A screengrab from the final “Interstellar” trailer showing Cooper (Matthew McConaughey) exploring an alien planet.
Credit: Paramount Pictures
At TU Wien, a system was built which creates a strong interaction between only two photons. This interaction is so strong that the phase of the photons is changed by 180 degrees. “It is like a pendulum, which should actually swing to the left, but due to coupling with a second pendulum, it swings to the right. There cannot be a more extreme change in the pendulum’s oscillation”, says Rauschenbeutel. “We achieve the strongest possible interaction with the smallest possible intensity of light.”
A Photon in a Bottle
To make this possible, the photon has to be sent on an unlikely journey. An ultra-thin glass fibre is coupled to a tiny bottle-like light resonator so that light can partly enter the resonator, move in circles and return to the glass fibre. This detour through the resonator leads to the phase of the photon being inverted: a wave crest appears where a wave trough would have been expected.
When, however, a single rubidium atom is coupled to the resonator, the system is changed dramatically. Due to the presence of the atom, hardly any light enters the resonator anymore and the oscillation phase of the photon cannot be inverted.
Two Photons at Once
Things change when two photons arrive at the same time. “The atom is an absorber which can be saturated”, says Arno Rauschenbeutel. “A photon is absorbed by the atom for a short while and then released into the resonator. During that time, it cannot absorb any other photons. If two photons arrive simultaneously, only one can be absorbed, while the other can still be phase shifted.”
From a quantum mechanical point of view, there is no difference between the two photons. They can only be understood as a joint wave-like object, which is located in the resonator and in the glass fibre at the same time. The photons are indistinguishable. No one can tell which of them is being absorbed and which one has passed. When both hit the resonator at the same time, both of them together experience a phase shift by 180 degrees. Two interacting photons arriving simultaneously show a completely different behaviour than single photons.
To make it work, the research team combined two kinds of non-invasive instruments. One participant (the “sender”) was hooked-up to an electroencephalography machine, which recorded brain signals and sent electrical pulses through the Web to the second participant (the “receiver”) who was wearing a swim cap with a transcranial magnetic stimulation (TMS) coil placed near the part of the brain that controls hand movements.
During the experiment, the sender issued a command to move the hand of the receiver by simply thinking about that hand movement. Three different pairs of participants were used for the experiment, each confronted with different roles and constraints. The volunteers worked in separate buildings about a half-mile apart, and they were unable to interact or communicate with each other in any way. Well, except for that mind-to-mind interface strapped to their heads.
Shall We Play A Game — With Our Thoughts?
Now here comes the fun part. The senders were tasked with playing a computer game in which he or she had to defend a city by firing a cannon and intercepting rockets launched by a pirate ship. But the senders weren’t given any kind of controller or joystick — the only way they could defend the city was by thinking about moving their hand to fire the cannon.
In the other building across campus, the receivers meanwhile sat wearing headphones in a dark room with no ability to see the computer game. Their right hand was positioned over a touchpad that could actually fire the cannon. If the interface was successful, the receiver’s hand would twitch, firing the cannon displayed on the sender’s computer screen.
Results showed that the accuracy varied among the pairs, ranging from 25% to 83%. Misses were mostly on account of the senders failing to execute the “fire” command with their thoughts.
To find out more, they examined the brain activity of seven individuals undergoing epilepsy surgery. Using a technique called electrocorticography, which involves measuring neuronal activity via electrodes placed on the surface of the brain, the team took recordings while the patients either read out loud or performed a silent reading task. Both of these tasks involved the subjects reading short pieces of text that scrolled across a video screen. The team also included a control situation in which recordings were taken while the participants weren’t doing anything.
During the overt (reading aloud) task, the researchers mapped which neurons became activated during specific aspects of speech, and used this to construct a decoder for each participant. After working out which firing patterns corresponded to particular words, they set their decoder to work on the participants’ brain activity during silent reading. Remarkably, they found it was able to translate words that several of the volunteers were thinking, using only their neuronal firing patterns.
The researchers are also using their decoder to predict what music a person is listening to by playing particular songs to the volunteers, and once again looking at the neuronal firing patterns during different aspects of the music.
“Sound is sound,” lead author Brian Pasley told New Scientist. “It all helps us understand different aspects of how the brain processes it.”
It may seem like an unlikely place to find a new species, but scientists have identified a frog not previously described by science in the very heart of the most populous city in the United States — New York City. Though similar to the leopard frog in appearance, the new species has a discrete croak and a distinct genetic makeup, reports Discovery.
“The discovery of a new frog species from the urban Northeast is truly remarkable and completes a journey that began six years ago with a simple frog call in the wilds of New York City,” said researcher Jeremy Feinberg from Rutgers University.
Feinberg, who is an expert in frog calls, first caught wind of the new species while wandering New York City. “What the heck is that?” he recalled asking himself six years ago when he first heard the short, repetitive croak. The local leopard frog usually sounds more like a long snore or a throaty laugh.
Hear the croak –
Ishaan Tharoor for the Washington Post reports that Saudi Arabia, key to Obama’s strategy, beheaded at least 8 people last month
The active cooperation of Saudi Arabia, with its vast oil wealth, its well-equipped military and its broader influence among the Middle East’s Sunni states, is key to any extended U.S. war effort in Iraq and Syria, as The Post’s Anne Gearan reports from Jiddah. Though long an incubator of the Salafist ideology that now inflames the Islamic State and militant groups of its ilk, the kingdom has grown increasingly concerned with the destabilizing chaos the Islamic State has wrought in the region.
But that doesn’t mean its state ideology is necessarily changing. The country is notorious for its draconian laws, which are derived from a strict Wahhabist interpretation of Islamic doctrine. In the space of two weeks last month, according to the rights group Amnesty International, Saudi Arabia executed as many as 22 people. At least eight of those executed were beheaded, U.N. observers say.
It appears that the majority of those executed in August were guilty of nonlethal crimes, including drug trafficking, adultery, apostasy and “sorcery.” Four members of one family, Amnesty reports, were beheaded for “receiving drugs.”
Saudi Arabia is conspicuous in being the sole country to regularly carry out beheadings; last year, a reported shortage of trained swordsmen led to some hope that the practice could wane, but recent evidence suggests otherwise. It’s an uncomfortable irony given that the United States’ current military mobilization was triggered after the Islamic State beheaded two American journalists.
Saudi Arabia has been beheading people, chopping off hands, etc., for years. From the BBC article published in 2003, Saudi Executioner tells all
It doesn’t matter to me: two, four, 10 – as long as I’m doing God’s will, it doesn’t matter how many people I execute”.
Under the Gulf kingdom’s strict Islamic Sharia laws, the death penalty can be imposed for murder, rape, apostasy, armed robbery, drug trafficking and repeated drug use.
The Saudi authorities report public executions regularly – and are condemned by Western human rights groups…
…Training focuses on how to hold the sword and where to bring the blade down.
Sometimes he also has to carry out amputations of hands or legs.
“I use a special sharp knife, not a sword. When I cut off a hand I cut it from the joint. If it is a leg the authorities specify where it is to be taken off, so I follow that.”
Our government has known about this all along. So has the media. So, why are they so shocked, shocked to find out that there are executions going on in this establishment?