two photon

Stars align in test supporting 'spooky action at a distance'

Quantum entanglement may appear to be closer to science fiction than anything in our physical reality. But according to the laws of quantum mechanics – a branch of physics that describes the world at the scale of atoms and subatomic particles – quantum entanglement, which Einstein once skeptically viewed as “spooky action at a distance,” is, in fact, real.

Imagine two specks of dust at opposite ends of the universe, separated by several billion light years. Quantum theory predicts that, regardless of the vast distance separating them, these two particles can be entangled. That is, any measurement made on one will instantaneously convey information about the outcome of a future measurement on its partner. In that case, the outcomes of measurements on each member of the pair can become highly correlated.

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Weak measurement allows one to empirically determine a set of average trajectories for an ensemble of quantum particles. However, when two particles are entangled, the trajectories of the first particle can depend nonlocally on the position of the second particle. Moreover, the theory describing these trajectories, called Bohmian mechanics, predicts trajectories that were at first deemed “surreal” when the second particle is used to probe the position of the first particle. We entangle two photons and determine a set of Bohmian trajectories for one of them using weak measurements and postselection. We show that the trajectories seem surreal only if one ignores their manifest nonlocality.
—  Experimental nonlocal and surreal Bohmian trajectories (Dylan H. Mahler, Lee Rozema, Kent Fisher, Lydia Vermeyden, Kevin J. Resc, Howard M. Wiseman, and Aephraim Steinberg)
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When a #photon (usually #polarized #laser #light) passes through matter, it will be absorbed by an #electron. Eventually, and spontaneously, the electron will return to its ground state by emitting the photon. Certain crystal structures increase the likelihood that the photon will split into two photons(Your Brain Is A Crystal Receiver), both of them with longer wavelengths than the original. Keep in mind that a longer #wavelength means a lower frequency, and thus less energy. The total energy of the two photons must equal the energy of the photon originally fired from the laser (conservation of energy).When the original photon splits into two photons, the resulting photon pair is considered 
#entangled.The process of using certain #crystals to split incoming photons into pairs of photons is called #parametric down-conversion. Normally the photons exit the crystal such that one is aligned in a horizontally polarized light cone, the other aligned vertically. By adjusting the experiment, the horizontal and vertical light cones can be made to overlap. Even though the polarization of the individual photons is unknown, the nature of quantum mechanics predicts they differ. You can take 2 entangled photons and separate them by infinite distance and when you change the information in one the other photon is changed instantly. This gives the illusion that information is traveling faster than the speed of light, when in reality the information travels instantly because #distance is an #illusion. At the most fundamental level #WE are all made of #photons. ALL matter and particles are STILL connected and information can be transferred instantly #bypassing space and time. This is how your meditation & prayer #consciousness syncs with the #SpiritualConsciousness #ChristConsciousness & It’s not religion. Its about Understanding how to utilize the #LawOfAttraction through #Love and #Light! #UniversalConsciousness #QuantumEntanglement #universalconsciousness Read this 11 times and research it for 11 days. 4biddenknowledge #UnifiedPhysics watch this show called #WhatTheBleepDoWeKnow

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A particle here can affect one on the other side of the universe, instantaneously

When an electron meets its antimatter twin, a positron, the two are annihilated in a tiny flash of energy. Two photons fly away from the blast.

Subatomic particles like photons and quarks have a quality known as “spin”. It’s not that they’re really spinning – it’s not clear that would even mean anything at that level – but they behave as if they do. When two are created simultaneously the direction of their spin has to cancel each other out: one doing the opposite of the other.

Due to the unpredictability of quantum behaviour, it is impossible to say in advance which will go “anticlockwise” and the other “clockwise”. More than that, until the spin of one is observed, they are both doing both.

It gets weirder, however. When you do observe one, it will suddenly be going clockwise or anticlockwise. And whichever way it is going, its twin will start spinning the other way, instantly, even if it is on the other side of the universe. This has actually been shown to happen in experiment (albeit on the other side of a laboratory, not a universe).

Supporting the damaged brain

A new study shows that embryonic nerve cells can functionally integrate into local neural networks when transplanted into damaged areas of the visual cortex of adult mice.

