Light photographed as a wave and a particle for the first time ever

For the first time ever, scientists have photographed light behaving simultaneously as both a particle and a wave.

The photograph, above,  is a momentous achievement, providing direct observation of both behaviours simultaneously for the first time, after decades of attempts by the scientific community. Previous research projects have successfully observed wave-like behaviours and particle-like behaviours in light, but not at the same time.

The dual behaviour of light, which is demonstrated through quantum mechanics and was first proposed by Albert Einstein, was only possible to capture by scientists at École polytechnique fédérale de Lausanne (EPFL), Switzerland, due to an unorthodox imaging technique.

The scientists generated the image with electrons, making use of EPFL’s ultrafast energy-filtered transmission electron microscope. This gave them a rare advantage over other institutions, as EPFL has one of only two such microscopes in the world.

The image was achieved first by firing a pulse of laser light at a miniscule metallic nanowire, adding energy to charged particles in the nanowire and making them vibrate.

The light waves  travel along the nanowire in opposite directions, like lanes of cars on a road, but when they meet from opposite directions they form a new wave then appears as if it is “standing in place”, effectively confined to the nanowire.

This wave, which radiates around the nanowire, was the light source that was imaged.

The scientists fired a stream of electrons in close proximity to the nanowire, and imaged their interaction with this “standing wave”. As they came into contact with the light, their changes in behaviour acted as a visualisation of the light’s behaviour.

The electrons that interacted with the light, or photons, either slowed down or sped up, together forming a visualisation of the light’s wave.

However, the changes in speed also appeared as an exchange of quanta – packets of energy – between the electrons and the photons.  These packets were the tell-tale sign of the light behaving as a particle.

light-photon-wave-1

The experiment is a significant step for future quantum mechanics research.

“This experiment demonstrates that, for the first time ever, we can film quantum mechanics – and its paradoxical nature – directly,” said research leader Fabrizio Carbone.

However, the research could also be important for the future development of quantum-based technology.

“Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing,” he added.

The research, which was a collaborative effort between EPFL, Trinity College and the Lawrence Livermore National Laboratory, is published today in the journal Nature Communications.


Image courtesy of Fabrizio Carbone/EPFL.

Journal Reference: Piazza L, Lummen TTA, Quiñonez E, Murooka Y, Reed BW, Barwick B, Carbone F. Simultaneous observation of the quantization and the interference pattern of a plasmonic near-field. Nature Communications 02 March 2015. DOI: 10.1038/ncomms7407


 

New research claims a video game can improve doctors’ ability to recognise severe trauma in patients

New research has concluded a specifically-designed video game improves doctors’ ability to recognise when patients need to be transferred to a severe trauma centre.

The research, by the University of Pittsburgh School of Medicine and published today in the BMJ, revealed the game Night Shift was better at preparing doctors to recognise patients who needed higher levels of care than reading traditional educational materials.

This was the case even though doctors who were made to play the game, in which doctors play as a fictitious, young emergency physician treating severe trauma patients, enjoyed it less than those who were asked to read relevant materials.

“Physicians must make decisions quickly and with incomplete information. Each year, 30,000 preventable deaths occur after injury, in part because patients with severe injuries who initially present to non-trauma centres are not promptly transferred to a hospital that can provide appropriate care,” said the game’s creator Deepika Mohan, MD, MPH and assistant professor in Pitt’s departments of Critical Care Medicine and Surgery.

“An hour of playing the video game recalibrated physicians’ brains to such a degree that, six months later, they were still out-performing their peers in recognising severe trauma.”

Night Shift was designed by Mohan to tap into the part of the brain that uses pattern recognition and previous experience to make snap decisions by using subconscious mental shortcuts – a process called heuristics.

Doctors in non-trauma centres typically see only about one severe trauma per 1,000 patients. As a result, their heuristic abilities can become skewed toward obvious injuries such as gunshot wounds, and miss equally severe traumas such as internal injuries from falls.

On average, 70% of severely injured patients who present to non-trauma centres are under-triaged and not transferred to trauma centres as recommended by clinical practice.

“There are many reasons beyond the doctor’s heuristics as to why a severe trauma patient wouldn’t be transferred to a trauma centre, ranging from not having an ambulance available to a lack of proper diagnostic tools,” said Mohan.

“So, it is important to emphasize that recalibrating heuristics won’t completely solve the under-triage problem and that the problem isn’t entirely due to physicians’ diagnostic skills. But it’s heartening to know we’re on track to develop a game that shows promise at improving on current educational training.”

For the study, Mohan recruited 368 physicians from across the US who did not work at hospitals specialising in severe trauma. Half were assigned to play the game and half were asked to spend at least an hour reading the educational materials.

Participants then responded to questionnaires and completed a simulation that tested how often they “under-triaged,” or failed to send severe trauma patients to hospitals with the resources necessary to handle them.

Physicians who played the game under-triaged 53% of the time, compared with 64% for those who read the educational materials.

Six months later, Mohan reassessed the physicians and found that the effect of the game persisted, with those who played the game under-triaging 57% of the time, compared to 74% for those who had read the educational materials.

Multimedia courtesy of Schell Games.

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Source: Gizmodo

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Source: Ars Technica

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Source: Reuters