ikenbot cwl -
pieceinthepuzzlehumanity This Is The Right One -
project-argus Hello, Universe. -
torgothegreat God Delusion
An Unhackable Baby Quantum Internet Was Born Yesterday
Years from now it may be said that the quantum Internet was born today. When the baby system matures, it will be able to process unfathomable amounts of data and never be hacked.
The system only has two nodes, but the Internet’s birth started in a similar way back in the late 1960s. The developers — physicists led by Stephan Ritter and Gerhard Rempe of the Max Planck Institute of Quantum Optics in Germany — published their work in this week’s issue of the journal “Nature.”
The quantum network was built using two atoms of rubidium that exchange photons, or particles of light. Each atom is placed inside a cavity with highly reflecting mirrors on each side, and at a very short distance from each other. The two so-called optical cavities are connected by an optical fiber.
Scientists aim a laser at the first atom, causing the atom to emit a single photon. That photon zooms along the optical fiber to other optical cavity containing the other atom. That’s where the mirrors come in — ordinarily it’s difficult to get an atom and a photon to interact reliably. But by bouncing the photon off the mirrors in the cavity thousands of times, it’s more likley to hit the atom and be absorbed by it. That absorbtion is what transmits the information about the first atom’s quantum state to the second atom.
Besides sending information, the two atoms were entangled, meaning that the atoms were linked. If the first node is in quantum state A, for example, the second node will also be in quantum state A. In this experiment, the atoms were entangled for 100 microseconds — a long time in quantum physics.
This entanglement is what makes hacking into a quantum computer and eavesdropping on impossible. As as soon as a hacker tapped into a quantum network, the states of the atoms wouldn’t match up — a big red flag that something was awary.
It’s a long way yet to a truly large-scale quantum network, but this is a first step.
ikenbot
Replica of Trojan asteroids fits in single atom
In a paper published in the journal Physical Review Letters, the Rice University team showed they could cause an electron in an atom to orbit the nucleus in precisely the same way that Jupiter’s Trojan asteroids orbit the sun.
The findings uphold a prediction made in 1920 by famed Danish physicist Niels Bohr about the relationship between the then-new science of quantum mechanics and Isaac Newton’s tried-and-true laws of motion.
Using atoms to model the solar system.
Badass.
It uses the strange “quantum states” of matter to perform calculations in a way that, if scaled up, could vastly outperform conventional computers.
The 6mm-by-6mm chip holds nine quantum devices, among them four “quantum bits” that do the calculations.
The team said further scaling up to 10 qubits should be possible this year.
Rather than the ones and zeroes of digital computing, quantum computers deal in what are known as superpositions - states of matter that can be thought of as both one and zero at once.
pieceinthepuzzlehumanity
Two diamonds as wide as earring studs have been made to share the spooky quantum state known as entanglement. The feat, performed at room temperature, blurs the divide between the classical and quantum worlds, since typically the quantum link has been made with much smaller particles at low temperatures.
Entanglement is one of the weird aspects of quantum mechanics, where the fates of two or more particles are intertwined – even when they are physically far apart. Electrons, for example, have been entangled, so that changing the quantum spin of one affects the spins of its entangled partners.
Macroscopic objects, on the other hand, are supposed to mind their own business – flipping one coin shouldn’t force a neighbouring flipped coin to come up heads.
But that’s just what happened with two 3-millimetre-wide diamonds on a lab bench at the University of Oxford. Physicists there led by Ka Chung Lee andMichael Sprague were able to show that the diamonds shared one vibrational state between them.
Imaged Above: A collision event recorded by Atlas at the LHC. Bloggers report rumours that evidence of the Higgs boson will be announced next Tuesday. Photograph: Cern/PA
A couple of blogs, including viXra and Peter Woit’s Not Even Wrong, have now posted rumours that the Atlas and CMS teams see Higgs-like signals around 125GeV, though they say the evidence is not robust enough to claim an official discovery.
More Evidence Found for Quantum Physics in Photosynthesis
Physicists have found the strongest evidence yet of quantum effects fueling photosynthesis.
Multiple experiments in recent years have suggested as much, but it’s been hard to be sure. Quantum effects were clearly present in the light-harvesting antenna proteins of plant cells, but their precise role in processing incoming photons remained unclear.
In an experiment published Dec. 6 in Proceedings of the National Academy of Sciences, a connection between coherence — far-flung molecules interacting as one, separated by space but not time — and energy flow is established.
“There was a smoking gun before,” said study co-author Greg Engel of the University of Chicago. “Here we can watch the relationship between coherence and energy transfer. This is the first paper showing that coherence affects the probability of transport. It really does change the chemical dynamics.”
‘Scientists at Chalmers have succeeded in creating light from vacuum - observing an effect first predicted over 40 years ago. In an innovative experiment, the scientists have managed to capture some of the photons that are constantly appearing and disappearing in the vacuum.’