(Image caption: Neuronal transplants (blue) connect with host neurons (yellow) in the adult mouse brain in a highly specific manner, rebuilding neural networks lost upon injury. Credit: Sofia Grade, LMU/Helmholtz Zentrum München)

When it comes to recovering from insult, the adult human brain has very little ability to compensate for nerve-cell loss. Biomedical researchers and clinicians are therefore exploring the possibility of using transplanted nerve cells to replace neurons that have been irreparably damaged as a result of trauma or disease. Previous studies have suggested there is potential to remedy at least some of the clinical symptoms resulting from acquired brain disease through the transplantation of fetal nerve cells into damaged neuronal networks. However, it is not clear whether transplanted intact neurons can be sufficiently integrated to result in restored function of the lesioned network. Now researchers based at LMU Munich, the Max Planck Institute for Neurobiology in Martinsried and the Helmholtz Zentrum München have demonstrated that, in mice, transplanted embryonic nerve cells can indeed be incorporated into an existing network in such a way that they correctly carry out the tasks performed by the damaged cells originally found in that position. Such work is of importance in the potential treatment of all acquired brain disease including neurodegenerative illnesses such as Alzheimer‘s or Parkinson’s disease, as well as strokes and trauma, given each disease state leads to the large-scale, irreversible loss of nerve cells and the acquisition of a what is usually a lifelong neurological deficit for the affected person.

In the study published in Nature, researchers of the Ludwig Maximilians University Munich, the Max Planck Institute of Neurobiology, and the Helmholtz Zentrum München have specifically asked whether transplanted embryonic nerve cells can functionally integrate into the visual cortex of adult mice. “This region of the brain is ideal for such experiments,” says Magdalena Götz, joint leader of the study together with Mark Hübener. Hübener is a specialist in the structure and function of the mouse visual cortex in Professor Tobias Bonhoeffer’s Department (Synapses – Circuits – Plasticity) at the MPI for Neurobiology. As Hübener explains, “we know so much about the functions of the nerve cells in this region and the connections between them that we can readily assess whether the implanted nerve cells actually perform the tasks normally carried out by the network.” In their experiments, the team transplanted embryonic nerve cells from the cerebral cortex into lesioned areas of the visual cortex of adult mice. Over the course of the following weeks and months, they monitored the behavior of the implanted, immature neurons by means of two-photon microscopy to ascertain whether they differentiated into so-called pyramidal cells, a cell type normally found in the area of interest. “The very fact that the cells survived and continued to develop was very encouraging,” Hübener remarks. “But things got really exciting when we took a closer look at the electrical activity of the transplanted cells.” In their joint study, PhD student Susanne Falkner and Postdoc Sofia Grade were able to show that the new cells formed the synaptic connections that neurons in their position in the network would normally make, and that they responded to visual stimuli.

The team then went on to characterize, for the first time, the broader pattern of connections made by the transplanted neurons. Astonishingly, they found that pyramidal cells derived from the transplanted immature neurons formed functional connections with the appropriate nerve cells all over the brain. In other words, they received precisely the same inputs as their predecessors in the network. In addition, they were able to process that information and pass it on to the downstream neurons which had also differentiated in the correct manner. “These findings demonstrate that the implanted nerve cells have integrated with high precision into a neuronal network into which, under normal conditions, new nerve cells would never have been incorporated,” explains Götz, whose work at the Helmholtz Zentrum and at LMU focuses on finding ways to replace lost neurons in the central nervous system. The new study reveals that immature neurons are capable of correctly responding to differentiation signals in the adult mammalian brain and can close functional gaps in an existing neural network.

That paper I linked to the other day establishes a pretty remarkable connection between the affordances of a pair of agents and the superselection rules which determine the kind of quantum-coherent signals they can exchange.

The example given in section II.B shows how a common phase reference (e.g. a pair of phase-locked lasers) is necessary for two agents to exchange photonic signals exhibiting coherence between different photon numbers. It’s not that Alice can’t prepare a coherent superposition of states with different photon number with respect to her own phase reference, but if she doesn’t know how her phase reference is related to Charlie’s, she cannot prepare such a superposition with respect to his phase reference.

This allows us to understand well-known superselection rules (e.g. our inability to prepare a coherent superposition of two states with different electric charge, which does not follow from quantum electrodynamics or charge conservation alone) as a practical (rather than axiomatic) limitation - the result of us lacking a certain kind of reference frame.

Watching thoughts — and addiction — form in the brain

More than a hundred years ago, Ivan Pavlov conducted what would become one of the most famous and influential psychology studies — he conditioned dogs to salivate at the ringing of a bell. Now, scientists are able to see in real time what happens in the brains of live animals during this classic experiment with a new technique. Ultimately, the approach could lead to a greater understanding of how we learn, and develop and break addictions. 

(Image caption: In a mouse brain, cell-based detectors called CNiFERs change their fluorescence when neurons release dopamine. Credit: Slesinger & Kleinfeld labs)

Scientists presented their work at the 252nd National Meeting & Exposition of the American Chemical Society (ACS).

The study presented is part of the event: “Kavli symposium on chemical neurotransmission: What are we thinking?” It includes a line-up of global research and thought leaders at the multi-disciplinary interfaces of the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative with a focus on chemists’ contributions. The effort was launched in 2013 by the Obama Administration to enable researchers to study how brain cells interact to form circuits.

“We developed cell-based detectors called CNiFERs that can be implanted in a mouse brain and sense the release of specific neurotransmitters in real time,” says Paul A. Slesinger, Ph.D., who used this tool to revisit Pavlov’s experiment. Neurotransmitters are the chemicals that transmit messages from one neuron to another.

CNiFERs stands for “cell-based neurotransmitter fluorescent engineered reporters.” These detectors emit light that is readable with a two-photon microscope and are the first optical biosensors to distinguish between the nearly identical neurotransmitters dopamine and norepinephrine. These signaling molecules are associated respectively with pleasure and alertness.

Slesinger, of the Icahn School of Medicine at Mount Sinai in New York, collaborated on the project with David Kleinfeld, Ph.D., at the University of California at San Diego. Their team conditioned mice by playing a tone and then, after a short delay, rewarding them with sugar. After several days, the researchers could play the tone, and the mice would start licking in anticipation of the sugar.

“We were able to measure the timing of dopamine surges during the learning process,” Slesinger says. “That’s when we could see the dopamine signal was measured initially right after the reward. Then after days of training, we started to detect dopamine after the tone but before the reward was presented.”

Slesinger and colleagues will also share new results on the first biosensors that can detect a subset of neurotransmitters called neuropeptides. Ultimately, Slesinger says they’d like to use this sensing technique to directly measure these neuromodulators, which affect the rate of neuron firing, in real time.

anonymous asked:

Could you please make a blog for Overwatch Scientific or just explain how Symmetra "build with ligth"?

While I definitely don’t have the time to run TWO science blogs, I’m happy to deviate from pokémon now and again!

Symmetra’s primary weapon is her Photon Projector, which fires laser-like beams and energy balls. Additionally, she can use it to build sentry turrets, teleporters, and shields – all made out of light. In Symmetra’s words, “I will shape order from chaos.”

Light, of course, is made of photons, which are tricky little particles. Unlike atoms, photons don’t interact with each other, they can pass through each other, they don’t have mass. Even in an orderly laser beam, photons each act independently. But, hypothetically, you could change that. If you could make individual photons interact, you could create solid light. Much like a Star Wars Lightsaber, light bridges from Portal 2, or Symmetra’s abilities.

Until about 5 years ago, solid light was purely hypothetical. The math showed that it could work, but no one had successfully created it in a lab. Until 2013, when it was observed in an experiment at MIT. What they did was slow the light down, by making it really, really, cold: almost absolute zero, or -460 F (-273 C). Their experiment only had two photons, but the photons slowed down so much that they bonded together, making a “molecule” of light. 

We’re obviously a long way from Symmetra or Star Wars, but solid light is a real, cool (no pun intended) thing!

Symmetra’s Photon Projector can both fire and slow down light, which solidifies it into solid light. She can use solid light to make teleporters, turrets, and shields.

(Add shameless plug for our Overwatch Tracer post found here)

The way you entangle them is to send them onto a half-silvered mirror, It reflects half of the photons, and transmits half. If you send two photons, one to the right and one to the left, then each of the two photons have forgotten where they come from. They lose their identities and become entangled. The idea is to create two particle pairs, send one to one computer, the other to another, Then if these two photons are entangled, the computers could use them to exchange information.
—  “Experimental delayed-choice entanglement swapping”: Xiao-song Ma, Stefan Zotter, Johannes Kofler, Rupert Ursin, Thomas Jennewein, Časlav Brukner, and Anton Zeilinger. Nature Physics
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In Laser Thruster Advance, Light Alone Pushes a Sled Down a Track

Here is the latest demonstration of a propulsion technology called a photonic laser thruster. In it, NASA Innovative Advanced Concepts Fellow Young Bae moved a one-pound object on a track using light alone for the first time. 