Our concept of a vacuum is something that has no matter which, in most cases, is a good enough definition. However, modern physics states that this vacuum is filled with virtual particles which come in and out of existence for such short periods of time that they cannot be detected (and if they are detected, they are no longer virtual particles). Most of the time, virtual particles are produced in pairs with a virtual antiparticle so that they annihilate each other fairly quickly.
The dynamic Casimir effect (not the static one which has been investigated in more depth) occurs when a mirror is brought to speeds near that of light. If a virtual photon collides with this fast-moving mirror, it can often be separated from its virtual antiparticle. This leaves us with light!
Rather than having a mirror travelling at speeds near that of light (which is impossible for our current standards) the scientists used a rapidly changing magnetic field to cause a superconductor to vibrate at a fourth of the speed of light which works to the same effect.
aamukherjee
LHC May Have Found Crack in Modern Physics
In late 2008, a few onlookers believed that the Large Hadron Collider (LHC) would bring the end of the world. Three years later, our planet remains intact, but the European particle smasher may have made its first crack in modern physics.
If this crack turns out to be real, it might help explain an enduring mystery of the universe: why there’s lots of normal matter, but hardly any of the opposite—antimatter. “If it holds up, it’s exciting,” says particle physicist Robert Roser of the Fermi National Accelerator Laboratory in Batavia, Illinois.
To understand why physicists are excited, look around: We’re surrounded by stuff. That might seem obvious, but scientists have long wondered why there’s anything at all. Accepted theories suggest that the big bang should have produced equal amounts of matter and antimatter, which would have soon annihilated each other. Clearly, the balance tipped in favor of normal matter, allowing the creation of everything we see today—but how, no one’s sure.
(via ikenbot)
Nyan Schrödinger cat
It must be seen on the #Science community.
cwnl:
Neutrinos: Everything You Need To Know
What exactly are they?
With a neutral charge and nearly zero mass, neutrinos are the shadiest of particles, rarely interacting with ordinary matter and slipping through our bodies, buildings and the Earth at a rate of trillions per second.
First predicted in 1930 by Wolfgang Pauli, who won a Nobel prize for this work in 1945, they are produced in various nuclear reactions: fusion, which powers the sun; fission, harnessed by humans to make weapons and energy; and during natural radioactive decay inside the Earth.
If they are so stealthy, how do we know they are there at all?
Wily neutrinos usually avoid contact with matter, but every so often, they crash into an atom to produce a signal that allows us to observe them. Fredrick Reines first detected them in 1956, garnering himself a Nobel prize in 1995.
Most commonly, experiments use large pools of water or oil. When neutrinos interact with electrons or nuclei of those water or oil molecules, they give off a flash of light that sensors can detect.
Where are these experiments found?
These days, a lot of expense and extreme engineering go into detectors that are sunk into the ground to shield them from extraneous particles that might interfere with them. For instance, OPERA, which detected the apparently faster-than-light neutrinos beamed from CERN, lies inside the Gran Sasso mountain in Italy. This works because neutrinos shoot straight through such shields.
Other detectors pick up naturally-produced neutrinos. One such detector – ANTARES – is miles under the Mediterranean Sea, while another, IceCube, is buried under Antarctic ice.
What’s cool about neutrinos?
Their stealth belies their potential importance. Take extra dimensions. Most particles come in two varieties: ones that spin clockwise and ones that spin anticlockwise. Neutrinos are the only particles that seem to just spin anticlockwise. Some theorists say this is evidence for extra dimensions, which could host the “missing”, right-handed neutrinos.
Anything else?
Unseen right-handed neutrinos may also account for mysterious dark matter. This is thought to make up 80 per cent of all matter in the universe and to stop galaxies from flying apart. The idea is that right-handed neutrinos might be much heavier than left-handed ones and so could provide the requisite gravity.
Photons Made To Change Colour & Shape
Forget the X-Men - photons are the true superheroes. Not only do they travel at the universe’s fastest possible speed, now they have been made to both change colour and shape-shift. The feat brings the dream of ultrafast quantum computers a step closer.
Photons are waves of electromagnetic energy that come in different wavelengths, or colours. The wave patterns also vary in shape, depending in part on how they came into being. The shape of a photon produced by a laser resembles a bell curve, for example, while a photon emitted spontaneously by an atom when an electron loses energy has a peak that rises quickly and tails off slowly. The shape can affect how a photon interacts in collisions.
Photons normally maintain their size and shape until they are absorbed by matter. Now Matthew Rakher at the National Institute of Standards and Technology in Gaithersburg, Maryland, has made photons behave like shape-shifting chameleons. They piped infrared photons with a wavelength of 1300 nanometres into a crystal, into which they also pumped photons from a 1550-nm-wavelength laser. Each had different shapes.
The crystal acted as a waveguide, channelling the photons to hit each other at a specific angle and place, making them blend together to form photons with a wavelength of 710 nm with the same shape as the laser photons (Physical Review Letters, DOI: 10.1103/physrevlett.107.083602).
(via fyeahcarlsagan)