The hope is that a laser fired from one spacecraft to another will provide enough push to make this form of propulsion viable for interplanetary travel. Back in 2013, the agency expanded research on the concept of photonic laser thrusters after discovering it could have “a much larger potential in NASA mission applications.” 

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Beam me up Scotty! Quantum teleportation of a particle of light six kilometers

What if you could behave like the crew on the Starship Enterprise and teleport yourself home or anywhere else in the world? As a human, you’re probably not going to realize this any time soon; if you’re a photon, you might want to keep reading.

Through a collaboration between the University of Calgary, The City of Calgary and researchers in the United States, a group of physicists led by Wolfgang Tittel, professor in the Department of Physics and Astronomy at the University of Calgary have successfully demonstrated teleportation of a photon (an elementary particle of light) over a straight-line distance of six kilometres using The City of Calgary’s fibre optic cable infrastructure. The project began with an Urban Alliance seed grant in 2014.

This accomplishment, which set a new record for distance of transferring a quantum state by teleportation, has landed the researchers a spot in the journal Nature Photonics. The finding was published back-to-back with a similar demonstration by a group of Chinese researchers.

“Such a network will enable secure communication without having to worry about eavesdropping, and allow distant quantum computers to connect,” says Tittel.

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Take a look at a living taste bud. The green objects are the taste receptor cells, red indicates blood vessels and blue is the collagen structure surrounding the bud. This is one of more than 2,000 taste buds scattered across the top of the tongue.

This 3-D rendering was part of a study at Harvard, the Australian National University and South Korea’s Sungkyunkwan University in which scientists captured the process of taste sensation live. In doing so, they provided more proof that the idea the tongue is broken into separate regions that sense salty, sour, sweet, bitter and umami is a myth.

They were able to watch taste reception by shining an infrared laser on a living mouse’s tongue and recording with a two-photon microscope what happened when they dripped sweet-tasting saccharin and acesulfame K or salt onto the buds. Each bud activated when exposed to both salty and sweet substances.

“With this new imaging tool we have shown that each taste bud contains taste cells for different tastes,” said Harvard Medical School’s Seok-Hyun Yun. Learn more and see photos below.

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calzones-rule  asked:

if a pansexual aromantic touches a panromantic asexual do they annihilate and produce two photons or does something else happen

If a pansexual aromantic and a panromantic asexual touch, the universe bursts into a bright light of pink, blue and yellow, and time stops for what would typically be known as three minutes, but cannot be measured as time has stopped. Non-human life forms are created all around the world at varying locations, including centaurs, sapient cyborgs, fairies, High Elves and the entire cast of Dangan Ronpa.

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Mutually tangled colloidal knots and induced defect loops in nematic fields 

Colloidal dispersions in liquid crystals can serve as asoft-matter toolkit for the self-assembly of composite materials with pre-engineered properties and structures that are highly dependent on particle-induced topological defects1, 2, 3. Here, we demonstrate that bulk and surface defects in nematic fluids can be patterned by tuning the topology of colloidal particles dispersed in them. In particular, by taking advantage of two-photon photopolymerization techniques to make knot-shaped microparticles, we show that the interplay of the topologies of the knotted particles, the nematic field and the induced defects leads to knotted, linked and other topologically non-trivial field configurations 

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astral-princess-123195-ygoz-dea  asked:

Kite: I'll summon two more Photon monsters in Defense Mode! *two Photon Wolves appear* I won't give up until Nita is back! *two traps appear* Nita: *sings then speaks* 'Master. He seems to be planning something, but I have another ability.

Whatever his plan is we will not let it succeed.

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Complex Nanoarchitecture Makes Tunable Materials

We’re getting another close-up look at extremely strong and ultra-lightweight materials being created at the California Institute of Technology.

Researchers in the lab of materials science and mechanics professor Julia Greer are using a direct laser writing method called two-photon lithography to develop intricate trusswork that are extremely low density. In this process, they fire a laser into a polymer, which hardens at the light’s focal point. After washing the rest of the unhardened polymer away, the hardened scaffold that remains is coated with any number of substances like metals, ceramic or semiconducting compounds. The trusses pictured above were coated with the brittle ceramic aluminum oxide.

Greer says that making complex structures at the nanoscopic scale–truss members can be billionths of a meter wide–allows engineers to impart desired characteristics to the tailored material. 

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